Physics question involving the speed of light?

Question

I really love physics, but all we're learning right now are vectors and d-t, a-t and v-t graphs. So i stayed after class and asked my teacher about blackholes, long story short he said if you're going at the speed of light you can see aroung the corner before you get there... i've been thinking about that for quite some time but i just don't understand what he meens.

Answer 1

thats actually a pretty complex phenomenon, as a result of special relativity. the closer you get to the speed of light, your forward field of vision becomes narrower, however if you look directly to the left or right, you would be seeing things that are physically behind you. if you looked directly backwards, you would see nothing. and if you looked forwards at an angle, you would see things that would seem like they were directly to your left or right, but infact would be infront of you, thus you would be able to see around corners infront of you.

when going infinitesimally close to speed of light, you would see nothing in any direction, except directly infront of you, and in that spot of light, would contain all the things infront and behind you. to the point where you wouldn't be able to distinguish individual objects, and it would just look like a really bright spot of light right infront of you. and everywhere else is black.

and dont forget about the Doppler effect of light when going fast, the faster you go, the bluer things infront of you will look, and the redder things will look behind you, when getting realllly close to the speed of light, the light infront of you will get blue shifted so much, that it will become gamma waves, and the light behind you will become long waves. another "proof" if you will, that you cant reach the speed of light, because if you could, the light you would see infront of you would have zero wavelength, and light behind you would have infinite wavelength, both of watch are impossible

heres a neat graphic i found on wikipedia, it shows your field of vision as you get faster and faster.

http://upload.wikimedia.org/wikipedia/en/e/e0/XYCoordinates.gif

Answer 2

If you are on the frame going at v = c, light speed, you will see no changes inside that frame. Why...because v = 0 relative to the frame (e.g., a spaceship). So time, mass, and length seem unchanged at T, M, and L the rest time, mass, and length.

On the other hand, an outside observer would see the ship's time come to a halt, mass increase to infinity, and length disappear. Which means, if an observer on the ship could look outside, time would speed by in an instant, the universe would disappear because mass would become zero, and length would become infinite in the direction the ship is traveling. It's all relative to whether the observer is inside or outside the frame moving at light speed.

Of course, this is just an impossible mind experiment. No mass can go light speed and you can see why. At infinite mass, it would take infinite force to accelerate further. This results from f = ma and a = f/m; so when m --> infinity a --> 0 and the mass can accelerate no further...it'll never reach v = c.

Answer 3

I would imagine that you would need an ultra-solid body to absorb some hits as the faster you travel the more things you have to avoid/absorb, and have advanced monitoring systems to avoid the larger things that could wipe you out with one hit. Maybe you would have some advanced laser/firing system that could target and destroy anything deemed "lethal on impact". It sounds confusing but if you are traveling at a slower speed then you wouldn't have to avoid as much because you would be able to absorb the impact of smaller bits of debris but traveling at high-speeds those small bits of debris that would have just harmlessly bounced off quickly become lethal "bullet" type projectiles that could cause serious problems to your spacecraft. I could be wrong, but then again not being able to travel at lightspeed it's a hard thing to test lol

Answer 4

Actually... no. If you're going at the speed of light then the light coming at you from the front is frequency-shifted up far beyond the visible spectrum. Just as a car horn coming at you is raised in pitch due to the Doppler effect the same thing happens with light, in this case a blue shift because the light is shifted up-frequency toward and then far beyond the blue end of the spectrum. You wouldn't be able to see anything.

Answer 5

According to Einstein's equations, moving at the speed of light is impossible. One of these equations states that you will experience a shrinkage of space in your direction of travel. If one were ever to be able to travel at the speed of light, they would literally be everywhere at once because space would have shrunken to the point where there is no space between any two objects in travel. Thus, you would be able to see around the corner before you got there because everything would be accessible to you if you traveled at the speed of light.

Answer 6

your question is very interesting in that it is more metaphysical than physical.

the problem lies in that an observer moving at a velocity equal or exceeding light experiences a state of frozen time ( as explained in einsteins theory ) . because material objects ( i.e. mass ) must exist BOTH in space AND time to have meaning , the answer to your question becomes illogical in a practical space-time.

to answer your question, dont bother thinking about the possiblity of observers moving at lightspeed ; it is something we cannot imagine nor is it possible in current physics.

Answer 7

perhaps he thought you were making reference to black holes whose density bend light waves with their immense gravity.

joe c