What Happens When You Travel Faster Than Light?

Do we ever listen?

Albert Einstein proposed the theory of special relativity in 1905, where he stated the speed of light is the maximum speed at which all physical interactions can occur. This means nothing can travel faster than the speed of light, including matter and energy. I repeat! NOTHING can travel faster than the speed of light!

But where is the fun in that?

If we ever achieve this, there will be implications, and these are some of the significant impacts:

Time Dilation

Time dilation is one of the most fascinating and mind-bending concepts to come out of special relativity. It was first proposed by Albert Einstein, stating that as an object approaches the speed of light, time appears to slow down for an observer on that object. This effect is known as time dilation. It means that if a thing were to travel faster than the speed of light, time would appear to stop altogether for an observer of that object. It's a concept that has been confirmed through various experiments, and it's one of the reasons why faster-than-light travel is considered impossible according to our current understanding of physics.

An example of time dilation in action can be seen in the famous "Twin Paradox." Imagine two identical twin brothers, one of whom stays on Earth while the other travels at high speeds in a spaceship. When the traveling twin returns to Earth, he will have aged less than his stationary twin due to the time dilation effect. From the observer's perspective on Earth, time would have passed normally for the stationary twin but would have slowed down for the traveling twin.

Causality violations

Causality is the principle that events occur in a particular order, with cause and effect. If an object could travel faster than the speed of light, it would mean that it could travel back in time. This would create the possibility of causality violations, where the cause and effect of events would be reversed, leading to logical paradoxes.

One classic example of a causality violation is the "grandfather paradox." Imagine that you have a time machine and decide to go back and kill your grandfather before your father is born. In this scenario, if you were successful in killing your grandfather, you would have never been born, and therefore, you would never have gone back in time to kill your grandfather in the first place. This creates a logical paradox, as it's unclear whether or not you would have been born or if you would have existed to go back in time to kill your grandfather.

Another example of a causality violation is the "predestination paradox." Imagine going back in time and preventing a significant historical event from occurring. In this scenario, the future would be drastically different from the one you remember. However, if the future is different, then the event you prevented from occurring would never have happened in the first place. This creates a logical paradox, as it needs to be clarified whether or not the event you prevented from occurring would have happened or if it would have been prevented.

In physics, causality violations are not allowed, as they would lead to logical paradoxes and break the laws of physics. This is one of the reasons why scientists believe that FTL travel is impossible and that the speed of light is a universal speed limit.

It's worth noting that the theory of special and general relativity doesn't rule out time travel, but it makes time travel to the past impossible because it would require traveling faster than the speed of light, which is not possible according to the laws of physics.

The concept of distance becomes meaningless.

The concept of distance is fundamental in physics and describes the separation between two points in space. It is a basic concept in many areas of physics, including classical mechanics, electromagnetism, and general relativity.

However, if faster-than-light (FTL) travel were possible, it would fundamentally change our understanding of distance. This is because the speed of light is considered the universal constant for measuring distance. It is the fastest thing in the universe, and as such, it is the benchmark by which all other speeds are measured.

To give an example, imagine a distant planet that is 10 light-years away from Earth. If it were possible to travel at speeds faster than light, an observer on Earth could reach this planet in less than 10 years. However, the distance to Earth would still be 10 light-years for an observer on the planet. This means that the concept of distance would no longer be universal but relative to the observer. This would lead to confusion and challenges in physics, as the traditional ways of measuring distance would no longer be valid.

It could also pose a problem for communication, as the distance between two points would not be a universal constant, making it difficult to predict how long it would take for a signal to reach its destination.

Theoretical challenges

Faster-than-light travel would fundamentally challenge our current understanding of physics. As we know them, the laws of physics set the speed of light as an unbreakable barrier that nothing can surpass. This means that if an object were to travel faster than the speed of light, it would require new theories to explain how it could happen. These new theories would have to consider how matter and energy would behave at such high speeds and how the laws of physics would be affected. This is a daunting task for physicists, requiring a complete rethinking of how we understand the universe.

An example is the concept of energy. The laws of physics tell us that as an object approaches the speed of light, its mass increases, and an infinite amount of energy is required to accelerate it to the speed of light. This would mean that faster-than-light travel would need an infinite amount of energy, which is impossible according to our current understanding of physics.

If we always followed the advice of experts, we'd never know the full potential of science. And I will ask again, where's the fun in that? While faster-than-light travel may not be a reality yet, the discussions and theories surrounding it open up the possibility for new technologies and discoveries. Sure, it may lead to some mind-bending time paradoxes, defying the laws of physics and building new theories/rules, but isn't that what makes science so exciting? And if you're worried about looking foolish in front of your friends, just remind them that science is all about taking risks.