The speed of light is the quickest thing in the cosmos.
So, what would happen if the speed of light were reduced to an incredible degree? The speed of light in a vacuum is about 300,000 kilometers per second (186,000 miles per second).
Humans would immediately become aware if it were hundreds of times slower.
In a computer game designed by Gerd Kortemeyer, director of educational development and technology at ETH Zurich, a science, technology, engineering and mathematics university in Switzerland, and his colleagues, you may witness this unlikely event.
A much slower speed of light would produce the strange side effects seen in the game, including changes in color and brightness, shapes distorting, and objects blinking in and out of existence.
The game is called the “Relativity Game” because it simulates how an observer would see moving objects under different speeds of light.
The objective of the game is to guide a ball bearing through a five-level maze without touching any walls or floors. You control the ball by tapping on it to give the ball a speed boost.
A quick tap increases its speed proportionally to your finger’s proximity above the ball, if you hold your finger on the screen, increasing levels of energy create increasingly more powerful boosts.
Sluggish human speeds
Humans are sluggish compared to light at even our fastest speeds.
The fastest speed any human has ever traveled was 0.0037 percent of the speed of light, and you need to ride in a spaceship to reach those speeds.
Philip Tan, a research scientist at the MIT Game Lab
Physicists have discovered that strange things would happen if people could travel at nearly light speed, according to Kortemeyer, who also an associate professor of physics at Michigan State University.
According to Albert Einstein’s special relativity theory — which explains how speed affects mass, time, and space-time would slow down as we sped by objects, and we would contract in length.
The Relativity Game demonstrates these concepts, Kortemeyer told Live Science.
On the first level, the ball moves at such a speed that it makes up for lost time and contracts to about half size, objects get brighter as they get closer to you, whereas they change color if you approach them from behind.
On the second level, light appears to bend at angles around corners, just as it would if you had slowed time by moving faster. By speeding up your motion with an increase in speed, objects on the third level appear to distort and stretch out.
We all remember the experiment with two clocks, in which one was fastened to a wall and one was kept by an observer. The mechanism used to make this happen is something known as light caging.
Light can’t escape, it’s like a cage for it.
How does that relate to time travel? Because humans are moving at speeds faster than light, they’re essentially creating a light cage by moving around. That’s why time slows down for us, the light is “trapped” inside of that cage (time).
A slower speed of light
Kortemeyer was a visiting professor at MIT while developing the game.
Tan and his colleagues at the MIT Game Lab created a computer game to illustrate what the world would be like if the speed of light were slowed enough that special relativity became apparent in daily life.
In 2012, Kortemeyer, Tan, and their team at the MIT Game Lab created the game called “Relativity.”
According to Einstein’s special theory of relativity, time slows down for people traveling at speeds approaching the speed of light.
The Relativity Game simulates this effect, slowing down everything around you as your speed increases.
You can play it via MIT’s website or by downloading it on iOS or Android devices. The game won’t cost you anything to play, but it does require an Internet connection even when played offline.
The Relativity Game’s objective is to guide a ball bearing through an obstacle course without touching any walls or floors (which would slow the ball down).
As your speed increases, time appears to slow down. At high speeds, objects appear to be stationary, and you’ll need to depend on the shifting colors of objects to tell if they’re moving towards or away from your ball.
At faster speeds, time moves slower — just as we see in films like Interstellar — and this Relativity Game illustrates that concept for us.
The game suggests that “at 90% of the speed of light, time would move half as fast,” Tan said. “At 99% of the speed of light, time would move one-third as fast.”
As you accelerate in this game, your progress freezes and no points are acquired until you reach a certain threshold at which point the ball is moving so quickly that it’s almost invisible.
In the game, however, the speed of light would not slow down as it does in reality. The speed of light in a vacuum is constant for every observer and never changes.
However, because materials pass through it at different speeds, the speed of light varies, but that does not negate special relativity or how we perceive it.
If we could observe the speed of light, we would see that it’s always traveling at the same speed.
If our astronaut was moving around with a constant speed inside something like water (to simulate the Earth), then the game would play out very differently, time would appear to pass normally for everyone else in space and on the surface of the planet.
Also, if our astronauts were orbiting a black hole or some other incredibly strong gravitational field, then time would again appear to pass normally for them.
In the game Relativity, if our player’s speed is constant, but her direction of travel changes from straight on to diagonal with velocity across the axis directing toward the center of the Earth, it looks as though she is being pulled toward the center of the Earth instead of accelerating.
In Relativity, if our player’s speed is constant, but her direction of travel changes from straight on to diagonal with velocity across the axis directing toward the center of the Earth, it looks as though she is being pulled toward the center of the Earth instead of accelerating.
Since she’s accelerating (which means she’s changing her speed) it will be different from the black hole scenario.
If, however, our player is not traveling with a constant velocity and changes her direction of travel while still having an increasing speed, time would appear to pass slower for her.
If we play the game and accelerate constantly at 9.8 meters per second, then time would slow down by 10%. If we travel at 99% of the speed of light, time will appear to slow down on the order of 40%.
“That’s because she is gaining duration. There are more ticks on her clock than on your watch,” Tan said “If you were standing still on Earth while she was moving at 99% the speed of light, you would see her time pass by slower than your time.”