# What would happen to perceived time in this scenario?

This is difficult for me to explain, but hopefully I can get my question across...

Let's say there is a planet called Planet X one million light years from Earth (there probably is). Let's also say there is a craft named Speedy 1, which could travel at the speed of light. If we hopped into Speedy 1 and travelled toward Planet X, we would arrive in one million years. If we could view Planet X from Earth, we would be seeing events from one million years ago. (Please stop me here if I'm wrong by the way.)

But traveling in Speedy 1 as a passenger, you are shortening the time delay between Planet X and yourself. You are now witnessing events from a variable-amount-of-time ago. Does anyone know how this would look to the passenger? While traveling, would we witness events unfolding at a faster rate than they actually are happening?

• "..which could travel at the speed of light." According to relativity, nothing but light (and fields) can travel at the speed of light. The relativistic formulas go to 0 (e.g. length) or infinity (e.g. mass and time) at the speed of light.. Commented Jul 27, 2015 at 7:55
• Sorry, my understanding was that nothing could travel faster than light. In that case, doesn't the question still have merit? Commented Jul 27, 2015 at 8:21
• The Lorentz factor is significant here. Note that at .99C it is 7.09, at .999C it is 22.37, at .9999C it is 70.71, at .99999C it is 223.61.. At C it is infinity. So as you can (hopefully) see, the 'infinity' figure is what makes it impossible for any matter to reach the speed of light, and minor variations in speed just before that have an enormous difference. "In that case, doesn't the question still have merit?" I am unable to comment on whether the question has merit, but it makes no sense .. Commented Jul 27, 2015 at 8:46
• .. to be talking about a ship travelling at a speed that it cannot ever reach. For any speed before that, it is necessary to pin it down precisely in order to get a number. Commented Jul 27, 2015 at 8:47

The only way you could travel at the speed of light, not assuming highly theoretical faster than light (FTL) travel which actually bends spacetime to shorten the distance between two points (highly simplifying here), is if you transfer consciousness as information about it into a distant neural network or any other physical medium later supporting its function. So in that sense, you wouldn't see anything (or otherwise perceive information) about the environment that the information about your consciousness would have traveled through.

With FTL, and bending or warping of spacetime, it would be more like taking a shortcut. You'd see the shortcut at the (likely non-relativistic) speed you're traversing it as your point of origin behind you and destination point in front of you, but you wouldn't see the long way around path or anything from it, because you're not on it. If you can traverse this shortcut at relativistic speeds approaching some significant portion of the speed of light (c), then you'd also see objects behind you redshifting and objects in front of you blueshifting, and length-contracted space between two points at your sides.

If you're of mass though, be it baryonic or any other exotic matter that we have yet to directly detect, define, and work with, you simply can't travel at 1 c throught spacetime. Energy required for it is infinite, and you'd be of infinite mass to your environment, attracting spacetime towards you at the speed of light. You would have been, literally, the end of everything. You wouldn't see anything, even if you were some Marvel's superhero that can withstand the lack of reality, as time, from your vantage point, would have dilated to 1/∞. Form your point of view, the whole Universe would have collapsed onto you before you'd be able to realize you're in a bit of a pickle.