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1. The AstrOlympics Project: DISTANCE
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We frequently ask: how far away is that? The concept of distance is very familiar to us. After all, we need to factor in distance whether it's for a trip around the corner or across the country. One way to define distance is the ground covered between two points.
Distance plays an important role in many Olympic sports. The ability to travel the distance around a track, across a swimming pool, or down the road faster than anyone else may lead to a gold medal. Olympic events like the marathon show how some athletes can excel over what most of us consider to be a very long distance.
Despite how large some Olympic distances may seem, they are just a tiny fraction of the lengths we see across space. For comparison purposes, let's look at everything in the widely accepted unit of meters. In the metric system, a kilometer simply means a thousand meters (which is equivalent to about 0.62 miles). The longest Olympic track and field event in terms of distance is the 50-kilometer, or 50,000-meter, race walk.
By comparison, it is about 7700 kilometers, or 7.7 million meters, from New York to Rio de Janeiro for those athletes and spectators making that trip. The distance around the equator of Earth is about 40 million meters. In space, however, distances get much, much bigger. It's about 150 billion meters to the Sun, and 40 quadrillion meters to Proxima Centauri, the next nearest star to us. That's a 40 followed by another 15 zeroes.
Because numbers get so large so quickly when talking about objects in space, astronomers most often use the unit of light years to describe distance. While it sounds like an amount of time, a light year is, in fact, a distance. It is equivalent to how far light travels over the course of one year, roughly 9,000 trillion meters. Rather than keeping track of all of those zeroes, we can measure that same distance to Proxima Centauri as being about 4.2 light years away. That's helpful because Proxima Centauri is actually very close to us, compared to many other things in space. For example, the center of the Milky Way galaxy is about 26,000 light years away. And astronomers have observed light left over from the Big Bang at some 13.7 billion light years away.
So whether it is around a track or across a galaxy, distance is something worth keeping in perspective.
[Runtime: 04:27]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (3.3 MB)
We frequently ask: how far away is that? The concept of distance is very familiar to us. After all, we need to factor in distance whether it's for a trip around the corner or across the country. One way to define distance is the ground covered between two points.
Distance plays an important role in many Olympic sports. The ability to travel the distance around a track, across a swimming pool, or down the road faster than anyone else may lead to a gold medal. Olympic events like the marathon show how some athletes can excel over what most of us consider to be a very long distance.
Despite how large some Olympic distances may seem, they are just a tiny fraction of the lengths we see across space. For comparison purposes, let's look at everything in the widely accepted unit of meters. In the metric system, a kilometer simply means a thousand meters (which is equivalent to about 0.62 miles). The longest Olympic track and field event in terms of distance is the 50-kilometer, or 50,000-meter, race walk.
By comparison, it is about 7700 kilometers, or 7.7 million meters, from New York to Rio de Janeiro for those athletes and spectators making that trip. The distance around the equator of Earth is about 40 million meters. In space, however, distances get much, much bigger. It's about 150 billion meters to the Sun, and 40 quadrillion meters to Proxima Centauri, the next nearest star to us. That's a 40 followed by another 15 zeroes.
Because numbers get so large so quickly when talking about objects in space, astronomers most often use the unit of light years to describe distance. While it sounds like an amount of time, a light year is, in fact, a distance. It is equivalent to how far light travels over the course of one year, roughly 9,000 trillion meters. Rather than keeping track of all of those zeroes, we can measure that same distance to Proxima Centauri as being about 4.2 light years away. That's helpful because Proxima Centauri is actually very close to us, compared to many other things in space. For example, the center of the Milky Way galaxy is about 26,000 light years away. And astronomers have observed light left over from the Big Bang at some 13.7 billion light years away.
So whether it is around a track or across a galaxy, distance is something worth keeping in perspective.
[Runtime: 04:27]
(NASA/CXC/A. Hobart)
2. The AstrOlympics Project: SPEED
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The concept of speed is infused into our lives, whether it is as we run, drive a car, or travel across the globe. Of course, the athletes in the Olympic Games are often the fastest in the world. This is apparent in many of the Olympic sports from track and field to cycling to downhill skiing and speed skating.
While we are used to asking, 'who is faster,' it's important to understand just what speed represents. Speed is defined as a distance traveled over a certain period of time. In science, we would write this as the equation "speed equals distance divided by time." We've become rather used to this equation - even if we don't realize it. Using this equation, for example, cars provide speed in miles or kilometers per hour. This gives the number of miles or kilometers that would be covered if you moved at that speed for one hour.
The international standard unit for speed is different. The distance is measured in meters, while the amount of time considered is one second. By converting speeds from common experiences into meters per second, we can use this as a reference point for exploring the enormous range of speeds around the world and across the Universe.
For example, a car moving at 20 miles per hour (or 32 kilometers per hour) is going the equivalent speed of about 9 meters per second. An Olympic athlete, however, can move even faster. Usain Bolt has been clocked running at 12.4 meters per second in the 100-meter sprint. And over a dozen cyclists at the velodrome at the 2012 London Games reached top speeds of over 20 meters per second.
These are incredibly impressive feats of speed in the arena of athletic competitions. They also make the speeds found elsewhere even more amazing. For example, the speed of sound in the Earth's atmosphere is about 340 meters per second. Meanwhile, the International Space Station orbits the Earth at about 7,600 meters per second, and the Earth travels around the Sun at some 30,000 meters per second.
Those blistering paces pale in comparison, however, to the Universe's real speedsters. Take, for example, the pulsar known as IGR J11014-6103. This dense core was created when a star collapsed, hurtling this object into space. Astronomers have calculated that this stellar nub is blazing away from its birthplace at a whopping one to two million meters per second. Now that's a speed that anyone -- Olympic athlete or otherwise -- might have to marvel at.
[Runtime: 04:35]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (3.4 MB)
The concept of speed is infused into our lives, whether it is as we run, drive a car, or travel across the globe. Of course, the athletes in the Olympic Games are often the fastest in the world. This is apparent in many of the Olympic sports from track and field to cycling to downhill skiing and speed skating.
While we are used to asking, 'who is faster,' it's important to understand just what speed represents. Speed is defined as a distance traveled over a certain period of time. In science, we would write this as the equation "speed equals distance divided by time." We've become rather used to this equation - even if we don't realize it. Using this equation, for example, cars provide speed in miles or kilometers per hour. This gives the number of miles or kilometers that would be covered if you moved at that speed for one hour.
The international standard unit for speed is different. The distance is measured in meters, while the amount of time considered is one second. By converting speeds from common experiences into meters per second, we can use this as a reference point for exploring the enormous range of speeds around the world and across the Universe.
For example, a car moving at 20 miles per hour (or 32 kilometers per hour) is going the equivalent speed of about 9 meters per second. An Olympic athlete, however, can move even faster. Usain Bolt has been clocked running at 12.4 meters per second in the 100-meter sprint. And over a dozen cyclists at the velodrome at the 2012 London Games reached top speeds of over 20 meters per second.
These are incredibly impressive feats of speed in the arena of athletic competitions. They also make the speeds found elsewhere even more amazing. For example, the speed of sound in the Earth's atmosphere is about 340 meters per second. Meanwhile, the International Space Station orbits the Earth at about 7,600 meters per second, and the Earth travels around the Sun at some 30,000 meters per second.
Those blistering paces pale in comparison, however, to the Universe's real speedsters. Take, for example, the pulsar known as IGR J11014-6103. This dense core was created when a star collapsed, hurtling this object into space. Astronomers have calculated that this stellar nub is blazing away from its birthplace at a whopping one to two million meters per second. Now that's a speed that anyone -- Olympic athlete or otherwise -- might have to marvel at.
[Runtime: 04:35]
(NASA/CXC/A. Hobart)
3. The AstrOlympics Project: ROTATION
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When something turns around an axis, we call this rotation. We see rotation all around us - a merry-go- round on a playground, a vinyl record on a turntable, even a washing machine that cleans our clothes. It can often be important - and interesting - to determine just how fast something spins. We call this rotational speed and it is measured as the number of rotations over a certain period of time.
In the Olympic Games, athletes often need to rotate in order to compete in their sports. Gymnasts rotate their bodies during routines, ice skaters rotate during their spins, and aerial skiers perform rotations high in the air. How do the spinning accomplishments of these amazing athletes compare to other rotating things that we know about?
Ferris wheels rotate about relatively slowly making one revolution every 600 seconds or so. A ceiling fan, on the other hand, typically rotates twice around every second. This translates into a rotational speed of 0.5 Hertz, the unit we use to talk about rotation. (Hertz=# of rotations per second). That is very quick, but a gymnast doing a back flip rotates with a speed of 1.5 Hertz, while an ice skater can spin with a rotational speed of 50 Hertz.
We also find things in space that rotate. For example, all of the planets, including Earth, rotate around an axis as they make their orbit around the Sun. This rotation, which happens once every 24 hours on Earth, gives us our day and night. The Sun also spins, making one rotation about every 25 days. Elsewhere in space, astronomers have found objects that rotate at a dizzying speed. For example, the dense cores left behind after stars explode - known as neutron stars - can rotate at remarkable rates. The neutron star at the center of the Crab Nebula is moving at 30 Hertz, in other words making 30 rotations in just one second. That's almost as fast as Olympic ice skaters, which is amazing especially when you consider that the neutron star is over 10 miles or 16 kilometers across!
Perhaps the next time you watch a gymnast tumble or a skier do a flip, think of the other examples in our lives and across space where rotation is taking place.
[Runtime: 04:00]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (3 MB)
When something turns around an axis, we call this rotation. We see rotation all around us - a merry-go- round on a playground, a vinyl record on a turntable, even a washing machine that cleans our clothes. It can often be important - and interesting - to determine just how fast something spins. We call this rotational speed and it is measured as the number of rotations over a certain period of time.
In the Olympic Games, athletes often need to rotate in order to compete in their sports. Gymnasts rotate their bodies during routines, ice skaters rotate during their spins, and aerial skiers perform rotations high in the air. How do the spinning accomplishments of these amazing athletes compare to other rotating things that we know about?
Ferris wheels rotate about relatively slowly making one revolution every 600 seconds or so. A ceiling fan, on the other hand, typically rotates twice around every second. This translates into a rotational speed of 0.5 Hertz, the unit we use to talk about rotation. (Hertz=# of rotations per second). That is very quick, but a gymnast doing a back flip rotates with a speed of 1.5 Hertz, while an ice skater can spin with a rotational speed of 50 Hertz.
We also find things in space that rotate. For example, all of the planets, including Earth, rotate around an axis as they make their orbit around the Sun. This rotation, which happens once every 24 hours on Earth, gives us our day and night. The Sun also spins, making one rotation about every 25 days. Elsewhere in space, astronomers have found objects that rotate at a dizzying speed. For example, the dense cores left behind after stars explode - known as neutron stars - can rotate at remarkable rates. The neutron star at the center of the Crab Nebula is moving at 30 Hertz, in other words making 30 rotations in just one second. That's almost as fast as Olympic ice skaters, which is amazing especially when you consider that the neutron star is over 10 miles or 16 kilometers across!
Perhaps the next time you watch a gymnast tumble or a skier do a flip, think of the other examples in our lives and across space where rotation is taking place.
[Runtime: 04:00]
(NASA/CXC/A. Hobart)
4. The AstrOlympics Project: What Do Olympic Athletes and Objects in Space have in Common?
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The athletes that compete in the Olympics can do amazing things. They run faster, jump higher, and spin quicker than most of us ever will.
Many of us are also in awe of what the Universe has to offer. Astronomers have explored the heavens with their telescopes and come up with findings that are so fantastic it can be hard to believe they're real.
What do Olympic athletes and objects in space have in common? The answer is matter in motion, often in extreme examples. Whether it is a human body moving at the fastest speeds possible or the debris from an exploded star blasting through space, the physics of that motion is, in many ways, the same.
The AstrOlympics project explores the spectacular range of science that we can find both in the impressive feats of the Olympic Games as well as in cosmic phenomena throughout the Universe. By measuring the range of values for such things as speed, mass, time, pressure, rotation, distance, and more, we can learn not only about the world around us, but also about the Universe we all live in.
The Olympics are an opportunity to behold the limits of human abilities in athletics. After all, the Olympic motto is Latin for "faster, higher, stronger." AstrOlympics enables us to appreciate the feats of the Olympic athletes and then venture far beyond into the outer reaches of space.
Let's find out just how far we've learned science can go.
[Runtime: 03:13]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (2 MB)
The athletes that compete in the Olympics can do amazing things. They run faster, jump higher, and spin quicker than most of us ever will.
Many of us are also in awe of what the Universe has to offer. Astronomers have explored the heavens with their telescopes and come up with findings that are so fantastic it can be hard to believe they're real.
What do Olympic athletes and objects in space have in common? The answer is matter in motion, often in extreme examples. Whether it is a human body moving at the fastest speeds possible or the debris from an exploded star blasting through space, the physics of that motion is, in many ways, the same.
The AstrOlympics project explores the spectacular range of science that we can find both in the impressive feats of the Olympic Games as well as in cosmic phenomena throughout the Universe. By measuring the range of values for such things as speed, mass, time, pressure, rotation, distance, and more, we can learn not only about the world around us, but also about the Universe we all live in.
The Olympics are an opportunity to behold the limits of human abilities in athletics. After all, the Olympic motto is Latin for "faster, higher, stronger." AstrOlympics enables us to appreciate the feats of the Olympic athletes and then venture far beyond into the outer reaches of space.
Let's find out just how far we've learned science can go.
[Runtime: 03:13]
(NASA/CXC/A. Hobart)
5. Bubbles, Bubbles, Everywhere
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For many kids (and those of us who are still kids at heart), bubbles are a lot of fun. We see bubbles blown out of soapy wands and others that float from the bottom of a fizzy drink to the top. But bubbles also represent important physical phenomena that can be found across many scales and in many different types of objects.
Let's look first at the soap bubble. Soap bubbles are formed when someone injects breath or air into a film of soapy water. This fits in with the definition of a bubble being a sphere enclosing liquid or gas. We can also find bubbles in space, where they are not made of soap like those here on Earth. Rather cosmic bubbles are blown out of the material we find in between stars and galaxies. Take, for example, this object. Its formal astronomical name is NGC 7635, but astronomers have nicknamed it the "Bubble Nebula." And it's easy to see why when you look at it. The bubble in the Bubble Nebula is being blown up by a massive star that sits in its center. This star has powerful winds that are driven off of its surface, pushing the gas and dust that surround the star outward. The Bubble Nebula is much bigger than any soap bubble you will find on Earth. It stretches across over 63 trillion miles in diameter.
Even bigger still are the bubbles that astronomers find carved out in galaxy clusters. Galaxy clusters are the largest structures in the Universe held together by gravity. In addition to the hundreds or even thousands of individual galaxies that make up these gigantic objects, enormous amounts of hot gas envelope galaxy clusters. By using X-ray telescopes like Chandra, astronomers can examine this superheated gas. In objects like the galaxy cluster called MS0735.6+7421, they find that enormous bubbles spanning over seven times the size of the entire Milky Way galaxy have been formed in the hot gas. What could blow up such an enormous bubble? The answer is a supermassive black hole, weighing nearly a billion times the mass of the Sun, that lies at the center of the cluster. This black hole is shooting out powerful jets that push the 50-million-degree hot gas outward and create these incredible bubbles.
So the next time you pick up a bottle of bubbles, you may want to take a moment to realize how far-reaching bubbles truly are. You might only be able to inflate a bubble the size of a few inches, but elsewhere in the Universe, bubbles are forming in places and in sizes that are almost impossible to imagine.
[Runtime: 03:53]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (2.8 MB)
For many kids (and those of us who are still kids at heart), bubbles are a lot of fun. We see bubbles blown out of soapy wands and others that float from the bottom of a fizzy drink to the top. But bubbles also represent important physical phenomena that can be found across many scales and in many different types of objects.
Let's look first at the soap bubble. Soap bubbles are formed when someone injects breath or air into a film of soapy water. This fits in with the definition of a bubble being a sphere enclosing liquid or gas. We can also find bubbles in space, where they are not made of soap like those here on Earth. Rather cosmic bubbles are blown out of the material we find in between stars and galaxies. Take, for example, this object. Its formal astronomical name is NGC 7635, but astronomers have nicknamed it the "Bubble Nebula." And it's easy to see why when you look at it. The bubble in the Bubble Nebula is being blown up by a massive star that sits in its center. This star has powerful winds that are driven off of its surface, pushing the gas and dust that surround the star outward. The Bubble Nebula is much bigger than any soap bubble you will find on Earth. It stretches across over 63 trillion miles in diameter.
Even bigger still are the bubbles that astronomers find carved out in galaxy clusters. Galaxy clusters are the largest structures in the Universe held together by gravity. In addition to the hundreds or even thousands of individual galaxies that make up these gigantic objects, enormous amounts of hot gas envelope galaxy clusters. By using X-ray telescopes like Chandra, astronomers can examine this superheated gas. In objects like the galaxy cluster called MS0735.6+7421, they find that enormous bubbles spanning over seven times the size of the entire Milky Way galaxy have been formed in the hot gas. What could blow up such an enormous bubble? The answer is a supermassive black hole, weighing nearly a billion times the mass of the Sun, that lies at the center of the cluster. This black hole is shooting out powerful jets that push the 50-million-degree hot gas outward and create these incredible bubbles.
So the next time you pick up a bottle of bubbles, you may want to take a moment to realize how far-reaching bubbles truly are. You might only be able to inflate a bubble the size of a few inches, but elsewhere in the Universe, bubbles are forming in places and in sizes that are almost impossible to imagine.
[Runtime: 03:53]
(NASA/CXC/A. Hobart)
6. Light Beyond the Bulb: Bent Light in Space
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One of the most interesting characteristics of light is that the path that it travels can bend. This happens when light is moving through one medium like air, and then enters another medium like glass or water. We experience this all of the time here on Earth. Whenever we put eyeglasses on or insert contact lenses, we are taking advantage of the fact that we can bend the path of light so it can properly focus onto the retinas of our eyes. We also see examples of bent light in the slightly oval appearance of the setting Sun or when we think we see water on in the distance on a hot highway.
Light being bent is also very important when we want to learn about things in space. In fact, some of the most exciting discoveries made by the Chandra X-ray Observatory and other telescopes involve light that has been bent. Take, for example, the Bullet Cluster. This system contains two galaxy clusters that have rammed into one another at tremendous speeds. The collision was so violent that normal matter has been wrenched away from dark matter. While we can't see the dark matter directly, we can learn where it is by light being lensed.
How does this work? When the light from very distant galaxies passes through a massive cluster of galaxies, like in the Bullet Cluster, the cluster can bend the path of the galaxy's light, in essence acting like a lens. From the vantage point of our telescopes, the distant galaxies appear distorted or elongated. Astronomers can use this information to build maps about where the dark matter is, which tells them more about this mysterious substance.
The ultimate light benders in the Universe are black holes, which can bend light rays into a closed loop so they never escape the black hole. Chandra has observed many black holes and their environments over the course of the mission. Whether they are the smaller black holes that are produced by the collapse of a giant star or the enormous supermassive black holes at the centers of galaxies, Chandra will continue to observe these objects that bend light in amazing ways across the Universe.
[Runtime: 03:40]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (2.4 MB)
One of the most interesting characteristics of light is that the path that it travels can bend. This happens when light is moving through one medium like air, and then enters another medium like glass or water. We experience this all of the time here on Earth. Whenever we put eyeglasses on or insert contact lenses, we are taking advantage of the fact that we can bend the path of light so it can properly focus onto the retinas of our eyes. We also see examples of bent light in the slightly oval appearance of the setting Sun or when we think we see water on in the distance on a hot highway.
Light being bent is also very important when we want to learn about things in space. In fact, some of the most exciting discoveries made by the Chandra X-ray Observatory and other telescopes involve light that has been bent. Take, for example, the Bullet Cluster. This system contains two galaxy clusters that have rammed into one another at tremendous speeds. The collision was so violent that normal matter has been wrenched away from dark matter. While we can't see the dark matter directly, we can learn where it is by light being lensed.
How does this work? When the light from very distant galaxies passes through a massive cluster of galaxies, like in the Bullet Cluster, the cluster can bend the path of the galaxy's light, in essence acting like a lens. From the vantage point of our telescopes, the distant galaxies appear distorted or elongated. Astronomers can use this information to build maps about where the dark matter is, which tells them more about this mysterious substance.
The ultimate light benders in the Universe are black holes, which can bend light rays into a closed loop so they never escape the black hole. Chandra has observed many black holes and their environments over the course of the mission. Whether they are the smaller black holes that are produced by the collapse of a giant star or the enormous supermassive black holes at the centers of galaxies, Chandra will continue to observe these objects that bend light in amazing ways across the Universe.
[Runtime: 03:40]
(NASA/CXC/A. Hobart)
7. Chandra Sketches: Highlights of Light
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Light comes in different forms. The light that we see with our eyes is just a fraction of all light. Light also encompasses wavelengths ranging from radio waves to gamma rays.
Nothing in the Universe can travel faster than light. In a vacuum, light travels at over 300,000 kilometers (186,000 miles) per second. This means light could circle the Earth 7.5 times in one second.
As light travels, its path can be bent when it goes from one medium to another (such as air to water). It can also be blocked (when a shadow occurs, for example), reflected (as with a mirror), or absorbed (like when a stone is heated by infrared light (waves) from the Sun.)
Humans have learned how to harness light and employ it in technologies ranging from medical devices (MRI/laser) to cell phones to giant telescopes.
[Runtime: 02:23]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (1.6 MB)
Light comes in different forms. The light that we see with our eyes is just a fraction of all light. Light also encompasses wavelengths ranging from radio waves to gamma rays.
Nothing in the Universe can travel faster than light. In a vacuum, light travels at over 300,000 kilometers (186,000 miles) per second. This means light could circle the Earth 7.5 times in one second.
As light travels, its path can be bent when it goes from one medium to another (such as air to water). It can also be blocked (when a shadow occurs, for example), reflected (as with a mirror), or absorbed (like when a stone is heated by infrared light (waves) from the Sun.)
Humans have learned how to harness light and employ it in technologies ranging from medical devices (MRI/laser) to cell phones to giant telescopes.
[Runtime: 02:23]
(NASA/CXC/A. Hobart)
8. Chandra Sketches: Our Connection With Light
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We rely on light - both natural and artificial - to brighten and power our world, but also for so much more.
We use light-based medical tools to help understand and defeat disease.
We use light to advance manufacturing, which helps drive the global economy and move us toward sustainable practices.
We use light to monitor our climate and forecast the weather.
We use light from the cosmos to understand distant galaxies, to look for signs of life out there, and to learn more about our own planet.
Whether it comes from the Sun, a distant galaxy or a neon sign around the corner, light is all around us. We use it to communicate, navigate, learn and explore.
[Runtime: 02:14]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (1.7 MB)
We rely on light - both natural and artificial - to brighten and power our world, but also for so much more.
We use light-based medical tools to help understand and defeat disease.
We use light to advance manufacturing, which helps drive the global economy and move us toward sustainable practices.
We use light to monitor our climate and forecast the weather.
We use light from the cosmos to understand distant galaxies, to look for signs of life out there, and to learn more about our own planet.
Whether it comes from the Sun, a distant galaxy or a neon sign around the corner, light is all around us. We use it to communicate, navigate, learn and explore.
[Runtime: 02:14]
(NASA/CXC/A. Hobart)
9. Light Beyond the Bulb: Over and Beyond the Rainbow
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For the millions of years that humans and our ancestors have roamed this planet, we have been familiar with light. While scientists and philosophers have tried to figure out exactly what light is for millennia, it's only been in the past several hundred years or so that we've really started to figure it out.
In 1665, Isaac Newton, then a young scientist at Cambridge University in England, took a glass prism and held it up to a beam of sunlight streaming through the window. He saw the sunlight that passed through the prism spread out into the colors of the rainbow - red, orange, yellow, green, blue and violet. This was a crucial step in beginning to understand some of the properties of light.
Of course, we know today that Newton was experimenting with what we call "visible light." In 1800, William Herschel made a huge step in revealing that there was light outside what humans could see with their eyes with the discovery of infrared light. The prefix "infra" means "below" and "beyond," which makes sense as this type of light falls just outside the red color of visible light. Soon thereafter, Johann Ritter discovered light on the other end of the visible light spectrum and named it "ultraviolet."
The latter half of the 19th century and the early 20th century saw a rapid explosion of discoveries in the field of light, including identifying X-rays, and gamma rays. Important theoretical work by such scientists as James Clerk Maxwell and Albert Einstein helped piece together all of these discoveries and better understand what light is and how it behaves.
Today, light in all its forms is used for countless applications. A vivid example of different types of light being used together is in modern astronomy. While visible light telescopes have been around since Galileo's time in the early 1600's, the last century has seen the development of telescopes in virtually every wavelength known. Telescopes such as NASA's Chandra X-ray Observatory could not be developed until rocket technology advanced far enough because the Earth's atmosphere blocks X-rays from space from reaching our planet's surface. Other types of light, including certain bands of infrared, ultraviolet, and gamma rays, are in the same situation. We are lucky to be in an era where astronomers can combine data from across the electromagnetic spectrum - from both telescopes on the ground and those in space. It's just one of the many ways that light helps us explore and learn about the world we live in and the Universe that surrounds us.
[Runtime: 03:59]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (2.7 MB)
For the millions of years that humans and our ancestors have roamed this planet, we have been familiar with light. While scientists and philosophers have tried to figure out exactly what light is for millennia, it's only been in the past several hundred years or so that we've really started to figure it out.
In 1665, Isaac Newton, then a young scientist at Cambridge University in England, took a glass prism and held it up to a beam of sunlight streaming through the window. He saw the sunlight that passed through the prism spread out into the colors of the rainbow - red, orange, yellow, green, blue and violet. This was a crucial step in beginning to understand some of the properties of light.
Of course, we know today that Newton was experimenting with what we call "visible light." In 1800, William Herschel made a huge step in revealing that there was light outside what humans could see with their eyes with the discovery of infrared light. The prefix "infra" means "below" and "beyond," which makes sense as this type of light falls just outside the red color of visible light. Soon thereafter, Johann Ritter discovered light on the other end of the visible light spectrum and named it "ultraviolet."
The latter half of the 19th century and the early 20th century saw a rapid explosion of discoveries in the field of light, including identifying X-rays, and gamma rays. Important theoretical work by such scientists as James Clerk Maxwell and Albert Einstein helped piece together all of these discoveries and better understand what light is and how it behaves.
Today, light in all its forms is used for countless applications. A vivid example of different types of light being used together is in modern astronomy. While visible light telescopes have been around since Galileo's time in the early 1600's, the last century has seen the development of telescopes in virtually every wavelength known. Telescopes such as NASA's Chandra X-ray Observatory could not be developed until rocket technology advanced far enough because the Earth's atmosphere blocks X-rays from space from reaching our planet's surface. Other types of light, including certain bands of infrared, ultraviolet, and gamma rays, are in the same situation. We are lucky to be in an era where astronomers can combine data from across the electromagnetic spectrum - from both telescopes on the ground and those in space. It's just one of the many ways that light helps us explore and learn about the world we live in and the Universe that surrounds us.
[Runtime: 03:59]
(NASA/CXC/A. Hobart)
10. Light Beyond the Bulb: Intro to Light
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The year 2015 has been declared to be the International Year of Light and Light-based Technologies by the United Nations. People around the world are using this year-long celebration, nicknamed IYL 2015, to look at all of the amazing things light can do.
Whether it comes from the Sun, a distant galaxy, or a neon sign around the corner, light is all around us. We use light to communicate, navigate, learn, explore, and much more.
Light comes in many forms. In fact, the light that we see with our eyes, the same light that makes up the colors of the rainbow,
Light is fascinating for many reasons, including the fact that it possesses qualities of both a wave and a particle. We often characterize light and its behavior based on how far apart the crests of its waves are. This is called wavelength. Alternately, light can be viewed as being composed of a stream of particles.
Another aspect of light that is so amazing is how fast it travels. Nothing in the Universe can travel faster than light. In a vacuum, light moves at an astonishing 1.08 billion kilometers per hour. In other units, this translates into 671 million miles per hour. To put this in perspective, this means light could circle around the Earth seven and a half times in just one second.
In upcoming episodes, we will look at different aspects of light. We will explore some of its intriguing properties and how humans have greatly benefited from learning all that we can about light, which goes far beyond the bulb.
[Runtime: 03:24]
(NASA/CXC/A. Hobart)
QuicktimeMPEG Audio Only
- Audio (2.1 MB)
The year 2015 has been declared to be the International Year of Light and Light-based Technologies by the United Nations. People around the world are using this year-long celebration, nicknamed IYL 2015, to look at all of the amazing things light can do.
Whether it comes from the Sun, a distant galaxy, or a neon sign around the corner, light is all around us. We use light to communicate, navigate, learn, explore, and much more.
Light comes in many forms. In fact, the light that we see with our eyes, the same light that makes up the colors of the rainbow,
Light is fascinating for many reasons, including the fact that it possesses qualities of both a wave and a particle. We often characterize light and its behavior based on how far apart the crests of its waves are. This is called wavelength. Alternately, light can be viewed as being composed of a stream of particles.
Another aspect of light that is so amazing is how fast it travels. Nothing in the Universe can travel faster than light. In a vacuum, light moves at an astonishing 1.08 billion kilometers per hour. In other units, this translates into 671 million miles per hour. To put this in perspective, this means light could circle around the Earth seven and a half times in just one second.
In upcoming episodes, we will look at different aspects of light. We will explore some of its intriguing properties and how humans have greatly benefited from learning all that we can about light, which goes far beyond the bulb.
[Runtime: 03:24]
(NASA/CXC/A. Hobart)
Revised: March 24, 2023