Speed of light and beyond?

Question

Right well, first of all, I could probably find out the answer to this if I search hard enough but I would prefer to have this explained to me.

So there it is.

If I were traveling at the speed of light, no source of light would leave my body in the direction of travel. Correct.

Now If lets say I were moving at 5m/s faster than I was in the same direction of travel( Impossible I know but..)
Would a person standing still in front of me, see me coming after they had been hit by me or would they see the speed of light + 5m/s? So effectively a new relative speed of light because of my increased 5m/s?

I know this is all impossible and the human brain couldn't even process it before it happened but I do like to think about these things. Any thoughts?

Thanks.

Answer 1

"If I were traveling at the speed of light, no source of light would leave my body in the direction of travel. Correct. "



Incorrect. Light would emanate from your body at the speed of light, C. Why? Because the speed of light is invariant with the reference frame. Plain talk...it's always C no matter what.



You know of course you can never go at the speed of light; it's impossible for anything with mass to reach that speed. So let's make your case possible by you traveling U = kC < C just a tad slower than light speed. Took you a year to get there, but now you're there.



And your image is reflected at V = C the speed of light, which can happen as photons are mass less. Your image is now traveling at W = (U + V)/(1 + UV/C^2) = (1 + k)C/(1 + kC^2/C^2) = C toward that observer. [The special theory of relativity]



And there you are. As you are going U < C and your image is going V = C, the observer will see you before your smash into her.

Answer 2

"If I were traveling at the speed of light, no source of light would leave my body in the direction of travel. Correct."



No, that's not correct. That's a common belief, but it's completely wrong.



Within a reference frame (yours or the external observers) light travels at the speed of light. You would see the light traveling at the speed of light. An external observer would see the same light also traveling at the speed of light. What the external observer would also see is your clock running slow, and the lengths in the direction of your travel as being shorter than usual. (In fact, they would see your clock at a standstill, and the lengths would be contracted to zero.) The reason is that space and time adjust to keep the light moving the speed of light when viewed from different reference frames.

Answer 3

The SPEED of light never changes. Doesn't matter how fast you go, the light that would leave your body (or your spaceship) will STILL travel at 300,000 m/s.



What CHANGES is the frequency of the light WAVES that leave your ship. For someone in front of you that you are approaching, the light WAVES appear to INCREASE in frequency. This is called a RED SHIFT. For someone behind you that you are going away from, the light WAVES seem to be less frequent. This is called a BLUE SHIFT



Yes, the people in front of and behind you will still see you, but you will appear to be a different COLOR than you are now, appearing more reddish or more bluish.



BUT . . . . .

If you were to go faster than the speed of light, you would get to the person you are approaching BEFORe the red-tinted images of you got there

Answer 4

First, one can't go that speed. People have given this some thought though, (no harm in thinking) and the conclusion is that you would travel back in time, so the future or anything happening in it would not exist for you. Just one of many "problems" with the idea.

Answer 5

"If I were traveling at the speed of light..." You cannot travel at the speed of light.



If you're going to start out by saying something that isn't possible, I'm not sure what we're supposed to base our answer on as it won't be physics. It will be fiction.

Answer 6

"If I were traveling at the speed of light, no source of light would leave my body in the direction of travel. Correct."



Nope, you would see the light leave your front at light speed. The speed of light is the same for all observers moving uniformly relative to each other. That is the basic starting point for special relativity theory and it is confirmed in many many experiments. To make sense of it, we have to change our notions of space and time, and that's what comes out of the theory.