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Giraffes grow about 4 feet (1.2 meters) in their first year of life. A newborn giraffe is about 6 feet (1.9 meters) tall at birth and weighs about 150 ...

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how tall are giraffes videos for kids - Google Search

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Please click here if you are not redirected within a few seconds. Giraffes grow about 4 feet (1.2 meters) in their first year of life. A newborn giraffe is about 6 feet (1.9 meters) tall at birth and weighs about 150 ...

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Reptiles for Kids | What is a reptile? Learn all about reptiles and their characteristics

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Mixing colors

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Mixed - A Colorful Story (Children’s Book Read Aloud)

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I Am An Artist | Read aloud | Marta Altes | Children's storybook

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12 Famous painters

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Famous PAINTERS for kids - famous paintings and artists, Picasso, Dali, Michelangelo, Van Gogh

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Famous Artists

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Vincent van Gogh for Children: Biography for Kids - FreeSchool

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Meet the Artist: Rachel Jones I Tate Kids

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Meet the Artist

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Becoming an Artist: Yayoi Kusama | Tate Kids

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Art as a career

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Art Careers for Kids | Pure Michigan Talent Connect

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A day in the life

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Learn To Be A Firefighter Tommy Flames - Toddler Firefighter Videos -  Learning Videos For Toddlers

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Visit to a Firestation

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SAMPLE FULL EPISODE- Firestation (Danny Go!)

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Explore jobs you can you have in the future

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There's a cool career for every kid! Explore career options from A to Z with the Lab Squad kids as they meet and interview career professionals. The kids share lots of career ideas in every episode so be sure to watch them all, A to Z!

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Are you in elementary school? Do you know what you want to do when you grow up? Learn about different jobs that will make you shine.

Job Profiles for Elementary School Students

Do you like math? An accountant, engineer or video game developer might be a good job for you. Do you want to care for people and keep them healthy? Learn about becoming a nurse or dentist. Do you like to draw? You could become an architect or graphic designer. Learn more about these jobs:

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Elementary School Students Find Your Career Today

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Are you in elementary school? Do you know what you want to do when you grow up? Learn about different jobs that will make your future shine brighter than ever!

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How tall are giraffes?

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Amphibians are cold-blooded vertebrates (vertebrates have backbones) that don’t have scales. They live part of their lives in water and part on land.

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Crustaceans are animals that usually have a hard covering, or exoskeleton, and two pairs of antennas, or feelers. People around the world eat many types of crustacean-for...

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Ready to learn some paw-some dog facts? Then you're in the right place! Join National Geographic Kids as we get the lowdown on our fur-tastic friends...

Dog facts!

1. Dogs are the most popular pet on the planet!

A third of ALL households around the world have a dog. These playful, friendly, loyal animals make great companions, but they can also be fierce and tough protectors, or intelligent helpers.

2. They evolved from a now-extinct species of wolf.

Dogs were the first animal domesticated (tamed) by humans, over 20,000 years ago! As they evolved from wolves, their skulls, teeth and paws shrank, and they became more docile and obedient.

FUN FACT!

Evidence from fossils suggests that five types of dog had evolved by the Bronze Age, around 4500BC. These were mastiffs, wolf-type dogs, dogs similar to greyhounds, pointing dogs and herding dogs. Bow wow!

3. They can learn over 100 words and gestures!

Dogs are thought to be as smart as two-year-old children (and much easier to train!), so many owners teach them commands and tricks.

4. Dog noses are at least 40x more sensitive than ours!

These clever canines have an incredible sense of smell - allowing them to follow scent trails days after they were left. Amazingly, bloodhounds' sense of smell is so spot on that it can be used as evidence in court!

FUN FACT!

Dogs also have fantastic hearing! They can detect high-pitched noises and spot sounds from much further away than humans can.

5. Many work as assistance dogs, helping humans!

Many dogs are trained to work as guide dogs, helping blind people get around safely. Others are assistance dogs, who keep their owners calm and safe, while some brave hounds are search and rescue dogs, who help human rescuers save people from danger.

WEIRD BUT TRUE!

Some working dogs are trained to use their super senses to sniff out explosives and illegal goods, or alert humans to potentially dangerous health issues. Wow!

6. They only sweat from their paws, and have to cool down by panting.

The sweat is much oilier than humans', and it contains lots of chemicals that only other dogs can detect. Weirdly, it also makes many dog paws smell of cheesy crisps!

7. They can be right or left-pawed!

Like humans, most dogs have a dominant hand - or in their case, paw! To figure out which one it is, you can conduct a simple science experiment ...

Watch a dog moving from standing still to walking forwards. Do they start walking with their left leg, or their right? Watch several times, noting down the starting leg each time, and see if there's a pattern. Many dogs will often lead with the same leg - their dominant one!

Ancient breeds like the Saluki lived in the lavish palaces of Egyptian royalty! The pampered pooches had their own servants, were decked out in jewelled collars, and ate only the finest meats.

WEIRD BUT TRUE!

Dead rulers were often buried with their doggy pals, as they believed the hounds would protect them from harm in the afterlife.

9. Dogs use body language to express their feelings.

From their ears to their eyebrows, shoulders, and tail, dogs often use signals and smells, rather than sound, to communicate! Their posture makes a big difference, too.

Next time you see a dog interacting with a person or other dog, pay close attention. Are they shrinking themselves down small, or standing up big and tall? What do you think they're trying to say?

10. Owning a dog is a BIG responsibility!

Just like humans, dogs have feelings and needs, and they have to be taken care of properly. They need regular walking, healthy food, a clean, cosy place to sleep and lots and lots of love and affection! Make sure you and your family think carefully before you get a dog (or any pet!) to make sure you have the time and means to take one on.

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Dog facts for kids! | National Geographic Kids

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Sink your teeth into 10 awesome dog facts from Nat Geo Kids! Find out about dogs' super senses, training talents, and more...

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Dibuja cinco de estos íconos en tu marco en tu diario. Generalización va en el centro.

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Dibuja cinco de estos íconos en tu marco en tu diario. Generalización va en el centro.

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Draw five of these icons on your frame in your journal. Big Idea goes in the center.

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Draw five of these icons on your frame in your journal. Big Idea goes in the center.

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Dogs ( Canis lupus familiaris) are domesticated mammals, not natural wild animals. They were originally bred from wolves. Dogs are sometimes called "canines," which comes from the Latin word for dog - canis. Sometimes people also use "dog" to describe other canids, such as wolves.

A baby dog is called a pup or puppy. A dog is called a puppy until it is about one year old. Domesticated dogs have been bred by humans for a long time and were probably the first animals to be domesticated. Domesticated dogs eat both meat and vegetables, often mixed together with other ingredients and sold in stores as dog food.

Today, some dogs are used as pets while others are used to help humans do their work. Dogs are popular pets because they are usually playful, friendly, and listen well to humans. Thirty million dogs in the United States are registered as pets. Dogs are sometimes referred to as "man's best friend" because they are kept as domestic pets and are usually loyal and like being around humans. Dogs often have jobs, including police dogs, army dogs, service dogs, fire dogs, messenger dogs, hunting dogs, herding dogs, or rescue dogs.

Appearance and behavior

Dogs have four legs and make a "bark," "woof," or "arf" sound. Different kinds of dogs have different kinds of fur. Dogs often chase cats, and most dogs will fetch a ball or stick.

Dogs can smell and hear better than humans, but cannot see well in color. Their eye structure helps dogs to see better in dim light than humans can. They can also see further around before moving their eyes than a human can.

Like wolves, wild dogs travel in groups called packs. Packs of dogs are ordered by rank, and dogs with low rank will submit to other dogs with a higher rank. The highest-ranked dog is called the alpha male. Each dog in a pack helps and cares for others. Domesticated dogs often view their owner as the alpha male.

Origin of dogs

All dogs are descended from wolves, by domestication and artificial selection. This is known because DNA genome analysis has been done to discover this. Dogs have been bred by humans.

The earliest known fossil of a domestic dog is said to be from 31,700 years ago in Belgium. Scientists believe that dogs have lived with people for at least 30,000 years. In 2013, a study was published that showed that the skull and teeth of a canid, dated to 33,000 years ago, had characteristics closer to a dog than to a wolf, and the authors determined that "this specimen may represent a dog in the very early stages of domestication."

Another sign of domestication is that sometimes, dogs were buried together with humans. Evidence of this is a tomb in Bonn, where the remains of a man of about 50 years of age, a woman of about 25 years of age, a dog, and other artifacts were found. Radiocarbon dating showed that the human bones were between 13,300 and 14,000 years old.

Different dog breeds (kinds) have different lifespans. In general, smaller dogs live longer than larger dogs. The size and the breed of the dog change the average lifespan of a dog. Breeds such as the Dachshund usually live for fifteen years, while Chihuahuas can reach age twenty. The Great Dane, on the other hand, has an average lifespan of six to eight years; some Great Danes have lived for ten years.

Dogs and humans

Dogs are often called "man's best friend" because they fit well with human life. Dogs can serve people in many ways. For example, there are guard dogs, hunting dogs, herding dogs, guide dogs for blind people (along with other service dogs), and police dogs. These dogs sometimes help police in airports or other areas. Sniffer dogs (usually beagles) are sometimes trained for this job. Dogs were sent by Russians into outer space a few years before any human being was sent. The first dog sent up was named Laika, but she died within a few hours.

It is estimated that three-quarters of the world's dog population lives in the developing world as feral, village, or community dogs. Dogs are not usually pets in these areas.

Pet dog populations grew after World War II. In the 1950s and 1960s, dogs were kept outside more often than they tend to be today and were still used as guard dogs, children's playmates, or walking companions.

Most modern dog owners describe their pets as part of the family. It is estimated there are 77.5 million people with pet dogs in the United States.

A 2014 study using magnetic resonance imaging (MRI) comparing humans and dogs showed that dogs have the same response to voices and use the same parts of the brain as humans do. This gives dogs the ability to recognize emotional human sounds, making them friendly social pets to humans.

Best dogs for kids

The best dogs for kids are ones that have calm personalities and are happy to socialize with everyone in the family.

Having a family dog can also teach children cooperation and responsibility. For example, a child can help with chores such as walking, feeding, and brushing the dog.

Here are some of the most popular dog breeds for kids:

There are at least 800 breeds (kinds) of dogs. Dogs whose parents were the same breed will also be that breed: these dogs are called purebred or pure pedigree dogs. Dogs with parents from different breeds no longer belong to one breed: they are called , mixed-breed dogs, , or . Some of the most popular breeds are sheepdogs, collies, poodles, and retrievers. It is becoming popular to breed two different breeds of dogs together and call the new dog's breed a name that is a mixture of the parents' breeds' two names. A puppy with a poodle and a pomeranian as parents might be called a Pomapoo. These kinds of dogs, instead of being called mutts, are known as designer dog breeds. These dogs are normally used for prize shows and designer shows. They can also be guide dogs.

10 interesting facts about dogs

There are hundreds of different breeds of dogs and around 400 million dogs in the world.

The dog has earned the nickname "man's best friend."

The largest breeds of dog in the world are the Great Dane, Irish wolfhound, Scottish Deerhound, Neapolitan Mastiff, English Mastiff, Anatolian shepherd, Dogue de Bordeaux, Leonberger, and Boerboel. The smallest dog breed is the Chihuahua (dog).

The oldest dog who ever lived was a cattle dog from Australia named Bluey who lived to be 29 years and 5 months old.

A dog's nose print is unique; it is similar to human fingerprints in that no two are the same.

Dalmatian puppies are born completely white and develop their spots as they grow.

Dogs dream just like humans do.

Little dogs are often called toy dogs, or lap dogs - because they're so little they look like a toy and can easily fit on your lap.

A dog is as smart as a 2-year-old child and can recognize around 150 words and gestures.

Dogs should not eat raisins, grapes, onion, chocolate, or garlic because it makes them sick.

Images for kids

In Spanish: Canis familiaris para niños

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Warning colouration (or aposematism) is how animals let other animals know that they are poisonous or dangerous. It is the exact opposite of camouflage. Warning colours are usually some combination of red, yellow, black and white.

Alfred Russel Wallace, a British naturalist, explained it this way, in 1889:

"The animals in question are possessors of some deadly weapons, as stings or poison fangs, or they are uneatable, and are thus so disagreeable to the usual enemies of their kind that they are never attacked when their peculiar powers or properties are known.
It is, therefore, important that they should not be mistaken for defenceless or eatable species... since they might suffer injury, or even death, before their enemies discovered the danger or uselessness of their attack. They require some signal or danger flag which shall serve as a warning to would-be enemies..."

Wallace predicted that birds and other predators would reject conspicuous prey whilst accepting cryptic prey. Later reports confirmed this.

Animals with warning colours move slowly and expose themselves to sight. The sluggishness and exposure helps to advertise their defence. Along with the colour and behaviour often goes the foul smell of their chemical weapons. The grasshopper Aularches miliaris is a very good example. Noxious caterpillars often have thick, leathery cuticles which help them to resist young birds making a 'test'. When the bird takes a peck, disgusting fluid seeps out from special glands on its back. The caterpillar (or other larva) will often survive such an attack, and the young bird has learnt a lesson it will never forget. All in all, the predator is given good warning. Tests show that warning colours definitely do deter predators.

Some individual animals will die or receive damage while birds or mammals on the attack learn about the connection between colour and taste. However, if warning costs less than hiding, the animal benefits. And the advertising traits such as colours may serve other functions as well. The patterns may help mate identification within the species, for instance.

Warning colouration is the basis of two different kinds of mimicry: Müllerian mimicry and Batesian mimicry.

Toxin resistance

There are a number of predators which eat toxic animals. Cases which have been studied suggest there is some kind of cost to be borne for their relative immunity to the toxin.

The Rough-skinned newt is toxic, and displays its warning colour by showing its abdomen. Throughout much of the newt's range, the common garter snake ( Thamnophis sirtalis) is resistant to the toxin. In several populations, these snakes successfully prey upon the newts. Toxin resistant garter snakes are the only known animals that can eat these newts and survive.

The snake's resistance to the toxin has resulted in a selective pressure that favours newts which produce more potent levels of toxin. Increases in newt toxicity then apply a selective pressure favouring snakes with mutations conferring even greater resistance. The price paid by the snakes is that their digestion and body metabolism is slower than related species. Really resistant snakes have slower crawl speeds than snakes with little or no resistance.

This is an example of co-evolution. This cycle of a predator and prey co-evolving is sometimes called an evolutionary arms race. In this case it results in the newts producing levels of toxin far in excess of what is needed to kill any other conceivable predator.

Bright colours

Animals can, and do, show bright colours which have other functions. The most common functions are:

However, the bright colours used for these functions tend to be different from the standard warning patterns and colours.

Unknown function

The colouring of many species has unknown function. This is usually because their life habits have not been studied sufficiently, and because no field tests have been done. One example is the extraordinary moth Utetheisa pulchella, the Crimson Speckled Moth. Its association with the plant Dittrichia viscosa, which has a somewhat unpleasant smell, suggest the moth has warning colouration, but the matter is not settled. The related species Utetheisa ornatrix, which feeds on other plants, is known to exude (squeeze out) alkaloids to put predators off.

Images for kids

Flamboyant cuttlefish colours warn of toxicity

Hycleus lugens, an aposematically coloured beetle

Skunk, Mephitis mephitis, advertising its powerful defences, scent glands near the tail, by raising its tail and displaying its warning coloration

There is evidence that nudibranchs like Phyllidia varicosa are aposematic.

Iridescent blue rings on the mantles of the venomous octopus Hapalochlaena lunulata are considered by some to be aposematic.

First edition of Edward Bagnall Poulton's The Colours of Animals, 1890, introduced a set of new terms for animal coloration including "aposematic".

A model (to be mimicked), the venomous and genuinely aposematic coral snake

In Spanish: Aposematismo para niños

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Learn Warning colouration facts for kids

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Biology is the science of life and living things, and their evolution. Living things include plants, animals, fungi (such as mushrooms), and microorganisms such as bacteria and archaea.

People who study biology are called biologists. Biology looks at how animals and other organisms behave and work, and what they are like. Biology also studies how organisms react with each other and the environment. It has existed as a science for about 200 years, and was preceded by natural history. Biology has many research fields and branches. Like all sciences, biology uses the scientific method. This means that biologists must be able to show evidence for their ideas, and that other biologists must be able to test the ideas for themselves.

Biology attempts to answer questions such as: "What are the characteristics of this living thing?" ( comparative anatomy); "How do the parts work?" ( physiology); "How should we group living things?" ( classification, taxonomy); "What does this living thing do?" ( behaviour, growth); "How does inheritance work? ( genetics); "What has been the history of life?" ( palaeontology). How do organisms relate to their environment? ( ecology). All modern biology is influenced by evolution, which answers the question: "How has the living world come to be as it is?"

Branches of biology

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Mutual symbiosis between clownfish of the genus Amphiprion that dwell among the tentacles of tropical sea anemones. The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protects the clown fish from its predators.

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Biology is the science of life and living things, and their evolution. Living things include plants, animals, fungi (such as mushrooms), and microorganisms such as bacteria and archaea. People who study biology are called biologists. Biology looks at how animals and other organisms behave and work, and what they are like.

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Sessile is a common term in biology; it is the opposite of motile. It means to stay in one place on the ground. It is used mainly for marine and freshwater species. They often have larvae which are motile, float or swim, and adult forms which are stationary. Many sessile forms can move from place if they need to. The key idea is that they choose a suitable place, and stay fixed as long as they can. They usually secrete some substance which holds them on.

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Sessile is a common term in biology; it is the opposite of motile. It means to stay in one place on the ground. It is used mainly for marine and freshwater species. They often have larvae which are motile, float or swim, and adult forms which are stationary.

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NASA engineers, seen here in mission control during Apollo 13, worked diligently to protect the lives of the astronauts on the mission.

Occupation

Names

Aerospace engineer
Engineer

Profession

Aeronautics, astronautics, science

Description

Competencies

Technical knowledge, management skills
(see also glossary of aerospace engineering)

Bachelor's Degree

Technology, science, space exploration, military

Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft. It has two major and overlapping branches: aeronautical engineering and astronautical engineering. Avionics engineering is similar, but deals with the electronics side of aerospace engineering.

"Aeronautical engineering" was the original term for the field. As flight technology advanced to include vehicles operating in outer space, the broader term "aerospace engineering" has come into use. Aerospace engineering, particularly the astronautics branch, is often colloquially referred to as "rocket science".

Flight vehicles are subjected to demanding conditions such as those caused by changes in atmospheric pressure and temperature, with structural loads applied upon vehicle components. Consequently, they are usually the products of various technological and engineering disciplines including aerodynamics, propulsion, avionics, materials science, structural analysis and manufacturing. The interaction between these technologies is known as aerospace engineering. Because of the complexity and number of disciplines involved, aerospace engineering is carried out by teams of engineers, each having their own specialized area of expertise.

Some of the elements of aerospace engineering are:

Radar cross-section - the study of vehicle signature apparent to remote sensing by radar.

Fluid mechanics - the study of fluid flow around objects. Specifically aerodynamics concerning the flow of air over bodies such as wings or through objects such as wind tunnels (see also lift and aeronautics).

Astrodynamics - the study of orbital mechanics including prediction of orbital elements when given a select few variables. While few schools in the United States teach this at the undergraduate level, several have graduate programs covering this topic (usually in conjunction with the Physics department of said college or university).

Statics and Dynamics (engineering mechanics) - the study of movement, forces, moments in mechanical systems.

Mathematics - in particular, calculus, differential equations, and linear algebra.

Electrotechnology - the study of electronics within engineering.

Propulsion - the energy to move a vehicle through the air (or in outer space) is provided by internal combustion engines, jet engines and turbomachinery, or rockets (see also propeller and spacecraft propulsion). A more recent addition to this module is electric propulsion and ion propulsion.

Control engineering - the study of mathematical modeling of the dynamic behavior of systems and designing them, usually using feedback signals, so that their dynamic behavior is desirable (stable, without large excursions, with minimum error). This applies to the dynamic behavior of aircraft, spacecraft, propulsion systems, and subsystems that exist on aerospace vehicles.

Aircraft structures - design of the physical configuration of the craft to withstand the forces encountered during flight. Aerospace engineering aims to keep structures lightweight and low-cost while maintaining structural integrity.

Materials science - related to structures, aerospace engineering also studies the materials of which the aerospace structures are to be built. New materials with very specific properties are invented, or existing ones are modified to improve their performance.

Solid mechanics - Closely related to material science is solid mechanics which deals with stress and strain analysis of the components of the vehicle. Nowadays there are several Finite Element programs such as MSC Patran/Nastran which aid engineers in the analytical process.

Aeroelasticity - the interaction of aerodynamic forces and structural flexibility, potentially causing flutter, divergence, etc.

Avionics - the design and programming of computer systems on board an aircraft or spacecraft and the simulation of systems.

Software - the specification, design, development, test, and implementation of computer software for aerospace applications, including flight software, ground control software, test & evaluation software, etc.

Risk and reliability - the study of risk and reliability assessment techniques and the mathematics involved in the quantitative methods.

Noise control - the study of the mechanics of sound transfer.

Aeroacoustics - the study of noise generation via either turbulent fluid motion or aerodynamic forces interacting with surfaces.

Flight testing - designing and executing flight test programs in order to gather and analyze performance and handling qualities data in order to determine if an aircraft meets its design and performance goals and certification requirements.

Images for kids

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NASA engineers, seen here in mission control during Apollo 13, worked diligently to protect the lives of the astronauts on the mission. Occupation Names Aerospace engineer Engineer Profession Aeronautics, astronautics, science Description Competencies Technical knowledge, management skills (see also glossary of aerospace engineering) Bachelor's Degree Technology, science, space exploration, military Aerospace engineering is the primary field of engineering concerned with the development of aircraft and spacecraft.

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Fighter aircraft are fixed-wing military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air superiority of the battlespace. Domination of the airspace above a battlefield permits bombers and attack aircraft to engage in tactical and strategic bombing of enemy targets.

The key performance features of a fighter include not only its firepower but also its high speed and maneuverability relative to the target aircraft. The success or failure of a combatant's efforts to gain air superiority hinges on several factors including the skill of its pilots, the tactical soundness of its doctrine for deploying its fighters, and the numbers and performance of those fighters.

Many modern fighter aircraft also have secondary capabilities such as ground attack and some types, such as fighter-bombers, are designed from the outset for dual roles. Other fighter designs are highly specialized while still filling the main air superiority role, and these include the interceptor, heavy fighter, and night fighter.

Since World War I, achieving and maintaining air superiority has been considered essential for victory in conventional warfare.

Fighters continued to be developed throughout World War I, to deny enemy aircraft and dirigibles the ability to gather information by reconnaissance over the battlefield. Early fighters were very small and lightly armed by later standards, and most were biplanes built with a wooden frame covered with fabric, and a maximum airspeed of about 100 mph (160 km/h). As control of the airspace over armies became increasingly important, all of the major powers developed fighters to support their military operations. Between the wars, wood was largely replaced in part or whole by metal tubing, and finally aluminum stressed skin structures (monocoque) began to predominate.

By World War II, most fighters were all-metal monoplanes armed with batteries of machine guns or cannons and some were capable of speeds approaching 400 mph (640 km/h). Most fighters up to this point had one engine, but a number of twin-engine fighters were built; however they were found to be outmatched against single-engine fighters and were relegated to other tasks, such as night fighters equipped with primitive radar sets.

By the end of the war, turbojet engines were replacing piston engines as the means of propulsion, further increasing aircraft speed. Since the weight of the turbojet engine was far less than a piston engine, having two engines was no longer a handicap and one or two were used, depending on requirements. This in turn required the development of ejection seats so the pilot could escape, and G-suits to counter the much greater forces being applied to the pilot during maneuvers.

In the 1950s, radar was fitted to day fighters, since due to ever increasing air-to-air weapon ranges, pilots could no longer see far enough ahead to prepare for the opposition. Subsequently, radar capabilities grew enormously and are now the primary method of target acquisition. Wings were made thinner and swept back to reduce transonic drag, which required new manufacturing methods to obtain sufficient strength. Skins were no longer sheet metal riveted to a structure, but milled from large slabs of alloy. The sound barrier was broken, and after a few false starts due to required changes in controls, speeds quickly reached Mach 2, past which aircraft cannot maneuver sufficiently to avoid attack.

Air-to-air missiles largely replaced guns and rockets in the early 1960s since both were believed unusable at the speeds being attained, however the Vietnam War showed that guns still had a role to play, and most fighters built since then are fitted with cannon (typically between 20 and 30 mm (0.79 and 1.18 in) in caliber) in addition to missiles. Most modern combat aircraft can carry at least a pair of air-to-air missiles.

In the 1970s, turbofans replaced turbojets, improving fuel economy enough that the last piston engine support aircraft could be replaced with jets, making multi-role combat aircraft possible. Honeycomb structures began to replace milled structures, and the first composite components began to appear on components subjected to little stress.

With the steady improvements in computers, defensive systems have become increasingly efficient. To counter this, stealth technologies have been pursued by the United States, Russia, India and China. The first step was to find ways to reduce the aircraft's reflectivity to radar waves by burying the engines, eliminating sharp corners and diverting any reflections away from the radar sets of opposing forces. Various materials were found to absorb the energy from radar waves, and were incorporated into special finishes that have since found widespread application. Composite structures have become widespread, including major structural components, and have helped to counterbalance the steady increases in aircraft weight-most modern fighters are larger and heavier than World War II medium bombers.

Because of the importance of air superiority, since the early days of aerial combat armed forces have constantly competed to develop technologically superior fighters and to deploy these fighters in greater numbers, and fielding a viable fighter fleet consumes a substantial proportion of the defense budgets of modern armed forces.

The global combat aircraft market was worth $45.75 billion in 2017 and is projected by Frost & Sullivan at $47.2 billion in 2026: 35% modernization programs and 65% aircraft purchases, dominated by the Lockheed Martin F-35 with 3,000 deliveries over 20 years.

Classification

A fighter aircraft is primarily designed for air-to-air combat. A given type may be designed for specific combat conditions, and in some cases for additional roles such as air-to-ground fighting. Historically the British Royal Flying Corps and Royal Air Force referred to them as "scouts" until the early 1920s, while the U.S. Army called them "pursuit" aircraft until the late 1940s. The UK changed to calling them fighters in the 1920s, while the US Army did so in the 1940s. A short-range fighter designed to defend against incoming enemy aircraft is known as an interceptor.

Recognized classes of fighter include:

Of these, the Fighter-bomber, reconnaissance fighter and strike fighter classes are dual-role, possessing qualities of the fighter alongside some other battlefield role. Some fighter designs may be developed in variants performing other roles entirely, such as ground attack or unarmed reconnaissance. This may be for political or national security reasons, for advertising purposes, or other reasons.

The Sopwith Camel and other "fighting scouts" of World War I performed a great deal of ground-attack work. In World War II, the USAAF and RAF often favored fighters over dedicated light bombers or dive bombers, and types such as the Republic P-47 Thunderbolt and Hawker Hurricane that were no longer competitive as aerial combat fighters were relegated to ground attack. Several aircraft, such as the F-111 and F-117, have received fighter designations though they had no fighter capability due to political or other reasons. The F-111B variant was originally intended for a fighter role with the U.S. Navy, but it was canceled. This blurring follows the use of fighters from their earliest days for "attack" or "strike" operations against ground targets by means of strafing or dropping small bombs and incendiaries. Versatile multi role fighter-bombers such as the McDonnell Douglas F/A-18 Hornet are a less expensive option than having a range of specialized aircraft types.

Some of the most expensive fighters such as the US Grumman F-14 Tomcat, McDonnell Douglas F-15 Eagle, Lockheed Martin F-22 Raptor and Russian Sukhoi Su-27 were employed as all-weather interceptors as well as air superiority fighter aircraft, while commonly developing air-to-ground roles late in their careers. An interceptor is generally an aircraft intended to target (or intercept) bombers and so often trades maneuverability for climb rate.

As a part of military nomenclature, a letter is often assigned to various types of aircraft to indicate their use, along with a number to indicate the specific aircraft. The letters used to designate a fighter differ in various countries. In the English-speaking world, "F" is often now used to indicate a fighter (e.g. Lockheed Martin F-35 Lightning II or Supermarine Spitfire F.22), though "P" used to be used in the US for pursuit (e.g. Curtiss P-40 Warhawk), a translation of the French "C" ( Dewoitine D.520 C.1) for Chasseur while in Russia "I" was used for Istrebitel, or exterminator (Polikarpov I-16).

Fighters were typically armed with guns only for air to air combat up through the late 1950s, though unguided rockets for mostly air to ground use and limited air to air use were deployed in WWII. From the late 1950s forward guided missiles came into use for air to air combat. Throughout this history fighters which by surprise or maneuver attain a good firing position have achieved the kill about one third to one half the time, no matter what weapons were carried. The only major historic exception to this has been the low effectiveness shown by guided missiles in the first one to two decades of their existence.

From WWI to the present, fighter aircraft have featured machine guns and automatic cannons as weapons, and they are still considered as essential back-up weapons today. The power of air-to-air guns has increased greatly over time, and has kept them relevant in the guided missile era. In WWI two rifle (approximately 0.30) caliber machine guns was the typical armament, producing a weight of fire of about 0.4 kg (0.88 lb) per second. In WWII rifle caliber machine guns also remained common, though usually in larger numbers or supplemented with much heavier 0.50 caliber machine guns or cannons. The standard WWII American fighter armament of six 0.50-cal (12.7mm) machine guns fired a bullet weight of approximately 3.7 kg/sec (8.1 lbs/sec), at a muzzle velocity of 856 m/s (2,810 ft/s). British and German aircraft tended to use a mix of machine guns and autocannon, the latter firing explosive projectiles. Later British fighters were exclusively cannon-armed, the US were not able to produce a reliable cannon in high numbers and most fighters remained equipped only with heavy machine guns despite the US Navy pressing for a change to 20mm.

Post war 20-30 mm revolver cannon and rotary cannon were introduced. The modern M61 Vulcan 20 mm rotary cannon that is standard on current American fighters fires a projectile weight of about 10 kg/s (22 lb/s), nearly three times that of six 0.50-cal machine guns, with higher velocity of 1,052 m/s (3450 ft/s) supporting a flatter trajectory, and with exploding projectiles. Modern fighter gun systems also feature ranging radar and lead computing electronic gun sights to ease the problem of aim point to compensate for projectile drop and time of flight (target lead) in the complex three dimensional maneuvering of air-to-air combat. However, getting in position to use the guns is still a challenge. The range of guns is longer than in the past but still quite limited compared to missiles, with modern gun systems having a maximum effective range of approximately 1,000 meters. High probability of kill also requires firing to usually occur from the rear hemisphere of the target. Despite these limits, when pilots are well trained in air-to-air gunnery and these conditions are satisfied, gun systems are tactically effective and highly cost efficient. The cost of a gun firing pass is far less than firing a missile, and the projectiles are not subject to the thermal and electronic countermeasures than can sometimes defeat missiles. When the enemy can be approached to within gun range, the lethality of guns is approximately a 25% to 50% chance of "kill per firing pass".

The range limitations of guns, and the desire to overcome large variations in fighter pilot skill and thus achieve higher force effectiveness, led to the development of the guided air-to-air missile. There are two main variations, heat-seeking (infrared homing), and radar guided. Radar missiles are typically several times heavier and more expensive than heat-seekers, but with longer range, greater destructive power, and ability to track through clouds.

The highly successful AIM-9 Sidewinder heat-seeking (infrared homing) short-range missile was developed by the United States Navy in the 1950s. These small missiles are easily carried by lighter fighters, and provide effective ranges of approximately 10 to 35 km (~6 to 22 miles). Beginning with the AIM-9L in 1977, subsequent versions of Sidewinder have added all-aspect capability, the ability to use the lower heat of air to skin friction on the target aircraft to track from the front and sides. The latest (2003 service entry) AIM-9X also features "off-boresight" and "lock on after launch" capabilities, which allow the pilot to make a quick launch of a missile to track a target anywhere within the pilot's vision. The AIM-9X development cost was U.S. $3 billion in mid to late 1990s dollars, and 2015 per unit procurement cost is $0.6 million each. The missile weighs 85.3 kg (188 lbs), and has a maximum range of 35 km (22 miles) at higher altitudes. Like most air-to-air missiles, lower altitude range can be as limited as only about one third of maximum due to higher drag and less ability to coast downward.

The effectiveness of infrared homing missiles was only 7% early in the Vietnam War, but improved to approximately 15%-40% over the course of the war. The AIM-4 Falcon used by the USAF had kill rates of approximately 7% and was considered a failure. The AIM-9B Sidewinder introduced later achieved 15% kill rates, and the further improved AIM-9D and J models reached 19%. The AIM-9G used in the last year of the Vietnam air war achieved 40%. Israel used almost totally guns in the 1967 Six-Day War, achieving 60 kills and 10 losses. However, Israel made much more use of steadily improving heat-seeking missiles in the 1973 Yom Kippur War. In this extensive conflict Israel scored 171 of 261 total kills with heat-seeking missiles (65.5%), 5 kills with radar guided missiles (1.9%), and 85 kills with guns (32.6%). The AIM-9L Sidewinder scored 19 kills out of 26 fired missiles (73%) in the 1982 Falklands War. But, in a conflict against opponents using thermal countermeasures, the United States only scored 11 kills out of 48 fired (Pk = 23%) with the follow-on AIM-9M in the 1991 Gulf War.

Radar guided missiles fall into two main missile guidance types. In the historically more common semi-active radar homing case the missile homes in on radar signals transmitted from launching aircraft and reflected from the target. This has the disadvantage that the firing aircraft must maintain radar lock on the target and is thus less free to maneuver and more vulnerable to attack. A widely deployed missile of this type was the AIM-7 Sparrow, which entered service in 1954 and was produced in improving versions until 1997. In more advanced active radar homing the missile is guided to the vicinity of the target by internal data on its projected position, and then "goes active" with an internally carried small radar system to conduct terminal guidance to the target. This eliminates the requirement for the firing aircraft to maintain radar lock, and thus greatly reduces risk. A prominent example is the AIM-120 AMRAAM, which was first fielded in 1991 as the AIM-7 replacement, and which has no firm retirement date as of 2016. The current AIM-120D version has a maximum high altitude range of greater than 160 km (>99 miles), and cost approximately $2.4 million each (2016). As is typical with most other missiles, range at lower altitude may be as little as one third that of high altitude.

In the Vietnam air war radar missile kill reliability was approximately 10% at shorter ranges, and even worse at longer ranges due to reduced radar return and greater time for the target aircraft to detect the incoming missile and take evasive action. At one point in the Vietnam war, the U.S. Navy fired 50 AIM-7 Sparrow radar guided missiles in a row without a hit. Between 1958 and 1982 in five wars there were 2,014 combined heat-seeking and radar guided missile firings by fighter pilots engaged in air-to-air combat, achieving 528 kills, of which 76 were radar missile kills, for a combined effectiveness of 26%. However, only four of the 76 radar missile kills were in the beyond-visual-range mode intended to be the strength of radar guided missiles. The United States invested over $10 billion in air-to-air radar missile technology from the 1950s to the early 1970s. Amortized over actual kills achieved by the U.S. and its allies, each radar guided missile kill thus cost over $130 million. The defeated enemy aircraft were for the most part older MiG-17s, −19s, and −21s, with new cost of $0.3 million to $3 million each. Thus, the radar missile investment over that period far exceeded the value of enemy aircraft destroyed, and furthermore had very little of the intended BVR effectiveness.

However, continuing heavy development investment and rapidly advancing electronic technology led to significant improvement in radar missile reliabilities from the late 1970s onward. Radar guided missiles achieved 75% Pk (9 kills out of 12 shots) in operations in the Gulf War in 1991. The percentage of kills achieved by radar guided missiles also surpassed 50% of total kills for the first time by 1991. Since 1991, 20 of 61 kills worldwide have been beyond-visual-range using radar missiles. Discounting an accidental friendly fire kill, in operational use the AIM-120D (the current main American radar guided missile) has achieved 9 kills out of 16 shots for a 56% Pk. Six of these kills were BVR, out of 13 shots, for a 46% BVR Pk. Though all these kills were against less capable opponents who were not equipped with operating radar, electronic countermeasures, or a comparable weapon themselves, the BVR Pk was a significant improvement from earlier eras. However, a current concern is electronic countermeasures to radar missiles, which are thought to be reducing the effectiveness of the AIM-120D. Some experts believe that as of 2016 the European Meteor missile, the Russian R-37M, and the Chinese PL-15 are more resistant to countermeasures and more effective than the AIM-120D.

Now that higher reliabilities have been achieved, both types of missiles allow the fighter pilot to often avoid the risk of the short-range dogfight, where only the more experienced and skilled fighter pilots tend to prevail, and where even the finest fighter pilot can simply get unlucky. Taking maximum advantage of complicated missile parameters in both attack and defense against competent opponents does take considerable experience and skill, but against surprised opponents lacking comparable capability and countermeasures, air-to-air missile warfare is relatively simple. By partially automating air-to-air combat and reducing reliance on gun kills mostly achieved by only a small expert fraction of fighter pilots, air-to-air missiles now serve as highly effective force multipliers.

Modern fighters

2000s-2020s: Fifth-generation

Currently the cutting edge of fighter design, fifth-generation fighters are designed from the start to operate in a network-centric combat environment. They have multifunction AESA radars with high-bandwidth, low-probability of intercept (LPI) data transmission capabilities.

thermoset and thermoplastic materials, advanced composites, conformal sensors, heat-resistant coatings, low-observable wire meshes to cover intake and cooling vents, heat ablating tiles on the exhaust troughs (seen on the Northrop YF-23), and coating internal and external metal areas with radar-absorbent materials and paint (RAM/RAP) are used for these fighters.

Such aircraft are sophisticated and expensive. The fifth generation was ushered in by the Lockheed Martin/Boeing F-22 Raptor in late 2005. The U.S. Air Force originally planned to acquire 650 F-22s, but now only 187 will be built. As a result, its unit flyaway cost (FAC) is around US$150 million. To spread the development costs - and production base - more broadly, the Joint Strike Fighter (JSF) program enrolls eight other countries as cost- and risk-sharing partners. Altogether, the nine partner nations anticipate procuring over 3,000 Lockheed Martin F-35 Lightning II fighters at an anticipated average FAC of $80-85 million. The F-35, however, is designed to be a family of three aircraft, a conventional take-off and landing (CTOL) fighter, a short take-off and vertical landing (STOVL) fighter, and a Catapult Assisted Take Off But Arrested Recovery (CATOBAR) fighter, each of which has a different unit price and slightly varying specifications in terms of fuel capacity (and therefore range), size and payload.

Other countries have initiated fifth-generation fighter development projects. In December 2010, it was discovered that China is developing the 5th generation fighter Chengdu J-20. The J-20 took its maiden flight in January 2011. The Shenyang FC-31 took its maiden flight on 31 October 2012, and developed a carrier-based version based on Chinese aircraft carriers. United Aircraft Corporation with Russia's Mikoyan LMFS and Sukhoi Su-75 Checkmate plan, Sukhoi Su-57 became the first fifth-generation fighter jets in service with the Russian Aerospace Forces on 2020, and launch missiles in the Russo-Ukrainian War in 2022. Japan is exploring its technical feasibility to produce fifth-generation fighters. India is developing the Advanced Medium Combat Aircraft (AMCA), a medium weight stealth fighter jet designated to enter into serial production by late 2030s. India also had initiated a joint fifth generation heavy fighter with Russia called the FGFA. As of 2018 May, the project is suspected to have not yielded desired progress or results for India and has been put on hold or dropped altogether. Other countries considering fielding an indigenous or semi-indigenous advanced fifth generation aircraft include South Korea, Sweden, Turkey and Pakistan.

2020s-present: Sixth-generation

As of November 2018, France, Germany, China, Japan, Russia, the United Kingdom and the United States have announced the development of a sixth-generation aircraft program.

France and Germany will develop a joint sixth-generation fighter to replace their current fleet of Dassault Rafales, Eurofighter Typhoons, and Panavia Tornados by 2035. The overall development will be led by a collaboration of Dassault and Airbus, while the engines will reportedly be jointly developed by Safran and MTU Aero Engines. Thales and MBDA are also seeking a stake in the project. Spain is reportedly planning to join the program in the later stages and is expected to sign a letter of intent in early 2019.

Currently at the concept stage, the first sixth-generation jet fighter is expected to enter service in the United States Navy in 2025-30 period. The USAF seeks a new fighter for the 2030-50 period named the "Next Generation Tactical Aircraft" ("Next Gen TACAIR"). The US Navy looks to replace its F/A-18E/F Super Hornets beginning in 2025 with the Next Generation Air Dominance air superiority fighter.

The United Kingdom's proposed stealth fighter is being developed by a European consortium called Team Tempest, consisting of BAE Systems, Rolls-Royce, Leonardo S.p.A. and MBDA. The aircraft is intended to enter service in 2035.

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Fighter aircraft are fixed-wing military aircraft designed primarily for air-to-air combat. In military conflict, the role of fighter aircraft is to establish air superiority of the battlespace. Domination of the airspace above a battlefield permits bombers and attack aircraft to engage in tactical and strategic bombing of enemy targets.

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Big aeroplanes for transporting people are called airliners. Airliners fly at more than 850 km/h (530 mph). Less than 100 years ago, the quickest ships needed more than seven days to travel across the Atlantic Ocean because it is 4,800 km (3,000 miles) wide.

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Fun Kids - the UK's children's radio station

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1. Roblox has been around since 2006

Roblox has been around since 2006 - making it 15-years-old!

2. Roblox was created by David Baszucki

Roblox was created by David Baszucki, the idea came from a 2D physics simulator he made.

3. The game was originally called Dynablocks

The game was originally called Dynablocks! We think Roblox is a much better name!

4. The currency in Roblox is called Robux

The currency in Roblox is called Robux.

Currency is something you use to buy things with, for example in the UK we use the Great British Pound (£) to purchase things from shops etc - but in the world of Roblox they use Robux (R$).

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5. Roblox is free to play

Roblox is free to play. Unlike some games where you have to pay to play, you can enjoy Roblox for free.

6. You can make your games on Roblox

You can make your games on Roblox. The most popular games are played by up to 100,000 people simultaneously!

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7. Nearly a quarter of British children play Roblox

Nearly a quarter of children play Roblox! An annual survey of 20,000 British children, suggested that 24% of 10- to 12-year-olds played Roblox.

8. Pet Simulator Adopt Me! Is the most popular Roblox game of all time

Pet simulator Adopt Me! Is the most popular Roblox game of all time, with over 23.78 billion visits as of July 2021!

That's 3 times the population of the whole entire world!

9. There's a Roblox University

There's a Roblox University!

For children who are serious about building games and various elements inside, Roblox has published a series of videos on YouTube which they have dubbed Roblox University.

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10. You can use Roblox on multiple platforms

You can use Roblox on multiple platforms. Roblox is available on iOS, Android, Amazon's App Store, Xbox One, and Windows 10, and Mac.

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Top 10 Facts About Roblox - Fun Kids - the UK's children's radio station

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Roblox has been around since 2006 - making it 15-years-old! Roblox was created by David Baszucki, the idea came from a 2D physics simulator he made. The game was originally called Dynablocks! We think Roblox is a much better name! The currency in Roblox is called Robux.

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Roblox

Developer(s)
Roblox Corporation

Publisher(s)

Roblox Corporation

Director(s)

David Baszucki,
Erik Cassel

Platform(s)

Windows, macOS, iOS, Android, Xbox One

Release date(s)

Windows
September 1, 2006
iOS
December 11, 2012
Android
July 16, 2014
Xbox One
November 20, 2015

Genre(s)

Game creation system, massively multiplayer online

Mode(s)

Single-player, multi-player

Roblox is an online game platform and game creation system developed by Roblox Corporation that allows users to program games and play games created by other users. Created by David Baszucki and Erik Cassel in 2004 and released in 2006, the platform hosts user-created games of multiple genres coded in the programming language Lua. For most of 's history, it was relatively small, both as a platform and a company. Roblox began to grow rapidly in the second half of the 2010s, and this growth has been accelerated by the COVID-19 pandemic.

Roblox is free to play, with in-game purchases available through a virtual currency called Robux. As of August 2020, Roblox had over 164 million monthly active users, including more than half of all American children under 16. Although Roblox has received generally positive reviews from critics, it has faced criticism for its moderation, microtransactions, and exploitative practices directed toward children.

Roblox Studio

Roblox allows players to create their own games using its proprietary engine, Roblox Studio, which can then be played by other users. Games (called "experiences" by the corporation) are made with an object-oriented & open-source programming language based on Lua, known as LuaU. Users are able to create purchasable content through one-time purchases, known as "game passes", as well as microtransactions which can be purchased more than once, known as "developer products" or "products". The majority of games produced using Roblox Studio are developed by minors, and a total of 20 million games a year are produced using it.

Items and currency

Roblox allows players to buy, sell, and create virtual items which can be used to decorate their virtual character that serves as their avatar on the platform. Clothes can be bought by anyone, but only players with a Premium membership can sell them. Only Roblox administrators can sell accessories, body parts, gear, and packages under the official Roblox user account; virtual hats and accessories can also be published by a select few users with past experience working with Roblox Corporation. There are several individuals who design items as a full-time job, with the highest-earning creators making over $100,000 a year off item sales. Items with a limited edition status can only be traded between or sold by users with a Roblox Premium membership.

Robux allows players to buy various items, and are obtained by purchase with real currency, from a recurring stipend given to members with premium membership, and from other players by producing and selling virtual content in Roblox. Prior to 2016, Roblox had another currency, Tix (short for "Tickets"), that was discontinued in April of that year. Robux acquired through the sale of user-generated content can be exchanged into real-world currency through the website's Developer Exchange system. There are a sizable amount of scams relating to Robux, largely revolving around automated messages promoting scam websites, scam games designed to appear to give out free Robux, and invalid Robux codes.

Roblox occasionally hosts real-life and virtual events. They have in the past hosted events such as BloxCon, which was a convention for ordinary players on the platform. Roblox operates annual Easter egg hunts, and also hosts an annual event called the "Bloxy Awards", an awards ceremony which also functions as a fundraiser. The 2020 edition of the Bloxy Awards, held virtually on the platform, drew 600,000 viewers. Roblox Corporation annually hosts the Roblox Developers Conference, a three-day invite-only event in San Francisco where top content creators on the site learn of upcoming changes to the platform. The company has also hosted similar events in London and Amsterdam.

Roblox occasionally engages in events to promote films, such as ones held to promote Wonder Woman 1984 and . In 2020, Roblox hosted its first virtual concert, which was compared by Rolling Stone to that of American rapper Travis Scott's virtual concert in Fortnite, during which American rapper Lil Nas X debuted his song "Holiday" to an audience of Roblox players. In 2021, Swedish singer Zara Larsson performed songs at a virtual party to celebrate her new album Poster Girl (Summer Edition). On September 17, 2021, a virtual concert by the American band Twenty One Pilots took place. In October 2021, Roblox partnered with Chipotle Mexican Grill to giveaway $1 million of burritos away to the first 30,000 people everyday as apart of Chipotle's Halloween Boorito promotion.

History and development

The beta version of Roblox was created by co-founders David Baszucki and Erik Cassel in 2004 under the name DynaBlocks. Baszucki started testing the first demos that year. In 2005, the company changed its name to Roblox, and it officially launched on September 1, 2006. In March 2007, Roblox became compliant with COPPA, with the addition of safe chat, a change that limited the communication ability of users under the age of 13 by restricting them to selecting predefined messages from a menu. In August, Roblox applied server improvements and released a premium membership service named "Builders Club". This paid membership feature was rebranded as Roblox Premium in September 2019.

In December 2011, Roblox held their first Hack Week, an annual event where Roblox developers work on outside-the-box ideas for new developments to present to the company. On December 11, 2012, an iOS version of Roblox was released, and on July 16, 2014, an Android version was released. On October 1, 2013, Roblox released its Developer Exchange program, allowing developers to exchange Robux earned from their games into real-world currencies.

On May 31, 2015, a feature called 'Smooth Terrain' was added, increasing the graphical fidelity of the terrain and changing the physics engine from a block-oriented style to a smoother and more realistic one. On November 20, Roblox was launched on Xbox One, with an initial selection of 15 games chosen by Roblox staff. New Roblox games for the Xbox One have to go through an approval process, and are subject to the Entertainment Software Ratings Board standards.

In April 2016, Roblox launched Roblox VR for Oculus Rift. At the time of release, more than ten million games were available in 3D. Around the same time period, the safe chat feature was removed and replaced by a system based on a whitelist with a set of acceptable words for users under 13 years old and a set of blacklisted words for other users. In June, the company launched a version compatible with Windows 10. While the game platform has had a presence on the PC since 2004, when its web version was created, this was the first time it was upgraded with a standalone launcher built for Windows.

Throughout 2017, Roblox engaged in a number of updates to its server technology, as the technology they were operating on until that point was out of date and led to frequent outages. Also in 2017, Roblox closed its official forums. In November 2018, the ability for a player to play as a "guest", without an account, which had been progressively restricted over the previous two years, was removed entirely. In July 2020, Roblox announced the creation of "Party Place", which functions as an online hangout. The feature was created using new technology that had been used during the 2020 Bloxy Awards, and was designed in response to the COVID-19 pandemic. Roblox was granted permission to release in China on December 3, 2020. In 2021, Roblox bought chat platform Guilded. In October 2021, Roblox experienced its longest downtime to date, with services being unavailable for three days.

Community and culture

Users of Roblox have been noted for their efforts against racism, with numerous regular users and co-founder Baszucki having declared their support for the George Floyd protests and Black Lives Matter. In August 2019, an investigation by NBC News revealed over 100 accounts linked to far-right and neo-Nazi groups. After being contacted about the accounts by NBC, Roblox moderators removed them.

Effects of the COVID-19 pandemic

The COVID-19 pandemic has affected Roblox in numerous ways. Due to quarantines imposed by the pandemic limiting social interaction, Roblox is being used as a way for children to communicate with each other. One of the most noted ways that this method of communication is being carried out is the phenomenon of birthday parties being held on the platform. COVID-19 has caused a substantial increase in both the platform's revenue and the number of players on it, in line with similar effects experienced by the majority of the gaming industry, as players forced to remain indoors due to COVID-19 lockdowns spent more time playing video games.

"Oof" sound effect

From its release to November 2020, Roblox's sound effect for when a character dies was an "oof" sound, which became a substantial part of the platform's reputation due to its status as a meme. The sound was originally produced by video game composer Tommy Tallarico for the 2000 video game Messiah, and he and Roblox entered into a copyright dispute. The dispute ended when Roblox agreed to pull the sound from their platform and replace it with another death sound, and Tallarico agreed to allow Roblox to release the sound again at a later date on its marketplace, which game developers on the platform would be able to purchase for a price of US$1.

In January 2017, toy fabricator Jazwares partnered with Roblox Corporation to produce toy minifigures based on user-generated content created by developers on the platform. The minifigures have limbs and joints similar to that of Lego minifigures, though they are about twice the size. The minifigures have limbs and accessories that are interchangeable. The sets included a code that was used to redeem virtual items, as well as blind boxes that contained random minifigures. In 2019, Roblox Corporation released a new line of toys, branded the "Roblox Desktop" series. On April 13, 2021, Roblox partnered with Hasbro to release Roblox themed Nerf guns and a Roblox themed edition.
List of Roblox games

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Roblox Developer(s) Roblox Corporation Publisher(s) Roblox Corporation Director(s) David Baszucki, Erik Cassel Platform(s) Windows, macOS, iOS, Android, Xbox One Release date(s) Windows September 1, 2006 iOS December 11, 2012 Android July 16, 2014 Xbox One November 20, 2015 Genre(s) Game creation system, massively multiplayer online Mode(s) Single-player, multi-player Roblox is an online game platform and game creation system developed by Roblox Corporation that allows users to program games and play games created by other users.

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Wheel gymnastics is a form of gymnastics which originated in Germany.

Wheel gymnasts do exercises in a large wheel known as the Rhönrad, gymnastics wheel, gym wheel, or German wheel.

There are three main categories of exercise in wheel gymnasts. They are: straight line, spiral, and vault.

While being a child, Otto Feick, the son of a blacksmith from Reichenbach, Germany, used to roll down a hill in two wagon tires which inspired him later to invent the wheel gymnastics between 1920-1922. The current wheel gymnastics obtained its final shape in 1974 with the introduction of the PVC coating. Now, it's a competitive sport practiced in Belgium, Denmark, Netherlands, Austria, Switzerland, Japan, and United States of America.

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Wheel gymnastics is a form of gymnastics which originated in Germany. Wheel gymnasts do exercises in a large wheel known as the Rhönrad, gymnastics wheel, gym wheel, or German wheel. There are three main categories of exercise in wheel gymnasts. They are: straight line, spiral, and vault.

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The balance beam is a rectangular artistic gymnastics apparatus, as well as the event performed using the apparatus. Both the apparatus and the event are sometimes simply referred to as "beam". The English abbreviation for the event in gymnastics scoring is BB. The beam is a small, thin beam which is typically raised from the floor on a leg or stand at both ends. The balance beam is only performed by female gymnasts. Beams are usually covered with leatherlike material, and are only 4 inches wide.

While learning new skills, gymnasts often work on floor beams that have the same dimensions and surface of regulation apparatus, but are set a very short distance from or on the ground. They may also work on medium beams, mini beams, road beams, or even lines on a mat.

Originally, the beam surface was plain polished wood. In earlier years, some gymnasts competed on a beam made of basketball-like material. However, this type of beam was eventually banned due to its extreme slipperiness. Since the 1980s, beams have been covered in leather or suede. In addition, they are now also sprung to accommodate the stress of high-difficulty tumbling and turns and poses.

Images for kids

Italian gymnast Lara Mori competes on the beam at the 2013 European Youth Olympic Festival.

Daniele Hypólito performing on the balance beam in 2007

Dorina Böczögő performing a one arm press hold during her mount, 2012.

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The balance beam is a rectangular artistic gymnastics apparatus, as well as the event performed using the apparatus. Both the apparatus and the event are sometimes simply referred to as "beam". The English abbreviation for the event in gymnastics scoring is BB.

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Rhythmic gymnastics (short:RG) is a sport in which individuals or teams of competitors (generally five) manipulate one or two apparatus: rope, hoop, ball, clubs, and ribbon. Rhythmic gymnastics is a sport that combines elements of ballet, gymnastics, dance, and apparatus manipulation. The victor is the participant who earns the most points, determined by a panel of judges, for leaps, balances, pirouettes, flexibilities, apparatus handling, execution, and artistic effect.

International competitions are split between Juniors, under sixteen by their year of birth; and Seniors, for women sixteen and over again by their year of birth. Gymnasts typically start training at a very young age and those at their peak are typically in their late teens or early twenties. The largest events in the sport are the Olympic Games, World Championships, and Grand-Prix Tournaments.

Rhythmic gymnastics is a type of gymnastics. People who do rhythmic gymnastics are called rhythmic gymnasts. In rhythmic gymnastics, there are different pieces of equipment that rhythmic gymnasts use while they do routines. They also do a group routine, which is a little bit different.

Rope is a piece of equipment that rhythmic gymnasts use. The length of the rope depends on how tall the gymnast using it is. They swing the rope, throw and catch the rope, make figure-eights, and more. They also leap and jump through the rope while they are holding it.

Hoop is used by rhythmic gymnasts too. The hoop is made of wood. Gymnasts toss it and catch it, spin it, swing it, and roll it. Gymnasts doing routines with the hoop are really exciting because gymnasts throw it very high and then catch it many different ways.

Another one of the pieces of equipment used by rhythmic gymnasts is the ball. The ball is made with rubber or plastic that is soft. Gymnasts throw balls and catch them, bounce and roll them, balance the ball on their hand, and do waves and circles.

The clubs are another piece of equipment that rhythmic gymnasts use. The clubs look a kind of like bowling pins or bottles. They are made of wood or plastic. Gymnasts use the clubs to do circles, throws, swings, plus tapping.

The group routine is a little bit different. It's not a piece of equipment; it's just a different kind of routine. In the group event, five rhythmic gymnasts will do a routine together. The gymnasts have to work together to make the routine work. In a group routine, gymnasts will exchange whatever equipment they are using with each other. Group routines are extremely exciting to watch!

Rhythmic gymnastics came from many different things, like ballet. It also came from the German way of using equipment and the Swedish way having freedom to work on rhythm.

Rhythmic gymnastics became official in 1963, and in 1964, the first competition happened. A gymnast from the Soviet Union named Ludmila Savinkova won.

The first time rhythmic gymnastics was in the Olympics was in 1984 in Los Angeles. That year, a Canadian gymnast called Lori Fung won.

Images for kids

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Rhythmic gymnastics (short:RG) is a sport in which individuals or teams of competitors (generally five) manipulate one or two apparatus: rope, hoop, ball, clubs, and ribbon. Rhythmic gymnastics is a sport that combines elements of ballet, gymnastics, dance, and apparatus manipulation.

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A vault is an apparatus that male and female gymnasts perform on. A vault is included in gymnastics competitions such as the olympics. The gymnasts first run before they flip on the vault. Either the male or female gymnast perform a flip in the air and land on the floor. When the gymnast lands on the floor, he or she has to be in balance.

Early forms of the vault were invented by German Friedrich Ludwig Jahn. The apparatus itself originated as a "horse", much like the pommel horse but without the handles. It was sometimes called a "vaulting horse". The horse was set up with its long side perpendicular to the run for women, and parallel for men. The vaulting horse was the apparatus used in the Olympics for over a century It began with the 1896 Summer Olympics and ending with the Gymnastics at the 2000 Summer Olympics.

Following a number of problems, International Gymnastics Federation (FIG) changed the apparatus. They did it for both safety reasons and for better acrobatics. The 2001 World Artistic Gymnastics Championships were the first international competition to make use of the "vaulting table". This was an apparatus made by Dutch gymnastics equipment company Janssen-Fritsen since the mid-1990s. It features a flat, larger, and more cushioned surface almost parallel to the floor. It slopes downward at the end closest to the springboard. Gymnasts nicknamed it the "tongue".

Images for kids

Original vaulting horse configuration (women)

A multiple-exposure image of a gymnast performing a vault (handspring double front salto tucked) during the 2012 Olympics.

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A vault is an apparatus that male and female gymnasts perform on. A vault is included in gymnastics competitions such as the olympics. The gymnasts first run before they flip on the vault. Either the male or female gymnast perform a flip in the air and land on the floor.

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Gymnastics is a sport which involves doing exercises which need strength, flexibility, balance and control. This may include running, jumping, tumbling, somersaulting, flipping and balancing.

In women's gymnastics, there are four activities: floor, uneven bars, balance beam, and vault. In men's gymnastics, there are six activities: floor exercise, parallel bars, high bar, pommel horse, vault, and rings.

Gymnastics is an Olympic sport.

Gymnastics began as a form of exercise in ancient Greece. It was one of the first sports in the Olympics. Originally, only men were allowed to compete in the Olympic Games, but there was another festival at which women competed, the Herean Games.

Forms of gymnastics

Artistic gymnastics

Artistic Gymnastics is usually divided into Men's and Women's Gymnastics. Men compete on six events: Floor Exercise, Pommel Horse, Still Rings, Vault, Parallel Bars, and Horizontal Bar, while women compete on four: Vault, Uneven Bars, Balance Beam, and Floor Exercise. In some countries, women at one time competed on the rings, high bar, and parallel bars (for example, in the 1950s in the USSR).

In 2006, FIG introduced a new points system for Artistic gymnastics in which scores are no longer limited to 10 points. The system is used in the US for elite level competition. Unlike the old code of points, there are two separate scores, an execution score and a difficulty score. In the previous system, the "execution score" was the only score. It was and still is out of 10.00, except for short exercises. During the gymnast's performance, the judges deduct this score only. A fall, on or off the event, is a 1.00 deduction, in elite level gymnastics. The introduction of the difficulty score is a significant change. The gymnast's difficulty score is based on what elements they perform and is subject to change if they do not perform or complete all the skills, or they do not connect a skill meant to be connected to another. Connection bonuses are where deviation happens most common between the intended and actual difficulty scores, as it can be difficult to connect multiple flight elements. It is very hard to connect skills if the first skill is not performed correctly. The new code of points allows the gymnasts to gain higher scores based on the difficulty of the skills they perform as well as their execution. There is no maximum score for difficulty, as it can keep increasing as the difficulty of the skills increase.

Artistic events for women

In the vaulting events, gymnasts sprint down a 25 metres (82 ft) runway, jump onto a springboard (or perform a roundoff or handspring entry onto a springboard), land momentarily inverted on the hands on the vaulting horse or vaulting table (pre-flight segment), then propel themselves forward or backward off that platform to a two-footed landing (post-flight segment). Every gymnast starts at a different point on the vault runway depending on their height and strength. The post-flight segment may include one or more multiple saltos, somersaults, or twisting movements. A round-off entry vault, called a Yurchenko, is the most common vault in the higher levels in gymnastics. When performing a Yurchenko, gymnasts "round off" so their hands are on the runway while their feet land on the springboard. From the roundoff position, the gymnast travels backwards and executes a back handspring so that the hands land on the vaulting table. The gymnast then blocks off the vaulting platform into various twisting and/or somersaulting combinations. The post-flight segment brings the gymnast to her feet. In the lower levels of gymnastics, the gymnasts do not perform this move. These gymnasts will jump onto the springboard with both feet at the same time and either do a front handspring onto the vault or a roundoff onto the vault.

In 2001, the traditional vaulting horse was replaced with a new apparatus, sometimes known as a tongue, horse or vaulting table. The new apparatus is more stable, wider, and longer than the older vaulting horse, approximately 1 m in length and 1 m in width, giving gymnasts a larger blocking surface. This apparatus is thus considered safer than the vaulting horse used in the past. With the addition of this new, safer vaulting table, gymnasts are attempting more difficult and dangerous vaults.

Uneven bars

On the uneven bars, the gymnast performs a timed routine on two parallel horizontal bars set at different heights. These bars are made of fiberglass covered in wood laminate, to prevent them from breaking. In the past, bars were made of wood, but the bars were prone to breaking, providing an incentive to switch to newer technologies. The width and height of the bars may be adjusted to the size needed by individual gymnasts. In the past, the uneven parallel bars were closer together. The bars have been moved increasingly further apart, allowing gymnasts to perform swinging, circling, transitional, and release moves that may pass over, under, and between the two bars. At the Elite level, movements must pass through the handstand. Gymnasts often mount the uneven bars using a springboard or a small mat. Chalk (MgCO ₃) and grips (a leather strip with holes for fingers to protect hands and improve performance) may be used by gymnasts performing this event. The chalk helps take the moisture out of gymnasts' hands to decrease friction and prevent rips (tears to the skin of the hands); dowel grips help gymnasts grip the bar.

Balance beam

The gymnast performs a choreographed routine of up to 90 seconds in length consisting of leaps, acrobatic skills, somersaults, turns and dance elements on a padded beam. The beam is 125 centimetres (4 ft 1 in) from the ground, 500 centimetres (16 ft 5 in) long, and 10 centimetres (3.9 in) wide. This stationary object can also be adjusted, to be raised higher or lower. The event requires balance, flexibility, grace, poise, and strength.

The event in gymnastics performed on floor is called floor exercise. The English abbreviation for the event in gymnastics scoring is FX. In the past, the floor exercise event was executed on the bare floor or mats such as wrestling mats. The floor event now occurs on a carpeted 12m × 12m square, usually consisting of hard foam over a layer of plywood, which is supported by springs generally called a "spring" floor. This provides a firm surface that provides extra bounce or spring when compressed, allowing gymnasts to achieve greater height and a softer landing after the composed skill. Gymnasts perform a choreographed routine up to 90 seconds in the floor exercise event; Depending on the level, they may choose their own, or, if known as a "compulsory gymnast," default music must be played. Levels three to six the music is the same for each levels along with the skills within the routine. However, recently, the levels have switched. Now, levels 6-10 are optional levels and they get to have custom routines made. In the optional levels (levels six to ten) there are skill requirements for the routine but the athlete is able to pick her own music without any words. The routine should consist of tumbling passes, series of jumps, leaps, dance elements, acrobatic skills, and turns, or pivots, on one foot. A gymnast can perform up to four tumbling passes that usually includes at least one flight element without hand support. Each level of gymnastics requires the athlete to perform a different number of tumbling passes. In level 7 in the United States, a gymnast is required to do 2-3, and in levels 8-10, at least 3-4 tumbling passes are required.

Artistic events for men

Male gymnasts also perform on a 12meter x 12meter spring floor. A series of tumbling passes are performed to demonstrate flexibility, strength, and balance. Strength skills include circles, scales, and press handstands. Men's floor routines usually have multiple passes that have to total between 60-70 seconds and are performed without music, unlike the women's event. Rules require that male gymnasts touch each corner of the floor at least once during their routine.

Pommel horse

A typical pommel horse exercise involves both single leg and double leg work. Single leg skills are generally found in the form of scissors, an element often done on the pommels. Double leg work however, is the main staple of this event. The gymnast swings both legs in a circular motion (clockwise or counterclockwise depending on preference) and performs such skills on all parts of the apparatus. To make the exercise more challenging, gymnasts will often include variations on a typical circling skill by turning (moores and spindles) or by straddling their legs (Flares). Routines end when the gymnast performs a dismount, either by swinging his body over the horse, or landing after a handstand variation.

Still rings

The rings are suspended on wire cable from a point 5.75 meters from the floor. The gymnasts must perform a routine demonstrating balance, strength, power, and dynamic motion while preventing the rings themselves from swinging. At least one static strength move is required, but some gymnasts may include two or three. A routine ends with a dismount.

Gymnasts sprint down a runway, which is a maximum of 25 meters in length, before hurdling onto a spring board. The gymnast is allowed to choose where they start on the runway. The body position is maintained while "punching" (blocking using only a shoulder movement) the vaulting platform. The gymnast then rotates to a standing position. In advanced gymnastics, multiple twists and somersaults may be added before landing. Successful vaults depend on the speed of the run, the length of the hurdle, the power the gymnast generates from the legs and shoulder girdle, the kinesthetic awareness in the air, how well they stuck the landing and the speed of rotation in the case of more difficult and complex vaults.

Parallel bars

Men perform on two bars executing a series of swings, balances, and releases that require great strength and coordination. The width between the bars is adjustable dependent upon the actual needs of the gymnasts and usually 2m high,.

Horizontal bar

A 2.8 cm thick steel or fiberglass bar raised 2.5 m above the landing area is all the gymnast has to hold onto as he performs giant swings or giants (forward or backward revolutions around the bar in the handstand position), release skills, twists, and changes of direction. By using all of the momentum from giants and then releasing at the proper point, enough height can be achieved for spectacular dismounts, such as a triple-back salto. Leather grips are usually used to help maintain a grip on the bar.

As with women, male gymnasts are also judged on all of their events including their execution, degree of difficulty, and overall presentation skills.

Scoring (code of points)

A gymnast's score comes from deductions taken from their start value. The start value of a routine is based on the difficulty of the elements the gymnast attempts and whether or not the gymnast meets composition requirements. The composition requirements are different for each apparatus; this score is called the D score. Deductions in execution and artistry are taken from a maximum of 10.0. This score is called the E score. The final score is calculated by taking deductions from the E score, and adding the result to the D score. Since 2007, the scoring system has changed by adding bonus plus the execution and then adding those two together to get the final score.

In a tumbling pass, dismount or vault, landing is the final phase, following take off and flight This is a critical skill in terms of execution in competition scores, general performance, and injury occurrence. Without the necessary magnitude of energy dissipation during impact, the risk of sustaining injuries during somersaulting increases. These injuries commonly occur at the lower extremities such as: cartilage lesions, ligament tears, and bone bruises/fractures. To avoid such injuries, and to receive a high performance score, proper technique must be used by the gymnast. "The subsequent ground contact or impact landing phase must be achieved using a safe, aesthetic and well-executed double foot landing." A successful landing in gymnastics is classified as soft, meaning the knee and hip joints are at greater than 63 degrees of flexion.

A higher flight phase results in a higher vertical ground reaction force. Vertical ground reaction force represents external force which the gymnasts have to overcome with their muscle force and affects the gymnasts' linear and angular momentum. Another important variable that affects linear and angular momentum is time the landing takes. Gymnasts can decrease the impact force by increasing the time taken to perform the landing. Gymnasts can achieve this by increasing hip, knee and ankle amplitude.

Rhythmic gymnastics

According to FIG rules, only women compete in rhythmic gymnastics. This is a sport that combines elements of ballet, gymnastics, dance, and apparatus manipulation. The sport involves the performance of five separate routines with the use of five apparatus; ball, ribbon, hoop, clubs, rope-on a floor area, with a much greater emphasis on the aesthetic rather than the acrobatic. There are also group routines consisting of 5 gymnasts and 5 apparatuses of their choice. Rhythmic routines are scored out of a possible 30 points; the score for artistry (choreography and music) is averaged with the score for difficulty of the moves and then added to the score for execution.

International competitions are split between Juniors, under sixteen by their year of birth; and Seniors, for women sixteen and over again by their year of birth. Gymnasts in Russia and Europe typically start training at a very young age and those at their peak are typically in their late teens (15-19) or early twenties. The largest events in the sport are the Olympic Games, World Championships, European Championships, World Cup and Grand-Prix Series. The first World Championships were held in 1963 with its first appearance at the Olympics in 1984.

Rhythmic gymnastics apparatus

Trampolining and tumbling

Trampolining

Trampolining and tumbling consists of four events, individual and synchronized trampoline, double mini trampoline, and tumbling (also known as power tumbling or rod floor). Since 2000, individual trampoline has been included in the Olympic Games. The first World Championships were held in 1964.

Individual trampoline

Individual routines in trampolining involve a build-up phase during which the gymnast jumps repeatedly to achieve height, followed by a sequence of ten bounces without pause during which the gymnast performs a sequence of aerial skills. Routines are marked out of a maximum score of 10 points. Additional points (with no maximum at the highest levels of competition) can be earned depending on the difficulty of the moves and the length of time taken to complete the ten skills which is an indication of the average height of the jumps. In high level competitions, there are two preliminary routines, one which has only two moves scored for difficulty and one where the athlete is free to perform any routine. This is followed by a final routine which is optional. Some competitions restart the score from zero for the finals, other add the final score to the preliminary results.

Synchronized trampoline

Synchronized trampoline is similar except that both competitors must perform the routine together and marks are awarded for synchronization as well as the form and difficulty of the moves.

Double-mini trampoline

Double mini trampoline involves a smaller trampoline with a run-up, two scoring moves are performed per routine. Moves cannot be repeated in the same order on the double-mini during a competition. Skills can be repeated if a skill is competed as a mounter in one routine and a dismount in another. The scores are marked in a similar manner to individual trampoline.

In tumbling, athletes perform an explosive series of flips and twists down a sprung tumbling track. Scoring is similar to trampolining. Tumbling was originally contested as one of the events in Men's Artistic Gymnastics at the 1932 Summer Olympics, and in 1955 and 1959 at the Pan American Games. From 1974 to 1998 it was included as an event for both genders at the Acrobatic Gymnastics World Championships. The event has also been contested since 1976 at the Trampoline World Championships. Since the recognition of Trampoline and Acrobatic Gymnastics as FIG disciplines in 1999, official Tumbling competitions are only allowed as an event in Trampoline gymnastics meets.

Acrobatic gymnastics

Acrobatic gymnastics (formerly Sport Acrobatics), often referred to as "Acro" if involved with the sport, acrobatic sports or simply sports acro, is a group gymnastic discipline for both men and women. Acrobats in groups of two, three and four perform routines with the heads, hands and feet of their partners. They may, subject to regulations (e.g. no lyrics), pick their own music.

Most competitions require a balance and dynamic routine for each event, though some will do a single mixed event.

Aerobic gymnastics

Aerobic gymnastics (formally Sport Aerobics) involves the performance of routines by individuals, pairs, trios or groups up to 6 people, emphasizing strength, flexibility, and aerobic fitness rather than acrobatic or balance skills. Routines are performed for all individuals on a 7x7m floor and also for 12-14 and 15-17 trios and mixed pairs. From 2009, all senior trios and mixed pairs were required to be on the larger floor (10x10m), all groups also perform on this floor. Routines generally last 60-90 seconds depending on age of participant and routine category. The World Championships have been held since 1995.

The events consist of:

On January 28, 2018 Parkour was given the go ahead to begin development as a FIG sport. The FIG is planning to run World Cup competitions from 2018 onwards and will hold the first Parkour World Championships in 2020.

The events consist of:

In rhythmic gymnastics, gymnasts perform with ribbons, rope, ball, hoop and clubs. Usually, only women do rhythmic gymnastics because they are more flexible then boys

Images for kids

Early 20th-century gymnastics in Stockholm, Sweden

In Spanish: Gimnasia para niños

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Dolphins are small-toothed cetaceans easily recognizable by their curved mouths, which give them a permanent "smile." There are 36 dolphin species, found in every ocean. Most dolphins are marine and live in the ocean or brackish waters along coastlines. There are a few species, however, like the South Asian river dolphin and the Amazon river dolphin, or boto, that live in freshwater streams and rivers.

The largest dolphin, the orca, can grow to be over 30 feet long. The smallest, the Maui dolphin, is just five feet long.

Dolphins feed chiefly on fish and squid, which they track using echolocation, a built-in sonar that bounces sound waves off prey and reveals information like its location, size, and shape. An echolocating bottlenose dolphin can make up to a thousand clicking noises per second.

Behavior and reproduction

Living in pods that can number a dozen or more, dolphins are intensely social mammals that communicate with squeaks, whistles, and clicks. Whether dolphins have language, as humans do, is a topic that scientists have debated for decades.

As mammals, they have warm blood and nurse their young. Dolphins have more than one mate, and generally produce a single offspring that will stay with the mother for up to six years, depending on the species.

Dolphins are graceful, sleek swimmers that can reach speeds of more than 18 miles an hour. They are also playful and often frolic in a boat's wake, leaping out of the water-possibly for fun, to communicate, or even shed pesky parasites.

Threats

For centuries, people have hunted dolphins for their meat and blubber. Today, their main threat comes from being caught accidentally in commercial fishing nets. Dolphins must rise regularly to the surface to breathe-becoming entangled in nets prevents this, leading to drowning. For maine dolphins, warming ocean temperatures because of climate change have caused some of their primary food sources to move into deeper, cooler water. Furthermore, marine heatwaves, also caused by climate change, appear to have a negative affect on dolphins' reproductive rates and ability to survive.

In addition to hunting and entanglement in fishing gear, freshwater dolphins face the additional threat of dams fragmenting and degrading habitat.

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The 36 dolphin species share more than a few characteristics. Among them, the aquatic mammals look like they're smiling, and they seem to love to play.

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In our Ocean Facts for Kids you will learn about the oceans of the world. Did you know that the o ceans cover over 71% of the Earth's surface?

Today is World Oceans Day! Let us learn more about the fascinating oceans which are the most important source of life for all of us.

The World Oceans

There are five oceans covering the surface of our globe:

Read here fun and important facts about our oceans everybody should know.

Pacific Ocean

The Pacific Ocean is the biggest ocean of the world and covers more than 30% of the Earth's surface.

The name 'Pacific' come from the Latin word ' pacificus' which means peaceful. Thus, Pacific Ocean means 'peaceful ocean'. However, the Pacific is not really calm and peaceful. The 'ring of fire' is located in the Pacific Ocean. There is a string of volcanoes in the Pacific basin which are still active and therefore many of the world's major earthquakes and volcanic eruptions happen in this region.

The lowest known point on earth is called Challenger Deep. It is located in the Pacific Ocean near Guam in the Philippine Sea at the end of the Mariana Trench. The depth recorded is 10,920 metres or 35,827 feet.

The largest coral reef in the world is located off the Australian coast and is called the Great Barrier Reef.

The coral reefs only grown in tropic waters, but due to climate change over 50% of the world's reefs have been lost in the last 30 years. Read more about Australia here.

More interesting Facts about the Pacific Ocean for Kids here.

Atlantic Ocean Facts for Kids

The Atlantic is the second biggest ocean in the world and is between the continents of America and Europe and Africa.

The Atlantic Ocean is about half the size of the Pacific Ocean and covers roughly 20% of the Earth's surface. However it is growing in size as it is spreading along the Mid-Atlantic Coasts.

Sharks, such as this Thresher Shark swimming in the gulf stream, are found in the waters of the Atlantic.
More interesting Facts about the Atlantic Ocean for Kids here.

Did you know that the Mid-Atlantic Ridge is the longest mountain range on Earth? It spreads from Iceland to Antarctica beneath the Atlantic.

Indian Ocean Facts for Kids

The Indian Ocean is located between Africa and Austral-Asia.

The waters of the Indian Ocean provides the largest breeding grounds of the world for humpback whales.

Also found in the Indian ocean, a fish which was thought to be extinct was discovered there. The Coelacanth is found in the warm waters off the Comoro islands between Mozambique and Madagascar.

The Northern Indian Ocean also is the most important transport route for oil as it connects the oil-rich countries of the Middle East Each with Asia. Every day tankers are carrying a cargo of 17 million barrels of crude oil from the Persian Gulf on its waters.

More interesting Facts about the Indian Ocean for Kids here.

Southern Ocean

The Southern Ocean is located around the South Pole across the Antarctic circle in the Southern Hemisphere off Antarctica.
Read more our top ten Southern Ocean facts here
The Southern Ocean is the home of Emperor Penguins and Wandering Albatrosses.

Arctic Ocean

The Arctic Ocean is located around the North Pole across the Arctic circle.

There are many polar bears living on the Arctic ice.

A jellyfish with the funny name 'Lion's Mane Jellyfish' can also be found in the Arctic Ocean's waters. It grows up to 2.4m or 8 feet across and lives on plankton and fishes.
Read more about the Arctic Ocean here.
Did you know that the Arctic Ocean's ice covers are shrinking by 8% every ten years?

Many Arctic ground features are named after early Arctic explorers, like Nansen Basin or Mendeleyev Ridge.

Ocean Quiz for Kids

Scroll down and tick the correct answers to our ten questions to see if you can master our ocean quiz for kids. Enjoy!

Popular Pages

World Oceans Resources

Image Credits on Ocean Facts for Kids: Tanya Puntti, Beth Swanson, Tory Kallman, Christopher Wood and mgsiv, shafiq (infographic) all at shutterstock.com, as well as other shutterstock and sxc photos and own images Return from Ocean Facts for Kids to Kids World Travel Guide Homepage
This page " Ocean Facts for Kids" was first published on 11 June 2011. Last update 8 June 2021.

National Ocean Service - Ocean Today. "Marine Life" Last accessed 8 June 2021

National Ocean Service - Ocean Today. "Ocean Facts." Last accessed 8 June 2021

Australian Government. "Resources." Great Barrier Reef Marine Park Authority. Last accessed 8 June 2021

Great Barrier Reef Marine Park Authority 2015. Exploring the Reef: Year 3 Australian science curriculum focus, GBRMPA, Townsville.

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Ocean Facts for Kids | Atlantic Ocean | Pacific Ocean | Indian Ocean

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In our Ocean Facts for Kids you will learn about the oceans of the world. Did you know that the o ceans cover over 71% of the Earth's surface? Today is World Oceans Day! Let us learn more about the fascinating oceans which are the most important source of life for all of us.

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How deep is the ocean?

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national oceanic and atmospheric administration

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In the U.S., where over half of us live along the coast and more than 78 percent of our overseas trade by volume comes and goes along our marine highways, the health of our coasts is intricately connected to the health of our nation's economy.

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A sport is commonly defined as an athletic activity or skill and involves a degree of competition, such as baseball, soccer, bowling, or basketball. Many people play sports with their friends. Sportsmen need coaches to teach or train teams or individuals how to do better. Sports can be played indoors or outdoors and by individuals or teams.

Some people like to watch other people play sports. Those who watch others playing sports are called . While some fans watch sports on television, others actually go to stadiums or other places where people pay to watch them in person. These fans are called spectators.

People engage in many kinds of sports, for example:

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Images for kids

Electronic sports are a recent development.

Spectators at the 1906 unofficial Olympic Games

Modern sports have complex rules and are highly organized.

A runner gives a friendly tap on the shoulder to a wheelchair racer during the Marathon International de Paris (Paris Marathon) in 2014.

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A sport is commonly defined as an athletic activity or skill and involves a degree of competition, such as baseball, soccer, bowling, or basketball. Many people play sports with their friends. Sportsmen need coaches to teach or train teams or individuals how to do better.

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In some sports one person competes against other individuals. Examples of these sports include boxing, wrestling, gymnastics, figure skating, diving, pole vaulting, long jumping, and horseback riding.

In team sports a group of people plays against another group, or team. A team may have as few as two members, or it may have many members. A doubles team in tennis has two players. Five players make up a basketball team. An ice hockey team has six players, and a baseball team has nine. Eleven players make up a football, soccer, or cricket team.

Sports can be amateur or professional. Amateur athletes do not get paid for participating in a sport. Professional athletes play for money.

Sports also can be organized or unorganized. Children who get together for neighborhood football games are playing unorganized sports. No organization controls their games. In organized sports athletes play for a school, a business, a club, a community, or some other organization. The organization schedules games and enforces the rules of the sport. Organized sports can be amateur or professional.

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In some sports one person competes against other individuals. Examples of these sports include boxing, wrestling, gymnastics, figure skating, diving, pole vaulting, long jumping, and horseback riding. In team sports a group of people plays against another group, or team. A team may have as few as two members, or it may have many members.

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Harmony Square - Kids Educational Videos -

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All About Weather - More Way Cool Science on the Learning Videos Channel

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Weather for Kids | What is weather, and how does it work?

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What are Ribosomes? | Ribosome Function and Structure

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mRNA, tRNA, and rRNA function | Types of RNA

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What is RNA | Genetics | Biology | FuseSchool

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Kids learn about proteins and amino acids in the science of biology including how they are made using DNA, transcription, and translation and different types of proteins.

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RNA Lesson for Kids - Video & Lesson Transcript | Study.com

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Learn about RNA, which stands for ribonucleic acid. Discover the relationship between RNA and DNA, the function of RNA, and how long RNA lives....