What Would Happen If We Could Travel at the Speed of Light?

image Nebula

It’s impossible.

Traveling at the speed of light cannot be accomplished for many reasons. Here’s why:

  1. Going the speed of light requires infinite energy. In order to accelerate an object with mass to the speed of light, an infinitely large amount of energy would be required according to the theory of relativistic mass. This is because an object’s mass increases as it approaches the speed of light, and with an increasing mass, more energy would be needed to continue accelerating.
  2. Infinite mass. The infinite energy would cause the foil in which we are travelling (and the person inside) to have infinte mass. Infinite mass would cause it to become so dense the atoms could no longer fit and therefore the entire thing would likely either explode or burst into flames due to the motion of the molecules. If we exceeded the speed of light, we would have infinite mass and then some, which obviously is impossible.
  3. Length below 0. If we travel the speed of light, we will become flat to an external observer. To the traveler he is absolutely fine. If we went any faster, our width would be a negative number, which is impossible.

How do we know this if we cannot test it? These effects are the mere consequences to simply obey the laws of physics. To say these effects are not going to happen would require breaking the laws of physics. Since these are laws we cannot alter them without experimental proof that they are false.

Say we could bypass the impossibilities…

Impossibilities set aside, what would happen if we could travel the speed of light?

Travelling instantly. According to Einstein’s theory of special relativity, time passes slower for objects moving at high speeds relative to those at rest. As an object approaches the speed of light, time dilation becomes significant. Therefore, if an object were to travel at the speed of light, time would essentially stop for it. This means that while the object might experience the journey instantly, an observer outside the spacecraft would perceive time passing normally.

Absolute darkness. If an observer were inside a spacecraft traveling at the speed of light, strange perceptual effects would occur. Since light would not be able to reach the observer’s eyes faster than they are traveling, they would be unable to see what is happening outside. This is primarily due to the complete destructive interference of the light wave. The universe outside the spaceship would appear completely black to the observer due to the absence of incoming light. However, if the observer held up a mirror and turned on a light inside the spacecraft, he would be able to see himself because all motion is relative to an arbitrary reference point.

Other questions? Feel free to drop a comment below!