# data[].attributes.attachment_link.readable_text
Archaeology is the study of the human past using material remains. These remains can be any objects that people created, modified, or used.

Subjects

Arts and Music, Geography, Human Geography, Physical Geography, Social Studies, World History

Archaeology is the study of the human past using material remains. These remains can be any objects that people created, modified, or used.

Portable remains are usually called artifacts. Artifacts include tools, clothing, and decorations. Non-portable remains, such as pyramids or post-holes, are called features.

Archaeologists use artifacts and features to learn how people lived in specific times and places. They want to know what these people's daily lives were like, how they were governed, how they interacted with each other, and what they believed and valued.

Sometimes, artifacts and features provide the only clues about an ancient community or civilization. Prehistoric civilizations did not leave behind written records, so we cannot read about them.

Understanding why ancient cultures built the giant stone circles at Stonehenge, England, for instance, remains a challenge 5,000 years after the first monoliths were erected. Archaeologists studying Stonehenge do not have ancient manuscripts to tell them how cultures used the feature. They rely on the enormous stones themselves-how they are arranged and the way the site developed over time.

Most cultures with writing systems leave written records that archaeologists consult and study. Some of the most valuable written records are everyday items, such as shopping lists and tax forms. Latin, the language of ancient Rome, helps archaeologists understand artifacts and features discovered in parts of the Roman Empire. The use of Latin shows how far the empire's influence extended, and the records themselves can tell archaeologists what foods were available in an area, how much they cost, and what buildings belonged to families or businesses.

Many ancient civilizations had complex writing systems that archaeologists and linguists are still working to decipher. The written system of the Mayan language, for instance, remained a mystery to scholars until the 20th century. The Maya were one of the most powerful pre-Columbian civilizations in North America, and their Central American temples and manuscripts are inscribed with a collection of squared glyphs, or symbols. A series of circles and lines represents numbers.

By deciphering the Mayan script, archaeologists were able to trace the ancestry of Mayan kings and chart the development of their calendar and agricultural seasons. Understanding the basics of the Mayan writing system helps archaeologists discover how Mayan culture functioned-how they were governed, how they traded with some neighbors and went to war with others, what they ate, and what gods they worshipped.

As archaeologists become more fluent in Mayan writing, they are making new discoveries about the culture every day. Today, some archaeologists work with linguists and poets to preserve the once-lost Mayan language.

History of Archaeology

The word "archaeology" comes from the Greek word "arkhaios," which means "ancient." Although some archaeologists study living cultures, most archaeologists concern themselves with the distant past.

People have dug up monuments and collected artifacts for thousands of years. Often, these people were not scholars, but looters and grave robbers looking to make money or build up their personal collections.

For instance, grave robbers have been plundering the magnificent tombs of Egypt since the time the Pyramids were built. Grave robbing was such a common crime in ancient Egypt that many tombs have hidden chambers where the family of the deceased would place treasures.

In Egypt in the mid-1800s, an Egyptian man searching for a lost goat stumbled across the tomb of Pharaoh Ramses I. (Many archaeologists doubt this story and say grave robbers, working as an organized group, routinely scouted and plundered many tombs in the area.) Ramses I ruled for a short time in the 1290s BCE. Besides the body of the pharaoh, the tomb held artifacts such as pottery, paintings, and sculpture. The man sold the mummies and artifacts from the tomb to anyone who would pay.

The mummy of Ramses I wound up in a museum in Niagara Falls, Ontario, Canada, where it remained until the museum closed in 1999. The Canadian museum sold the Egyptian collection to the Michael C. Carlos Museum in Atlanta, Georgia, United States, which confirmed the mummy's royal status through the use of CT scanners, X-rays, radiocarbon dating, computer imaging, and other techniques. Ramses I was returned to Egypt in 2003.

One of the most well-known archaeological finds is the tomb of Pharaoh Tutankhamun, also known as King Tut. Unlike many other Egyptian tombs, grave robbers had never discovered King Tut. His resting place lay undisturbed for thousands of years, until it was discovered in 1922. In addition to mummies of Tutankhamun and his family, the tomb contained some 5,000 artifacts.

Many early archaeologists worked in the service of invading armies. When Gen. Napoleon Bonaparte of France successfully invaded Egypt in 1798, he brought artists, archaeologists, and historians to document the conquest. Napoleon's troops took home hundreds of tons of Egyptian artifacts: columns, coffins, stone tablets, monumental statues. Today, these Egyptian antiquities take up entire floors of the Louvre Museum in Paris, France.

Some archaeologists of this time were wealthy adventurers, explorers, and merchants. Often, they were from Western European colonial powers from places different from where they excavated. These amateur archaeologists often had a sincere interest in the culture and artifacts they studied. However, their work is also tied to colonialism and cultural exploitation. They profited off cultures that was not their own, and took sacred objects and remains away from their historical and traditional sites.The so-called Elgin Marbles are an example of this controversy.

In 1801, Greece had been taken over by the Ottoman Empire. The British ambassador to the Ottoman Empire, Lord Elgin, received permission to remove half of the sculptures from the famous Acropolis of Athens, Greece. These marble sculptures were a part of buildings such as the Parthenon. Lord Elgin claimed he wanted to protect the valuable sculptures from damage caused by conflict between the Greeks and the Ottomans.

The government of Greece has been lobbying for the return of the Elgin Marbles ever since. Most Greeks view the sculptures as part of their cultural heritage. Greece has cut off diplomatic relations to the United Kingdom several times, demanding the return of the sculptures, which remain in the British Museum in London.

Eventually, archaeology evolved into a more systematic discipline. Scientists started using standard weights and measures and other formalized methods for recording and removing artifacts. They required detailed drawings and drafts of the entire dig site, as well as individual pieces. Archaeologists began to work with classicists, historians, and linguists to develop a unified picture of the past.

In the 20th century, archaeologists began to re-assess their impact on the cultures and environments where they dig. Today, in most countries, archaeological remains become the property of the country where they were found, regardless of who finds them. Egypt, for example, is scattered with archaeological sites sponsored by American universities. These teams must obtain permission from the Egyptian government to dig at the sites, and all artifacts become the property of Egypt.

Disciplines of Archaeology

Archaeology is based on the scientific method. Archaeologists ask questions and develop hypotheses. They use evidence to choose a dig site, then use scientific sampling techniques to select where on the site to dig. They observe, record, categorize, and interpret what they find. Then they share their results with other scientists and the public.

Underwater archaeologists study materials at the bottom of lakes, rivers, and oceans. Underwater archaeology encompasses any prehistoric and historic periods, and almost all sub-disciplines as archaeology. Artifacts and features are simply submerged.

Artifacts studied by underwater archaeologists could be the remains of a shipwreck. In 1985, National Geographic Explorer-in-Residence Dr. Robert Ballard helped locate the wreck of RMS , which sank in the North Atlantic Ocean in 1912, killing about 1,500 people. Ballard and other scientists used sonar to locate the wreck, which had been lost since the ocean liner sank. By exploring Titanic using remote-controlled cameras, Ballard and his crew discovered facts about the shipwreck (such as the fact the ship broke in two large pieces as it sank) as well as hundreds of artifacts, such as furniture, lighting fixtures, and children's toys.

Underwater archaeology includes more than just shipwrecks, however. Sites include hunt camps on the continental shelf of the Gulf of Mexico, and portions of the ancient city of Alexandria, Egypt, submerged due to earthquakes and sea level rise.

This basic framework carries across many different disciplines, or areas of study, within archaeology.

Prehistoric and Historic Archaeology
There are two major disciplines of archaeology: prehistoric archaeology and historic archaeology. Within these groups are subdisciplines, based on the time period studied, the civilization studied, or the types of artifacts and features studied.

Prehistoric archaeology deals with civilizations that did not develop writing. Artifacts from these societies may provide the only clues we have about their lives. Archaeologists studying the Clovis people, for instance, have only arrowheads-called projectile points- and stone tools as artifacts. The unique projectile points were first discovered in Clovis, New Mexico, in the United States, and the culture was named after the town. So-called Clovis points establish the Clovis people as one of the first inhabitants of North America. Archaeologists have dated Clovis points to about 13,000 years ago.

A subdiscipline of prehistoric archaeology is paleopathology. Paleopathology is the study of disease in ancient cultures. (Paleopathology is also a subdiscipline of historical archaeology.) Paleopathologists may investigate the presence of specific diseases, what areas lacked certain diseases, and how different communities reacted to disease. By studying the history of a disease, paleopathologists may contribute to an understanding of the way modern diseases progress. Paleopathologists can also find clues about people's overall health. By studying the teeth of ancient people, for example, paleopathologists can deduce what kinds of food they ate, how often they ate, and what nutrients the foods contained.

Historic archaeology incorporates written records into archaeological research. One of the most famous examples of historic archaeology is the discovery and decipherment of the Rosetta Stone. The Rosetta Stone is a large slab of marble discovered near Rashid, Egypt, by French archaeologists in 1799. It became an important tool of historic archaeology.

The stone is inscribed with a decree made on behalf of Pharaoh Ptolemy V. The decree was written and carved into the stone in three different languages: hieroglyphic, demotic, and Greek. Hieroglyphics are the picture-symbols used for formal documents in ancient Egypt. Demotic is the informal script of ancient Egypt. Before the discovery of the Rosetta Stone, Egyptologists did not understand hieroglyphics or demotic. They could, however, understand Greek. Using the Greek portion of the Rosetta Stone, archaeologists and linguists were able to translate the text and decipher hieroglyphs. This knowledge has contributed vastly to our understanding of Egyptian history.

Historic archaeology contributes to many disciplines, including religious studies. The Dead Sea Scrolls, for instance, are a collection of about 900 documents. The tightly rolled parchment and other writing sheets were found between 1947 and 1956 in 11 caves near Qumran, West Bank, near the Dead Sea. Among the scrolls are texts from the Hebrew Bible, written in Hebrew, Aramaic, and Greek.

The Dead Sea Scrolls are the oldest versions of Biblical texts ever found, dating from between the third century BCE to the first century CE. The scrolls also contain texts, psalms, and prophecies that are not part of today's Bible. Discovery of the scrolls has increased our knowledge of the development of Judaism and Christianity.

A subdiscipline of historic archaeology is industrial archaeology. Industrial archaeologists study materials that were created or used after the Industrial Revolution of the 1700s and 1800s. The Industrial Revolution was strongest in Western Europe and North America, so most industrial archaeologists study artifacts found there.

One of the most important sites for industrial archaeologists is the Ironbridge Gorge in Shropshire, England. The River Severn runs through the gorge, and during the Industrial Revolution, it allowed for the transport of raw materials such as coal, limestone, and iron. In fact, the world's first iron bridge spans the Severn there. By studying artifacts and features (such as the iron bridge), industrial archaeologists are able to trace the area's economic development as it moved from agriculture to manufacturing and trade.

Other Disciplines
Ethnoarchaeologists study how people use and organize objects today. They use this knowledge to understand how people used tools in the past. Archaeologists researching the ancient San culture of southern Africa, for instance, study the way modern San culture functions. Until the mid-20th century, the San, maintained a somewhat nomadic lifestyle based on hunting and gathering. Although the San culture had evolved significantly, archaeologists studying the tools of the modern San could still study the way ancient San tracked and hunted animals and gathered native plants.

Environmental archaeologists help us understand the environmental conditions that influenced people in the past. Sometimes, environmental archaeology is called human paleoecology. Environmental archaeologists discovered that the expansion of the Taquara/Itararé people of the Brazilian highlands is closely linked with the expansion of the evergreen forest there. The forest grew as the climate became wetter. As the forest provided more resources to the Taquara/Itararé people (timber, as well as plants and animals that depended on the evergreen trees), they were able to expand their territory.

Experimental archaeologists replicate the techniques and processes people used to create or use objects in the past. Often, re-creating an ancient workshop or home helps experimental archaeologists understand the process or method used by ancient people to create features or artifacts. One of the most famous examples of experimental archaeology is the , a large raft built by Norwegian explorer Thor Heyerdahl. In 1947, Heyerdahl sailed the Kon-Tiki from South America to Polynesia to show that ancient mariners, with the same tools and technology, could have navigated the vast Pacific Ocean.

Forensic archaeologists sometimes work with geneticists to support or question DNA evidence. More often, they excavate the remains of victims of murder or genocide in areas of conflict. Forensic archaeology is important to the understanding of the "Killing Fields" of Cambodia, for instance. The Killing Fields are the sites of mass graves of thousands of victims of the Khmer Rouge regime of the 1970s. After the fall of the Khmer Rouge, forensic archaeologists studied the remains of the bodies in the Killing Fields, discovering how and when they died. The forensic archaeologists helped establish that the Khmer Rouge used starvation and overwork, as well as direct killing, to silence opponents of the regime.

Archaeologists working in the field of cultural resource management help assess and preserve remains on sites where construction is scheduled to occur. Archaeologists working as cultural resource managers often collaborate with local governments to balance the infrastructure and commercial needs of a community with historic and cultural interests represented by artifacts and features found on construction sites.

Where to Dig?

Most archaeology involves digging. Winds and floods carry sand, dust and soil, depositing them on top of abandoned features and artifacts. These deposits build up over time, burying the remains. Sometimes catastrophes, like volcanic eruptions, speed up this burial process. In places where earth has been carved away-like in the Grand Canyon in the U.S. state of Arizona-you can actually see the layers of soil that have built up over the centuries, like layers of a cake.

Cities and communities also tend to be built in layers. Rome, Italy, has been an urban center for thousands of years. The streets of downtown Rome today are several meters higher than they were during the time of Julius Caesar. Centuries of Romans have built it up-medieval home on top of ancient home, modern home on top of medieval home.

Establishing a dig site in an inhabited area can be a very difficult process. Not only are the inhabitants of the area inconvenienced, archaeologists don't know what they may find. Archaeologists looking for an ancient Roman fortress, for instance, may have to first excavate a Renaissance bakery and medieval hospital.

Because most artifacts lie underground, scientists have developed methods to help them figure out where they should dig. Sometimes they choose sites based on old myths and stories about where people lived or where events occurred. The ancient city of Troy, written about by Greek poet Homer as early as 1190 BCE, was thought to be a work of fiction. Homer's epic poem the was named after Troy, which the Greeks knew as Ilion. Using the Iliad as a guide, German amateur archaeologist Heinrich Schliemann discovered the ruins of the city near the town of Hisarlik, Turkey, in 1870. Schliemann's find helped provide evidence that the Trojan War may have actually taken place, and that ancient manuscripts may be based on fact.

Sometimes, archaeologists use historical maps to find ancient artifacts. In 1973, for instance, archaeologists used historical maps and modern technology to locate the wreck of the USS , an "ironclad" ship used by the Union during the Civil War. The Monitor sunk in a storm off the coast of Cape Hatteras, North Carolina, in 1862. After archaeologists identified the ironclad, the United States designated the area as the nation's first marine sanctuary.

Before securing a site, an archaeological team surveys the area, looking for signs of remains. These might include artifacts on the ground or unusual mounds in the earth. New technology has greatly increased their ability to survey an area. For example, aerial and satellite imagery can show patterns that might not be visible from the ground.

Other technologies give clues about what lies under the surface. These techniques involve radar and sonar. Radar and sonar technologies often use radio waves, electrical currents, and lasers. Archaeologists send these signals into the earth. As the signals hit something solid, they bounce back up to the surface. Scientists study the time and paths the signals take to familiarize themselves with the underground landscape.

Accidental finds can also lead archaeologists to dig sites. For instance, farmers plowing their fields might come across sherds of pottery. A construction crew might discover ruins beneath a building site.

Another monumental discovery was made by accident. In 1974, agricultural workers in Xian, China, were digging a well. They discovered the remains of what turned out to be an enormous mausoleum for Qin Shi Huangdi, China's first emperor. The complex includes 8,000 life-sized clay soldiers, horses, chariots, and artillery, popularly known as the Terra Cotta Warriors. The archaeological research surrounding the Terra Cotta Warriors has provided insight on the organization and leadership style of Qin Shi Huangdi and the development of Chinese culture.

Once a site is chosen, archaeologists must get permission to dig from the landowner. If it is public land, they must obtain the proper permits from the local, state, or federal government.

Before moving a single grain of dirt, archaeologists make maps of the area and take detailed photographs. Once they begin digging, they will destroy the original landscape, so it is important to record how things looked beforehand.

The last step before digging is to divide the site into a grid to keep track of the location of each find. Then archaeologists choose sample squares from the grid to dig. This allows the archaeological team to form a complete study of the area. They also leave some plots on the grid untouched. Archaeologists like to preserve portions of their dig sites for future scientists to study-scientists who may have better tools and techniques than are available today.

For example, during the Great Depression in the 1930s, programs to create jobs led to many archaeological digs around the United States. Some scientists on these digs removed artifacts, such as pottery, but threw away charcoal and animal bones. These items were considered junk. Today, scientists are able to carbon-date the charcoal and analyze the bones to see what kinds of animals people were domesticating and eating at the time. It is important that archaeologists today keep some parts of each site pristine.

Not all archaeology involves digging in the earth. Archaeologists and engineers work with sophisticated technology to probe the earth below without disturbing the ground. National Geographic Emerging Explorer Dr. Albert Yu-Min Lin leads an innovative archaeological project centered in Mongolia. The Valley of the Khans project is using digital imaging, aerial photography, radar, and digital surveying to locate the tomb of Genghis Khan. Using satellite technology, Lin and his team can access information about the project without disturbing the land or even going to Mongolia.

The Big Dig

The process of researching and securing a dig site can take years. Digging is the field work of archaeology. On occasion, archaeologists might need to move earth with bulldozers and backhoes. Usually, however, archaeologists use tools such as brushes, hand shovels, and even toothbrushes to scrape away the earth around artifacts.

The most common tool that archaeologists use to dig is a flat trowel. A trowel is a hand-held shovel used for smoothing as well as digging. Archaeologists use trowels to slowly scrape away soil. For very small or delicate remains, archaeologists might also dig with dental picks, spoons, or very fine blades. Often, they will sift dirt through a fine mesh screen. Tiny remains, such as beads, can often be found this way.

Archaeologists take lots of notes and photographs along each step of the process. Sometimes they include audio and video recordings. Global positioning system (GPS) units and data from geographic information systems (GIS) help them map the location of various features with a high level of precision.

When archaeologists find remains, they are often broken or damaged after hundreds or even thousands of years underground. Sunlight, rain, soil, animals, bacteria, and other natural processes can cause artifacts to erode, rust, rot, break, and warp.

Sometimes, however, natural processes can help preserve materials. For example, sediments from floods or volcanic eruptions can encase materials and preserve them. In one case, the chill of an Alpine glacier preserved the body of a man for more than 5,300 years! The discoverer of the so-called "Iceman," found in the Alps between Switzerland and Italy, thought he was a recent victim of murder, or one of the glacier's crevasses. Forensic archaeologists studying his body were surprised to learn that he was a murder victim-the crime just took place more than 5,000 years ago.

Uncovered Artifacts

As artifacts are uncovered, the archaeological team records every step of the process through photos, drawings, and notes. Once the artifacts have been completely removed, they are cleaned, labeled, and classified.

Particularly fragile or damaged artifacts are sent to a conservator. Conservators have special training in preserving and restoring artifacts so they are not destroyed when exposed to air and light. Textiles, including clothing and bedding, are especially threatened by exposure. Textile conservators must be familiar with climate, as well as the chemical composition of the cloth and dyes, in order to preserve the artifacts.

In 1961, Swedish archaeologists recovered the ship Vasa, which sank in 1628. Conservators protected the delicate oak structure of Vasa by spraying it with polyethylene glycol (PEG). The ship was sprayed with PEG for 17 years, and allowed to dry for nine. Today, Vasa sits in its own enormous museum, a hallmark of Swedish heritage.

Then the artifacts are sent to a lab for analysis. This is usually the most time-consuming part of archaeology. For every day spent digging, archaeologists spend several weeks processing their finds in the lab.

All of this analysis-counting, weighing, categorizing-is necessary. Archaeologists use the information they find and combine it with what other scientists have discovered. They use the combined data to add to the story of humanity's past. When did people develop tools, and how did they use them? What did they use to make clothing? Did their clothing styles indicate their social ranks and roles? What did they eat? Did they live in large groups or smaller family units? Did they trade with people from other regions? Were they warlike or peaceful? What were their religious practices? Archaeologists ask all of these questions and more.

The scientists write up their findings and publish them in scientific journals. Other scientists can look at the data and debate the interpretations, helping us get the most accurate story. Publication also lets the public know what scientists are learning about our history.

Fast Fact

The ABCs of Dating
Sometimes dates are listed as BC or AD. Other times they show up as B.C.E. or C.E. What is the difference?

BC stands for Before Christ, and it is used to date events that happened before the birth of Jesus, whom Christians consider the son of God. AD refers to Anno Domini, Latin for year of our Lord, and refers to all the years from Jesus birth onward. In the late 20th century, scientists realized they were basing the entire history of the world around the birth of one religious figure.

Many archeologists now prefer the terms B.C.E. (Before Common Era) and C.E. (Common Era). The dates are still the same, only the letters have changed.

Fast Fact

Ancient Cannibals
Some ancient humans may have indulged in cannibalism on a regular basis. Archaeologists discovered 800,000-year-old remains from an early human species, Homo antecessor, in a Spanish cave. Among the remains were human bones with marks on them that appear to come from stone tools used to prepare meals.

Fast Fact

Sherds and Shards
Many archaeologists study broken bits of pottery. These fragments are called potsherds, and sometimes just sherds. Sherds can be anything from bits of a broken water jug to a piece of a clay tablet to the components of China's "Terra Cotta Warriors."

Shards are broken bits of glass, which are also important to archaeology. Shards include fragments of ancient windows, wine bottles, and jewelry.

Fast Fact

Trashy Science
Most archaeologists study the past, but some study people who are still alive. For example, Dr. William Rathje uses his archaeological skills to dig through present-day garbage bins and landfills to learn about what Americans consume, discard, and waste.

Media Credits

The audio, illustrations, photos, and videos are credited beneath the media asset, except for promotional images, which generally link to another page that contains the media credit. The Rights Holder for media is the person or group credited.

Illustrators

Mary Crooks, National Geographic Society

Editors

Jeannie Evers, Emdash Editing, Emdash Editing

Producer

National Geographic Society

other

Last Updated

August 19, 2022

For information on user permissions, please read our Terms of Service. If you have questions about how to cite anything on our website in your project or classroom presentation, please contact your teacher. They will best know the preferred format. When you reach out to them, you will need the page title, URL, and the date you accessed the resource.

Media

If a media asset is downloadable, a download button appears in the corner of the media viewer. If no button appears, you cannot download or save the media.

Text

Text on this page is printable and can be used according to our Terms of Service.

Interactives

Any interactives on this page can only be played while you are visiting our website. You cannot download interactives.

# data[].attributes.attachment_link.description
Archaeology is the study of the human past using material remains. These remains can be any objects that people created, modified, or used.

# data[].attributes.body
Any object made by human work; esp., a simple or primitive tool, weapon, vessel, etc.

# data[].attributes.body
The time-period in which personal computers and other technologies were introduced to provide users the ability to easily and rapidly transfer information.

# data[].attributes.body
A place in which public records or historical materials (such as documents) are preserved.

# data[].attributes.body
Describes a complex way of life that came about as people began to develop networks of urban settlements.

# data[].attributes.body
Artificial intelligence (AI) is when a computer can think and make choices by itself. Computers with AI can learn from what they see and do new things without being told. They can solve problems and do jobs without people telling them step-by-step what to do.

# data[].attributes.body
Robotics is a technology that involves making and using robots to do jobs. Robots are machines that can do tasks by themselves or with someone controlling them.

# data[].attributes.headline
augmented reality (AR) vs virtual reality (VR)

# data[].attributes.subject
augmented reality (AR) vs virtual reality (VR)

# data[].attributes.body
1. a panel designed to absorb the sun's rays as a source of energy for generating electricity or heating.

# data[].attributes.attachment_link.readable_text
Green has ordered a review into the Lahaina fire on Maui, the deadliest since 1918's Cloquet fire in northern Minnesota killed 453 people.

State of play: Rep. Jill Tokuda (D-Hawai'i), whose district includes the historic town of Lahaina that the wildfires destroyed much of, walked through the area with FEMA officials Saturday.

"It was shocking - surreal," Tokuda said on CBS News' "Face the Nation" Sunday.

"We've heard all these words, but to actually walk those streets and to still see fires smoldering in the distance, to see cars literally melted into puddles that have hardened over on the road, Xs on buildings and cars to say that it has been searched for signs of casualties or even life," she added.

The Lahaina fire was 85% contained Sunday. Maui officials said Saturday they were working to extinguish flare-ups across Lahaina and parts of Upcountry Maui.

Maui Police Chief John Pelletier said Monday only 20% of the search area had been cleared.

Zoom out: Green said the fire destroyed more than 2,700 structures in Lahaina and caused damages estimated at $5.6 billion.

The Pacific Disaster Center and FEMA estimated that 2,170 acres of Maui has burned, per a statement from Maui officials Saturday.

An estimated 4,500 residents had sought shelter, the center and FEMA also noted.

Water advisories are in effect on Maui's Lahaina and Upper Kula areas, after the fires damaged parts of the water system.

Details: A Saturday statement from the County of Maui said just two of the victims had been identified so far.

Identifying discovered remains is especially difficult, Pelletier said, in part because of the condition they are found in.

"When we find our family and our friends, the remains that we're finding is through a fire that melted metal," he said, adding that authorities were using rapid DNA tests to help expedite the process.

Pelletier also encouraged family member missing loved ones to take a DNA test to help generate matches with victims.

Teams were using cadaver dogs during the search. "One of the challenging things is, many of the areas that they're in searching, there's structures that are partially standing and so the engineers are embedded with them to evaluate the stability of that structure," FEMA administrator Deanne Criswell told CBS' "Face the Nation" Sunday.
Go deeper: Editor's note: This article has been updated with new details throughout. Before and after: Satellite images show Hawai'i wildfire devastation
Context: Parts of Maui are experiencing severe drought and more flammable invasive plants in Hawai'i have exacerbated wildfire risk, per the U.S. Drought Monitor.

# data[].attributes.attachment_link.title
Maui fire becomes deadliest in over a century, at least 111 killed

# data[].attributes.attachment_link.description
Maui Police Chief John Pelletier said that only 3% of the search area has been cleared, and that the death toll is sure to grow.

# data[].attributes.attachment_link.readable_text
Table of Contents

When was Franklin D. Roosevelt born?

When did Franklin D. Roosevelt die?

What is Franklin D. Roosevelt best known for?

Where did Franklin D. Roosevelt go to school?

When did Franklin D. Roosevelt get married?

Read a brief summary of this topic

Franklin D. Roosevelt, in full Franklin Delano Roosevelt, byname FDR, (born January 30, 1882, Hyde Park, New York, U.S.-died April 12, 1945, Warm Springs, Georgia), 32nd president of the United States (1933-45). The only president elected to the office four times, Roosevelt led the United States through two of the greatest crises of the 20th century: the Great Depression and World War II. In so doing, he greatly expanded the powers of the federal government through a series of programs and reforms known as the New Deal, and he served as the principal architect of the successful effort to rid the world of German National Socialism and Japanese militarism.

Early life

Roosevelt was the only child of James and Sara Delano Roosevelt. The family lived in unostentatious and genteel luxury, dividing its time between the family estate in the Hudson River valley of New York state and European resorts. Young Roosevelt was educated privately at home until age 14, when he entered Groton Preparatory School in Groton, Massachusetts. At Groton, as at home, he was reared to be a gentleman, assuming responsibility for those less fortunate and exercising Christian stewardship through public service.

In 1900 Roosevelt entered Harvard University, where he spent most of his time on extracurricular activities and a strenuous social life; his academic record was undistinguished. It was during his Harvard years that he fell under the spell of his fifth cousin, Pres. Theodore Roosevelt, the progressive champion who advocated a vastly increased role for the government in the nation's economy. It was also during his Harvard years that he fell in love with Theodore Roosevelt's niece, Eleanor Roosevelt, who was then active in charitable work for the poor in New York City. The distant cousins became engaged during Roosevelt's final year at Harvard, and they were married on March 17, 1905. Eleanor would later open her husband's eyes to the deplorable state of the poor in New York's slums.

Roosevelt attended Columbia University Law School but was not much interested in his studies. After passing the New York bar exam, he went to work as a clerk for the distinguished Wall Street firm of Carter, Ledyard, and Milburn, but he displayed the same attitude of indifference toward the legal profession as he had toward his education.

Early political activities

Motivated by his cousin Theodore, who continued to urge young men of privileged backgrounds to enter public service, Roosevelt looked for an opportunity to launch a career in politics. That opportunity came in 1910, when Democratic Party leaders of Dutchess county, New York, persuaded him to undertake an apparently futile attempt to win a seat in the state senate. Roosevelt, whose branch of the family had always voted Democratic, hesitated only long enough to make sure his distinguished Republican Party relative would not speak against him. He campaigned strenuously and won the election. Not quite 29 when he took his seat in Albany, he quickly won statewide and even some national attention by leading a small group of Democratic insurgents who refused to support Billy Sheehan, the candidate for the United States Senate backed by Tammany Hall, the New York City Democratic organization. For three months Roosevelt helped hold the insurgents firm, and Tammany was forced to switch to another candidate.

In the New York Senate Roosevelt learned much of the give-and-take of politics, and he gradually abandoned his patrician airs and attitude of superiority. In the process, he came to champion the full program of progressive reform. By 1911 Roosevelt was supporting progressive New Jersey Gov. Woodrow Wilson for the Democratic presidential nomination of 1912. In that year Roosevelt was reelected to the state senate, despite an attack of typhoid fever that prevented him from making public appearances during the campaign. His success was attributable in part to the publicity generated by an Albany journalist, Louis McHenry Howe. Howe saw in the tall, handsome Roosevelt a politician with great promise, and he remained dedicated to Roosevelt for the rest of his life.

Get a Britannica Premium subscription and gain access to exclusive content. Subscribe Now

For his work on behalf of Wilson, Roosevelt was appointed assistant secretary of the navy in March 1913. Roosevelt loved the sea and naval traditions, and he knew more about them than did his superior, navy secretary Josephus Daniels, with whom he was frequently impatient. Roosevelt tried with mixed success to bring reforms to the navy yards, which were under his jurisdiction, meanwhile learning to negotiate with labour unions among the navy's civilian employees.

After war broke out in Europe in 1914, Roosevelt became a vehement advocate of military preparedness, and following U.S. entry into the war in 1917, he built a reputation as an effective administrator. In the summer of 1918 he made an extended tour of naval bases and battlefields overseas. Upon his return, Eleanor Roosevelt discovered that her husband had been romantically involved with her social secretary, Lucy Mercer. She offered him a divorce; he refused and promised never to see Mercer again (a promise he would break in the 1940s). Although the Roosevelts agreed to remain together, their relationship ceased to be an intimate one.

# data[].attributes.attachment_link.title
Franklin D. Roosevelt | Accomplishments, New Deal, Great Depression, World War II, & Death

# data[].attributes.attachment_link.description
Franklin D. Roosevelt, in full Franklin Delano Roosevelt, byname FDR, (born January 30, 1882, Hyde Park, New York, U.S.-died April 12, 1945, Warm Springs, Georgia), 32nd president of the United States (1933-45). The only president elected to the office four times, Roosevelt led the United States through two of the greatest crises of the 20th century: the Great Depression and World War II.

# data[].attributes.attachment_link.title
Explained: What is Juneteenth and why is it so important?

# data[].attributes.body
3D printing is a way to make 3D objects. A 3D printer uses plastic or other materials to build a 3D object layer by layer.

# data[].attributes.attachment_link.title
A global history of women’s rights, in 3 minutes

# data[].attributes.attachment_link.provider_name
Centers for Disease Control and Prevention

# data[].attributes.attachment_link.description
This timeline provides information about select moments in the COVID-19 pandemic in the United States and around the world beginning from its known origins to today.

# data[].attributes.attachment_link.title
Understanding Traditions and Cultures for Kids

# data[].attributes.body
The traditional ways cultures think about life, including religion, ideas, values, and stories.

# data[].attributes.attachment_link.readable_text
Background

The conduct of the 2020 presidential election was significantly affected by the deadly COVID-19 pandemic in the United States, the early stages of which coincided with the first presidential primary elections in February and March. Because of the evident risk to public health, governors and election officials in several states postponed primary elections or implemented changes to election procedures to enable voters to cast their ballots safely. Among such measures were extending early-voting periods and loosening or eliminating requirements for obtaining or casting absentee (mail-in) ballots, which millions of voters were expected to use as a safer alternative to in-person voting. Correctly anticipating that Democratic voters would be more likely than Republican voters to use absentee ballots (in part because Trump had repeatedly downplayed the extent of the pandemic and the seriousness of the illness), the Trump campaign, the Republican National Committee (RNC), and Republican leaders in several states filed scores of lawsuits alleging that the changes undermined the constitutional authority of state legislatures to make election law or that they invited individual voter fraud. Nearly all of the suits were dismissed or withdrawn. Amid those failed challenges, Trump continued to falsely claim that Democrats were plotting to "rig" the election through voter fraud and by systematically forging, altering, or discarding absentee ballots, among other illegal means. His accusations were of a piece with his frequent assertions during the 2016 presidential campaign that the election of that year, which he won, would be rigged by Democrats.

In a press encounter in the early morning of November 4, the day after the election, Trump maintained his false narrative of Democratic cheating by declaring himself the winner and denouncing the ongoing counting of absentee ballots as a "fraud on the American people." During the next several weeks he continually accused Biden and the Democrats of having stolen the presidential election and repeated conspiracy theories involving ballot stuffing, dead voters, and malicious voting-machine software that deleted or changed millions of votes for Trump. His false accusations were indirectly endorsed by several Republican members of Congress who expressed uncertainty about the election's outcome or who simply refused to publicly acknowledge Biden's victory. Their calculated reticence helped to spread false doubts about the integrity of the election among rank-and-file Republicans. (Such manufactured doubts were later cited by Republican governors and election officials in several states to justify new "election integrity" laws that made it harder for some Democrats to vote and easier for partisan state legislatures to improperly influence or overturn statewide elections- see voter suppression.)

As vote counting continued, various groups of radicalized Trump supporters quickly coalesced around the idea that forceful protests and even violent direct action were necessary to stop the counting of fraudulent ballots and thereby to prevent Biden from taking office. A short-lived Facebook group calling itself "Stop the Steal" was created on November 4 and grew to some 320,000 members in less than 24 hours before the social media company shut it down because of posts containing disinformation and calls for violence ( see also collective violence). Stop the Steal enthusiasts soon migrated to other social media venues, where they repeated and elaborated conspiracy theories about the election and organized on-the-ground demonstrations in several cities, including at polling stations where supposedly fraudulent vote counting was underway.

After the electors from each state cast their votes for president and vice president on December 14, giving Biden a victory of 306 electoral votes to 232, Trump and his allies, as well as leaders of Stop the Steal and other pro-Trump groups across the country, turned their attention to the last, formal step in the election of a U.S. president, the ceremonial opening and counting of the electoral votes of each state in a joint session of Congress, presided over by the vice president and commencing on January 6, a date fixed in federal law. Some allies reportedly advised Trump-incorrectly-that the vice president's role in the electoral-vote counting would give Trump's vice president, Mike Pence, the constitutional authority to replace Democratic slates of electors with Republican ones and thereby to block Congress's confirmation of Biden's victory.

The attack and its aftermath

Meanwhile, in several tweets beginning in mid-December, Trump encouraged his supporters to attend a rally and march on January 6 to protest the vote-counting ceremony. In one of the tweets, Trump stated, "Be there, will be wild!" At the rally, held at a public park near the White House, a crowd of thousands, which included members of paramilitary organizations and other right-wing extremists, listened to speeches by Trump's personal attorney Rudy Giuliani and Trump's sons Donald, Jr., and Eric, among others. In his own address, which began at about noon, Trump repeated well-worn falsehoods and conspiracy theories about the stolen election; called on Pence to block Congress's confirmation of the electoral college vote-declaring that, if Pence failed to act, the rally crowd would not let the confirmation take place ("We're just not going to let that happen"); encouraged the crowd to "walk down Pennsylvania Avenue" to the Capitol building; and urged his audience to "fight like hell" or "you're not going to have a country anymore." Although Trump did not explicitly direct those in attendance to commit illegal acts, his generally incendiary language plainly suggested to many in the crowd that they would be justified in violently attacking the Capitol and members of Congress to prevent Biden from becoming president.

Even before Trump finished his address shortly after 1:00 pm, and just as the joint session of Congress was being convened, a mob of his supporters-including members of right-wing extremist organizations, such as the Proud Boys, the Oath Keepers, and the Three Percenters, as well as self-identified adherents of the QAnon conspiracy theory-pushed through fences at the western perimeter of the Capitol grounds, forcing Capitol Police officers to retreat to additional barricades closer to the building ( see United States: The 2020 U.S. election and United States presidential election of 2020: Aftermath: Trump's refusal to concede and the insurrection at the Capitol). The mob grew larger as ever more people arrived from the rally at which Trump had spoken. Capitol Police officers, along with reinforcements from the Metropolitan Police Department of the District of Columbia, were overwhelmed. Many officers were brutally beaten with deadly weapons (bats, pipes, and flag poles), sprayed with chemical irritants, or crushed and trampled by the surging crowd. As the rioting continued outside, the joint session was temporarily adjourned to allow the House and Senate to separately debate a Republican challenge to the Democratic slate of electors from Arizona. By about 2:00 pm the rioters had breached the last barrier on the west side of the building and were running up the Capitol steps and scaling the walls of the West Terrace. Another mob also had broken through barriers on the east side of the Capitol.

Shortly after 2:00 pm the rioters shattered windows to break into the west side of the building, and for the next few hours they vandalized and looted the interior and ransacked offices as they searched for their perceived enemies in Congress. They also looked for Pence, whom they now denounced as a traitor for having refused to interfere in Congress's tabulation of electoral votes. (Shortly before the start of the joint session, Pence had released a letter in which he stated that "it is my considered judgment that my oath to support and defend the Constitution constrains me from claiming unilateral authority to determine which electoral votes should be counted and which should not.") At about 2:20 pm Trump condemned Pence in a tweet to his followers, claiming that "Mike Pence didn't have the courage to do what should have been done to protect our Country and our Constitution." Only minutes after the break-in, members of the House and Senate were notified that protesters had entered the building. Realizing that their lives were in danger, many lawmakers fled or were evacuated from the building or hid behind desks or in barricaded offices and even closets. Pence was evacuated to a secure location within the complex.

The governors of Virginia and Maryland eventually dispatched National Guard units and state troopers to assist in securing the building; because of bureaucratic delays, the District of Columbia National Guard was not mobilized until about three hours after the start of the attack. The Capitol was finally cleared of rioters at about 6 pm, some four hours after they first entered the building. The vast majority of the attackers were not arrested on-site and simply walked away. Congress then resumed its tabulation of electoral votes (after dismissing Republican challenges to the slates of electors from Arizona and Pennsylvania), and Biden was certified as the winner of the 2020 presidential election in the early morning hours of January 7.

The attack on the Capitol was broadcast live on major news networks. Trump himself watched some of the assault and reportedly was pleased and excited by what he saw. After initially resisting pressure from White House aides and House minority leader Kevin McCarthy to condemn the attack, Trump reluctantly tweeted (at about 2:40 pm) a call to his followers to support the Capitol Police and to "stay peaceful." A similar tweet was issued about half an hour later. At about 4:20 pm Trump tweeted a brief video in which he once again asserted that the election had been stolen. Expressing his "love" for the rioters, he urged them to "go home," stating that "we have to have peace." Later that day he tweeted:

These are the things and events that happen when a sacred landslide election victory is so unceremoniously & viciously stripped away from great patriots who have been badly & unfairly treated for so long. Go home with love & in peace. Remember this day forever!

On January 8 Trump was banned from Twitter for having posted tweets before, during, and after the assault that violated the company's policy against glorification of violence. The ban was rescinded after Elon Musk took over the social media company.

According to a Justice Department report released in July 2021, approximately 140 Capitol and Metropolitan police officers were criminally assaulted by the rioters in the January 6 attack. Among those victims, one died of a series of strokes after being hospitalized for injuries sustained in the attack, and two others committed suicide. One of the rioters was shot and killed by police, another died of a heart attack, and a third was apparently crushed to death by the stampeding mob. The rioters caused an estimated $1.5 million in damage to the Capitol building.

On January 13, 2021, the House of Representatives, by a vote of 232 to 197, adopted a single article of impeachment against Trump for incitement of insurrection. At his Senate trial in February, which began three weeks after he left office on January 20, Trump was acquitted after only 57 senators, 10 short of the required two-thirds majority, voted to find him guilty.

During the first year after the attack, the FBI and the Justice Department arrested more than 725 of the rioters, charging them with a variety of federal crimes, including injuring law-enforcement officers, destruction and theft of government property, and conspiracy to obstruct a congressional proceeding. As of early January 2022, the FBI had yet to identify and apprehend more than 350 additional persons believed to have committed violent crimes on the Capitol grounds.

In May 2021 Senate Republicans blocked passage of a House-passed bill that would have created a national commission to investigate the January 6 attack, claiming that it would unnecessarily duplicate ongoing investigations by two Senate committees and the Justice Department (the Senate investigation, however, was focused on intelligence and communication failures by law-enforcement agencies prior to the attack). In response, the House voted along near-party lines to create its own committee, the Select Committee to Investigate the January 6th Attack on the United States Capitol. After Speaker of the House Nancy Pelosi refused to seat two of the Republican representatives chosen by minority leader Kevin McCarthy to serve on the committee investigating the January 6th attack ( Jim Jordan and Jim Banks), McCarthy withdrew his other nominees and sought to block Republican involvement in the committee, which he branded a "sham process." When Representatives Adam Kinzinger and Liz Cheney ignored that directive, the Republican National Committee censured them, and McCarthy saw that Cheney was stripped of her leadership role within the party. The committee began holding hearings in July and by early January 2022 the committee had interviewed more than 300 people and collected thousands of pages of records related to the attack. It had also subpoenaed testimony and records from high-level members of the Trump administration and other Trump associates and supporters, some of whom refused to cooperate with the investigation.

In October 2021 Trump filed suit against the committee in federal district court, seeking to block the release of several hundred pages of records relating to his activities and communications before and during the attack, which the committee had originally requested in August. In December, after the district court rejected Trump's request and an appellate court upheld that decision, Trump filed an emergency petition with the Supreme Court, asking that it review the district court's ruling and that it block release of the documents pending its final decision in the case. The Supreme Court denied Trump's request in January 2022, allowing the committee to begin receiving the documents from the National Archives.

See also Donald J. Trump: Presidential election of 2020.
Brian Duignan

# data[].attributes.attachment_link.title
January 6 U.S. Capitol Attack| Background, Events, Criminal Charges, & Facts

# data[].attributes.attachment_link.description
United States Capitol attack of 2021, assault on the United States Capitol on January 6, 2021, by a mob of supporters of President Donald J. Trump. The attack disrupted a joint session of Congress convened to certify Joe Biden's victory over Trump in the presidential election of 2020.

# data[].attributes.body
An example of a positive school culture is a school that places high value on respect, diversity, academic integrity, and honesty. An example of a bad school culture is one that punishes creativity, honesty, or integrity.

# data[].attributes.wish_content.attachment_props.alternative_text
what is the history of remote learning for kids

# data[].attributes.body
a specific type of music

# data[].attributes.body
Pop music is eclectic, often borrowing elements from urban, dance, rock, Latin, country, and other styles.

# data[].attributes.attachment_link.title
Miles Davis - Blue In Green (Official Audio)

# data[].attributes.body
A music genre that originated in Jamaica in the late 1950s, combining elements of Caribbean mento and calypso with American jazz and rhythm and blues.

# data[].attributes.attachment_link.title
Madness - One Step Beyond (Official 4k Video)

# data[].attributes.attachment_link.title
Top 65 Classical Music Masterpieces Everyone Knows, But Not Everybody Knows Their Titles

# data[].attributes.body
Hip-hop or hip hop music, also known as rap, is a genre of popular music that originated in the early 1970s by African Americans and Afro-Caribbean immigrants in the Bronx, a borough of New York City.

# data[].attributes.body
K-pop, short for Korean popular music, is a form of popular music originating in South Korea as part of South Korean culture.

# data[].attributes.body
Heavy metal is traditionally characterized by loud distorted guitars, emphatic rhythms, dense bass-and-drum sound and vigorous vocals.

# data[].attributes.body
Musical style of Jamaican origin derived from rock whose songs are characterized by a happy, repetitive and marked rhythm, soft melodies and committed lyrics in favor of peace, aid to the Third World, etc.

# data[].attributes.body
Techno is a genre of electronic dance music that is characterized by a repetitive four on the floor beat which is generally produced for use in a continuous DJ set.

# data[].attributes.body
Country is a music genre originating in the southern regions of the United States, both the American South and the Southwest.

# data[].attributes.body
a form of dance music of Puerto Rican origin, characterized by a fusion of Latin rhythms, dancehall, and hip-hop or rap.

# data[].attributes.body
Rhythm and blues, frequently abbreviated as R&B or R'n'B, is a genre of popular music that originated within African-American communities in the 1940s.

# data[].attributes.body
a song originating among the people of a country or area, passed by oral tradition from one singer or generation to the next, often existing in several versions, and marked generally by simple, modal melody and stanzaic, narrative verse.

# data[].attributes.attachment_link.readable_text
The collection of markup symbols or codes entered into a file to be displayed on the Internet is known as Hyper Text Markup Language (HTML). The markup instructs web browsers to display the text and pictures on a web page.

HTML determines the web page's structure, and an interactive web page cannot be created using just this framework. So, to create your HTML appealing and add interactivity, you'll need assisting technologies like JavaScript and CSS.

HTML Definition

Hypertext: Hypertext is the text arranged to link similar elements (sometimes with embeds like images, too).

Markup: It is a style manual for typesetting anything that will be printed, whether in hardcopy or digital form.

Language: The language which a computer system utilizes to comprehend orders is known as language.

Hyper Text Markup Language is referred to as HTML.

The most used markup language for making Web pages is HTML.

A Web page's structure is described in HTML.

HTML is made up of several components.

HTML components determine the content's presentation in the browser.

The labels "this is a header," "this is a paragraph," "this is a link," etc., are provided by HTML elements.

There are several uses for HTML, including:

1. Web development: HTML code is used by developers to control how browsers display text, hyperlinks, and file types.

2. Internet navigation: As HTML is widely used to include hyperlinks, users may easily explore and insert connections between relevant pages and websites.

3. Web-based instruction: HTML allows for document organization and formatting, like Microsoft Word.

HTML cannot provide dynamic functionality, so it is not regarded as a programming language and is currently regarded as a recognized web standard. The HTML standards are developed and updated often by the World Wide Web Consortium (W3C).

Hypertext Markup Language Fundamentals

HTML is just a set of shortcodes entered into a text file. An HTML text file is saved, and a web browser is used to see it. Following the author's instructions for writing the codes that result in visible representation, the browser examines the file and converts the content into a visual form.

While writing HTML, tags must be utilized appropriately to convey the author's intent. These tags power the capabilities of HTML, and tags distinguish normal text and HTML code. The words included within angular brackets (<>) are called tags, enabling the appearance of graphics, pictures, and tables on the website.

Various tags have different purposes. JavaScript and Cascading Style Sheets (CSS) applications may be employed when web interfaces need to be made more dynamic. Web pages are made more powerful and accessible by CSS and JavaScript, respectively.

HTMLBasic Elements

An HTML element is a component within a tag that can contain name-value combinations known as attributes. A text file is additionally marked with HTML content specifying how the page should be presented. A unique, distinctive HTML syntax is maintained to show the markup different from the HTML file's real content. These unique elements are referred to as HTML tags.

There are always starting tags, middle content, and closing tags for HTML components. The opening tag contains attributes that can provide the element with further details. There are two methods to characterize an element:

The document's block-level elements begin on a new line and occupy space, and paragraphs and headings tags are a few examples of these components.

Inline elements contain things like text format tags and hyperlinks. Typically, the contents of these components are formatted at the block level. In the document, inline elements occupy the required space and do not begin on a new line.

HTML Tags

Like keywords, HTML tags specify how a web browser will structure and display the text. Using tags, a browser can differentiate between plain text and HTML content. The opening tag, content, and closing tag are the three essential components of an HTML tag. Yet, certain HTML tags are not closed.

A web browser views an HTML document from left to right and top to bottom. To generate HTML documents and display their characteristics, HTML tags are employed. Every HTML tag has a unique set of features.

A web browser needs a few basic tags in an HTML file to distinguish between ordinary text and HTML text. According to the needs of your code, you may incorporate as many tags as you like.

All HTML tags must be wrapped inside angular brackets (< >).

In HTML, every tag has a specific function.

If you have already used an open tag <tag>, you have to add a close tag </tag> after using it (except for some tags).

Common HTML Tags

The layout of a page is determined by its HTML tags, which also specify how each element will be seen in the browser. HTML tags that are often used include:

<h1>, a top-level heading description

<h2>, a second-level heading description

<p>, a paragraph tag

<table>, tabular data tag

<ol>, ordered list information tag

<ul>, unordered list information tag

As previously indicated, the information they enhance is surrounded by opening and closing tags.

A starting tag has the following format: <p>.

The same rules apply to closing tags, except they include a backslash to signify that the provided HTML element has ended.

The closing tag is written as </p>.

HTML Attributes

HTML tags can also accept something known as attributes. These properties, which include style, ids, and classes, are added to the opening tag.

They accept values that provide more details about the element and enable JavaScript styling and manipulation.

HTML attributes are specialized terms that offer further details about the components or act as a modifier for HTML elements.

Each component or tag may contain attributes that specify how the element will behave.

The start tag should always be used when applying attributes.

The name and value pair for the attribute must always be utilized when applying attributes.

It is advised to write the attribute's names and values exclusively in lowercase since they are case-sensitive.

One HTML element can add several attributes, but there must be space between each attribute addition.

Using and Implementing HTML

As HTML is entirely text-based, it is possible to modify an HTML file by opening it in an application like Notepad++, Vi, or Emacs. An HTML file may be created or edited in any text editor, and as long as it has a ".html" file extension, any web browser, including Chrome or Firefox, can view the file as a webpage.

There are several WYSIWYG "what you see is what you get" editors available for use by professional software developers to create web pages. WYSIWYG editors are offered as plugins or standard components by NetBeans, IntelliJ, Eclipse, and Microsoft's Visual Studio, making HTML very simple to use and implement.

Although contemporary online browsers sometimes come with web developer plugins that show issues with Html documents, such as a blank ending tag or syntax that doesn't produce well-formed HTML, these WYSIWYG editors also offer HTML debugging capabilities.

Both Chrome and Firefox come with HTML developer features that let you immediately examine a webpage's whole HTML file, edit HTML while browsing, and update HTML while the browser is open.

CSS, HTML, and JavaScript

Although it may be used to build webpages, HTML has several restrictions regarding completely responsive elements. As a result, adding text components and organizing them inside a website should be the primary uses for HTML. Combining HTML with CSS and JavaScript enables more complicated functionalities (JS).

An HTML file can have a link to a cascading style sheet (CSS)or JS file, often at the top of the page with a defined file path, that contains information on the display of HTML elements, including the colors and fonts to use. Moreover, JavaScript enables website designers to incorporate more dynamic features like pop-up windows and image sliders. Tags known as class attributes are employed to link HTML components to their matching CSS or JS elements.

The same fundamental approach is used with JS sheets but with different functionality. For example, a user may add code to the CSS file with a class property that makes text red if they want a specific quantity of text to be that color. Finally, they may add the same class property to all of the text in the HTML page that they wish to be red.

Difference Between HTML and HTML5

There were 18 tags in the original HTML, and since then, more tags and properties have been introduced to the markup with each subsequent edition.

HTML5 includes new types of form controls, which is the primary distinction (difference) between HTML and HTML5. Also, HTML5 added several semantic elements like "article," "header," and "footer" that precisely define the content.

XML vs. HTML

Unlike HTML, Extensible Markup Language, or XML, enables users to customize their markup.

Just one predetermined tag can be used in HTML to indicate certain data. As XML documents only include syntax and content, they are designed to be simple to read and contain user-defined tags.

Benefits and drawbacks of HTML

The following are some benefits of utilizing HTML:

It is widely used and a complete source of data.

It runs natively on all browsers.

It is rather simple to learn.

It has a clear and reliable source code.

It is free to use and open source.

It is compatible with different backend programming languages, including PHP.

A few drawbacks to take into account are:

It is mostly used for static web pages and does not have a lot of dynamic capability.

Even though they share similar parts, each component must be designed independently.

Browser behavior can be inconsistent. For example, newer features might not work with outdated browsers.

# data[].attributes.attachment_link.description
HTML Definition with Definitions List, Business Definition, Acceleration Definition, Nursing Definition, Current Definition, Voltage Definition, Democracy, Internet Definition etc.

# data[].attributes.body
A firewall is a security system designed to prevent unauthorized access into or out of a computer network. Firewalls are often used to make sure internet users without access are not able to interface with private networks, or intranets, connected to the internet.

# data[].attributes.attachment_link.readable_text
Cryogenics produces and studies materials in extremely cold temperatures. Ultra-cold temperatures change the chemical properties of materials. This has become an area of study for researchers who examine different materials as they transition from a gas to a liquid to a solid state. These studies have led to advances in not only our understanding of different materials but the creation of entirely new technologies and industries.

The temperature of any material is the measure of the energy that it contains. Rapidly moving molecules have a higher temperature than slower-moving molecules.

For example, while water transforms from a liquid to a solid at 32° F (0° C), cryogenic temperatures range much lower; from -150°C to -273° C. The temperature -273° C is the absolute lowest that can be achieved. At this temperature, the actions of all molecules stop, causing the molecules to be at the lowest possible state of energy.

Liquid gases at or below -150° C are also used to freeze other materials. Once a gas begins to liquefy, the environment is considered a cryogenic one. The most common gases that are turned into liquid for cryogenics are oxygen, nitrogen, hydrogen and helium.

History of Cryogenics

The word cryogenics comes from the Greek word "Kryos," which means cold. This combined with the abbreviated English word "to generate" make the word we know as cryogenics.

Temperatures that are very cold are not measured in degrees Fahrenheit or Celsius but in Kelvins. Kelvins use the unit symbol K. It is named after Baron Kelvin who believed that at very low temperatures a new scale was needed that was not measured by the material state change of water like Fahrenheit or Celsius. Zero degrees Kelvin (0 K) is the theoretically coldest possible temperature.

In 1877 Rasul Pictet and Louis Cailletet liquefied oxygen for the first time, both using different methods for the process. Eventually, a third method of liquefying oxygen was discovered, and at this point in history oxygen was able to be liquefied at 90 K. Soon after, liquid nitrogen was achieved at 77 K. Scientists all over the world began competing to lower the temperature of matter to absolute zero.

The next breakthrough came in 1898 when James DeWar liquefied hydrogen at 20 K. This presented a new problem to researchers, as 20 K is also at a boiling temperature. However, this presented a further issue on how to handle and store gases at such temperatures. Hence the creation of DeWar flasks, which are used to store gases today.

The last major advance in the cryogenics industry came in 1908 when the physicist Heike Kamerling Onnes liquefied Helium at 4.2 K and then 3.2 K. The advances in cryogenics following this development have been much smaller because it is thermodynamic law that you can approach absolute zero, but never actually reach it. Technology has advanced much more since this last major discovery, and we can now freeze materials within very small distances from absolute zero, yet scientists still have not been able to break thermodynamic law where every particle has zero energy.

What Is Cryogenics Used For?

Cryogenics is used in a variety of low-temperature physics research and applications. It can be used to produce cryogenic fields for rockets, in MRI machines that use liquid helium and require cryogenic cooling, storing large quantities of food, special effects fog, recycling, freezing blood and tissue samples, and even cooling superconductors.

Applications and uses:

Cryosurgery

Cryosurgery is a minimally invasive surgical technique that involves the use of extreme cold to destroy or remove abnormal tissues, such as tumors or warts. The procedure involves applying a freezing agent, such as liquid nitrogen or argon gas, directly onto the targeted area. This causes the tissue to freeze and ultimately die, allowing the body to naturally eliminate the damaged cells.

The science behind cryosurgery is based on the principle of controlled tissue destruction by rapid freezing and thawing. When the targeted tissue is exposed to extreme cold, the water inside the cells freezes and expands, causing the cell walls to rupture and the cells to die. The body's immune system then works to remove the dead tissue, leaving healthy tissue behind.

Cryosurgery has many advantages over traditional surgical techniques. It is a minimally invasive procedure that can be performed on an outpatient basis, reducing the need for hospitalization and recovery time. It also results in less scarring and pain compared to traditional surgery, and has a lower risk of infection and complications.

Cryosurgery is commonly used in dermatology to treat skin conditions such as warts, actinic keratosis, and skin cancers. It is also used in other medical specialties such as gynecology, urology, and gastroenterology to treat various conditions.

Cryoelectronic Cooling

Cryoelectronic cooling is an innovative technology that has revolutionized the field of superconductivity and spacecraft design. It involves the use of extreme cold temperatures to enable electrons in materials to move freely with little resistance. This technology has many advantages over traditional cooling methods, such as liquid cooling, because it is more efficient, reliable, and cost-effective.

In superconductivity research, cryogenic engineering plays a vital role in maintaining the low temperatures required for superconducting materials to operate at their full potential. These materials have the ability to conduct electricity with zero resistance when they are cooled to near absolute zero (-273.15°C). By using cryoelectronic cooling, scientists are able to achieve and maintain these extremely low temperatures, allowing for the creation of more efficient and powerful superconductors.

In addition to superconductivity research, cryoelectronic cooling is also used in spacecraft design. Spacecraft that travel through outer space are exposed to extreme temperatures, which can cause damage to their electronic systems. Cryoelectronic cooling provides a reliable and efficient way to maintain the temperature of electronic systems in spacecraft, ensuring that they operate at optimal performance levels.

One of the major advantages of cryoelectronic cooling is that it is a highly efficient method of cooling, requiring only a small amount of energy to maintain the required low temperatures. This makes it an ideal choice for space applications, where energy conservation is critical. Additionally, cryoelectronic cooling is a reliable and cost-effective method of cooling, with few moving parts and minimal maintenance requirements.

Cryobiology

Cryobiology is the study of the effects of low temperatures on organisms. There are six major areas of cryobiology:

The study of cold-adaptation of microorganisms, plants, animals and vertebrates

Cryopreservation of cell tissues and embryos used in invitro fertilization

Preservation of organs

Lyophilization, the freeze-drying of pharmaceuticals

Cryosurgery

Supercooling as applied to biological systems

Food Preservation

Cryogenics keeps foods fresh without chemical risk. It is an effective technique for food preservation that is used to maintain the quality and freshness of various food products.

Cryogenic preservation isn't just about cold - it freezes food products quickly so that it maintains its consistency, texture and taste. This makes cryogenic preservation an excellent option for high-value food items such as seafood, meat, and vegetables. This technique is particularly useful for maintaining the texture and quality of delicate food products that are easily damaged by other preservation methods such as heat treatment or dehydration.

Another benefit of cryogenic preservation is its ability to extend the shelf life of food products. By freezing food products at ultra-low temperatures, the growth of microorganisms that can cause spoilage and decay is inhibited, reducing the risk of foodborne illness and increasing the overall safety of the product.

To preserve packaged foods such as produce, the food items are typically sprayed with liquid nitrogen to absorb the heat within the produce. The nitrogen quickly evaporates before the food is packaged.

Transportation of Gases

Cryogenics is also used to transport gases that are not typically cryogenic. For example, using cryotechnology, gases can be transformed into liquids to make them easier to transport from one place to another. Take natural gas (LNG) which is a combination of ethane, methane and other gases. When these gases become liquefied, they take up far less space than if they remained gaseous. Therefore, transportation expenses become lower and the process becomes much easier.

Cryotherapy

Cryotherapy is a medical treatment that involves exposing the body to extremely cold temperatures. This can be achieved through various methods, including cryosaunas and cryospas, which allow individuals to stand in a chamber filled with cryogenic fluids for several minutes.

Proponents of cryotherapy claim that it offers numerous benefits to the body, including reducing inflammation, increasing energy, managing pain, and boosting metabolism. While research on cryotherapy is still relatively new, several studies have shown that it can be effective in reducing inflammation and pain in certain conditions, such as rheumatoid arthritis and fibromyalgia.

However, there are also potential risks associated with cryotherapy. Excessive exposure to cold temperatures can lead to hypothermia, which can be life-threatening. Additionally, cryotherapy can cause skin damage, particularly if the skin is wet or has open wounds.

Furthermore, while some individuals may experience immediate relief from pain and inflammation following cryotherapy, the long-term benefits of the treatment are still unclear. Some studies have suggested that cryotherapy may not be effective for all individuals and may even be harmful in some cases.

Cryonics

Cryonics is the process of cryo-preservation of humans or animals in the hope of reviving them at a later time when medical technology is advanced enough to cure the underlying cause of their death. Cryonics involves cooling the body to very low temperatures in a cryonic container filled with liquid nitrogen.

The cryopreservation process is performed immediately after death or sometimes even before if the individual is terminally ill and has chosen to undergo cryonic preservation. The goal of cryonics is to preserve the brain and other vital organs to enable future medical professionals to revive the person with their memories, consciousness, and personality intact.

While cryonics is a controversial topic, proponents argue that it offers hope for individuals who have been diagnosed with terminal illnesses or who may die from other causes. They argue that the advances in medical technology may one day make it possible to revive and cure the underlying cause of death, allowing individuals to continue living. Critics, however, argue that cryonics is a pseudoscience and that the chances of successfully reviving an individual are extremely slim. They also argue that the process of cryopreservation can cause significant damage to the body, and that it is unethical to offer false hope to individuals and their families.

What are the cryogenic fluids?

What's Next for Cryogenics?

As technology rapidly evolves areas of cryogenics will continue to develop and eventually expand to more applications. While we can't predict what developments will come next, what we do know is that safety around cryogenic fluids is a must, no matter which direction the research will progress.

It is important that all applications handling, studying and using cryogenic liquids use the proper safety precautions and cryogenic oxygen depletion monitors to ensure both safe and accurate monitoring of gas concentrations.
References https://academickids.com/encyclopedia/index.php/Cryogenics https://schoolworkhelper.net/cryogenics-history-overview/ https://www.encyclopedia.com/science-and-technology/physics/physics/cryogenics https://www.azonano.com/article.aspx?ArticleID=5091 https://science.jrank.org/pages/1893/Cryogenics.html https://www.thoughtco.com/cryogenics-definition-4142815
https://www.healthline.com/health/cryotherapy-benefits#benefits
https://www.chilledcryospa.com/what-is-cryo https://en.wikipedia.org/wiki/Cryosurgery https://en.wikipedia.org/wiki/Cryoelectronics https://en.wikipedia.org/wiki/Cryobiology

# data[].attributes.attachment_link.description
Cryogenics is the production of and behavior of materials at very low temperatures. Learn about the science and uses.