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Einstein's Theory To Go Beta Testing
pinqkandi writes: "This article over at CNN looks into the relativity of Einstein's theory of relativity (pun intended) as equipment becomes more and more precise. Soon atomic clocks will be placed in the International Space Station to analyze the accuracy of Einstein's theories. One of the lead researchers says that if Einstein's theory is not right, it will only need minor adjustments to account for changes in space-time, due to its deadly accurate precision."
If you don't understand either one, take a look
here:
Deadly precision? What has space-time done to you lately?
Karma: Good (despite my invention of the Karma: sig)
I remember in the seventies they got two atomic clocks and stuck one on a plane and after two years of the plane flying around aimlessly they found a minute difference
in time.
The joke of it all is that after a year some journalist asked why they didn't just stick it on a regular commercial jet but they didn't think of it at the time.
Mouse powered Chips, Open source Processors and Lego
is here, with a little more information on Lorentz and CPT violation.
AFAIK the current GPS satelite system makek adjustments for relativity in the signals it is sending around and they have been adjusting for this for years. See the articles at Metaresearch and lsu.edu for more info.
Soon accurate telescopes will be installed to make extremely careful measurements of Mercury's orbit to analyze the accuracy of Newton's theories. One of the lead researchers says that if Newton's theory is not right, it will only need minor adjustments, due to its deadly accurate precision.
Real Daleks don't climb stairs - they level the building.
It hasn't been proved, it just hasn't been disproved. That's why it's a theory.
-Tolerate my intolerance
Too bad Einstein isn't around anymore...
He would have made for one heck of a great match on Fox Celebrity Boxing 3 with Stephen Hawking.
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Agreed. This whole thing is a lot more like benchmarking. Those geeks want to find a way to squeeze another nanosecond out of reality.
Who moderates the meta-moderators?
The tests that Kostelecky is proposing are somewhat different than the earlier tests. In the previous tests researchers looked for changes in the frequency difference between two clocks when they were moving at different velocities or when they were at different heights in the earth's gravitational field. These tests looked at standard relativity theory (either special or general) and checked that the predictions it made were correct. In the new tests, one looks for changes in the frequency of a clock as it points in different directions (which would be akin to an ether, picking out a prefered direction in space) or a similar effect as the velocity of the clock changes.
These tests have been performed on the ground recently by measuring the frequency of a clock as its direction relative to the stars changes due to the rotation of the earth. (For example, see Phillips, et al., Physical Review D 63, 111101 (2001) or Physical Review Letters 85, 5038 (2000)- showing off is always good.) In space, one could use the faster rotation of the space station as the atomic clocks in space which may substantially outperform ground based clocks.
-Oh, my goodness, is that the time? (Rik points at Mike's wristwatch)
-No, time is an abstract concept. This is a wristwatch.
But to be truly pedantic, you will have to distinguish between "What's the time?", "What's time?" and "Is it Miller time yet?". ;-)
Money for nothing, pix for free
Technically, you're never going to get zero gravity. And yes, you're right, ISS isn't anywhere near that -- it's in orbit, and uses gravity to stay that way. ISS and the like are weightless (or near weightless) because they are effectually in a free fall; this state is termed "microgravity".
What is wrong with using existing equipment, like that hive of atomic clocks in the GPS system? They already transmit their time to just anybody that wants to receive it and all of the adjustments for relativity, etc., are known and can be removed for "raw" time measurement.
I guess the hammer and feather experiment just gets more expensive in proportion to the expansion of the beurocracy.
Eve Fairbanks says I drive a hybrid!LOL
Hasn't this been proved already? What's wrong with those older proofs?
You can't prove anything in physics, you can try to disprove something and fail, and thus you may have reason to believe that the theory was correct.
But there is always a posibility that your theory may be disproved later. (Which doesn't mean the theory is rendered useless. Newton's mechanics for example, stood for a very long time, until they were replaced by the theories of relativity. But they are still used, because in most "normal" conditions they work good enought, and the math is easier to work with.)
"First lesson," Jon said. "Stick them with the pointy end."
Atomic clocks on ISS are a trivial test of relativity compared to Gravity Probe B, hopefully to be launched soon after DECADES of development. A one-pager "GPB for Dummies" is here. GPB tests not for alterations in time but another phenomenon known as "frame dragging" which has never been directly measured. There's been lots of criticism about GPB as being too ambitious, so there's been lots of independent reviews.
Maybe it's just the way the guy was quoted in the article, but if they need to test in a "zero gravity" environment, how would the ISS be applicable?
I'd consider it a "weightless" environment, but not "zero gravity".
True, but I'm sure they've taken that into account. The problem is, when the results come back a certain way, the same persons responsible for this article will write another about how "Einstein was wrong" because they don't understand what was actually decided here.
It's like testing the lifespan of Goldfish in water. But I didn't have any water, so I used Tequila. By the way, it's 26 seconds, but after about 15 the fish started using emacs. But the example remains the same...you can "prove" or "disprove" anything depending on who's reading it. It's all relative.
An article (membership requires) in May Physics Today details the extensive corrections GPS must make for both special relativity (velocity corrections) and general relativity (gravity corrections). This has tested Einstein every day of the past 20 years, and he has held up.
I wonder if Scientists ever play practical jokes on each other and sneak into the lab to make the Atomic Clock blink 12:00
http://www.kubuntu.org/
Time most assuredly does exist. I am perceiving time, therefore I am perceiving something. Whatever this something is, I define as "time". Viola.
You may think you can wiggle out of this by claiming that what I'm perceiving is an illusion, but no such luck; I define your claimed illusion as "time" (without conceding your illusion point.) It doesn't matter how you try to do this, I can always go one meta-level higher. You can't win without throwing out logic, at which point I declare moral victory anyhow.
The parent is really a hidden instance of "overgeneralization".
- "I know of this thing 'x'", where "x" is "time" today (no pun intended).
- "This thing 'x' does not exist."
- "Therefore, no thing thought of under the word 'x' exists."
I hope I don't need to spell out why that's fallacious logic? (Hint: Just because you don't understand something doesn't affect the universe. Hint 2: You can't go "Newtonian gravity is incorrect. Therefore, there is no such thing as gravity." It's the same form, honest.)Of course the universe cannot be totally explained and there's a lot of mystery out there. Indeed, that's exactly why making up fake mystery is a waste of time! There's plenty to exercise your sense of wonder on or whatever other reason your subconcious is rebelling at this message for; why make up fake stuff like this? You need all the help you can get; throwing out logic pretty much leaves you adrift, with no clue. You wanna be that way, fine, no skin off my nose, but don't suffer under the illusion that you're any more 'enlightened' then me.
whereas the general theory is concerned with bodys that are accelerating ( In general relativity acceleration and gravity are equivalent).
Common misconception. Acceleration and gravity are not equivalent in General Relativity. They are *locally* (that word is extremely significant here) indistinguishable. The fact of the matter is that Special Relativity can handle acceleration just fine by using calculus. General Relativity is only needed where spacetime is not flat (i.e. in the presence of gravity), since the two postulates of Special Relativity only hold in regions of flat spacetime.
As coauthor of the Lorentz-violation paper being discussed, I'd like to reply to a few comments that have been made. This comment seems like a good starting point.
_Special_ relativity and quantum mechanics have no trouble getting along. In fact, the so-called Standard Model of particle physics, based on relativistic quantum physics, is an enormously successful theory. The trouble lies in getting relativistic gravity (i.e., _general_ relativity) to play nice with quantum mechanics. This is where string theory comes in.
The good thing about string theory is that it allows gravity and quantum mechanics to get along. The bad thing about string theory is that there is absolutely _no_ experimental evidence for it, and there are almost no possible tests of it that could be conducted in the near future. Lorentz violation is a major exception:
The afore-mentioned Standard Model obeys a certain symmetry called ``Lorentz symmetry'', which lies at the heart of special relativity. However, string theory allows Lorentz symmetry to be broken. Thus, any experimental detection of Lorentz violation could be a great signature of string theory, and, maybe, quantum gravity. Moreover, there exist current experiments that are capable of detecting Lorentz violation to a very high precision.
To summarize: We are studying Lorentz violation because (1) It is a possible signature of quantum gravity, and (2) It can presently be studied to very high precision.
Chuck
Remember, none of this has totaly been proven.
But remember, nothing is even totally proven in science. The best we ever have is a theory that hasn't been proven wrong yet.
In fact the opposite is the case. No one has any reason to believe that general relativity is in error, but as part of good science it is being tested anyway. One can never prove a theory; one can only disprove it. So the best you can do is test your theories with greater and greater precision as the opportunities present themselves.
It's a case where this is, in effect, a pretty mundane story (a very well-established theory is being routinely tested), but the journalist in question is implying that there is some doubt as to its validity. Of course, it's possible the experiment will reveal deviations from general relativity's predictions, which would indeed involve "minor corrections" to the theory since it is so accurate in other areas, but there is a definite spin being put on the story which isn't in the underlying facts.