Light is the fastest moving thing in the universe. What would happen if light traveled at a slower speed?
In a vacuum the speed of light is approximately 186,000 miles per second (3300,000 km per second). It would be a matter of seconds before humans notice it.

This scenario can be experienced by any gamer in a computer-game Gerd Kortemeyer and his colleagues, who are the director of educational technology and technological development at ETH Zurich. ETH Zurich is a Swiss university that combines science, technology and engineering. The game allows you to see the strange effects of changing colors, brightness, and even changes in the perceived lengths and dimensions of objects. This would be due to a slower speed of light.

Related: What if Earth were to have rings?

Humans are slow

Even at their fastest speeds, people are slower than light.

Philip Tan, a researcher at the MIT Game Lab, stated that the fastest human beings have traveled about 0.0037% faster than the speed of light. To reach these speeds, you must be in a space vehicle.

However, thought experiments have shown that unusual things could happen if humans could travel at a near-light speed. Kortemeyer is an associate professor of Physics at Michigan State University. Albert Einstein's theory about special relativity, which describes how speed affects mass, space, and time, would mean that objects would be shorter as we passed them, and the Doppler effect, among other changes, would become visible to light.

These same changes would happen if light was slowing down and humans instead of speeding up. Both cases would result in us moving at a near-light speed.

Light travels at a slower pace

Kortemeyer, Tan, and other MIT Game Lab colleagues created a computer game that showed what the world would look like if the speed at which light travels was slower than normal. The game was released in 2012, and is called "A Slower Speed of Light". It features a character that collects orbs shaped like beach balls. The speed of light slows every time the character collects any of the 100 orbs.

The speed of light in real life would not slow down as it does in the game. In a vacuum, the speed of light is constant and does not change. Kortemeyer stated that although the speed of light can change depending on what materials it passes through, this doesn't alter the effects of special relativity or how we perceive them.

However, if we could see special relativity, we would be able to notice changes in colors and distance. The team then incorporated these effects into their game.

Image 1 of 5. In the computer game "A slower speed of Light", players try to get closer to the speed of light by collecting more orbs. Image credit: MIT Game Lab 2020 Massachusetts Institute of Technology. Image 2 of 5. In the computer game "A slower speed of light," players approach the speed of the light as they collect more orbs. Image 3 of 5 in the computer game "A Slower Speed of Light" Players approach the speed of the light as they collect more orbs. Image credit: MIT Game Lab 2020 Massachusetts Institute of Technology. Image 4 of 5. In the computer game "A slower speed of Light", players approach the speed of the light as they collect more orbs. (Image credit to MIT Game Lab 2021 Massachusetts Institute of Technology. Image 5 of 5. In the computer game "A slower speed of Light," players try to reach the speed of light by collecting more orbs. (Image credit to MIT Game Lab 2021 Massachusetts Institute of Technology

Color changes

The relativistic Doppler effect is a phenomenon where the speed at which human motion approaches that of light becomes apparent. This is because light acts both as a particle or a wave. It is characterized as a wave by its wavelength or distance from crests to crests. This determines its color and frequency (how many crests it passes in a given period).

Related: What if gravity didn't exist?

Kortemeyer explained that similar to how Doppler effect makes approaching a sound source make its frequency or pitch seem higher as it crests near your ear faster and more frequently, moving towards a light source makes its wavelength appear shorter, shifting its apparent color toward the violet and blue ends of the spectrum. On the other hand, moving away from an object shifts its apparent colour toward the red side of the spectrum. Kortemeyer stated that "the thing coming towards you looks bluer or the thing moving away looks redder."

The relativistic Doppler effect can be seen when human motion speeds approach the speed light. The apparent color of light changes when it is moved toward a source of light. It shifts toward the violet and blue ends of the spectrum. Moving away from an object changes its apparent color towards the red end. (Image credit: Shutterstock)

Time and distance changes

One of the most well-known effects of special relativity, is the slowing down of time for those who move at the speed of light. A person moving at a speed of light would age slower. This is known as time dilation.

Tan stated that "technically you are experiencing time delatation; but without having anything to compare it with, it doesn’t really mean anything." Tan explained that while time dilation is not visible during the game, at the end players will see a screen telling them that they have experienced less time than a stationary clock. Because the game's protagonist is moving at the speed of light, time dilation occurs, just like other effects of special relativity.

Special relativity also causes the lengths of stationary objects and objects moving at near the speed light to decrease. This phenomenon is known as length contraction. Kortemeyer explained that the effect can be complicated. Kortemeyer explained that objects zooming at very close to the speed light can experience length contraction. However, they might appear shorter to a stationary observer due to another effect called the runtime effect.

Imagine a bicycle coming towards you. Light from the front of a bike travels a shorter distance than light from its back. This means that you can see the front of your bike as it is now, and the back as it was in the past. Kortemeyer stated that overall, the bicycle appears longer. This effect can sometimes make objects appear warped.

This means that objects moving at a slower speed would appear to be longer or more warped to stationary observers.

Related: What if Earth had an orbit that was shared with another planet?

Brightening changes

You might notice that your feet are wetter at the front than at the back when you walk in rain. You will encounter more raindrops when you walk in the rain than if you were standing still. However, the raindrops are protected by the front of your body. Kortemeyer explained that something similar might happen if you moved at the speed of light.

This is because light can sometimes behave like a collection or particles called photons. These are tiny droplets of light. Because you are walking into the photons of an object in the computer games, it will appear brighter when you move towards it. This phenomenon is known as the searchlight effect.

Mr. Tompkins in Wonderland

Tan and Kortemeyer were not the only ones to envision a world with slower speeds of light. George Gamow, a physicist, published a picture book called "Mr. Tompkins in Wonderland" in 1939. The title character rides a bicycle through a city at a slower speed of light and experiences relativistic results. Kortemeyer stated that Einstein liked the little booklet.

What did the great physicist have to say about "A Slower Speed Of Light"? Kortemeyer stated that he might have been curious to play the game in the first instance. After all, he had asked his 16-year-old self what he would see if he rode a beam light. But, in the game, he can achieve almost the speed light. He would probably have played the videogame until he became hopelessly motion sick, but most physicists are still playful.

Original publication on Live Science

Light is the fastest moving thing in the universe. What would happen if light traveled at a slower speed?

In a vacuum the speed of light is approximately 186,000 miles per second (3300,000 km per second). It would be a matter of seconds before humans notice it.

This scenario can be experienced by any gamer in a computer-game Gerd Kortemeyer and his colleagues, who are the director of educational technology and technological development at ETH Zurich. ETH Zurich is a Swiss university that combines science, technology and engineering. The game allows you to see the strange effects of changing colors, brightness, and even changes in the perceived lengths and dimensions of objects. This would be due to a slower speed of light.

Related: What if Earth were to have rings?

Humans are slow

Even at their fastest speeds, people are slower than light.

Philip Tan, a researcher at the MIT Game Lab, stated that the fastest human beings have traveled about 0.0037% faster than the speed of light. To reach these speeds, you must be in a space vehicle.

However, thought experiments have shown that unusual things could happen if humans could travel at a near-light speed. Kortemeyer is an associate professor of Physics at Michigan State University. Albert Einstein's theory about special relativity, which describes how speed affects mass, space, and time, would mean that objects would be shorter as we passed them, and the Doppler effect, among other changes, would become visible to light.

These same changes would happen if light was slowing down and humans instead of speeding up. Both cases would result in us moving at a near-light speed.

Light travels at a slower pace

Kortemeyer, Tan, and other MIT Game Lab colleagues created a computer game that showed what the world would look like if the speed at which light travels was slower than normal. The game was released in 2012, and is called "A Slower Speed of Light". It features a character that collects orbs shaped like beach balls. The speed of light slows every time the character collects any of the 100 orbs.

The speed of light in real life would not slow down as it does in the game. In a vacuum, the speed of light is constant and does not change. Kortemeyer stated that although the speed of light can change depending on what materials it passes through, this doesn't alter the effects of special relativity or how we perceive them.

However, if we could see special relativity, we would be able to notice changes in colors and distance. The team then incorporated these effects into their game.

Image 1 of 5. In the computer game "A slower speed of light", players try to get closer to the speed of the sun as they collect more orbs. Image credit: MIT Game Lab 2020 Massachusetts Institute of Technology. Image 2 of 5. In the computer game "A slower speed of Light", players approach the speed of the light as they collect more orbs. Image 3 of 5 in the computer game "A Slower Speed of Light" Players approach the speed of the light as they collect more orbs. Image credit: MIT Game Lab 2020 Massachusetts Institute of Technology. Image 4 of 5. In the computer game "A slower speed of light," players approach the speed of the light as they collect more orbs. (Image credit to MIT Game Lab 2021 Massachusetts Institute of Technology. Image 5 of 5. In the computer game "A slower speed of Light," players try to reach the speed of light by collecting more orbs. (Image credit to MIT Game Lab 2021 Massachusetts Institute of Technology

Color changes

The relativistic Doppler effect is a phenomenon where the speed at which human motion is increasing approaches that of light. This is because light acts both as a particle or a wave. It is a wave because it has a wavelength. This determines the color and frequency of the light.

Related: What if gravity didn't exist?

Kortemeyer explained that similar to how Doppler effect makes approaching a sound source make its frequency or pitch seem higher as it crests near your ear faster and more frequently, moving towards a light source makes its wavelength appear shorter, shifting its apparent color toward the violet and blue ends of the spectrum. On the other hand, moving away from an object shifts its apparent colour toward the red side of the spectrum. Kortemeyer stated that "the thing moving towards you appears bluer" and "the thing moving away form you looks redder."

The relativistic Doppler effect can be seen when human motion speeds approach the speed light. The apparent color of light changes when it is moved toward a source of light. It shifts toward the violet and blue ends of the spectrum. Moving away from an object changes its apparent color towards the red end. (Image credit: Shutterstock)

Time and distance changes

One of the most well-known effects of special relativity, is the slowing down of time for those who move at the speed of light. A person moving at a speed of light would age slower. This is known as time dilation.

Tan stated that "technically you are experiencing time delatation; but without having anything to compare it with, it doesn’t really mean anything." Tan explained that while time dilation is not visible during the game, at the end players will see a screen telling them that they have experienced less time than a stationary clock. Because the game's protagonist is moving at the speed of light, time dilation occurs, just like other effects of special relativity.

Special relativity also causes the lengths of stationary objects and objects moving at near the speed light to decrease. This phenomenon is known as length contraction. Kortemeyer explained that the effect can be complicated. Kortemeyer explained that objects zooming at close range to light speed might experience length contraction. However, they might appear shorter to a stationary observer due to another special relativity effect called the runtime effect.

Imagine a bicycle coming towards you. Light from the front of a bike travels a shorter distance than light from its back. This means that you can see the front of your bike as it is now, and the back as it was in the past. Kortemeyer stated that overall, the bicycle appears longer. This effect can sometimes make objects appear warped.

This means that objects moving at a slower speed would appear to be longer or more warped to stationary observers.

Related: What if Earth had an orbit that was shared with another planet?

Brightening changes

You might notice that your feet are wetter at the front than at the back when you walk in rain. You will encounter more raindrops when you walk in the rain than if you were standing still. However, the raindrops are protected by the front of your body. Kortemeyer explained that something similar might happen if you moved at the speed of light.

This is because light can sometimes behave like a collection or particles called photons. These are tiny droplets of light. Because you are walking into the photons of an object in the computer games, it will appear brighter when you move towards it. This phenomenon is known as the searchlight effect.

Mr. Tompkins in Wonderland

Tan and Kortemeyer were not the only ones to envision a world with slower speeds of light. George Gamow, a physicist, published a picture book called "Mr. Tompkins in Wonderland" in 1939. The title character rides a bicycle through a city at a slower speed of light and experiences relativistic results. Kortemeyer stated that Einstein liked the little booklet.

What did the great physicist have to say about "A Slower Speed Of Light"? Kortemeyer stated that he might have been curious to play the game in the first instance. After all, if historians are correct, he had asked at 16 what he would see if he rode a beam light. But in the game, he can almost reach the speed of light. He would probably have played the videogame until he became hopelessly motion sick, but most physicists are still playful.

Original publication on Live Science

Light is the fastest moving thing in the universe. What would happen if light traveled at a slower speed?

In a vacuum the speed of light is approximately 186,000 miles per second (3300,000 km per second). It would be a matter of seconds before humans notice it.

This scenario can be experienced by any gamer in a computer-game Gerd Kortemeyer and his colleagues, who are the director of educational technology and technological development at ETH Zurich. ETH Zurich is a Swiss university that combines science, engineering, and mathematics. The game allows you to see the strange effects of changing colors, brightness, and even changes in the perceived lengths and dimensions of objects. This would be due to a slower speed of light.

Related: What if Earth were to have rings?

Humans are slow

Even at their fastest speeds, people are slower than light.

Philip Tan, a researcher at the MIT Game Lab, stated that the fastest human beings have traveled about 0.0037% faster than the speed of light. To reach these speeds, you must be in a space vehicle.

However, thought experiments have shown that extraordinary things could happen if humans could travel at a near-light speed. Kortemeyer is an associate professor of Physics at Michigan State University. Albert Einstein's theory about special relativity, which describes how speed affects mass, space, and time, would mean that objects would be shorter as we passed them, and the Doppler effect, among other changes, would be visible to light.

These same changes would happen if light was slowing down and humans instead of speeding up. Both cases would result in us moving at a near-light speed.

Light travels at a slower pace

Kortemeyer, Tan, and other MIT Game Lab colleagues created a computer game that showed what the world would look like if the speed at which light travels was slower than normal. The game was released in 2012, and is called "A Slower Speed of Light". It features a character that collects orbs shaped like beach balls. The speed of light slows every time the character collects any of the 100 orbs.

The speed of light in real life would not slow down as it does in the game. In a vacuum, the speed of light is constant and does not change. Kortemeyer stated that although the speed of light can change depending on what materials it passes through, this doesn't alter the effects of special relativity or how we perceive them.

However, if we could see special relativity, we would be able to notice changes in colors and distance. The team then incorporated these effects into their game.

Image 1 of 5. In the computer game "A slower speed of light", players try to get closer to the speed of the sun as they collect more orbs. (Image credit to MIT Game Lab 2021 Massachusetts Institute of Technology. Image 2 of 5. In the computer game "A slower speed of Light", players approach the speed of the light as they collect more orbs. (Image credit to MIT Game Lab 2021 Massachusetts Institute of Technology. Image 3 of 5. In the computer game "A slower speed of light," players approach the speed of the light as they collect more orbs. Image credit: MIT Game Lab 2020 Massachusetts Institute of Technology. Image 4 of 5. In the computer game "A slower speed of light," players approach the speed of the light as they collect more orbs. Image 5 of 5 In "A Slower Speed of Lighting," players are able to approach the speed of light by collecting more orbs. (Image credit to MIT Game Lab 2021 Massachusetts Institute of Technology

Color changes

The relativistic Doppler effect is a phenomenon where the speed at which human motion approaches that of light becomes apparent. This is because light acts both as a particle or a wave. It is a wave because it has a wavelength. This determines the color and frequency of the light.

Related: What if gravity didn't exist?

Kortemeyer explained that similar to how Doppler effect makes approaching a sound source make its frequency or pitch seem higher as it crests near your ear faster and more frequently, moving towards a light source makes its wavelength appear shorter, shifting its apparent color toward the violet and blue ends of the spectrum. On the other hand, moving away from an object shifts its apparent colour toward the red side of the spectrum. Kortemeyer stated that "the thing coming towards you looks bluer or the thing moving away looks redder."

The relativistic Doppler effect can be seen when human motion speeds approach the speed light. The apparent color of light changes when it is moved toward a source of light. It shifts toward the violet and blue ends of the spectrum. Moving away from an object changes its apparent color towards the red end. (Image credit: Shutterstock)

Time and distance changes

One of the most well-known effects of special relativity, is the slowing down of time for those who move at the speed of light. A person moving at a speed of light would age slower. This is known as time dilation.

Tan stated that "technically you are experiencing time delatation; but without having anything to compare it with, it doesn’t really mean anything." Tan explained that while time dilation is not visible during the game, at the end players will see a screen telling them that they have experienced less time than a stationary clock. Because the game's protagonist is moving at the speed of light, time dilation occurs, just like other effects of special relativity.

Special relativity also causes the lengths of stationary objects and objects moving at near the speed light to decrease. This phenomenon is known as length contraction. Kortemeyer explained that the effect can be complicated. Kortemeyer explained that objects zooming at the speed of light may experience length contraction, and might appear shorter, according to stationary observers' measurements. However, they would actually appear longer due to another effect called the runtime effect.

Imagine a bicycle coming towards you. Light from the front of a bike travels a shorter distance than light from its back. This means that you can see the front of your bike as it is now, and the back as it was in the past. Kortemeyer stated that overall, the bicycle appears longer. This effect can sometimes make objects appear warped.

This means that objects moving at a slower speed would appear to be longer or warped to stationary observers if they were closer to the speed of light.

Related: What if Earth had an orbit that was shared with another planet?

Brightening changes

You might notice that your feet are wetter at the front than at the back when you walk in rain. You will encounter more raindrops when you walk in the rain than if you were standing still. However, the raindrops are protected by the front of your body. Kortemeyer explained that something similar might happen if you moved at the speed of light.

This is because light can sometimes behave like a collection or particles called photons. These are tiny droplets of light. Because you are walking into the photons of an object in the computer games, it will appear brighter when you move towards it. This phenomenon is known as the searchlight effect.

Mr. Tompkins in Wonderland

Tan and Kortemeyer were not the only ones to envision a world with slower speeds of light. George Gamow, physicist, published a picture book called "Mr. Tompkins in Wonderland" in 1939. The title character rides a bicycle through a city at a slower speed of light and experiences relativistic results. Kortemeyer stated that Einstein liked the little booklet.

What did the great physicist have to say about "A Slower Speed Of Light"? Kortemeyer stated that he might have been curious to play the game in the first instance. After all, he had asked his 16-year-old self what he would see if he rode a beam light. But, in the game, he can achieve almost the speed light. He would probably have played the videogame until he became hopelessly motion sick, but most physicists are still playful.

Original publication on Live Science