Wrong, Einstein based his theory on the notion that the speed of light is constant. which is wrong.
The speed of light varies, it may have a maxium speed, but that speed is not at infinity. And yes, I’ve proven Einstein wrong.

Yes, the speed of light is not constant, a photon can be slowed down. It has a maximum speed however, which is constant at roughly 3x10^8 m/s.

What is this infinity garbage? It has nothing to do with the speed of light, the speed of light is well known to be finite. The speed limit of the universe is the speed of light. Anything that is accelerated to speeds of substantial fractions of the speed of light will have an increasing mass, thus making it increasingly harder to accelerate further. This is called relativistic mass.

Read that site, it explains everything. Stop making wild claims lacking reason and a good knowledge in the topic.

I should probably clarify my statement that the speed of light is not constant. It is, but it can appear not to be.

In a vacuum, the speed of light is a constant 3x10^8 m/s and there is nothing we can do to slow it down. However, light will appear to move slower through a medium, but it is actually not.

When a photon hits an atom in a material, it is absorbed by that atom. The photon losses some energy and then is re-emitted. This absorption process takes time, and this is what makes light appear it is slowing down in a medium.

When einstein sees a ball thrown up on the train. It appears to him that time have slowed, which is not the case. But light has slowed. And creates the impression that time have slowed.

Light travels at a constant speed in a vacuum. Tell me where I can find some information that this is false. You may be looking for it for a loooong time.

No matter what speed you are travelling at, the speed of light will remain the same. If I am travelling on a spaceship at half the speed of light and shine a light from the leading edge of the space ship, the photons emitted from that torch will still travel away from me at the speed of light.

We are not travelling at the speed of light and unless you are a photon it is impossible to. It is too difficult to explain the theory of relativity to you here. Look at that site I gave you and have a good think about it.

I have studied the theory of relativity and gave it serious thought. I am content with its logic, and its supporting evidence. Have you even given it any thought? You are making a fool of yourself. Stop being ignorant and go and learn about what you are talking about.

I will prove it.
Hey, I can make a car travel at a constant speed too!

hum… please think about what I said, before refuting me.
I said, is a photon traveling at the speed of light. If yes, then relativly, I should not be in motion.

You are failing to make any sense. I ask you to tell me where I can find evidence that the speed of light is not constant in a vacuum and you say you can make a car travel at constant speed. For someone who is a “Pinnacle of Reason” you sure aren’t showing any.

Why does the fact that a photon is travelling at the speed of light mean that you should not be in motion?

Unfortunately, I have to go and will not be able to post till tomorrow. How about you use that time to do some reading and thinking.

I don’t have time to debunk both of these proofs, so I will just tackle the first one. Here is a quote from the first guy, explaining his “proof” that the theory of relativity is incorrect:

This guy has totally missed the point, like you, he does not understand the theory of relativity. Lets assume that this observers velocity, v, is fast enough for relativistic effects to come into play. If this person moves towards a source of light, the light travelling towards him will be travelling at the speed of light c. If he is travelling away from a source of light, the light travelling towards him will be travelling at the speed of light c.

If you run at a car which is travelling at a constant speed v, the car will still be travelling towards you at v. If you are running away from a car, the car, it will still be travelling towards you at v. This guy has totally missed the point. Time dilation and length contraction will only occur to ANOTHER observer who is at rest relative to the velocity of the first observer, who is travelling at relativistic speeds.

Once again, I can’t explain to you the theory of relativity easily in this way. Here is a great site with animated descriptions of how all this works. Please read it and think about it before posting again.

hum… thanks for the site. I go to the same uni. UNSW. I’ll consult the professor who made the site. I put some serious thought into relativity last night, despite I have exams on Friday.

Light if ‘independant of its medium’ did travel ‘extra’ distances. From that angle, yes, times has slowed down.

But the experiment won’t work if we used a ball. The motion of a ball can be explained through newtonian physics.

The whole concept of relativity is dependant on the fact that light is independant of its medium. If a light flashes on a moving car, it is traveling at a constant velocity. I can’t accept that.

I am beginning to think, the whole thing is an optical illusion. Because light hasn’t travelled that extra distance at all. It just appears to have.

Anyway, I’ll consult the professor.

You haven’t answered my question. If a photon is travelling at the speed of light. From the perspective of that photon, aren’t we still?
Because, if someone travells at the speed of light, we seem still. And a photon travells at the speed of light, shouldn’t we be still, relativ to the photon?

It can be at speeds not approaching significant fractions of the speed of light. However, if the ball were to reach relativistic speeds, it would then be in the realm of the theory of relativity.

It still seems to me that you don’t have a very good grasp on this topic, but anyway I will continue.

Lets think of this another way. If you are travelling forward in a car at velocity v1, and you fire a gun out the front windshield, the bullet will move away from you at a velocity of v2. However, someone on the street, which you are driving away from, will observe the bullet travelling at v1+v2 away from them. Ok, no dramas so far, this is still in the realm of newtonian physics.

Now, lets look at light. If the same driver turns on his headlights, he will observe light travelling away from him at the speed of light, c. The second observer will also see the light travelling away from him at c, not c+v1. This is counter-intuitive if we are thinking in terms of newtonian physics.

Lets propose a mind experiment. We have two observers, both carrying a double sided digital clock, in that, when both observers are facing each other, each observer can see the time on both their clock and the other observer’s clock. One of these observers, lets say observer B speeds away does a large loop, accelerates and then speeds past observer A at half the speed of light, travelling directly away from observer A so he/she can see the time on his/her clock. Observer A stays at rest with respect to observer B.

Ok, Observer A measures 1 second has passed on his clock. After 1 second of flight at half the speed of light, observer B is 1.5x10^8m away from observer A. Therefore, when observer B’s digital clock clicks over at 1 second, the light travelling from the clock will need to travel 1.5X10^8m, which will take half a second to reach observer A. Therefore, when observer A sees observer B’s clock reach 1 second, his clock will read 1.5 seconds. Therefore he observes time to be moving slower for observer B, and vice versa for observer B. If you are at observer B’s reference point, you will see observer A move away from you at half the speed of light.

This time-dilation has been physically measured. In a NASA mission called NAVEX, an extremely precise atomic clock was mounted on a shuttle in orbit that was syncronised with one on earth. While the shuttle was travelling only a tiny fraction of the speed of light, nevertheless a time difference was measured between the two clocks which corresponded exactly with the time dilation predicted by Einstien’s theory of relativity.

So I’m sorry, but the Theory of Relativity has made many predictions which have been verified with physical experiments. Here is another: web.mit.edu/newsoffice/nr/1997/blackholes.html

And there is much more.

Well if you think of the reference of a photon, everything would be travelling away from it at the speed of light…lets not go there. The theory of relativity applies to inertial frames of reference, that is, objects with inertia. Because a photon is massless and has no inertia, you cannot look at it in this way. The nature of the photon is still not understood completely.
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I think more needs to be known about the nature of light. I’ve read an article, that says approximately X tons of sunlight falls on earth every day.

Correct me if I am wrong. If X relative to Y is travelling at the speed of light. To X, Y is staying still. Y’s watch stops. But does X’s watch still tick?

Nah seriously though, you are wrong. It all depends on how you look at it. If X relative to Y is travelling at the speed of light (which is impossible as we have said before, unless you’re a photon), you could also say that X is still and Y is moving away at the speed of light. There is no absolute frame of reference in the universe. So, if we look at a slower event. If I throw a ball away from me with a velocity v, you could just as easily say that the ball is stationary and myself (and thus also the earth) is moving away from it at v.