settle an argument, speed of light?

Question

if you are traveling at the speed of light and you looked in a mirror you would not see your reflection , correct?

I don't belive that is true in this case LeAnne because we are not dealing with mass such as an airplane, something to drop , wind resistance, ect. thanks for your input!

Steve, thinking like that got us knowhere, thanks for not participating!

Answer 1

This is the very same question that Einstein asked himself before he developed the Theory of Special Relativity. The correct answer is that the speed of light is constant and equal to 300,000 km/sec no matter what reference frame you're in. This means that even if you were moving at the speed of light, and you shine a beam of light at a mirror in front of you, the light would be moving at 300,000 km/sec away from you and then back from the mirror (so you would see yourself).

The implication of this fact (the speed of light is constant in all reference frames) is that time is NOT absolute, and that simultaneity is also NOT absolute, meaning that time passes at different rate for different observers and it depends on their velocities.

Answer 2

If we discount all of the reasons that you can't travel at the speed of light and perform only a thought experiment - you would be able to see your reflection whether the mirror was in front or in back of you. All of your references, including the speed of light would be exactly the same as if you were stationary. This is true for any observer - regardless of their velocity.

(Think of when you are on an airplane at 500+ mph - any experiment you try inside the plane will give you the same exact results as when you are on the ground, stationary.)

Without a reasonable background in theoretical physics, this is an extremely difficult concept to accept - let alone visualize.
This phenomenon is due to the time and distance dilation at speeds approaching those of light.

Answer 3

Strictly this is not a question that you can answer, because the speed of light is unattainable - in other words, to answer the question you would have to assume you could break the laws of physics you are trying to ask questions about, which is a bit redundant.

So lets answer the question what would happen if you were at 99.9999999999999999999999% of the speed of light. And the answer is that you would see your reflection with no problem, because the speed of light relative to you would still be exactly the same. This constancy of the speed of light is an axiom of the theory of special relativity, and is borne out by all of the experimental support for the theory.

Answer 4

Physics dude is the only correct answer. I know this as i am also a physicist. Light travels at the same speed for all observers regardless of reference frame. No mass does not shrink as you approach the speed of light. Yes time does slow down for the person in motion from an outside reference frame but from the person in motions perspective it is the same. If you have any other questions about the general and the special theories of relativity i recommend reading Einsteins books as they do a good job of explaining these concepts without to much in depth mathematics.

Answer 5

Theoreticlly speaking, you would see your reflection as that speciman of light would move along at the same speed as you. However, the image would be unchanging and the mirror would look more like a picture. Any movement would have to travel from you to the mirror and then the reflection would have to travel from the mirror back to you. Any movements since you started your hypothetical trip would have to travel at twice the speed of light to be noticable in the image of the mirror.

Answer 6

You are moving with the speed of light C and in front of you there is a mirror which is also moving with your speed. You are holding the mirror in front of you.

A ray of light starting from you will travel with the speed of light.

A light beam that starts from you will never leave you and it will be always with you, because you are moving with the speed of light.

With respect to you (who is moving with the speed of light) the relative speed of light must be zero.

This was the theory believed to be in classical Physics.

Experimental evidence has proved that what ever be your speed, the light will move with a constant speed of 3x10^8m/s.

If the speed of light is C and if you are moving with the speed of light, there are two possibilities.

1. as it was thought by many before the introduction of Einstein’s theory of relativity, the speed of light the relative speed of light must be zero.

2. The other possibility is as stated by Einstein. The speed of light is independent of the source’s speed and is always one and the same by all moving observers irrespective of their speed.

As per the second possibility, the length, mass and time becomes relative and is not absolute. Therefore the length decreases and time dilates as one’s speed is increased.
Consequent of that if one moves with the speed of light then the length becomes
zero and any clock stops showing time. Time takes rest.

In that situation, even if one measures the speed of light it must be a constant. This is absurd. That is the reason that it is said that no one can move with the speed of light.

But theoretically one can move with a speed of light which is little less than the speed of light.

But even in that case the length, mass and time are altered in such a way that one measures the speed as C.

As all the three has cahnged their value every thing will be as normal as in a frame at rest.

Thus in that case also one can see his image in a mirror.

Those who are still lingering on the first possibility (classical Physics) cannot understand the new concepts.

Except Soundsgoo all who have answered so far have given you the correct answer but viewing in different perspective.

Mr. Steve has given you the simplest correct answer. Others have given lengthy but correct answer.

Answer 7

I guess you can't possibly 'look' at your mirror than eh? This would be something difficult to visualize. Your clock slow to stand still and you're crossing beyond boundary of conventional physics. Yea you probably won't see your face, but I have no clue what else will go haywire.

That's weird question, since you assume you can some how see where the mirror is which also require light to bounce off, but not your face. Unless it is one uglyass face mirror refuse to show for some reason. See the weirdness? That's why even though thought experiments are cool and fun you have to do math to make sense of it all.

Answer 8

Well, that's a theoretically impossible statement.

According to relativity you shrink the faster you go and mass can't retain complex shapes at the speed of light.

Atomic particles can't get smaller than their state at particles tranvelling near or at light.

Your body's atoms can't shrink further that that limit without altering your mass somehow.

Now, if you're talking the rhetorical arguement, yes you can see your reflection.

The retorical argument is a space ship travelling at the spped of light with a light facing forward outside the ship. Both the ship and the light are travelling at the speed of light RELATIVE to your position.

Inside the ship, rhetorically speaking, you are motionless (not moving at any speed). If you walk from the BACK of the ship to the FRONT of the ship you are NOT walking at the speed of light plus 3 MPH. You are walkinga t 3MPH and if you turn on a flash light that light travels across the room at the speed of light.

When you are in a moving bus (35 MPH) and you walk from the back to the front, from YOUR position RELATIVE to the inside you are NOT moving until you start walking, then you walk the same speed as you would on the non moving sidewalk 3 MPH.

From the observer outside the bus you are moving at 38 MPH.

You couldn't measure the flashlight from the blur if something went by the street at the speed of ligth.

That type of relativist measurement can't be done.

Remember the Earth is moving in three directions around at 1,000 MPH, around the sun at 20,000 MPH and the sun is mooving??

If you were to STEP OFF and grind to a total halt (and impossiblity) an observer moving would see you grow a little in size. Maybe half an inch. Maybe more or less.

You'd also age faster once at rest.

Answer 9

If the mirror is stationary, and you are moving away from the mirror at the speed of light, then you surely won't see your reflection. If you can even travel faster than the speed of light, you would see in that mirror things from the past, such as you looking in that mirror moments ago. That is the paradox created when we assume that we can travel than the speed of light. That is the reason many scientists believe that we, objects of mass, never can travel at or faster than light-speed. Kind of sad, really.

Answer 10

Absolutely correct. If the mirror were behind you youd be traveling as fast as the light that reflected off of the mirror, so there would be no way of it catching up to you.

but this is only true IF the mirror is behind you.

Edit: Okay, to all the people disagreeing with me. If a light leaves a source, and light also leaves a source simultaneously 500m away and they both travel in the same direction, would the two light sources ever come in contact? thats all this question is asking.

i think there might also be a lot of ambiguity in the question, such as position of the mirror, when its put in place, how its looked at. But the way we were always taught it, it was a stationary mirror (not moving with the reference frame, im not sure how that ever became part of it.)