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Online guided reading program with interactive ebooks, downloadable books, and reading quizzes.

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Invention Of BULB | The Dr. Binocs Show | Best Learning Video for Kids | Preschool Learning

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Telegram television (also known as a TV) is a machine with a screen. Televisions receive broadcasting signals and change them into pictures and sound. The word "television" comes from the words tele ( Greek for far away) and vision ().

Sometimes a television can look like a box. Older TVs had a large cathode ray tube in a large wooden frame and sat on the floor like furniture. Newer TVs are much lighter and flatter.

A TV can show pictures from many television networks. Computers and mobile devices also can be used for watching television programs.

The television was invented in the 1920s but the equipment was expensive and the pictures were poor. By the 1950s, these problems had been fixed and TVs became widespread.

At first, all televisions used an antenna (or aerial). This would pick up television programmes from broadcasting stations. A TV station could be many miles or kilometers away, and still be received. TVs can also show movies from VCD and DVD players or VCRs. Cable TV and Satellite television can provide more programs at once than broadcast can. Video game consoles connect to most modern TVs. Some computers can also use a TV as a computer monitor.

All TVs have screens where the picture is viewed. Before the 1950s these were usually " black and white", which made everything look grey, but all modern TVs show colors. Most 20th century screens also had rounded corners. That is because television screens were cathode ray tubes. These are like heavy glass jars with one side bulging out to form the screen.

Today flat panel displays are the usual kind. These are usually flat rectangles with straight edges. This long rectangle looks more like the shape of a movie theatre screen. This is called widescreen. If a widescreen set was 30 cm tall, it would be 53 cm wide. For this to work best, TV shows also need to be made in widescreen. Widescreen sets can still be any size, but they have the same widescreen shape.

The early 21st century is also when digital television transmission became more common than analog television.

Related pages

Images for kids

Baird in 1925 with his televisor equipment and dummies "James" and "Stooky Bill" (right).

Coaxial cable is used to carry cable television signals into cathode ray tube and flat panel television sets.

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Telegram television (also known as a TV) is a machine with a screen. Televisions receive broadcasting signals and change them into pictures and sound. The word "television" comes from the words tele ( Greek for far away) and vision (). Sometimes a television can look like a box.

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Newsela | Vaccines are like giving your body's defenses a cheat sheet

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Vaccines act as a firewall that prevents the spread of disease.

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The printing press is a machine for printing. It makes many copies of identical pages. The printing press today is used to print books and newspapers. It had a great influence on society, especially western society.

Woodcut printing has been done for several centuries. That was whole pages cut into wood, words and pictures. In the 15th century Johannes Gutenberg improved the process. He used separate alloy letters screwed into a frame. This way a large set of letters could make almost any page for printing. This process was called typesetting. Each letter was in a block of metal, fixed in a frame. He could then move paper and ink over it, much like a stamp. This method was called letterpress. The letters would leave ink on the paper in the shape of the letters, creating text or illustrations.

Bigger and much faster presses were invented in the industrial revolution. The main improvements were made in the 19th century. Two ideas altered the design of the printing press entirely. First was the use of steam power to run the machinery. Second was the replacement of the printing flatbed with the rotary motion of cylinders. Both were done by the German printer Friedrich Koenig between 1802 and 1818. Having moved to London in 1804, Koenig got financial support for his project in 1807. In 1810, Koenig patented a steam press "much like a hand press connected to a steam engine".

Soon other inventions were added, such as the making of cheaper paper by using wood pulp instead of rags. Later in the 19th century came machines which speeded up typesetting, which was previously done by hand, letter by letter. A machine for hot metal typesetting was designed by Linotype Inc. It turned molten lead into type ready for printing.

Many further developments in printing happened in the 20th century. Today printing presses are controlled by special-purpose computers, and the material to be printed is prepared on computers. As a consequence of these inventions, the cost of printing has fallen significantly compared to other commodities. Now the price of a book or magazine is less determined by its production, and more by other factors, such as marketing.

Images for kids

This woodcut from 1568 shows the left printer removing a page from the press while the one at right inks the text-blocks. Such a duo could reach 14,000 hand movements per working day, printing ca. 3,600 pages in the process.

"Modern Book Printing" sculpture, commemorating Gutenberg's invention on the occasion of the 2006 World Cup in Germany

In Spanish: Imprenta para niños

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Newsela | Bringing COVID-19 vaccines to much of world is hard

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There are many challenges to overcome as the world struggles to vaccinate people in all countries.

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Newsela | After sad Mother's Day 2020, vaccines offer sweet reunions this year

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Thanks to vaccinations, Mother's Day 2021 will bring happy reunions to many.

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Newsela | Instructional Content Platform

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Newsela is an Instructional Content Platform that supercharges reading engagement and learning in every subject.

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Remember to watch the video

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The printing press is a machine that uses ink to transfer words and images to paper. It is used to print newspapers, books, pamphlets, and other written works. Few inventions...

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A vaccine gives immunity to an infectious disease caused by a particular bacterium or virus. This means the vaccine makes a person less likely to get that disease. For example, the flu vaccine makes it less likely that a person will get the flu.

Vaccines are usually made from something that is alive, or was alive.

The word "vaccine" comes from the Latin words vaccīn-us (from the word vacca, meaning " cow"). In 1796, Edward Jenner used cows infected with cowpox ( variolae vaccinae) to protect people against smallpox. The use of vaccines is called vaccination.

Edward Jenner created the first vaccine in the 1770s. At this time, smallpox was a deadly disease. Jenner noticed that people who had already had cowpox (a disease that is related to smallpox) usually did not get smallpox. He thought that getting cowpox protected people against smallpox.

To test this idea, Jenner gave a boy cowpox. Then he infected the boy with smallpox. The boy did not get sick because he had already had cowpox. Jenner was right: having cowpox protected people against smallpox.

Because cowpox inoculation made fewer people sick than smallpox inoculation, England made smallpox inoculation illegal in 1840. In 1853, they made another law that said every child had to be vaccinated against smallpox using Jenner's vaccine.

In the 19th century, Louis Pasteur made a rabies vaccine.

In the 20th century, scientists created vaccines to protect people against diphtheria, measles, mumps, and rubella. In the 1950s, Jonas Salk created the polio vaccine.

However, vaccines still do not exist for many important diseases, like malaria and HIV.

Many countries have passed compulsory vaccination laws - laws that require certain people to get vaccinated. For example, in many countries, children have to be vaccinated against certain diseases in order to go to public school.

Types of vaccines

There are many different types of vaccines.

One common type of vaccine is a "live vaccine." This type of vaccine contains a small amount of a live virus or bacteria. Before the vaccine is given, scientists weaken the virus or bacteria so it cannot make a person sick. When a person gets a live vaccine, their immune system learns to recognize and fight off that virus or bacteria. Then, if the person is exposed to the virus or bacteria in the future, their immune system will already "know" how to fight it off. Examples of live vaccines include vaccines for measles, mumps, and chickenpox.

Another common type of vaccine is an "inactivated vaccine." These vaccines contain dead viruses or bacteria. These do not cause the immune system to react as strongly as live vaccines. Because of this, people may need "booster shots" - extra doses of the vaccine, given at certain times, so their immune system can "learn" how to fight off the infection. Examples of inactivated vaccines include vaccines for pertussis (whooping cough), rabies, and hepatitis B.

Scientists can make some types of vaccines in a laboratory.

Effectiveness

Vaccines do not guarantee complete protection from a disease. In other words, a person can get a disease that they were vaccinated against.

Sometimes, this happens because the person's immune system did not respond to the vaccine (it did not "learn" how to fight off the disease after the person got the vaccine). This may happen because the person's immune system is already weak (for example, because of diabetes, HIV infection, old age, or steroid use). It may also happen because the person's immune system cannot make the particular B cells which make the antibodies that stick to the pathogen.

Some vaccines work better than others at protecting people from diseases. There are many reasons for this:

Vaccination works better for some diseases than for others

The vaccine may be for a certain strain of a disease. If a person gets a different strain of the disease, they can still get sick.

Vaccines usually do not have permanent effects, so a person might need many different vaccinations on a schedule. If a person missed a scheduled vaccine, they might lose their protection against a disease.

Some people are "non-responders" to certain vaccines. This means that their immune systems just do not create antibodies to fight off a disease, even after they are vaccinated correctly.

Other things, like ethnicity, age, and genetics, can affect how a person reacts to a vaccine. In some cases, larger doses are used for older people (50-75 years and up), whose immune response to a given vaccine is not as strong.

Economics of development and patents

One challenge in developing vaccines is economic. The diseases that most need vaccines today - HIV, malaria, and tuberculosis - exist mostly in poor countries. Companies that make vaccines would not profit much from developing vaccines for these diseases, because many of the people who need them are too poor to pay for them. There would also be financial and other risks to these companies if they tried making new vaccines for these diseases.

Throughout history, most vaccines have been developed by governments, universities, and non-profit organizations. Many vaccines have been highly cost-effective and good for public health. In recent decades, the number of vaccines given throughout the world has increased dramatically. This increase, particularly in the number of different vaccines given to children before they start school, may be due to laws and support from governments.

Another obstacle to making new vaccines is that when a new vaccine is made, the maker often files a patent on their vaccine. These patents can keep the process used to make the vaccine secret. That can make it harder to make other vaccines using the same process.

Additional components in vaccines

Vaccines often contain other things besides the active vaccine (the weakened or dead virus or bacteria). For example, vaccines may contain:

Aluminum salts or gels. These are added to help the immune system respond earlier, and more strongly, to the vaccine. They allow a lower dose of the vaccine to be given.

Antibiotics are added to some vaccines to prevent bacteria from growing while the vaccine is being made or stored.

Egg protein is present in influenza and yellow fever vaccines, because they are made using chicken eggs. Vaccines may also contain other proteins.

Formaldehyde is used to to kill bacteria for certain vaccines. It is also used to kill unwanted viruses and bacteria that might get into the vaccine while it is being made.

Monosodium glutamate (MSG) and 2-phenoxyethanol are used as stabilizers in a few vaccines to make sure the vaccine does not change if it is exposed to heat, light, acidity, or humidity.

Thimerosal is a preservative that contains mercury. It is added to vials of vaccine that contain more than one dose, to keep harmful bacteria from growing in the vaccine.

Preservatives in vaccines, such as thiomersal, phenoxyethanol, and formaldehyde, prevent serious adverse effects. Thiomersal is more effective against bacteria, lasts longer in storage, and makes the vaccine stronger, safer, and more stable (less likely to be changed by things like heat). However, in the United States, the European Union, and a few other developed countries, it is no longer used as a preservative in childhood vaccines because it contains mercury. Some people have argued that thimerosal contributes to autism. However, no convincing scientific evidence says this is true.

If no preservative is added to a vaccine, harmful bacteria may grow in the vaccine. For example, in 1928, Staphylococcus bacteria grew in a diphtheria vaccine that had no preservative in it. Of 21 children who got that vaccine, 12 died.

Use in veterinary medicine

Animals are vaccinated to keep them from getting diseases, and to keep them from infecting humans with diseases. Pets as well as livestock are routinely vaccinated.

In some instances, populations of wild animals may be vaccinated. Sometimes, wild animals are vaccinated by spreading vaccine-laced food in a disease-prone area. This method has been used to try to control rabies in raccoons. Where rabies occurs, laws may require dogs to get rabies vaccinations.

Dogs can also be vaccinated against many other diseases, including canine distemper, canine parvovirus, infectious canine hepatitis, adenovirus-2, leptospirosis, bordatella, canine parainfluenza virus, and Lyme disease.

Several trends in vaccine development

Nowadays, vaccines are given to people of all ages.

Combinations of vaccines are becoming more common. Vaccines containing five or more components are used in many parts of the world.

New methods of giving vaccines are being developed. Some of these new delivery systems include skin patches, aerosols given through inhalation devices, and eating genetically engineered plants.

Scientists are designing vaccines to make people's natural immune responses stronger.

Scientists are trying to make vaccines to help cure chronic infections, instead of only preventing disease.

Public health officials might change their strategies for giving vaccines based on differences in how men, women, and pregnant women react to vaccines.

Scientists are also working on vaccines against many noninfectious human diseases, such as cancers and autoimmune disorders. For example, the experimental vaccine CYT006-AngQb has been investigated as a possible treatment for high blood pressure.

Images for kids

Maurice Hilleman's measles vaccine is estimated to prevent 1 million deaths every year.

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A vaccine gives immunity to an infectious disease caused by a particular bacterium or virus. This means the vaccine makes a person less likely to get that disease. For example, the flu vaccine makes it less likely that a person will get the flu. Vaccines are usually made from something that is alive, or was alive.

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Leveled Book Lesson

High-Frequency Words

many, put, use

Story Words

airplanes, detail, grow, idea, machines, main, places, tricks, ways

Premade vocabulary lessons at VocabularyA-Z.com
Use of vocabulary lessons requires a subscription to VocabularyA-Z.com.

Teach the Objectives

Reading Strategy

Connect to prior knowledge to better understand text

Comprehension

Main Idea and Details : Identify the main idea and details in a text

Phonological Awareness

Initial Consonants : Discriminate initial consonant /p/ sound

Phonics

Consonants : Identify initial consonant Pp

Grammar and Mechanics

Capitalization and Punctuation : Capitalize sentence beginnings and punctuate sentence endings

Word Work

High-Frequency Words : Identify and use high-frequency words many, put, use

Think, Collaborate, Discuss

Promote higher-order thinking for small groups
or whole class

Assessment Resources

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Leveled Book Lesson High-Frequency Words many, put, use Story Words airplanes, detail, grow, idea, machines, main, places, tricks, ways Premade vocabulary lessons at VocabularyA-Z.com Use of vocabulary lessons requires a subscription to VocabularyA-Z.com.

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Great Innovators: “Gutenberg and the Printing Press,” by StoryBots | Netflix Jr

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Great Innovators: "Thomas Edison and the Light Bulb," by StoryBots | Netflix Jr

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Explanation of what it is and how it works

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Explanation of what it is and how it works

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Printing Press Facts - Facts Just for Kids

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In this section you'll learn about the printing press. You'll learn who invented the printing press and how the printing press worked. How the printing press evolved and other printing press facts. Printing Press Facts

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This web page contains vaccine facts for kids and is an excellent resource for anyone of any age looking to learn about vaccinations. Our goal is to provide you with accurate, up to date facts about vaccines. In addition to facts about vaccines, we provide additional resources to help you with your research on vaccines and immunizations.

The vaccine facts below will help you learn about vaccines, who invented the first vaccine, if vaccines are safe, if vaccines cause autism, what diseases have an available vaccine and other vaccine related facts. We hope these vaccine facts are interesting and help you learn more about these life saving medical advancements.

If any of the below vaccine facts are inaccurate, please contact us and let us know.

17 Vaccine Facts for Kids

1. A vaccine is given to a human or animal to activate immunity to a specific disease.

2. A vaccine will teach the immune system to identify a specific disease, destroy that specific disease and remember that specific disease for future defense against it.

3. Vaccination is the administration of a vaccine to a human or animal.

4. A vaccine can be administered (given) by a shot, orally (via the mouth) or inhalation (via the nose).

5. The first vaccine created was for the smallpox virus in 1796, by English physician Edward Jenner.

6. The World Health Organization (WHO) estimates that vaccines help prevent over 2.5 million deaths every year.

7. During the 19th century, vaccines were created for bubonic plague, cholera, rabies, tetanus and typhoid fever.

8. During the 20th century, 27 vaccines were created. Some of the notable vaccines were for hepatitis A, hepatitis B, influenza (the flu), measles, mumps, pneumonia (Streptococcus pneumoniae) and tuberculosis.

9. As of 2019, there have been six vaccines, and they are for the human papillomavirus (HPV), hepatitis E, enterovirus 71, malaria, dengue fever and Ebola.

10. The influenza (the flu) vaccine is an annual vaccine that the Centers for Disease Control (CDC) recommends for everyone that is six months or older. It protects against the strains of influenza expected to appear during the annual flu season. Due to the rapid mutations of the influenza virus, vaccination is required annually.

11. The smallpox vaccination resulted in the eradication of the smallpox virus. The World Health Organization (WHO) reported the last naturally occurring smallpox case was in October 1997 and officially declared the disease eradicated worldwide in 1980.

12. The polio vaccination has virtually eliminated polio virus infections. However, it's not yet eradicated and appears in countries with low vaccination rates and poor healthcare systems.

13. Herd immunity is the concept that if most of the population is vaccinated from a specific disease that the minority of the population that isn't vaccinated is less likely to be infected, since the disease has less hosts to spread among the total population.

14. A common myth is vaccines can cause autism in children. Extensive testing and research have proven there is no link between autism and vaccines.

15. A common myth is vaccines don't need to be administered at a young age. The diseases that vaccines help prevent can be far more dangerous in very young children. The sooner a child can be safely vaccinated the better.

16. A common myth is vaccines give you the disease they prevent. No vaccines have an active virus, they mimic the virus to stimulate your immune system and teach it to build antibodies to fight the disease.

17. A common myth is vaccines has never been proven effective. Research has proven that a child has between 95 and 100 percent chance of a vaccine being effective. The best evidence to prove how effective vaccines are is the plummeting reported cases of the diseases after the start of the vaccination program.

Vaccine Pictures

A vaccine being administered via an injection. Credit: CNN

A vaccine being administered via nasal inhalation. Credit: U.S. Army

A vaccine being administered via the mouth. Credit: Karel Prinsloo

Additional Resources with Vaccine Facts

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This web page contains vaccine facts for kids and is an excellent resource for anyone of any age looking to learn about vaccinations. Our goal is to provide you with accurate, up to date facts about vaccines. In addition to facts about vaccines, we provide additional resources to help you with your research on vaccines and immunizations.

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Newsela | Hyundai's vision for the future: A car that walks on four legs

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A recent technology show in Las Vegas, Nevada, introduced a car designed to walk as easily as it rolls.

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Evolution of Television 1920-2020 (updated)

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How Vaccines Work? | VACCINATION | Importance Of Vaccine | The Dr Binocs Show | Peekaboo Kidz

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Students learn about the human side of vaccine development to understand that the discoveries of numerous scientists contribute to our understanding of a scientific topic, such as vaccines.

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Students learn about the human side of vaccine development to understand that the discoveries of numerous scientists contribute to our understanding of a scientific topic, such as vaccines.

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From Academic Kids

The printing press is a mechanical device for printing many copies of a text on rectangular sheets of paper. First invented in China in 1041, the printing press as we know it today was invented in the West by a German goldsmith and eventual printer, Johann Gutenberg in the 1450s. This event has been awarded number 1 of the Top 100 Greatest Events of the Millennium by LIFE Magazine. Apart from Gutenberg, the Dutch Laurens Janszoon Coster has also been credited with this invention.

Development of the printing press

The original method of printing was block printing, pressing sheets of paper into individually carved wooden blocks ( xylography). It is believed that block printing originated in China and the earliest known printed text, the Diamond Sutra (a Buddhist scripture), was printed in China in 868 A.D. The technique was also known in Europe, where it was mostly used to print Bibles. Because of the difficulties inherent in carving massive quantities of minute text for every block, and given the levels of peasant illiteracy at the time, texts such as the "Pauper's Bibles" emphasized illustrations and used words sparsely. As a new block had to be carved for each page, printing different books was an incredibly time consuming activity.

Moveable clay and metal type are processes much more than hand copying. The use of movable type in printing was invented in 1041 AD by Bi Sheng in China. Sheng used clay type, which broke easily, but eventually Goryeo (Korea) sponsored the production of metal type (a type foundry with brass was established by the Korean government in 1234 AD). Since there are thousands of Chinese characters (Koreans also used Chinese characters in literature), the benefit of the technique is not as apparent as with alphabetic based languages. Movable type did spur, however, additional scholarly pursuits in Song China and facilitated more creative modes of printing. Nevertheless, movable type was never extensively used in China until the European style printing press was introduced in relatively recent times (thus bringing the technology full circle).

Although probably unaware of the Chinese/Korean printing methods (with substantial evidence for both sides of argument), Gutenberg refined the technique with the first widespread use of movable type, where the characters are separate parts that are inserted to make the text. Gutenberg is also credited with the first use of an oil-based ink, and using "rag" paper introduced into Europe from China by way of Muslims, who had a paper mill in operation in Baghdad as early as 794. Before inventing the printing press in 1440, Gutenberg had worked as a goldsmith. Without a doubt, the skills and knowledge of metals that he learned as a craftsman were crucial to the later invention of the press. The claim that Gutenberg introduced or invented the printing press in Europe is not accepted by all. The other candidate advanced is the Dutchman Laurens Janszoon Coster.

Impact of printing

Diffusion of printing in Europe

Previously, books were copied mainly in monasteries, or (from the 13th century) in commercial scriptoria, where scribes wrote them out by hand. Books were therefore a scarce resource. While it might take someone a year to hand copy a Bible, with the Gutenberg press it was possible to create several hundred copies a year, with two or three people that could read, and a few people to support the effort. Each sheet still had to be fed manually, which limited the reproduction speed, and the type had to be set manually for each page, which limited the number of different pages created per day. Books produced in this period, between the first work of Johann Gutenberg and the year 1500, are collectively referred to as incunabula.

The supplantation of hand copied manuscripts with printed works was not received with unanimous encomium. Not only did the papal court contemplate making printing presses an industry requiring a licence from the Catholic Church (an idea rejected in the end), but as early as in the 15th century some nobles refused to have printed books in their libraries to sully their valuable handcopied manuscripts. Similar resistance was later encountered in much of the Islamic world, where calligraphic traditions were extremely important, and also in the Far East.

Despite some resistance, Gutenberg's printing press spread rapidly across Europe. Within thirty years of its invention in 1453, towns from Hungary to Spain, and from Italy to Britain had functional printing presses. It has been theorized that this incredibly rapid expansion shows not only a higher level of industry (fueled by the high-quality European paper mills that had been opening over the previous century) than expected, but also a significantly higher level of literacy than has often been estimated.

The first printing press in a Muslim territory opened in Andalusia (Muslim Spain) in the 1480s. This printing press was run by a family of Jewish merchants who printed texts with the Hebrew script. After the reconquista in the 1490s, the press was moved from Granada to Istanbul (a popular destination for thousands of Andalusian Jews).

Effects of printing on culture

The discovery and establishment of the printing of books with moveable type marks a paradigm shift in the way information was transferred in Europe. The impact of printing is comparable to the development of language, the invention of the alphabet, and the invention of the computer as far as its effects on the society.

Gutenberg's findings not only allowed a much broader audience to read Martin Luther's German translation of Bible, it also helped spread Luther's other writings, greatly accelerating the pace of Protestant Reformation. They also led to the establishment of a community of scientists (previously scientists were mostly isolated) that could easily communicate their discoveries, bringing on the scientific revolution. Also, although early texts were printed in Latin, books were soon produced in common European vernacular, leading to the decline of the Latin language.

In Korea and China, there were no texts similar to the Bible which could guarantee a printer return on the high capital investment of a printing press, and so the primary form of printing was wood block printing which was more suited for short runs of texts for which the return was uncertain.

Some credit the printing press with giving Europe the technological and communication edge over Eastern countries in the end, one of the major questions in world history.

Because of the printing press, authorship became more meaningful. It was suddenly important who had said or written what, and what the precise formulation and time of composition was. This allowed the exact citing of references, producing the rule, "One Author, one work (title), one piece of information" (Giesecke, 1989; 325). Before, the author was less important, since a copy of Aristotle made in Paris might not be identical to one made in Bologna. For many works prior to the printing press, the name of the author was entirely lost.

Because the printing process ensured that the same information fell on the same pages, page numbering, tables of contents, and indices became common. The process of reading was also changed, gradually changing from oral readings to silent, private reading. This gradually raised the literacy level as well, revolutionizing education.

It can also be argued that printing changed the way Europeans thought. With the older illuminated manuscripts, the emphasis was on the images and the beauty of the page. Early printed works emphasized principally the text and the line of argument. In the sciences, the introduction of the printing press marked a move from the medieval language of metaphors to the adoption of the scientific method.

In general, knowledge came closer to the hands of the people, since printed books could be sold for a fraction of the cost of illuminated manuscripts. There were also more copies of each book available, so that more people could discuss them. Within 50-60 years, the entire library of "classical" knowledge had been printed on the new presses (Eisenstein, 1969; 52). The spread of works also led to the creation of copies by other parties than the original author, leading to the formulation of copyright laws. Furthermore, as the books spread into the hands of the people, Latin was gradually replaced by the national languages. This development was one of the keys to the creation of modern nations.

Some theorists, such as McLuhan, Eisenstein, Kittler, and Giesecke, see an "alphabetic monopoly" as having developed from printing, removing the role of the image from society. Other authors stress that printed works themselves are a visual medium.

The art of book printing and typeface

For years, book printing was considered a true art form. Typesetting, or the placement of the characters on the page, including the use of ligatures, was passed down from master to apprentice. In Germany, the art of typesetting was termed the "black art", and it has largely been lost, due to advances in computer typesetting programs, which make it possible to get similar results with less human involvement. Some few practitioners continue to print books the way Gutenberg did. There is a yearly convention of traditional book printers in Mainz, Germany.

Printing in the industrial age

The Gutenberg press was much more efficient than manual copying, as testament to its effectiveness, it was essentially unchanged from the time of its invention until the Industrial Revolution, some three hundred years later.

The invention of the steam powered press is credited to Friedrich Gottlob K? and Andreas Friedrich Bauer in 1812 made it possible to print tens of thousands of copies of a page in a day.

K? and Bauer sold two of their first models to in London in 1814, capable of 1,100 impressions per hour. The first edition so printed was on November 28, 1814. K? and Bauer went on to perfect the early model so that it could print on both sides of a sheet at once. This began to make newspapers available to a mass audience, and from the 1820s changed the nature of book production, forcing a greater standardization in titles and other metadata.

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Printingp_c_and_a_diagram.png
Diagram of a single-side printing press c.1820

K? and Bauer's press was improved by Applegath and Cooper. The diagram indicates the principle operation of a Cowper and Applegath's Single Machine. The press is built up from a large flat inking table (A) which moves regularly back and forth, the form (B) on the table holds the type. The paper travels clockwise round a large cloth covered cylinder, the impression roller (C), and is pressed against the table. The ductor roller (D) rotates and so draws ink from the attached reservoir. The ink passes from the ductor roller to the vibrating roller (E), this moves, on its arms, in a regular motion between the ductor roller and the table. The ink is spread thinly and evenly by the distributing rollers (F) and then, as the table moves, passes onto the inking rollers (G). The axles of the inking rollers rest in groves, allowing them to rise and fall, they are also position at a slight angle to the table to improve ink distribution. As the table continues to move the form passes alternately under the inking rollers, twice, and then under the impression roller.

Later on in the middle of the 19th century the rotary press (invented in 1843 in the United States by Richard M. Hoe) allowed millions of copies of a page in a single day. Mass production of printed works flourished after the transition to rolled paper, as continuous feed allowed the presses to run at a much faster pace.

Movable type has been credited as the single most important invention of the millennium.

Later inventions in this field include:

References

Fontaine, Jean-Paul. L'aventure du livre: Du manuscrit medieval a nos jours. Paris: Bibliotheque de l'image, 1999.

See also

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The printing press is a mechanical device for printing many copies of a text on rectangular sheets of paper. First invented in China in 1041, the printing press as we know it today was invented in the West by a German goldsmith and eventual printer, Johann Gutenberg in the 1450s.

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From Academic Kids

Television is a telecommunication system for broadcasting and receiving moving pictures and sound over a distance. The term has come to refer to all the aspects of television programming and transmission as well. The word television is a hybrid word, coming from both Greek and Latin. "Tele-" is Greek for "far", while "-vision" is from the Latin "visio", meaning " vision" or " sight". It is often abbreviated as TV.

History

The development of television technology can be partitioned along two lines: those developments that depended upon both mechanical and electronic principles, and those which are purely electronic. From the latter descended all modern televisions, but these would not have been possible without discoveries and insights from the mechanical systems.

The German student Paul Gottlieb Nipkow proposed and patented the first electromechanical television system in 1885. Nipkow's spinning disk design is credited with being the first television image rasterizer, however, it wasn't until 1907 that developments in amplification tube technology made the design practical. Meanwhile, Constantin Perskyi had coined the word television in a paper read to the International Electricity Congress at the International World Fair in Paris on August 25, 1900. Perskeyi's paper reviewed the existing electromechanical technologies, mentioning the work of Nipkow and others.

From 1907 to 1910, Boris Rosing and his student Vladimir Zworykin demonstrated a television system that used a mechanical mirror-drum scanner in the transmitter and the electronic Braun tube ( cathode ray tube) in the receiver. Rosing disappeared during the Bolshevik revolution of 1917, but Zworykin later went to work for RCA to build a purely electronic television, the design of which was eventually found to violate patents by Philo Taylor Farnsworth.

A mechanically-scanned ( analogue television system was first demonstrated in London in February 1924 by John Logie Baird with an image of Felix the Cat and a moving picture by Baird on October 30, 1925. In 1928 Baird's company (Baird Television Development Company / Cinema Television) broadcast the first transatlantic Television signal, between London and New York, and the first shore to ship transmission. He also demonstrated an electromechanical colour, infrared (dubbed "Noctovision"), and stereoscopic television, using additional lenses, disks and filters. In parallel he developed a video disk recording system dubbed "Phonovision"; a number of the Phonovision[1]http://www.tvdawn.com/tvimage.htm) recordings, dating back to 1927, still exist. In 1929 he became involved in the first experimental electromechanical television service in Germany. In 1931 he made the first live transmission, of the Epsom Derby. In 1932 he demonstrated ultra-short wave television. Baird's system was tested by the BBC, who later discontinued its use in 1937 in favor of purely electronic television.

In the U. S. Ernst Alexanderson demonstrated a mechanically-scanned television broadcasting system in 1927.

Electronic television

Although the discoveries of Nipkow, Rosing, Baird and others were extraordinary, little of their technology is used in modern television. By 1934, all electromechanical television systems were outmoded.

A.A. Campbell-Swinton wrote a letter to on the 18 June 1908 describing his concept of electronic television using the cathode ray tube, which had been invented in 1897 by the German physicist and Nobel prize winner Karl Ferdinand Braun. He proposed using an electron beam in both the camera and the receiver, which could be steered electronically to produce moving pictures. He lectured on the subject in 1911 and displayed circuit diagrams, but no one, including Swinton, knew how to realize the design. Even though his system was never built, the cathode ray tube is still used in almost all television sets to display images until today.

Vladimir Zworykin is also sometimes cited as the father of electronic television because of his invention of the iconoscope in 1923 and his invention of the kinescope in 1929. His design was one of the first to demonstrate a television system with all the features of modern picture tubes. His previous work with Rosing on electromechanical television gave him key insights into how to produce such a system, but his (and RCA's) claim to being its original inventor was largely invalidated by three facts: a) Zworykin's 1923 patent presented an incomplete design, incapable of working in its given form (it was not until 1933 that Zworykin achieved a working implementation), b) the 1923 patent application was not granted until 1938, and not until it had been seriously revised, and c) courts eventually found that RCA was in violation of the television design patented by Philo Taylor Farnsworth, whose lab Zworykin had visited while working on his designs for RCA.

The controversy over whether it was first Farnsworth or Zworykin who invented modern television is still hotly debated today. Some of this debate stems from the fact that while Farnsworth appears to have gotten there first, it was RCA that first marketed working television sets, and it was RCA employees who first wrote the history of television. Even though Farnsworth eventually won the legal battle over this issue, he was never able to fully capitalize financially on his invention.

Broadcast television

In 1932 the BBC launched a service using Baird's 30-line system and these transmissions continued until 11 September 1935. On November 2, 1936 the BBC began broadcasting a dual-system service, alternating on a weekly basis between Marconi-EMI's high-resolution (405 lines per picture) service and Baird's improved 240-line standard from Alexandra Palace in London. Six months later, the corporation decided that Marconi-EMI's electronic picture gave the superior picture, and adopted that as their standard. This service is described as "the world's first regular high-definition public television service", since a regular television service had been broadcast earlier on a 180-line standard in Germany. The outbreak of the Second World War caused the service to be suspended. TV transmissions only resumed from Alexandra Palace in 1946.

The first regular television transmissions in Canada began in 1952 when the CBC put two stations on the air, one in Montreal, Quebec on September 6, and another in Toronto, Ontario two days later.

Missing image
Early_portable_tv.jpg

The first live transcontinental television broadcast took place in San Francisco, California from the Japanese Peace Treaty Conference on September 4, 1951. In 1958, the CBC completed the longest television network in the world, from Sydney, Nova Scotia to Victoria, British Columbia. Reportedly, the first continuous live broadcast of a breaking news story in the world was conducted by the CBC during the Springhill Mining Disaster which began on October 23 of that year.

Programming is broadcast on television stations (sometimes called channels). At first, terrestrial broadcasting was the only way television could be distributed. Because bandwidth was limited, government regulation was normal. In the US, the Federal Communications Commission allowed stations to broadcast advertisements, but insisted on public service programming commitments as a requirement for a license. By contrast, the United Kingdom chose a different route, imposing a television licence fee on owners of television reception equipment, to fund the BBC, which had public service as part of its Royal Charter. Development of cable and satellite means of distribution in the 1970s pushed businessmen to target channels towards a certain audience, and enabled the rise of subscription-based television channels, such as HBO and Sky. Practically every country in the world now has developed at least one television channel. Television has grown up all over the world, enabling every country to share aspects of their culture and society with others.

By the late 1980s, 98% of all homes in the U.S. had at least one TV set. On average, Americans watch four hours of television per day. An estimated two-thirds of Americans got most of their news about the world from TV, and nearly half got all of their news from TV. These figures are now estimated to be significantly higher.

Color Television

Guillermo González Camarena (1917-1965), invented the first color TX and first TV XEG. He holds the design and patent to color television systems from 1940, 1942, 1960 and 1962.

In August 31, 1946 he sent his first color transmission from his lab in the offices of The Mexican League of Radio Experiments in Lucerna St. #1, in Mexico City. The video signal was transmited in 115 MHz. and the audio in a band of 40 meters.

RCA claims they did it in 1946 but Camarena's patent has an earlier month. Also, there are previous attempts or designs but none worked properly. Camarena's was the first successful one.

Technology

Broadcasting

See broadcast television systems.

There are many means of distributing television broadcasts, including both analogue and digital versions of:

Receiving

TV sets

The earliest television sets were radios with the addition of a television device consisting of a neon tube with a mechanically spinning disk (the Nipkow disk, invented by Paul Gottlieb Nipkow) that produced a red postage-stamp size image . The first publicly broadcast electronic service was in Germany in March 1935. It had 180 lines of resolution and was only available in 22 public viewing rooms. One of the first major broadcasts involved the 1936 Berlin Olympics. The Germans had a 441-line system in the autumn of 1937. An example of an early television set is called a rotary dial-tune TV is outdated technology for a television set. This is one of the earliest technologies for TV turners. When the quartz-synthesized turners for TVs came out, rotary dial-tune turner technology was gradually obsoleting.

Rotary dial-tune TVs discontinued production somewhere around the mid and late 90's. (Source: ( Early Electronic TV http://www.earlytelevision.org/pendleton_paper.html))

Television usage skyrocketed after World War II with war-related technological advances and additional disposable income. Prior to the war, in the 1930s, TV receivers cost the equivalent of US$7000 in 2001, and had little available programming. Rotary dial-tune TVs were the earliest method of channel tuning until it became obsolete in the 90's.

For many years different countries used different technical standards. France initially adopted the German 441-line standard but later upgraded to 819 lines, which gave the highest picture definition of any analogue TV system, approximately four times the resolution of the British 405-line system. Eventually the whole of Europe switched to the 625-line standard, once more following Germany's example. Meanwhile in North America the original 525-line standard was retained.

Television in its original and still most popular form involves sending images and sound over radio waves in the VHF and UHF bands, which are received by a receiver (a television set). In this sense, it is an extension of radio. Broadcast television requires an antenna ( aerial). This can be an external antenna mounted outside or smaller antennas mounted on or near the television. Typically this is an adjustable dipole antenna called "rabbit ears" for the VHF band and a small loop antenna for the UHF band.

Some early television sets, especially British ones, contained valves and other pre- solid state electronic components which generated a considerable amount of heat even when the set was switched off. As a result, up until at least the mid-1970s, television stations would air announcements reminding viewers to unplug their sets before going to bed for the night, since the heat build-up in the back of the set was a considerable fire hazard.

Color television became available in the U.S. on December 30 of 1953, backed by the Columbia Broadcasting System (CBS) network. The government approved the color broadcast system proposed by CBS, but when RCA came up with a subcarrier system that made it possible to view color broadcasts in black and white on unmodified old black and white TV sets, CBS dropped their own proposal and used the new one (see NTSC).

The first publicly announced experimental TV broadcast of a program using RCA's "compatible color" system was an episode of Kukla, Fran and Ollie on August 30, 1953. NBC was the first network to have a regularly scheduled color program on the air (, starting in 1959). The networks slowly reformed into the color standard, and all three broadcast networks were airing full color schedules by the 1966-67 broadcast season.

European color television was developed somewhat later and was hindered by a continuing division on technical standards. Having decided to adopt a higher-definition 625-line system for monochrome transmissions, with a lower frame rate but with a higher overall bandwidth, Europeans could not directly adopt the US color standard, which was widely perceived as wanting anyway, because of its tint control problems. There was no urgency either, since there were still few sets overall and no commercial motivations, European television broadcasters being state-owned at the time.

The first color broadcast in Europe was by BBC2 in the UK in the summer of 1967, using PAL. Germans did their first broadcast in September (PAL), while the French in October (SECAM). PAL was eventually adopted by West Germany, the UK, Australia, New Zealand, much of Africa, Asia and South America, and most Western European countries except France.

Modern displays

Starting in the 1990s, modern television sets diverged into three different trends:

standalone TV sets;

integrated systems with DVD players and/or VHS VCR capabilities built into the TV set itself (mostly for small size TVs with up to 17" screen, the main idea is to have a complete portable system);

component systems with separate big-screen video monitor, tuner, audio system which the owner connects the pieces together as a high-end home theater system. This approach appeals to videophiles who prefer components that can be upgraded separately.

There are many kinds of video monitors used in modern TV sets. The most common are direct view CRTs for up to 40 inch or 100 cm (in 4:3) and 46 inch or 115 cm (in 16:9) diagonally; most big screen TVs (up to over 100 inch (254 cm)) use projection technology. Three types of projection systems are used in projection TVs: CRT-based, LCD-based, and DLP(reflective micromirror chip)-based.

Modern advances have brought flat screens to TV that use active matrix LCD or plasma display technology. Flat panel LCDs and plasma displays are as little as 4 inch or 10 cm thick and can be hung on a wall like a picture or put over a pedestal. They are multifunctional, because they are used like computer monitors too ( VGA and DVI or HDMI connections).

Nowadays some TVs integrates a pair of ports to connect computer cases and peripherals to it or to connect the set to an A/V home network ( HAVI) ( USB port for cord connection and BlueTooth/ WiFi for wireless).

See also: Liquid crystal display television; plasma display

Signal connections

Even for simple video, there are six standard ways to connect a device to a television. These are as follows:

HDMI - a small 19 pin connector that carries all-digital video and audio signals via High-Definition Multi-media Interface. Essentially an enhanced version of DVI that includes copy protection with HDCP, designed to carry HDTV but also used in current DVD players and latest digital displays. This provides the highest quality picture and sound currently available.

Component video - three separate RCA jacks (colored red, green and blue) carry three video signals, one brightness (luminance) and two colors (chromas), and is usually referred to as "Y, B-Y, R-Y", "Y Cr Cb" (interlaced) or "Y Pr Pb" (progressive), or YUV. Audio is not carried on this cable. This connection provides for picture quality superior to S-Video and is typically used in home theater for DVDs, satellite and analogue HTDV; less common in Europe but is starting to become more widely available.

SCART - a large 21 pin connector that may carry: one video signal composite video; or two video signals S-Video; or for picture quality similar to Component video, three signals of separate red, green and blue or RGB; or for best picture quality, four video signals of separate red, green, blue and sync or RGBS; plus right and left line-level audio channels; along with a number of control signals including an aspect-ratio flag (e.g. widescreen). This system has been standard in Europe since mid-1980s for all consumer electronics, which meant that RGBS was available on even the earliest PAL DVD players and satellite receivers, but this multi-format connector is rarely found elsewhere.

S-Video - small round connector with two separate video signals, one carrying brightness (luminance), the other carrying color (chroma). Also referred to as Y/C video. Provides most of the benefit of component video, with slightly less color fidelity. Use started in the 1980s for S-VHS, Hi-8, and early NTSC DVD players to relay high quality video before component was available. Audio is not carried on this cable.

Composite video - The most common form of connecting external devices, putting all the video information into one signal. Most televisions provide this option with a yellow RCA jack. Audio is not carried on this cable, though two separate cables with similar red and white RCA jacks for right and left line-level audio are commonly bonded to composite video cables.

Coaxial RF - All audio channels and picture components are transmitted through one coaxial cable and modulated on a radio frequency. Most TVs manufactured during the past 15-20 years accept coaxial connection, and the video is typically "tuned" on channel 3 or 4. This is the type of cable usually used for cable television. Unfortunately, many DVD players and some other components now fail to provide an RF coaxial output, forcing consumers to buy a somewhat expensive modulator in order to view it on older TV sets made before composite video jacks became commonplace.

Aspect ratios

In the 1950s, movie studios moved towards widescreen aspect ratios such as Cinerama in an effort to distance their product from television. Although this was initially just a gimmick widescreen is still the format of choice today and square aspect ratio movies are rare. Some people argued that widescreen is actually a disadvantage when showing objects that are tall instead of panoramic, others would say that natural vision is more panoramic that tall and therefore widescreen is easier on the eye.

Recently "widescreen" has spread from television to computing where both desktop and laptop computers are commonly equipped with widescreen displays, and it remains to be seen whether work or movie enjoyment will take over. There are some complaints about distortions of movie picture ratio due to some DVD playback software not taking account of aspect ratios; but this will subside as the DVD playback software matures. Futhermore, computer and laptop widescreen displays are in the 16:10 aspect ratio both physically in size and in pixel counts, and not in 16:9 of consumer televisions, leading to further complexity.

Aspect ratio incompatibility

The television industry changing aspect ratios is not without teething difficulties, and can presents a considerable problem.

Displaying a widescreen aspect (rectangular) image on a conventional aspect (square) display can be shown:

in "letterbox" format, with black stripes at the top and bottom

with part of the image being cropped, usually the extreme left and right of the image being cut off (or in "pan and scan", parts selected by an operator)

with the image horizontally compressed

A conventional aspect (square) image on a widescreen aspect (rectangular) display can be shown:

in "pillarbox" format, with black vertical bars to the left and right

with upper and lower portions of the image cut off

with the image horizontally distorted

A common compromise is to shoot or create material at an aspect ratio of 14:9, and to lose some image at each side for 4:3 presentation, and some image at top and bottom for 16:9 presentation.

Horizontal expansion has advantages in situations in which several people are watching the same set, as it compensates for watching at an oblique angle.

Sound

New developments

Geographical usage

US networks

Main article: Television in the United States

In the US, the three traditional commercial television networks ( ABC, CBS, and NBC) provide prime-time programs for their affiliate stations to air from 8pm-11pm Monday-Saturday and 7pm-11pm on Sunday. (7pm to 10pm, 6pm to 10pm respectively in the Central and Mountain time zones). Most stations procure other programming, often syndicated, off prime time. The FOX Network does not provide programming for the last hour of prime time; as a result, many FOX affiliates air a local news program at that time. Three newer broadcasting networks, The WB, PAX, and UPN also do not provide the same amount of network programming as so-called traditional networks. Sinclair Broadcast Group operates the largest network of local television stations, reaching about 24% of US households. In 2004 it was involved in controversies surrounding editorial control by the company over the content of its local stations.

Canadian networks

Latin American networks

National networks and stations

Television has reached a great expansion in all the Latin American scope. Currently, there exist more than 500 television stations in all Latin America, according to the number of apparatuses by homes (more than 60 million), of more than two hundred million people. Because of the financial and political troubles that occurred between the mid- 1970s and the early 1990s, television networks in some countries of this region had a development more irregular than the North American and European networks. In countries like Mexico or Brazil, one or two networks claim almost all the audience. In other countries like Colombia, television broadcasting has historically been state dominated until the 1990s. In countries like Nicaragua or Peru, television had a troubled history. Some prominent Latin American Television Networks are:

Mexico:

Bolivia:

Brazil:

Chile:

European networks

National

In much of Europe television broadcasting has historically been state dominated, rather than commercially organised, although commercial stations have grown in number recently.

Europe-wide networks

Euronews, a pan-European news station, broadcasting both by satellite and terrestrially (timesharing on State TV networks) to most of the continent. Broadcasted in several languages (English, French, German, Spanish, Russian, Portuguese and Italian) it draws on contributions from State broadcasters and the ITN news network. It also produces Romanian language programs for the Romanian Television.

Euro1080, the first HDTV broadcaster available in the whole of Europe.

Asian networks and stations

In Asia, television has traditionally been state-controlled, although the number of private stations is increasing, as is competition from satellite television. Japan's NHK is a non-commercial network similar to the BBC, funded by a television licence fee, and has more editorial independence over news and current affairs than broadcasters like India's state-run Doordarshan or China's China Central Television. Star TV based in Hong Kong has expanded to other areas recently. Number of private broadcasters are indeed increasing in some countries (2004) for example: Indonesia's 10 private national stations compare to only 1 in 1989.

Middle East networks and stations

Similarly in the Middle East, television has been heavily state-controlled, with considerable censorship of both news coverage and entertainment, particularly that imported from the West. This control of the medium has been eroded by the increasing availability of satellite TV, and the number of satellite channels in Arabic is second only to the number of satellite channels in English, the best known of which being the Qatar-based news service Al-Jazeera.

African networks and stations

(See the list of television stations in Africa.)

Australian networks and stations

Australian television began in ( 1956, just in time for the Melbourne Olympics. Australia has three nationwide metropolitan commercial networks ( Seven, Nine and Ten) as well as the ABC (Australian Broadcasting Corporation), a government owned, commercial free network; and SBS (Special Broadcasting Service) a commercial-supported, multi-lingual, government-owned station. The Australian Broadcasting Authority http://www.aba.gov.au/) has also issued licenses to community groups to establish "community television stations" in most capital cities on the UHF Ch 31 frequency.

Content

Advertising

From the earliest days of the medium, television has been used as a vehicle for advertising. Since their inception in the USA in the late 1940s, TV commercials have become far and away the most effective, most pervasive, and most popular method of selling products of all sorts. US advertising rates are determined primarily by Nielsen ratings.

Programming

Getting TV programming shown to the public can happen in many different ways. After production the next step is to market and deliver the product to whatever markets are open to using it. This typically happens on two levels:

1. Original Run or First Run - a producer creates a program of one or multiple episodes and shows it on a station or network which has either paid for the production itself or to which a license has been granted by the producers to do the same.

2. Syndication - this is the terminology rather broadly used to describe secondary programming usages (beyond original run). It includes secondary runs in the country of first issue, but also international usage which may or may not be managed by the originating producer. In many cases other companies, TV stations or individuals are engaged to do the syndication work, in other words to sell the product into the markets they are allowed to sell into by contract from the copyright holders, in most cases the producers.

In most countries, the first wave occurs primarily on FTA television, while the second wave happens on subscription TV and in other countries. In the US however, the first wave occurs on the FTA networks and subscription services, and the second wave travels via all means of distribution.

First run programming is increasing on subscription services outside the US, but few domestically produced programs are syndicated on domestic FTA elsewhere. This practice is increasing however, generally on digital only FTA channels, or with subscriber-only first run material appearing on FTA.

Unlike the US, repeat FTA screenings of a FTA network program almost only occur only on that network. Also, affiliates rarely buy or produce non-network programming that isn't intensely local.

Social aspects

Dangers

Paralleling television's growing primacy in family life and society, an increasingly vocal chorus of legislators, scientists and parents is raising objections to the uncritical acceptance of the medium. For example, the ( Swedish government imposed a total ban on advertising to children under twelve in 1991 (see advertising). In the US, the National Institute on Media and the Family http://www.mediafamily.org/facts/facts_tveffect.shtml) (not a government agency) points out that US children watch an average of 25 hours of television per week and features studies showing it interferes with the educational and maturational process.

A ( February 23 2002 article in Scientific American http://www.sciam.com/print_version.cfm?articleID=0005339B-A694-1CC5-B4A8809EC588EEDF) suggested that compulsive television watching was no different from any other addiction, a finding backed up by reports of withdrawal symptoms among families forced by circumstance to cease watching.

The 1957 film " A Face In The Crowd" critiques the television industry, in this tale of a TV reporter who turns a hobo into a TV star.

Technology Trends

In its infancy, television was an ephemeral medium. Fans of regular shows planned their schedules so that they could be available to watch their shows at their time of broadcast. The term appointment television was coined by marketers to describe this kind of attachment.

Today, the viewership's dependence on schedule has lessened due to the invention of programmable video recorders, such as the Videocassette recorder and the Digital video recorder. Consumers can watch programs on their own schedule once they are broadcast and recorded. Television service providers also offer video on demand, a set of programs which can be watched at any time.

Mobile phone networks are capable of carrying video streams, and some predict that video on demand will be soon available through them.

Suitability for Audience

Recently, television broadcasting companies have come under fire for the content of their shows. A flurry of fines by the FCC have fallen on various stations following the Janet Jackson affair at the 2004 Super Bowl halftime show. Even radio shows have been affected. Measures are being considered to have certain shows only air past certain times of night.

Colloquial names

telly

the box

the idiot box

the tube

boob tube

glass teat

cultural barbiturate

goggle box

the cyclops

die Kiste, die Glotze (German)

kijkbuis (Dutch)

telkku, telkkari, töllö (Finnish)

bilžukaste, teļļuks (Latvian)

electronic babysitter

la máquina cazabobos (Spanish)

Familie alteret (Danish) The Family Alter

Further Reading

Erik Barnouw: Tube of Plenty: The Evolution of American Television, Oxford University Press 1992.

Pierre Bourdieu: On Television, The New Press 2001

Guy Debord: The Society of the Spectacle, Zone Books 1995

Jerry Mander, Four Arguments for the Elimination of Television, Perennial 1978

References

David E. Fisher and Marshall J. Fisher, Tube, the Invention of Television, Counterpoint, Washington D.C. USA, (1996) ISBN 1887178171

Related articles

External links

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Television is a telecommunication system for broadcasting and receiving moving pictures and sound over a distance. The term has come to refer to all the aspects of television programming and transmission as well. The word television is a hybrid word, coming from both Greek and Latin.

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The first time kids had to get a vaccine to go to school was more than 200 years ago. The disease? Smallpox.

For the past four decades, all 50 U.S. states have required that parents, if they want to enroll their children in any school, public or private, must vaccinate them against contagious diseases like polio and measles. The reason is simple: High rates of vaccination dramatically cut deaths and have all but eliminated some diseases.

But as long as there have been vaccines, there have been people who oppose them, formerly known as "anti-vaccinationists." They have brought many legal challenges over the years, but the U.S. Supreme Court ruled on the constitutionality of school vaccine mandates nearly a century ago, and that has pretty much been upheld to this day.

That said, there's also a strong tradition of granting exemptions to vaccine requirements based on religious and philosophical beliefs. There has also, at times, been lax enforcement and an unwillingness to punish students by keeping them out of school.

But when diseases break out or come back, so do vaccine campaigns and the really strong stuff: mandates.
Scroll on to take a look at a historical timeline of vaccines in schools:

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COMIC: If history is a guide, schools will start requiring COVID vaccines

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The first time kids had to get a vaccine to go to school was more than 200 years ago. The disease? Smallpox. For the past four decades, all 50 U.S. states have required that parents, if they want to enroll their children in any school, public or private, must vaccinate them against contagious diseases like polio and measles.

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From Academic Kids

A vaccine is an antigenic preparation used to produce active immunity to a disease, in order to prevent or ameliorate the effects of infection by any natural or 'wild' strain of the organism. The term derives from vaccinia, the infectious viral agent of cowpox, which, when administered to humans, provided them protection against smallpox. The process of ditributing and administrating vaccines is referred to as vaccination.

Origin of vaccines

In 1796, during the heyday of the smallpox virus in Europe, an English country doctor, Edward Jenner, observed that milkmaids would sometimes become infected with cowpox, through their interactions with dairy cows' udders. Cowpox is a mild relative of the deadly smallpox virus. Building on the foundational practice of innoculation, Jenner took infectious fluid from the hand of milkmaid Sarah Nelmes. He inserted this fluid, by scratching or injection, into the arm of a healthy local eight year old boy, James Phipps. Phipps then showed symptoms of cowpox infection. Forty-eight days later, after Phipps had fully recovered from cowpox, Jenner injected smallpox-infected matter into Phipps, but Phipps did not later show signs of smallpox infection.

Types of vaccines

Vaccines may be living, weakened strains of viruses or bacteria which intentionally give rise to inapparent-to-trivial infections. Vaccines may also be killed or inactivated organisms or purified products derived from them.

There are three types of traditional vaccines ([1]http://www.immunecentral.com/infotemplate.cfm-1702-72-1):

Inactivated - these are previously virulent micro-organisms that have been killed with chemicals or heat. Examples are vaccines against flu, cholera, plague, and hepatitis A. Most such vaccines may have incomplete or short-lived immune responses and are likely to require booster shots.

Live, attenuated - these are live micro-organisms that have been cultivated under conditions to disable their virulent properties. They typically provoke durable immunological responses. Examples include yellow fever, measles, rubella, and mumps.

Toxoids - these are inactivated toxic compounds from micro-organisms in cases where these (rather than the micro-organism itself) causes illness. Examples of toxoid-based vaccines include tetanus and diphtheria

The live tuberculosis vaccine is not the contagious TB strain, but a related strain called " BCG"; it is used in the United States very infrequently.

A number of innovative vaccines are also in development and also in use:

Conjugate - certain bacteria have outer coats that inexperienced immune systems don't recognize. By linking these unknown outer coats to proteins and toxins that reliably provoke an immune response the body, the immune system can begin to recognize and destroy the coated bacteria

Subunit - rather than introducing a whole inactivated or attenuated micro-organism to an immune system, a fragment of it can create an immune response

Recombinant Vector - by combining the physiology of one micro-organism and the DNA of the other, immunity can be created against diseases that have complex infection processes

In recent years a new type of vaccine, created from an infectious agent's DNA called DNA vaccination, has been developed. It works by insertion (and expression, triggering immune system recognition) into human or animal cells, of viral or bacterial DNA. These cells then develop immunity against an infectious agent, without the effects other parts of a weakened agent's DNA might have. As of 2003, DNA vaccination is still experimental, but shows some promising results.

Developing immunity

The immune system recognizes vaccine agents as foreign, destroys them, and 'remembers' them. When the virulent version of an agent comes along, the immune system is thus prepared to respond, by (1) neutralizing the target agent before it can enter cells, and (2) by recognizing and destroying infected cells before that agent can multiply to vast numbers.

Vaccines have contributed to the eradication of Smallpox, one of the most contagious and deadly diseases known to man. Other diseases such as rubella, polio, measles, mumps, chickenpox, and typhoid are no where near as common as they were just a hundred years ago. As long as the vast majority of people are vaccinated it is much more difficult for an outbreak of disease to occur, let alone spread. This effect is called herd immunity.

Controversy surrounding the use of vaccines

See article: Vaccine controversy

Opposition to vaccination, from a wide array of vaccine critics, has existed since the earliest vaccination campaigns: ([2]http://bmj.bmjjournals.com/cgi/reprint/325/7361/430?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&andorexacttitle=and&andorexacttitleabs=and&fulltext=anti-vaccinationists&andorexactfulltext=and&searchid=1113046719196_3655&stored_search=&FIRSTINDEX=0&sortspec=relevance&resourcetype=1,2,3,4).

Prior to 1997, a number of vaccines, including those given to very young children, used thimerosal, a preservative that metabolizes into ethylmercury. It is used in some influenza, DTP ( diphtheria, tetanus and pertussis) vaccine formulations.

In the late 1990s, controversy over vaccines escalated in both the US and the ( ( ( ( ( United Kingdom when a study, published in the respected journal Lancet, by Dr. Andrew Wakefield suggested a possible link between bowel disorders, autism and MMR vaccine, and urged further research [3]http://briandeer.com/mmr/lancet-paper.htm). His report garnered significant media attention, leading to a drop in the uptake of the MMR vaccine in the UK and some other countries. The study garnered criticism for its small sample size, and for failing to use healthy controls. In response to the controversies, a number of studies with larger sample sizes were conducted, and failed to confirm the findings.[4]http://bmj.bmjjournals.com/cgi/reprint/325/7361/419?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&andorexacttitle=and&andorexacttitleabs=and&fulltext=vaccines+history+&andorexactfulltext=and&searchid=1113045633124_3161&stored_search=&FIRSTINDEX=0&sortspec=relevance&resourcetype=1,2,3,4) [5]http://bmj.bmjjournals.com/cgi/reprint/324/7334/393?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=1&author1=taylor%2C+b&author2=miller%2C+e&andorexacttitle=and&andorexacttitleabs=and&andorexactfulltext=and&searchid=1113249908936_21240&stored_search=&FIRSTINDEX=0&sortspec=relevance&resourcetype=1,2,3,4). In 2004, 10 of the 13 authors of the original Wakefield study retracted the paper's interpretation, without disputing the central finding of a consistent set of bowel disorders among the autistic study subjects, stating the data were insufficient to establish a causal link between MMR vaccine and autism.[6]http://briandeer.com/mmr/lancet-retraction.htm) In 2004 and 2005, England and Wales have seen an increase in the incidence of mumps infections among adolescents and young adults, which health authorities attribute to a decline in booster shots from 92% to 80%, which they believe is due to the alleged misinformation generated by Wakefield's study [7]http://www.nzherald.co.nz/index.cfm?c_id=2&ObjectID=10125382).

Also in 2004, the United States' ( Institute of Medicine reported that evidence "favors rejection" of any a link between vaccines containing thiomerosal, or MMR, and the development of autism [8]http://www.iom.edu/report.asp?id=20155).

Potential for adverse side effects in general

Some people refuse to immunize themselves or their children, because they believe vaccines' adverse side effects outweigh their benefits. A variation of this reasoning is that not enough is known of the adverse effects to determine whether the potential benefits make the risks worthwhile. Since most people are vaccinated against contagious and potentially fatal diseases, the chances of someone who is not vaccinated becoming ill is a good deal smaller than it might be if their opinion was held by more people. Thus it could be argued that they reap some of the benefits of vaccines, through herd immunity, without assuming the risks those who choose to vaccinate do.

Advocates of routine vaccination argue that side effects of approved vaccines are either far less serious than actually catching the disease, or are very rare, and argue that the calculus of risk/benefit ratio should be based on benefit to humanity rather than simply on the benefit to the immunized individual. The main risk of rubella, for example, is to the fetuses of pregnant women, but this risk can be effectively reduced by the immunization of children to prevent transmission to pregnant women.

Efficacy of vaccines

It's worthwhile to note that vaccines don't guarantee that you are protected from the disease. That is, even having been vaccinated, there is still a remote possibility that you may get the disease. The efficacy or performance of the vaccine is dependent on a number of factors:

the disease itself (for some diseases vaccination performs better than for other diseases)

whether you kept to the timetable for the vaccinations

perhaps other factors such as ethnicity or genetic predisposition

If you have been vaccinated and do catch the disease, it's likely that it will be much milder than if you had not been vaccinated.

Economics of vaccine development

One challenge in vaccine development is economic: many of the diseases most demanding a vaccine, including HIV, Malaria and Tuberculosis, exist principally in poor countries. Pharmaceutical firms and biotech companies have little incentive to develop vaccines for these diseases because there is so little revenue potential. Most vaccine development to date has relied on "push" funding by government and non-profit organizations, of government agencies, universities and non-profit organizations. To date, there has been very little involvement of private industry on a commercial basis.

Many researchers and policymakers are calling for a different approach, using "pull" mechanisms to motivate industry. Mechanisms such as prizes, tax credits, or advance market commitments could ensure a financial return to firms that successfully developed an HIV vaccine. If the policy were well-designed, it might also ensure that people have access to a vaccine if and when it is developed.

See also

External links

(AAPPublications.org http://pediatrics.aappublications.org/cgi/content/full/112/3/604) - 'Thimerosal and the Occurrence of Autism: Negative Ecological Evidence From Danish Population-Based Data' Pediatrics, Vol 112, No 3, September 2003 (Danish study showing continued increase in autism after discontinuation of MMR vaccine thimerosal formulations)

(bmj.bmjjournals.com http://bmj.bmjjournals.com/cgi/content/full/319/7206/352) - 'Comparative efficacy of three mumps vaccines', Matthias Schlegel, Joseph J. Osterwalder, Renato L. Galeazzi, Pietro J. Vernazza, British Medical Journal' Vol 319, No 352, August 7, 1999

(BrianDeer.com http://briandeer.com/mmr/lancet-paper.htm) - 'Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children' Andrew Wakefield, et al., The Lancet, Vol 351, No 9103, February 28, 1998

(JPandS.org (pdf)http://www.jpands.org/vol8no1/geier.pdf) - 'Thimerosal in Childhood Vaccines, Neurodevelopment Disorders, and Heart Disease in the United States', Mark Geier, M.D., Ph.D., and David Geier, B.A., Journal of American Physicians and Surgeons, Vol 8, No 1, Spring, 2003

(TruthCampaign.ukf.net http://www.truthcampaign.ukf.net/articles/health/vaccination.html) - 'Vaccination Assault on the Human Species', Pat Rattigan, NDca:Vacuna

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From Academic Kids

(Redirected from Light bulb)

The incandescent light bulb ( archaically known as the electric lamp) uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation or incandescence). The bulb is the glass enclosure which keeps the filament in a vacuum or low- pressure noble gas, or a halogen gas in the case of quartz-halogen lamps (see below) in order to prevent oxidisation of the filament at high temperatures. In Australia a light bulb is also called a light globe, but this term is not used elsewhere.

History of the light bulb

The invention of the light bulb is sometimes attributed to Thomas Alva Edison, who made contributions to its development producing a practical and viable electric lamp and succeeded in marketing the device, but today it is well-known that Heinrich Göbel built functional bulbs three decades earlier. Many others also contributed to the development of a truly practical device for the production of electrically generated lighting.

In 1801 Sir Humphry Davy, an English chemist, made platinum strips glow by passing an electric current through them, but the strips evaporated too quickly to make a useful lamp. In 1809 he created the first arc lamp, which he demonstrated to the Royal Institution of Great Britain in 1810, by creating a small but blinding arc between two charcoal rods connected to a battery.

In 1820 a British scientist Warren De la Rue enclosed a platinum coil in an evacuated tube and passed an electric current through it. The design was based on the concept that the high melting point of platinum would allow it to operate at high temperatures and that the evacuated chamber would contain less gas molecules to react with the platinum, improving its longevity. Although it was an efficient design, the cost of the platinum made it impractical for commercial use.

In 1841 Frederick de Moleyns of England was granted the first patent for an incandescent lamp, with a design using powdered charcoal heated between two platinum wires.

In 1854, the German inventor Heinrich Göbel developed the first 'modern' light bulb: a carbonised bamboo filament, in a vacuum bottle to prevent oxidation. In the following five years he developed what many call the first practical light bulb. His lamps lasted for up to 400 hours. He did not immediately apply for a patent, but his priority was established in 1893.

Joseph Wilson Swan (1828-1914) was a physicist and chemist born in Sunderland, England. In 1850 he began working with carbonised paper filaments in an evacuated glass bulb. By 1860 he was able to demonstrate a working device but lack of a good vacuum and an adequate supply of electricity resulted in a short lifetime for the bulb and inefficient light. By the mid-1870s better pumps became available, and Swan returned to his experiments. Swan received a British patent for his device in 1878. Swan reported success to the Newcastle Chemical Society and at a lecture in Newcastle in February 1879 he demonstrated a working lamp that utilised a carbon fibre filament. The most significant feature of Swan's lamp was that there was little residual oxygen in the vacuum tube to ignite the filament, thus allowing the filament to glow almost white-hot without catching fire. From this year he began installing light bulbs in homes and landmarks in England and by the early 1880s had started his own company.

Across the Atlantic, parallel developments were also taking place. On July 24 1874 a Canadian patent was filed for the Woodward and Evan's Light by a Toronto medical electrician named Henry Woodward and a colleague Mathew Evans, who was described in the patent as a "Gentleman" but in reality a hotel keeper. They built their lamp with a shaped rod of carbon held between electrodes in a glass globe filled with nitrogen. Woodward and Evans found it impossible to raise financial support for the development of their invention and in 1875 Woodward sold a share of their Canadian patent to Thomas Edison.

In January 1882, Lewis Latimer received a patent for the "Process of Manufacturing Carbons," an improved method for the production of light bulb filaments which yielded longer lasting bulbs than Edison's technique.

In Britain, Swan took Edison to court for patent infringement. Edison lost and as part of the settlement, Edison was forced to take Swan in as a partner in his British electric works. The company was called the Edison and Swan United Electric Company. Eventually, Edison acquired all of Swan's interest in the company. Swan sold his United States patent rights to the Brush Electric Company in June 1882.

The United States Patent Office had ruled on October 8, 1883 that Edison's patents were based on the prior art of William Sawyer and were invalid. Litigation continued for a number of years. Eventually on October 6, 1889, a judge ruled that Edison's electric light improvement claim for "a filament of carbon of high resistance" was valid. Research exposed in " A Streak of Luck" by Robert Conot ( 1979), shows that Edison and his attorneys hid significant information from the judge. They cut out the October 7-21, 1879 section of a notebook that the judge might have determined showed that they were simply extending Sawyer's (or Swan's) work with carbon "burners" or "rods" in an evacuated glass bulb.

Edison and his team did not find a commercially workable filament (bamboo) until more than 6 months after Edison filed the patent application. The weak and short lived (40 to 150 hours) carbon filament was eventually superseded by the tungsten filament. In 1903 Willis Whitnew invented a filament that would not blacken the inside of a light bulb. It was a metal-coated carbon filament. In 1906, the General Electric Company was the first to patent a method of making tungsten filaments for use in incandescent lightbulbs. The filaments were costly, but by 1910 William David Coolidge ( 1873- 1975) had invented an improved method of making tungsten filaments. The tungsten filament outlasted all other types of filaments and Coolidge made the costs practical.

One of the major problems of the standard electric light bulb is evaporation of the filament. The inevitable variations in resistivity along the filament cause nonuniform heating, with 'hot spots' forming at higher resistivity. Thinning by evaporation increases resistivity. But hot spots evaporate faster, increasing their resistivity faster-a positive feedback which ends in the familiar tiny gap in an otherwise healthy-looking filament. Irving Langmuir suggested that an inert gas, instead of vacuum, would retard evaporation and still avoid combustion, and so ordinary incandescent light bulbs are now filled with nitrogen, argon, or krypton.

A typical filament light bulb lasts about 1000 hours. See the section below, Voltage, light output, and life, for a discussion of the tradeoffs involved in setting a lamp life specification.

The halogen lamp

The problem of short bulb life is addressed in the halogen lamp which is filled with a halogen gas such as iodine or bromine. This creates an equilibrium reaction where evaporated filament is chemically re-deposited at the hot-spots, preventing the early failure of the lamp. This allows halogen lamps to be run at higher temperatures which would cause unacceptable low lamp lifetimes in ordinary light bulbs, allowing for greater brightness and efficiency.

Because the lamp envelope must be very hot for this to work, the envelopes are made of quartz glass instead of ordinary glass, which would soften and flow too much at these temperatures. Thus halogen lamps are sometimes called tungsten halogen lamps and are sometimes called quartz halogen lamps. They were once called quartz iodine lamps.

Perhaps the most significant side effect of using quartz instead of ordinary glass is that the lamp becomes a source of UV-B light, because the quartz is transparent to this spectral range and ordinary glass is not. One consequence is that it is possible to get a sunburn from excess exposure to the light of a quartz halogen lamp. Quartz halogen lamps are used in some scientific instruments as UV-B light sources.

The quartz glass can be damaged by residue from fingerprints. These bulbs should be handled without touching the quartz capsule (the actual light bulb). If the quartz capsule is touched, it must be cleaned with rubbing alcohol.

The incandescent light bulb is still widely used in domestic applications, and is the basis of most portable lighting (for instance, some car headlamps and electric torches). Halogen lights have become more common in auto headlights and domestic situations, particularly where light is to be concentrated on a particular point. The fluorescent light, has, however, replaced many applications of the light bulb with its superior life and energy efficiency. LED lights are beginning to see increased home and auto use, replacing incandescent bulbs. Newer headlights are going to high-intensity discharge lighting, such as halogen metal oxide, which look purplish instead of yellowish.

Standard fittings

Most domestic and industrial light bulbs have standard fittings compatible with standard lampholders. The most common types of fitting are:

MES or medium Edison screw (aka E26), used in the USA and Japan for most 120 and 100 volt lamps

BC or double-contact bayonet cap, used in the UK, Ireland and Australia for most 240 volt mains lamps (although MES is also common in the UK)

E14 / E27 screw fittings, used in continental Europe. (E27 is very similar to MES, but not identical.)

In each designation, the E stands for Edison, who created the screw-base lamp, and the number is in millimetres. (This is true even in the United States, where other designations involving the diameter of the bulb itself are still given in eighths of an inch.) In North America, there are four standard sizes of screw-in sockets used for line-voltage lamps: candelabra (E12), intermediate (E17), medium or standard (E26), and mogul (E39). In continental Europe, these are instead slightly different: candelabra (E10 or E11), intermediate (E14), medium or standard (E27), and mogul (E40). There is also a rare "admedium" size (E29), and a very miniature size (E5), generally used only for low voltage applications such as with a battery. Bayonet bulbs have similar sizes, and are given a B designation.

Halogen bulbs often come inside one of these standard bulbs, but also come with pin bases. These are given a G designation, with the number being the centre-to-centre distance in millimetres.

Efficiency

A different measure, the overall luminous efficiency, is defined as the ratio of luminous flux to total energy input. This is less than or equal to the luminous efficiency.

http://www.dgs.state.md.us/lighting/faqs.html http://freespace.virgin.net/tom.baldwin/bulbguide.html http://www.coffj.com/veg1/lamp.htm http://www.pti-nj.com/obb_lamps.html http://members.misty.com/don/led.html http://physics.ccri.cc.ri.us/keefe/light.htm http://de.wikipedia.org/wiki/Bild:Blackbodyvisiblerp.png

Power

Filament light bulbs are usually marketed according to the electrical power consumed. This is measured in watts and depends mainly on the resistance of the filament, which in turn depends mainly on the filament's length, thickness and material. It is difficult for the average consumer to predict the light output of a bulb given the power consumed but it can be safely assumed, for two bulbs of the same type, that the higher power bulb is brighter. Actual light output ratings are given in lumens, however most buyers do not check for this. Some manufacturers engage in deceptive advertising, such that the claimed "long" bulb life is achievable at normal household voltages, but the light output is only attainable at a higher voltage which does not normally exist, such as 130 volts in the United States.

The table below shows the approximate typical output (in lumens) of standard incandescent light bulbs at various power:

The 34, 52, 67, 90 and 135 watt bulbs are designed for use at 130 volts.

Heat

Most incandescent lamps waste about 90% of the power they consume in heat.

Quality halogen incandescents are closer to 15% efficiency, which, although still extremely low, will allow a 60 watt bulb to provide nearly as much light as (and a 75 watt to provide even more than) a non-halogen 100 watt. However, small halogen lamps are often still high power, causing them to get extremely hot. This is both because the heat is more concentrated on the smaller bulb surface, and because the surface is closer to the filament. This high temperature is essential to their long life (see the section on Halogen lamps above). Left unprotected, these can cause fires much more easily than a regular incandescent, which may only scorch things like drapery. Most safety codes now require these bulbs to be protected by a grid or grille, or by the glass and metal housing of the fixture. Bulbs over 300 watts are usually banned from indoor use.

Voltage, light output, and life

Incandescent lamps are very sensitive to changes in the supply voltage. These characteristics are of great practical and economic importance. For a supply voltage V,

Light output is approximately proportional to V3.4

Power consumption is approximately proportional to V1.6

Life is approximately inversely proportional to V¹⁶

Color temperature is approximately proportional to V0.42

This means that 5% reduction in operating voltage will double the life of the bulb, at the expense of reducing its light output by 20%. This may be a very acceptable tradeoff for a light bulb that is a difficult-to-access location (for example, traffic lights or fixtures hung from high ceilings). So-called "long-life" bulbs are simply bulbs in which this tradeoff is designed in.

According to the relationships above (which are probably not accurate for such extreme departures from nominal ratings), operating a 100 watt, 1000 hour, 1700 lumen bulb at half voltage would extend its life to about 65,000,000 hours or over 7000 years - while reducing light output to 160 lumens, about the equivalent of a normal 15 watt bulb. The Guinness Book of World Records states that a firehouse in Livermore, California has a light bulb that is said to have been burning continuously for over a century since 1901 (presumably apart from power outages). However, the bulb is powered by only 4 watts. A similar story can be told of a 40 watt bulb in Texas which has been illuminated since September 21, 1908. It once resided in an opera house where notable celebrities stopped to take in its glow, but is now in an area museum.

Lamps also vary in the number of support wires used for the tungsten filament. Each additional support wire makes the filament mechanically stronger, but removes heat from the filament, creating another tradeoff between efficiency and long life. Many modern 120 volt lamps use no additional support wires, but lamps designed for "rough service" often have several support wires and lamps designed for "vibration service" may have as many as five. Lamps designed for low voltages (for example, 12 volts) generally have filaments made of much heavier wire and do not require any additional support wires.

See also

External links, references, resources

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(Redirected from Light bulb) The incandescent light bulb ( archaically known as the electric lamp) uses a glowing wire filament heated to white-hot by electrical resistance, to generate light (a process known as thermal radiation or incandescence).

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A telephone, also known as a phone, is a communication tool. Originally it was an electric tool transmitting analogue speech along wires. Now it is an electronic tool sending digital signals on wires or radio transmission. Using a telephone, two people who are in different places can talk to each other. Early telephones needed to be connected with wires which are called fixed or landline telephones. Modern mobile phones use radio waves.

Alexander Graham Bell was the first person to patent the telephone, in 1876. Early telephones were wired directly to each other and could only talk to the phone that they were connected to. Later, telephone exchanges allowed connecting to other telephones. During the 20th century the machines that made the connections were automated.

Types of telephones

There are many different types of telephone. A telephone that can be carried around is called a mobile phone or cell phone. These became popular in the late 1980s. It has become common for people to carry mobile phones and in some places it is unusual to not have one. The majority are smartphones, which can be used as computers. Some mobile phones are able to make telephone calls using communications satellites instead of masts on the ground, which means people can make calls from anywhere in the world.

In most countries there are public payphones. To use one, people pay with coins, a credit card or a prepaid card.

Computers can use a machine called a modem or a Digital subscriber line router to talk to other computers over a telephone line. This allows a computer to connect to other computer networks including the Internet.

Most countries have a telephone network. The telephones in one place are connected to a telephone exchange. The exchanges are connected together in a world-wide network. In less developed countries cell phones are used as a cheaper and faster way to connect the countryside to the network.

Telephone number

Most telephones have their own number. Today, telephone numbers are about seven to ten digits long. In many countries, part of the telephone number is called the area code. Area codes are used to make sure the numbers are not the same in two different places. Areas have their own area code, and countries have their own country code.

By the end of 2009, there were a total of nearly 6 billion mobile and fixed-line telephone subscribers worldwide. This included 1.26 billion fixed-line subscribers and 4.6 billion mobile subscribers.

Images for kids

In Spanish: Teléfono para niños

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From Academic Kids

An automobile is a wheeled vehicle that carries its own motor. Different types of automobiles include cars, buses, trucks, and vans, with cars being the most popular by far. Older terms include horseless carriage and motor car, with motor referring to what is now usually called the engine. The act of operating an automobile is called An automobile has seats for the driver and, almost without exception, one or more passengers.

History

It is generally claimed that the first automobiles with gasoline-powered internal combustion engines were completed almost simultaneously in 1886 by German inventors working independently: Carl Benz on 3 July 1886 in Mannheim, resp. Gottlieb Daimler and Wilhelm Maybach in Stuttgart (also inventors of the first motor bike) and Austrian inventor Siegfried Marcus in Vienna.

Steam-powered self propelled vehicles were devised in the late 18th century. Nicolas-Joseph Cugnot successfully demonstrated such a vehicle as early as 1769. The first vehicles were steam engine powered; probably the most notable advances in steam power evolved in Birmingham, England by the Lunar Society. It was here that the term Horsepower was first used. It was in Birmingham also that the first four wheel petrol-driven automobiles were built in Britain in 1895 by Frederick William Lanchester who also patented the disc brake in the city. Electric vehicles were produced by a small number of manufacturers.

Popularity

Cugnot's invention initially saw little application in his native France, and the center of innovation passed to Great Britain, where Richard Trevithick was running a steam-carriage in 1801. Such vehicles were in vogue for a time, and over the next decades such innovations as hand brakes, multi-speed transmissions, and improved speed and steering were developed. Some were commercially successful in providing mass transit, until a backlash against these large speedy vehicles resulted in passing laws that self-propelled vehicles on public roads in the United Kingdom must be preceded by a man on foot waving a red flag and blowing a horn. This effectively killed road auto development in the UK for most of the rest of the 19th century, as inventors and engineers shifted their efforts to improvements in railway locomotives. The red flag law was not repealed until 1896.

The many varieties of automobile racing collectively constitute one of the most popular categories of sport in the world. Today, the USA has more cars than any other nation.

There are offers to get a new car for free or get paid to drive them in return for displaying advertisement on the cars, and hence only available to individuals of certain profiles.

Innovation

The first automobile patent in the United States was granted to Oliver Evans in 1789; in 1804 Evans demonstrated his first successful self-propelled vehicle, which not only was the first automobile in the USA but was also the first amphibious vehicle, as his steam-powered vehicle was able to travel on wheels on land and via a paddle wheel in the water.

On November 5, 1895, George B. Selden was granted a United States patent for a two-stroke automobile engine ( Template:US patent). This patent did more to hinder than encourage development of autos in the USA. A major breakthrough came with the historic drive of Berta Benz in 1888. Steam, electric, and gasoline powered autos competed for decades, with gasoline internal combustion engines achieving dominance in the 1910s.

The large scale, production-line manufacturing of affordable automobiles was debuted by Oldsmobile in 1902, then greatly expanded by Henry Ford in the 1910s. Early automobiles were often referred to as 'horseless carriages', and did not stray far from the design of their predecessor. Through the period from 1900 to the mid 1920s, development of automotive technology was rapid, due in part to a huge (hundreds) number of small manufacturers all competing to gain the world's attention. Key developments included electric ignition and the electric self-starter (both by Charles Kettering, for the Cadillac Motor Company in 1910-1911), independent suspension, and four-wheel brakes.

By the 1930s, most of the technology used in automobiles had been invented, although it was often re-invented again at a later date and credited to someone else. For example, front-wheel drive was re-introduced by Andre Citroï¿½n with the launch of the Traction Avant in 1934, though it appeared several years earlier in road cars made by Alvis and Cord, and in racing cars by Miller (and may have appeared as early as 1897). After 1930, the number of auto manufacturers declined sharply as the industry consolidated and matured. Since 1960, the number of manufacturers has remained virtually constant, and innovation slowed. For the most part, "new" automotive technology was a refinement on earlier work, though these refinements were sometimes so extensive as to render the original work nearly unrecognizable. The chief exception to this was electronic engine management, which entered into wide use in the 1960s, when electronic parts became cheap enough to be mass-produced and rugged enough to handle the harsh environment of an automobile. Developed by Bosch, these electronic systems have enabled automobiles to drastically reduce exhaust emissions while increasing efficiency and power.

Model changeover and design change

Cars are not merely continually perfected mechanical contrivances; since the 1920s nearly all have been mass-produced to meet a market, so marketing plans and manufacture to meet them have often dominated automobile design. It was Alfred P. Sloan who established the idea of different makes of cars produced by one firm, so that buyers could "move up" as their fortunes improved. The makes shared parts with one another so that the larger production volume resulted in lower costs for each price range. For example, in the 1950s, Chevrolet shared hood, doors, roof, and windows with Pontiac; the LaSalle of the 1930s, sold by Cadillac, used the cheaper mechanical parts made by the Oldsmobile division.

He also conceived of the notion of the yearly model change-over, which became a three-year cycle. In the second year of the cycle, the superficial appearance of the cars changed incidentally; for the third, major changes took place, e.g., the fender dies for the 1957 Chevrolet had to be modified to produce thin, pointed fins and squarish headlamp housings. In the next cycle, the doors, roof, trunk, and often the suspension would have to be redesigned. Factories and the yearly work schedule had to be specialized to accommodate these changeovers.

Such a patterns became dominant for the Big Three automakers in the US, though European firms neither amalgamated nor could afford the changeover. After the 1950s, when American firms tackled the technical problems of high-compression V-8 engines, automatic transmissions, and air conditioners, investment shifted to meeting the market for non-technical matters. This was criticized as "planned obsolescence," although by this it was meant that the car would simply be made to go out of style rather than really being technically surpassed. For example, only those few American cars of the 1960s with front-wheel drive or a rear engine had a fully independent rear suspension because the Hotchkiss drive was cheaper, and people were used to it. Such malinvestment left American firms unprepared for the Oil Crisis of the 1970s and the rise of imported luxury cars in the 1980s.

Regulation

In almost every nation, laws have been enacted governing the operation of motor vehicles. Most of this legislation, including limits on allowable speed and other rules of the road, are designed to ensure the smooth flow of traffic and simultaneously protect the safety of vehicle occupants, cyclists, and pedestrians.

In 1965, in California, legislation was introduced to regulate exhaust emissions, the first such legislation in the world. Answering this new interest in environmental and public safety issues, the Department of Transportation (DOT) and the Environmental Protection Agency (EPA) both introduced legislation in 1968 which substantially altered the course of automotive development. Since the US market was the largest in the world (and California the largest market in the US), manufacturers worldwide were forced to adapt. For the first time, safety devices were mandatory, as were controls on harmful emissions. Prior to this legislation, even seat belts were considered extra-cost options by many manufacturers. Other countries followed by introducing their own safety and environmental legislation. In time, meeting regulations became the main challenge for the engineers designing new cars. In the decade from 1975 to 1985, the world's manufacturers struggled to meet the new regulations, some producing substandard cars with reduced reliability as a result. However, by the end of this period, everyone had learned how to handle the newly regulated environment. The manufacturers discovered that safety and environmentalism sold cars, and some began introducing environmental and safety advances on their own initiative.

Environmental improvements

Among the first environmental advances are the so-called alternative fuels for the internal combustion engine, which have been around for many years. Early in automotive history, before gasoline was widely available at corner pumps, cars ran on many fuels, including kerosene (paraffin) and coal gas. Alcohol fuels were used in racing cars before and just after World War II. Today, methanol and ethanol are used as petrol extenders in some countries, notably in Australia and the United States. In countries with warmer climates, such as Brazil, alcohol derived from sugar cane is often used as a substitute fuel.

In many countries, plentiful supplies of natural gas have seen methane sold as compressed natural gas (CNG) and propane sold as liquified petroleum gas (LPG) alongside petrol and diesel fuels since the 1970s. While a standard automotive engine will run on these fuels with very low exhaust emissions, there are some performance differences, notably a loss of power due to the lower energy content of the alternative fuels. The need to equip filling stations and vehicles with pressurized vessels to hold these gaseous fuels and more stringent safety inspections, means that they are only economical when used for a long distance, or if there are installation incentives. They are most economical where petrol has high taxes and the alternative fuels do not.

Alternative fuels and batteries

With heavy taxes on fuel, particularly in Europe and tightening environmental laws, particularly in California, and the possibility of further restrictions on greenhouse gas emissions, work on alternative power systems for vehicles continues.

Diesel-powered cars can run with little or no modification on 100% pure biodiesel, a fuel that can be made from vegetable oils. Many cars that currently use gasoline can run on ethanol, a fuel made from plant sugars. Most cars that are designed to run on gasoline are capable of running with 15% ethanol mixed in, and with a small amout of redesign, gasoline-powered vehicles can run on ethanol concentrations as high as 85%. All petrol fueled cars can run on LPG. There has been some concern that the ethanol-gasoline mixtures prematurely wear down seals and gaskets. Further, the use of higher levels of alcohol require that the automobile carry/use twice as much. Therefore, if your vehicle is capable of 300 miles on a 15-gallon tank, the efficiency is reduced to approximately 150 miles. Of course, certain measures are available to increase this efficiency, such as different camshaft configurations, altering the timing/spark output of the ignition, or simply, using a larger fuel tank.

In the United States, cars in the 1890s used ethanol, an alcohol fuel; petrol (called gasoline in the U.S. and Canada) and diesel engines were implemented later. Many U.S. farmers continued to make their own alcohol fuel in corn-alcohol stills until Prohibition criminalized the production of alcohol in 1919. Brazil is the only country which produces ethanol-running cars, since the late 1970s.

Attempts at building viable battery-powered electric vehicles continued throughout the 1990s (notably General Motors with the EV1), but cost, speed and inadequate driving range made them uneconomical. Battery powered cars have used lead-acid batteries which are greatly damaged in their recharge capacity if discharged beyond 75% on a regular basis and NiMH batteries.

Current research and development is centered on " hybrid" vehicles that use both electric power and internal combustion. Other alternatives being explored involve methane and hydrogen-burning vehicles using fuel cells, alternative forms of combustion such as GDI and HCCI and even the stored energy of compressed air (see Air Engine).

Safety

Accidents seem as old as automobile vehicles themselves. Joseph Cugnot crashed his steam-powered "Fardier" against a wall in 1770. The first recorded automobile fatality was Bridget Driscoll on August 17, 1896 in London and the first in the United States was Henry Bliss on September 13, 1899 in New York City.

Every year more than a million people are killed and about 50 million people are wounded in collisions (according to WHO estimates). Cars also cause innumerable injuries and deaths among millions of animals (see roadkill). Major factors in accidents include driving under the influence of alcohol or other drugs, inattentive driving, overtired driving, road hazards such as snow, potholes, and animals, and reckless driving. Special safety features have been built into cars for years, some for the safety of car's occupants only, some for the safety of others.

Cars have two basic safety problems: They have human drivers who make mistakes, and the wheels lose traction near a half gravity of deceleration. Automated control has been seriously proposed and successfully prototyped. Shoulder-belted passengers could tolerate a 32 G emergency stop (reducing the safe intervehicle gap 64-fold) if high-speed roads incorporated a steel rail for emergency braking. Both safety modifications of the roadway are thought to be too expensive by most funding authorities, although these modifications would dramatically increase the number of vehicles that could safely use a high-speed highway.

Early safety research focused on increasing the reliability of brakes and reducing the flammability of fuel systems. For example, modern engine compartments are open at the bottom so that fuel vapors, which are heavier than air, drain to the open air. Brakes are hydraulic so that failures are slow leaks, rather than abrupt cable breaks. Systematic research on crash safety started in 1958 at Ford Motor Company. Since then, most research has focused on absorbing external crash energy with crushable panels and reducing the motion of human bodies in the passenger compartment.

There are standard tests for safety in new automobiles, like the ( ( EuroNCAP and the US NCAP http://www.nhtsa.dot.gov/cars/testing/ncap/) tests. There are also tests run by organizations such as IIHS http://www.hwysafety.org/) and backed by the insurance industry.

Despite technological advances, the death toll of car accidents remains high: About 40,000 people die every year in the US, with similar trends in Europe. This figure increases annually in step with rising population and increasing travel, but the rate per capita and per mile travelled decreases steadily. The death toll is expected to nearly double worldwide by 2020. A much higher number of accidents result in injury or permanent disability.

Future of the car

There will always be a strong demand for the door-to-door, on-demand service but there are likely to be radical changes in the cars of the future.

See also

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An automobile is a wheeled vehicle that carries its own motor. Different types of automobiles include cars, buses, trucks, and vans, with cars being the most popular by far. Older terms include horseless carriage and motor car, with motor referring to what is now usually called the engine.

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The early history of the automobile can be divided into a number of eras, based on method of propulsion. Later periods were defined by trends in exterior styling, size, and utility preferences. The question of who invented the first automobile depends on how you define the words "automobile" and "invent". The history of the automobile is rich and varied. It goes back to Leonardo da Vinci in the 15th century who created early designs and models of transportation vehicles.

Early pioneers

In 1807 François Isaac de Rivaz designed the first hydrogen-powered internal combustion engine. In 1813 he built a car 6 metres (20 ft) long and weighing over 1 metric ton (0.98 long tons; 1.1 short tons).

Between 1832 and 1839, Robert Anderson built the first electric-powered carriage in Scotland.

In 1864 Siegfried Marcus built the first gasoline powered internal combustion engine. In 1870 he placed it on a pushcart making it the first four wheeled gasoline-powered vehicle. He built four more combustion-engine cars over a 10-to-15-year span that influenced later cars. Marcus created the two-cycle combustion engine. The car's second version in 1880 introduced a four-cycle, gasoline-powered engine. It had an ingenious carburetor design, and magneto ignition. He created an additional two models further refining his design with steering, a clutch, and brakes. His second car is on display at the Technical Museum in Vienna. During his lifetime, he was honored as the originator of the motorcar. But his place in history was all but erased by the Nazis during World War II. Because Marcus was of Jewish descent, the Nazi propaganda office ordered his work to be destroyed, his name expunged from future textbooks, and his public memorials removed. They gave credit instead to Karl Benz.

In 1885-1886, Karl Benz developed a petrol- or gasoline-powered automobile. It was called the Benz Patent-Motorwagen. This is also considered to be the first "production" automobile.

In 1886, Gottlieb Daimler built the first four-wheeled, four-stroke engine called the "Cannstatt-Daimler."

In 1893, Charles Duryea and his brother J. Frank Duryea built the first successful gasoline-powered car with a two-stroke engine. The two brothers set up the first American car manufacturing company.

In 1895, George Baldwin Selden received the patent for the combined internal-combustion engine with a carriage. He never produced the vehicle and only seldom collected royalties for using his patent.

In 1908, Henry Ford began producing affordable, simple and reliable cars anyone could drive.

Evolution of the automobile

Invention era

This is the period starts with the car made by Karl Benz in 1885. There were earlier inventions that used mainly steam-power to move the vehicles but the Benz car was the first to use a gasoline powered internal combustion engine in what could be called an automobile. The period goes up to the start of the production of Henry Ford's Model T.

Manufacturing era

This period dates from 1908 to 1914 and the beginning of World War I. While earlier designs were more ornamental, vehicles from this period are simpler and more affordable. It is the time when hundreds of smaller automobile manufacturers were trying to compete for attention and sales. A number of improvements were developed during this time. These include the electric ignition system, four-wheel brakes and the independent suspension. Transmissions were adopted. Along with throttle controls, these allowed the vehicles to travel at a number of speeds depending on conditions.

Coachwork era

From about 1920 to 1930, car manufacturers began creating a closed body on the vehicle. This protected the driver and passengers from the weather. Vehicles began using curved glass and the new enclosed bodies gave a sense of privacy. Heaters were added for comfort. Many of the features of modern cars came from this period. These include four-wheel drive, front-wheel drive, and hybrid electric vehicles. Safety glass protected those inside the car from sharp glass in cases of an accident. By the end of the 1920s cars were becoming faster and were showing a level of style and beauty.

Classic era

The classic era began about 1930 during the Great Depression and ended just before World War II. The Great Depression was a time when many in the United States were just trying to survive. But it is also the era of some of the most significant improvements to the automobile. Cars took on a great deal of style and sophistication. They became works of art in many cases.

Many new features were introduced during this era including the automatic transmission, the V-8, the V-12 and the V-16 engines. The gearshift lever moved to the steering column, hydraulic brakes were introduced for faster stopping and cars got trunks to carry luggage and cargo.

The car industry changed during the 1930s. It saw the rise of the Big Three automakers. These were General Motors, Ford Motor Company and Chrysler. They were able to successfully design and sell cars during the Great Depression when fewer people could afford a new car.

Integration period

In 1949, the automobile industry finally got back on its feet after World War II. This same year General Motors, Cadillac and Oldsmobile introduced the integrated one-piece automobile body. The process joined all the different parts of the body into one body shell. Cars produced during this period concentrated on safety. Cars were big during this time. But in the late 1960s carmakers tried to market much smaller cars. The attempts by General Motors, Chrysler and Ford were all marketing failures. Instead, what sold was the performance car. Cars like the Ford Mustang and the Plymouth Barracuda were very successful. During the late 1950s, many smaller countries began producing cars. Both India and Iran were making cars from about 1959. The first Indian car design from 1950 was very similar to the Opel Kapitän. The first Iranian cars were very similar to several American cars. Both were designed in the United Kingdom.

This period started about 1968 and continues to today. Body styles changed dramatically. The three most popular are the hatchback, the Minivan and the Sport utility vehicle (SUV). Starting in the Integration period, car manufacturers began designing cars for men while others are designed to attract women. The body shapes, colors and other cues are designed to appeal to a particular sex.

Today, women tend to prefer crossovers more than men. Examples are the Kia Sportage and the Honda CR-V. Men seem to prefer powerful cars like the Chevrolet Camaro and the GMC Sierra pickup truck. In car colors, men seem to prefer brighter colors while more women seem to prefer traditional neutral colors.

Related pages

Images for kids

German Flocken Elektrowagen of 1888, regarded as the first electric car of the world

In My Merry Oldsmobile songbook featuring an Oldsmobile Curved Dash automobile (produced 1901-1907) and period driving clothing

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History of the automobile Facts for Kids

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The early history of the automobile can be divided into a number of eras, based on method of propulsion. Later periods were defined by trends in exterior styling, size, and utility preferences. The question of who invented the first automobile depends on how you define the words "automobile" and "invent".

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Biography of the Wright Brothers for Children: Orville and Wilbur Wright for Kids - FreeSchool

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Top 10 facts

1. Birds may have been flying for millions of years but it's something relatively new to humans!

2. Orville and Wilbur Wright are famous for creating the first successful airplane. American aviation pioneers, the Wright brothers were the brains behind the first controlled and sustained human flight on December 17 1903.

3. The Wrights' first powered flight was one of many early 20th century inventions in health, sanitation and transportation.

4. Their aircraft was called the Wright Flyer and it flew about 120 feet. Today the newest Boeing 787 can fly 10,000 miles on a single tank of fuel!

5. The famous artist, scientist and inventor, Leonardo da Vinci designed parachutes, helicopters and the ornithopter flying machine (on which the concept of the modern day helicopter is based!).

6. The Stratolaunch is currently the world's largest airplane, with a wingspan longer than a football field. It weighs in at a hefty 500,000 pounds!

7. Concorde is one of the most famous aircraft ever built. It used to reach 60,000 feet, a height of over 11 miles, which meant that passengers were able to see the curvature of the Earth! Concorde was built by French and British engineers and the first successful flight took place on 1 October 1969. In both French and English 'Concorde' means agreement.

8. In 1986 a plane called Voyager completed the first nonstop, around-the-world flight without refuelling.

9. The first direct flight between Perth in Australia and London (9000 miles), passed a major milestone in aviation history in March 2018 by reducing to 17 hours a trip that once took 12 and a half days.

10. Every year since 2000, Hartsfield-Jackson Atlanta International has been the world's busiest airport. London, with all its airports combined, has the world's busiest city airport system.

Did you know?

Insects, birds and bats are the only living things capable of powered flight. Gliding uses little or no movement or flapping of wings; a number of animals use this method of movement but do not actually "fly". Flying squirrels, flying fish and some snakes have skin that they can stretch out and use to glide through the air. Flying fish have been known to glide for hundreds of metres thanks to enlarged fins that act like wings!

Around 350 BC the Chinese began to make kites using bamboo frames covered in paper and silk. This got people thinking about the possibility of flying! (A kite is a form of glider and does not technically fly; it is instead moved by air currents.)

Leonardo da Vinci, the famous artist, scientist and inventor, was fascinated by birds in flight and spent time observing how their bodies worked. In 1670, scientist Giovanni Borelli proved that human muscles wouldn't be strong enough to hold the big wings needed to lift a human off the ground.

December 17, 1903 was a date that made aviation history thanks to American brothers Orville and Wilbur Wright. Orville took to the sky in his first ever motor-powered aircraft. The airplane, known as the Wright Flyer, flew 120 feet (36 meters) for just 12 seconds but people were amazed that their dream of flying was now possible. Wilbur Wright's first flight was not so successful - he actually ended up damaging the airplane!
Neil Armstrong apparently carried a piece of the Wright Flyer with him to the moon!
The wings of an airplane make up just one element of flight. There are actually four forces of flight that push the plane up, down, forward, or slow it down: lift, thrust, drag, and weight.

All flight controllers and all commercial pilots who fly on international flights must be able to speak English.

On March 8, 1910 Raymonde de Laroche was the first woman to receive a pilot's license. Harriet Quimby was the first woman in the US to become licensed to fly a plane in 1911. She was also the first woman to fly across the English Channel. One of the most famous female aviators was Amelia Earhart (1897-1937), the first woman to fly solo across the Atlantic Ocean.

Supersonic flight, which means breaking the sound barrier, is achieved when an object travels at a speed faster than sound (1235 kilometres per hour or 768 miles per hour).

Look through the gallery and see if you can spot the following:

The Wright Flyer, designed and built by the Wright brothers

Hot air balloons

A modern aeroplane

In the 21st century we can fly all over the world from airports

The Wright Brothers Memorial in Kitty Hawk, North Carolina, USA

Today's passenger aircraft

Gallery

About

For many centuries, humans have wanted to fly just like birds. Watching their feathered friends inspired them to make wings of feathers or light wood which they attached to their arms to test their ability to fly - often with disastrous consequences!

Around 350 BC, people in China began to make kites using bamboo frames covered in paper and silk. Discovering kites could fly in the air got humans thinking about the possibility of flying. Colourful kites were used by the Chinese in religious ceremonies although more sophisticated models were used to test weather conditions. Kites were key in the invention of flight as they led the way for balloons and gliders.

The first real studies of flight were produced by the famous inventor Leonardo da Vinci in the 1480s. He was fascinated by birds in flight and closely observed how their bodies worked while flying, producing over 100 drawings that illustrated his theories on flight. Although it was never built, Leonardo designed the Ornithopter flying machine. It was a very clever design that showed just how man could fly and the modern day helicopter is in fact based on this concept!

The first hot air balloon was designed by brothers Joseph Michel and Jacques Etienne Montgolfier in the 1780s. They used the smoke from a fire to blow hot air into a silk bag, which was attached to a basket. The hot air then rose and allowed the balloon to float. Their first passengers weren't of the human variety! In 1783, a sheep, rooster and a duck climbed aboard. The colourful balloon climbed to a height of about 6,000 feet and traveled more than a mile. The brothers went from strength to strength and made their first manned flight on November 21, 1783, with two passengers.

George Cayley was the brains behind the first glider that could actually go short distances, built in 1799. He spent 50 years making improvements to the gliders, changing their wing shape and adding tails. He also realised that there would be a need for power if a flying machine was to be in the air for a long time.

German engineer, Otto Lilienthal (1848-1896), became known as the 'Glider King'! He studied aerodynamics and was the first person to design a glider that could fly a person and long distances. The Wright brothers said he was a major inspiration. Like Da Vinci, Otto based his studies on birds and how they fly. In 1889, he wrote a book on aerodynamics. The Wright Brothers used this as the basis for their designs. Berlin's busiest airport is named after Lilienthal.

The Wright Brothers first tested their ideas of flight with a kite. They learned about how the wind would help with the flight and how it could affect the surfaces once up in the air. Time and dedication were key! The brothers spent three years testing and learning about how gliders could be controlled. They designed and used a wind tunnel to test the shapes of the wings and the tails of the gliders. Once they had perfected the glider shape, they then set to creating a propulsion system that would create the thrust needed to fly. Amazingly the first engine they designed generated almost 12 horsepower, the same power as two hand-propelled lawn mower engines!

On December 17, 1903, the 'Flyer' travelled 120 feet in 12 seconds with Orville as pilot, but it was unstable and difficult to control. The Wright brothers spent two more years perfecting their design. On 5 October, 1905, Wilbur piloted the Flyer III for 39 minutes and about 24 miles of circles!

Humans were now able to fly!

Related Videos

Just for fun...

Use your knowledge of the Wright brothers' aircraft to build your own plane online
Report on the Wright brothers' first flight by writing your own eye-witness account
Complete a NASA paper airplane challenge

Try making your own loop airplane

The How Things Fly page on the Smithsonian National Air and Space Museum website is packed with activities: explore wing shapes and the other factors affecting lift, take an aeroplane Distance Challenge, practise flying with a Controlled Flight simulator and build a rocket

America by Air: interactive activities about the history of flight
4 activities to help you celebrate the Wright brothers' flight
Engineering the Wright Way is an online game

Understand more about the Wright airplane designs

Look at posters advertising air travel in the early 20th century

Best books about the history of flight for kids

Find out more

Watch BBC Bitesize videos: a whistle stop tour through the history of flight, information about how planes fly and details of air travel in the 20th century

Explore the history of flight in an interactive timeline of aviation history

Information about the early years of air transportation

Read about the history of aircraft on the DK findout! site

Find out more about the Wright brothers and their achievements in a biography for children

The Kiddle Encyclopedia's entries on the Wright brothers and flight

Find lots of information about the Wrights' first flight

Look at all the different aircraft humankind has produced

Discover more about how the Wright brothers invented their flying machine
Flight facts explained for kids
Learn more about airplane anatomy and the 1903 Wright Flyer
Northern Ireland has a long history of pioneering aviation
NASA's guide to the history of flight and the dynamics of air travel

See for yourself

Visit the National Museum of Flight in Scotland

The Wright Brothers National Memorial is in Kitty Hawk, North Carolina, USA

The Flight gallery in London's Science Museum is dedicated to the history of aviation

The Royal Air Force Museum explores the milestones of flight

Get up close to over a century of aviation with hundreds of aircraft and objects on display at IWM Duxford

Also see

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1. Birds may have been flying for millions of years but it's something relatively new to humans! 2. Orville and Wilbur Wright are famous for creating the first successful airplane. American aviation pioneers, the Wright brothers were the brains behind the first controlled and sustained human flight on December 17 1903.