# Perception @ light speed

My question is about what a human would perceive when travelling at the speed of light. Presume that we figure out a way of propulsion and our craft has no mass etc.

Would time for the occupants of the ship come to a complete stand still and everything would be frozen like being asleep, making the journey seem instantaneous? Or would we be aware that we were indeed travelling on a space craft and playing games like "would you rather", Uno or Monopoly with each other (depending on how far we were going).

• It can't happen, formulas are going to infinite. You can approximate it with going nearly c. Aug 21, 2019 at 8:58

## 2 Answers

MIT made a little demo game, called A Slower Speed of Light, which attempts to show what would happen as you reach the speed of light by slowing the speed of light in the game.

Watch the Youtube trailer to see the relativistic effects, or download the game from MIT's game lab.

This game purely shows how visual problems appear very quickly - red- and blue-shift becomes a major issue very quickly. On the spacecraft, your local frame of reference would be just fine as you got closer to the speed of light, but your interaction with the outside universe would have the same problems.

And of course, this excludes things like the propulsion problem as your mass increases etc...

Nothing with mass can move at the speed of light. A massless particle (such as a photon) moving at the speed of light experiences no duration (also known as proper time) at all. As an illustration of this, when we observed that neutrinos can change flavour in transit, we could deduce that they must have mass (and so travel below the speed of light) because otherwise they could not change.