Faster than light

[PurpleYouko]

For observer in a box everything is going to look as if he were standing still

I know that is what is supposed to happen. I just don't buy it!

for there to be no frequency shift, the distance between the source and detector must remain in the same proportions to the velocity of the light beam.

Oh Crap!  :(

I just figured out that the frequency change at the detector will be cancelled out by the frequency change at the source so this won't work anyway.

Still doesn't explain the perpendicular example though.

And yes I have read the information at the site that you linked. I have also read bunches of textbooks and taken university level physics courses about the subject.

No book and no Physics professor has ever managed to fully answer my questions. All the answers I get just use circular reasoning. Relativity says this will happen so this is the reason why that happens. All the explanations are based on the assumption that relativity is correct. Nobody is willing to put a foot outside the box.

I even had a physics proffessor who told me that if I could prove that Einstein was wrong then he would kill himself because he had wasted his entire career.

"What a complete twat!"  I thought. Nobody with that attitude should be allowed to call themselves a scientist. Science is about pushing the bounds of knowledge, not sticking to some religious notion that what we know is what we know "so just deal with it!". That is the attitude I always come up against.

Let's all bow down to the great God Einstein  :pray:

 :angry:  PY  :angry:

[shvarz]

Nice smiley, PY

You are right about the professor - this kind of attitude is a shame for a scientist.  It is the reason why some people believe that science is a sort of religion.

One thing to remember though - theory of relativity appeared to explain an already observed fact - that speed of light is the same for all observers in inertial systems.  You may not buy the theory, but you have to accept the fact :)  And explain it somehow :)

[Zelos]

schvarz, why does light have to be ruled by newtonia physics? relativistic is good as any, relativity does alot of sense.
all speeds are different relative to different things, exept the speed of light which is the same relative to everything

[shvarz]

zelos:  I can't quite place your post.  Is this a question or a comment?  What are you trying to tell me here?

[Zelos]

im trying to tell that relativity does make as much sense for speeds close to light as newtonia do for speeds belowe 0,1C, and the "all speeds are different relative to different things, exept the speed of light which is the same relative to everything " is just a comment that is true, think it matches in this topic

[shvarz]

OK....

But why are you telling me this?  I never argued with this.

[Zelos]

just got the picture you did

[PurpleYouko]

One thing to remember though - theory of relativity appeared to explain an already observed fact - that speed of light is the same for all observers in inertial systems. You may not buy the theory, but you have to accept the fact  And explain it somehow 

This may just be me being out of touch but I haven't actually seen any incontravertable proof that the speed of light actually is the same for all observers in inertial systems.
Do you have any links to actual experiments in which this has been observed? (particularly before Einstein came up with the theory)
I don't actually know of any but as I said, this could just be me being out of touch with physics research papers.

I know they did some experiment with an atomic clock on a fast airplane that circumnavigated the world. while its twin stayed behind. The claim was that they read different times afterwards but if they did then it kind of screws up the explanation given for the twins paradox.
More than likely, the acceleration, different air pressure, magnetic fields or whatever, messed with the workings of the clock on the plane so that it didn't keep accurate time during the trip.

 :D  PY  :D

[Numsgil]

I do know that mercury's observed orbit was off from its newtonian orbit, and that relativity helped explain it just about perfectly.

There was another thing too, another celestial event, that occurred just a bit after Einstein released his theory but I don't remember what it was.

[shvarz]

In the same website: http://www.phys.vt.edu/~takeuchi/relativit.../section07.html
he is talking about Michelson-Morley experiment.  I am not a physicist, so I can't tell the details and setup and validity.  I just assume that scientists who did this knew what they were doing.  I also assume that many similar experiments have been performed many times after the theory has been put forward.  Or at the very least that many experiements relied on the fact that speed of light is constant for all inertial observers and got the expected results.

[PurpleYouko]

I will go back and read your article again to see if I can find specifics.

By my understanding though, there is no experiment that we are able to do in which relativity comes up with a different answer than Newtonian physics.

In order to see any divergence we would need to be travelling at a very significant fraction of light speed.

We simply don't have accurate or precise enough instruments to tell the difference at the speeds that we are able to travel.

Num: I haven't heard about this Mercury orbit thing. Do you have any references?

 :unsure:  PY  :unsure:

[Botsareus]

ahhh ic , light is really traveling on the same speed, but because the abserver on the ground is in a "different time frame" it "seams" to him that the speed of light is different for bouth directions.

[Numsgil]

PY, try this out.

I think that's what I'm talking about.  Second section entitled 'Mercury's Changing Orbit'.

Also, I think there have been some tests using the mirror on the moon to test the idea of the speed of light being constant for all intertial frames.  Could be wrong though, I'm not a scientist.


Bots, are you talking about the Ether?  Because that was proved wrong later, which is why they needed relativity.

[Botsareus]

No I am quoteing some of my comprehansion of the link shvartz posted, just never mind or somthing.

[PurpleYouko]

The ETHER was never actually proved wrong.

Using this contraption



The Michelson Morley experiment showed that there was not the expected flow in the ether on the surface of the Earth. They did, however, measure some differences.
This discepency could be explained either by relativity or by the Fitzgerald-Lorentz contraction.

Another possible solution was found in the Fitzgerald-Lorentz contraction. In this theory all objects physically contract along the line of motion relative to the aether, so while the light may indeed transit slower on that arm, it also ends up travelling a shorter distance that exactly cancels out the drift.

Other suggested reasons for the results include the magnetic field of the planet dragging the ether along with it. After all we know that gravity effects light.


And even to this day there is a small difference noted when the experiment is repeated with modern lasers over much longer path lengths. They just don't match up to the effect expected by the presence of a universally stationary ether.

The ETHER theory has now been all but abandoned in favor of relativity even though, with certain ammendments, it can explain pretty much everything as well as relativity can.

 :D  PY  :D