Discussion in 'Physics & Math' started by Lua, Feb 4, 2002.
double post Please Register or Log in to view the hidden image!
Please Register or Log in to view the hidden image!
Log in or Sign up to hide all adverts.
Imahamster made an interesting comment on that ... let us see
James, let me reply with some of the thoughts that occure to me when I read your explanation of FOR's. When a photon travels from the sun the to earth, would you say that the earth is moving towards the photon (and the sun)? Or the opposite? It's simple, it's the photon which travels to the earth from the sun. When you imagine this and imagine that (only me in space), you take away information for the observer. Because we lack information a new priniciple is suddenly a law of nature? It only means that we as observer are limited in doing science.
Let us see, I see the earth coming towards me. What could be the reason? I am still in the solar system, right? We know our solar system does have a velocity. But, I am IN the solar system. I have the momentum of the solar system. I travel along with the solar system. Earth is coming closer you said? There can be only one reason and that is because I have accelerated. I don't need other reference frames. What the observer needs is information of both entities (put a light source on of the two and you can calculate the only variable you need which is Time). What relativity does in the equations is drag in a third observer. This is why you get time dilation and the rest. If you have logic and the necesairry information, you will be able to know who's moving. You will be able to show with quantum mechanics why the clock of the moving observer will slow down.
And let us not forget in this discussion the question "Did the Michelson-Morley experiments prove there was no "aether wind"?
They have been accepted by almost everyone as giving a "null" result, but in point of fact they showed a very interesting periodic variation indicating the presence of an aether wind, though not the one they'd been looking for! Dayton Miller devoted a great deal of time and effort to doing more experiments to investigate the variations, which proved to be reproducible but to show systematic changes with time of year and some other factors. He also showed, incidentally, that the effect disappeared if you put the apparatus in a thick-walled enclosure!!! (he summarised his work in great detail in a review paper in 1933: Miller, Dayton C, “The Ether-Drift Experiments and the Determination of the Absolute Motion of the Earth”, Reviews of Modern Physics 5, 203-242 (1933)
The most reasonable interpretation of his results was that either the earth was moving pretty fast (about 200 km/sec, faster than it moves around the sun) in a direction roughly perpendicular to the plane of the solar system, or the aether was moving in the opposite direction at that speed. The aether seems to be moving like a fluid (in fact, it is like a crystal fluid), going with much slower relative velocity near solid bodies, thus accounting for the apparently modest speed (about 10 km/sec) indicated by Miller's experiments.
It appears that there was a major difference of opinion between Miller and Einstein. Einstein's Special Relativity theory demanded that the Michelson-Morley experiments must have been null. The aether was not acceptable.
By 1955 the aether had become a dirty word. Even in 1940 or so, you can find no reference to Miller's existence in Herbert Ives' papers (I'm still seeking more info of the latter, cause as some here will know this famous scientist performed some experiments which he said contradicted relativity). The 1979 Brillet and Hall experiment*, currently accepted as an accurate confirmation of Michelson and Morley's "null" result, appears to have been conducted in ignorance of Miller's work. They seem to have been unaware of Miller's conclusion that the aether wind can only be detected in the open!!! Their temperature-controlled Fabry-Perot interferometer would have had little chance!
The Michelson-Morley experimental result has been confirmed many many times. There is no detectable aether. Perhaps there is an aether which contrives to be undetectable, but in that case it is ruled out by Occam's razor.
Regarding reference frames, here's what Galileo had to say:
"Shut yourself up with some friend in the main cabin below decks on some large ship, and have with you there some flies, butterflies, and other small flying animals. Have a large bowl of water with some fish in it; hang up a bottle that empties drop by drop into a wide vessel beneath it.
With the ship standing still, observe carefully how the little animals fly with equal speed to all sides of the cabin.
The fish swim indifferently in all directions; the drops fall into the vessel beneath; and, in throwing something to your friend, you need to throw it no more strongly in one direction than another, the distances being equal; jumping with your feet together, you pass equal spaces in every direction.
When you have observed all of these things carefully (though there is no doubt that when the ship is standing still eveything must happen this way), have the ship proceed with any speed you like, so long as the motion is uniform and not fluctuating this way and that.
You will discover not the least change in all the effects named, nor could you tell from any of them whether the ship was moving or standing still.
In jumping, you will pass on the floor the same spaces as before, nor will you make larger jumps toward the stern than towards the prow even though the ship is moving quite rapidly, despite the fact that during the time that you are in the air the floor under you will be going in a direction opposite to your jump.
In throwing something to your companion, you will need no more force to get it to him whether he is in the direction of the bow or the stern, with yourself situated opposite.
The droplets will fall as before into the vessel beneath without dropping towards the stern, although while the drops are in the air the ship runs many spans.
The fish in the water will swim towards the front of their bowl with no more effort than toward the back, and will go with equal ease to bait placed anywhere around the edges of the bowl.
Finally the butterflies and flies will continue their flights indifferently toward every side, nor will it ever happen that they are concentrated toward the stern, as if tired out from keeping up with the course of the ship, from which they will have been separated during long intervals by keeping themselves in the air....
Galileo Galilei, Dialogues Concerning the Two Chief World Systems (February 1632)
In fact, there is <i>no</i> experiment you can do inside the ship which will distinguish the ship moving at a constant velocity from when it is at rest. That's the basis of relativity. There simply is no universal standard of rest.
Presumably an astronaut in orbit can compare his orbiting clock to signals coming from a clock on earth and detect that the clock on earth is ticking faster. This doesn’t contradict Special Relativity as the astronaut is experiencing continual acceleration.
If the astronaut wasn’t orbiting the earth but was moving with constant velocity, then Special Relativity says the astronaut would see the earth clock as ticking slower while C’est moi seems to believe the astronaut would still see the earth clock as ticking faster.
What experiment could be performed to resolve this question?
What about communication between earth and Voyager? Voyager is traveling fast and shouldn’t be very affected by the sun’s gravity field. After correcting for Newtonian Doppler affects what frequency adjustment is needed for communications frequency synchronization with the Earth station? Presumably the Voyager instrument frequency setting should suffice as an observation from a moving frame of a “stationary” Earth clock? Just have Voyager telemetry report the instrument frequency setting and one should know whether Voyager sees the Earth clock moving slower (lower frequency) or faster (higher frequency).
(Don’t expect the Voyager instruments to be sufficiently accurate for this measurement but future missions might do this.)
I suspect that there would be a frequency shift in two-way communication with Voyager, which would be small but detectable. This could well confirm the relativistic time dilation. However, I'm not sure if this has been published. I am reasonably certain that it would need to be taken into account by the guys at NASA, but I'm equally sure they take relativity so much for granted that they would not make a big deal out of this.
"The Michelson-Morley experimental result has been confirmed many many times."
you are wrong and it seems you didn't even read what I said
see 'Fresnel drag' now
--> do we have to assume that the aether had to be something at absolute rest on a universal scale?? NO
the aether is 'that unseen something that can store energy and affect light propagation but yet fills any free space in and around the protons and electrons and their derivative particles that we do see as the matter form'.
the aether which was not detected is the aether that they thought to be at absolute rest
correlation with the Fresnel drag: if you measure the speed of light in a block of glass or in a tank of water the speed is reduced below that applicable in the vacuum, reduced by the refractive index IF the glass or the water is moving through space and relative to the laboratory frame, then the speed of light in passage through that medium is affected by that speed. It is a function of the speed of the test medium and the speed of that medium relative to the laboratory frame. The experiments on this provide the formula for the drag coefficient involved and is called the 'Fresnel drag coefficient'.
There need be no matter in the space between the optical components of the aether experiment, but yet the aether can be affected as if its density were changed. "How?"
19th century physicists were puzzled by the aether because it exhibits some properties telling us it is a fluid and some telling us it is a solid. That was the perception from a time when little if anything was known about 'fluid crystals'.
So if the apparatus of the Michelson-Morley experiment entrains effects akin to the action of electric fields, why should it not drag some of the structured solid-like (or crystalline) aether along with it, only to allow this to dissolve into fluid-like form which can flow backwards freely through the interstices of the solid portions of the aether to keep density constant and, indeed, avoid setting up any linear aether momentum.
Fresnel drag coefficient and its relevance to the aether and the interpretation of the null finding in the Michelson-Morley Experiment.
quote from "The Elusive Ether, A T Jackson writing about the detection of the ether (Physics Education 1974, v. 9, p. 265):
"the most important fallacy in Fresnel's drift theory would seem to be that he assumed the moving medium dragged both the light and the ether along with it, although the existence of the ether had not been established'."
Yet Fresnel's formula was verified by Fizeau and it was Michelson and Morley who assumed that the ether did not move with the earth and then were surprised to find that the earth's motion through the ether defied detection.
If the role of the ether in controlling light propagation is analogous to the role of a substance in transmitting sound, the propagation velocity c1 is proportional to (P/d)1/2, where P is a pressure modulus and d is density. Since the speed of light is fixed at c and refractive index n is c/c1, we then find that n2 is proportional to d. Now, Fresnel said that the velocity of light would be increased by u(1-1/n2) due to motion of a disturbing medium at velocity u. If then the ether has structure and its bulk has density dk that moves as a disturbance at velocity u, we may write:
n2 = 1 - k
uk + v(1 - k) = 0
because n equals 1 when k equals zero and the ether exerts no linear force on matter, meaning that its momentum is conserved as k varies.
It is then a simple matter of algebra to show that u(1-1/n2) is simply v. This means that the velocity of light relative to the earth frame is constant, as Michelson and Morley found
It defies all logic to quote the Michelson-Morley experiment as evidence disproving the existence of the aether when all it did show was that the speed of light is affected by the motion of that medium through which it is propagated.
We see no discussion in the textbooks of the fact that the light rays in the experiment were not propagating freely through empty space, as was assumed. Those rays were encountering full frontal collision with their own reflection from mirrors, meaning that the energy they conveyed had to struggle to penetrate through the energy associated with those reflected waves!! The null result of the Michelson-Morley experiment should never have been regarded as a sufficient reason to abolish belief in the existence of an aether. At best it proved that some preconceived notions about the aether were false but the aether cannot be eliminated because a few physicists had some false ideas!
"In fact, there is no experiment you can do inside the ship which will distinguish the ship moving at a constant velocity from when it is at rest. That's the basis of relativity. There simply is no universal standard of rest."
again, does it matter?? what Galileo is doing is (again) taking information from the observer
I don't say it is wrong, I simply say that because of this lack of info, we shouldn't believe SR which says more that all laws of physics are the same in ineterial frames (--> this is exactly why it is not allowed to search for mechanical effects which would cause a clock to change its rate)
(your example on earth and moving observer was equally easy to explain, it is basically always the same: lack of information + if there is an aether then we do have an absolute frame of reference)
the more I understand relativity in this very valuable discussions (at least for me Please Register or Log in to view the hidden image! ) the more I am convinced that I choose the right side. Luckily, science is still doesn't work like democracy. One little man can change everything. When the time will be ripe, relativity will slowly get replaced.
Unfortunately, the more you write, the more I don't think you understand relativity. To me, it seems like you are cutting and pasting chunks of text from other sites (mostly nutter "alternative physics" sites). If you are doing that, you should acknowledge your sources. If not, I apologise for getting the wrong impression.
One of the things you wrote above was:
<i>IF the glass or the water is moving through space and relative to the laboratory frame, then the speed of light in passage through that medium is affected by that speed. It is a function of the speed of the test medium and the speed of that medium relative to the laboratory frame.</i>
This is incorrect.
"Unfortunately, the more you write, the more I don't think you understand relativity."
I said what I thought about the very principle of relativity
got nothing more to say
I think that you can't even think outside relativity
and indeed, the quote is taken from aspden's site cause I have no such book here
so is the piece with "n2 = 1 - k
uk + v(1 - k) = 0
because n equals 1 when ..........."
i gave the site so many times, you could have recognised it .... and i am a lazy guy
Is quoting from http://www.energyscience.co.uk/tu/tu05.htm
Dr. Aspden also believes the Sun is not powered by Fusion. I seem to recall a conversation I had with Dr. Aspden arguing about this.
"Dr. Aspden also believes the Sun is not powered by Fusion. I seem to recall a conversation I had with Dr. Aspden arguing about this."
the sun is powered by fusion (I'm sure there's a lot of stuff I don't agree with him)
but how does the fusion happen? you can overwin statistics by huge density and squeesing matter very hard or you can have it happen in a similar way that scientist do it here on earth
How do scientist do fusion on Earth?? Are you referring to cold fusion??? :bugeye:
I am simply talking about 'hot' fusion --> speeding particles up and kaboum (no high density required, isn't it?)
drop the aether
I said some things which are 100% of my own concerning Galileo's principle of relativity
BUMP 4 that last thing
I guess you won't answer
Doesn't look like it. Are you talking about bombs or something, because fusion cannot be controlled as far as we know (or I know). We've only got lamo fission now.
This is my first post in these forums btw Please Register or Log in to view the hidden image!
Fusion can indeed be controlled.
Well call me a monkey and spank me bitter! That certainly looks like fusion work! So fusion must be possible...although it does not say it has been harnessed...the title itself "European Fusion Development Agreement" suggests that it is not presently possible, "development" being the key word.
But they're working on it. And good too, 'cos there's a lot of useful power in that little reaction (if 'reaction' is the right word).
But thanks for that enlightenment, Adam.
I believe the Joint European Torus broke even on power input-output a year or so back as well. It's quite an impressive project.
Separate names with a comma.