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Is the Earth in a Vortex of Space-Time?
da6d writes "Apparently, we'll soon know for sure.... NASA has announced in an article that 'A NASA/Stanford physics experiment called Gravity Probe B (GP-B) recently finished a year of gathering science data in Earth orbit. The results, which will take another year to analyze, should reveal the shape of space-time around Earth--and, possibly, the vortex.'" More from the article: "If Earth were stationary, that would be the end of the story. But Earth is not stationary. Our planet spins, and the spin should twist the dimple, slightly, pulling it around into a 4-dimensional swirl. This is what GP-B went to space to check."
Live long and vortexed?
Is Dr. Gene Ray behind this discovery?
http://www.timecube.com/
"If Earth were stationary, that would be the end of the story. But Earth is not stationary."
Are you on crack!? The earth is stationary. It is the sun that's moving.
If the Earth is in one of those time vortex things do I get paid overtime?
that explains the Bermuda Triangel huh ?, Maybe we will find flight 19 and a bunch of missing Millitary too.
CH
If Earth were stationary, that would be the end of the story. But Earth is not stationary.
I see they found that universal frame of reference they were looking for.
On the bright side if we did get flushed through the vortex at least we would no longer be located in the unfashionable western edge of the galaxy.
It's only paranoia if your wrong...
My Cortex is in Gore-Tex contemplating the Vortex. I'm getting a complex! I need a cold compress! I need to undress. I'm relatively impressed. Er... where's Eminem when you need him? Am I off-topic here?
The baby's fine -- please stop sending business cards.
I hope this gets proven because then Tempest will go down in history not as a video game but rather an interactive documentary on gravity.
There are no karma whores, only moderation johns
Well, if there's something wrong, it's best to not be caught without your Visual Guide to Surviving Timeless Space.
Behind the Gravity Probe B is here and here . It is a fascinating read, esp. about the gyroscopes.
"The four gyro rotors are made of fused quartz, fabricated to an extreme level of material homogeneity and then ground to the near-absolute sphericity (Figure 1). The spheres are round to within 40 atomic layers, which is proportionally equivalent to an Earth-sized sphere with surface height variations of only 16 feet...."
"It's one thing to have a virtually perfect gyro rotor, but that alone does not provide the necessary performance for this experiment......The electric fields center the rotors to a few millionths of an inch. They did not perform the spinning up electrically, however. Instead, they directed a precise stream of helium gas, traveling at nearly Mach 1, at the rotors. It takes about half an hour for the rotor to reach full speed, and it loses less than 1% of this speed over 1000 years in the super-vacuum of the cavity."
I think it's interesting - general relativity makes some very hard to verify but specific predictions. Many competing theories to it over the last 50 years have made predicitions that have, one by one, turned out to be false. Rotational frame dragging is (I think?) one of the last unverified ones. According to Newtonian gravitation & mechanics, the rotation or non-rotation of the earth should not affect an orbiting satellite a whit (ignoring "complications" like variable atmospheric drag based on rotation rate, different shape of earth at different rotation rates, etc.), or put more abstractly, the rotation of an axially symmetric mass distribution should not have anything to do with its gravitational field. General relatitivity does not agree with Newtonian mechanics here, which brings up yet another interesting question:
Is there a difference between rotating reference frames and non-rotating reference frames because of the universe of matter around them, or is it self-generated? In other words, if we "removed" the entire universe except the rotating Earth, would rotation still have meaning? Could we still do an experiment and detect its rotation, or is that an artifact of the universe of matter around it that would vanish when it did? As far as I understand general relativity (and IANAP), it does not make a hypothesis one way or the other. Is the question meta-physical? Or is there some clever way to set up an experiment to actually tell?
Sigh - sometimes, I wish I was a physicist!
The "vortex" is a analogy. The relativity formulae predict a behaviour of the universe that this probe is trying to observe. If "vortex" makes you dizzy then think corriolis effect or centrifugal forces, both of which are bogus simplifications humans use to describe messy bits of Newtonian mechanics. So, think of the vortex as a simplified mathematical/physics construction to describe some horrifically complicated equations.
Oh, and don't try this experiment in Kansas. Relativity is only a theory, after all.
-AD
Only once the data is analyzed will the vortex phenomona considered proven (or disproven, obviously).
Not so obvious. The word 'inconclusive' comes to mind.
Mod down people who tell people how to mod in their sigs
Parent's link is nice and making fun of the average impression people hold on "no time" (at least that's why I get a laugh out of it) as it doesn't make sense to think of "no time" as hitting pause on your remote control. It seems much more likely (almost a logical certainty?) that "no time" is like hitting a button on your remote control and suddenly you see the whole dvd/whatever in an instant, and in the next instant (not that it would be easy to differentiate between it) you see the whole dvd/whatever as well, and in the next instant, and the next and so on forever (forever is all that exists outside time).
s /universe.html
:)
Welcome to how god sees the complete existence of the universe or would see it if such an entity (god) exists. Realize that such a point of view removes the inherent contradiction between free will and fate. Also savour the following implication of "no time" or "outside time": unlimited bandwidth/information communication. That has implications making it possible for such an entity to be absolutely moral as it has absolute knowledge of everything that has ever happened, all causations and effects: if one didn't have such complete knowledge one couldn't make any kind of justifiably correct decisions; which in itself has further implications for everybody that are aware that their knowledge is less than absolute - humility.
Could it be that a phenomena such as spooky action at a distance through entanglement is our first observed clue into practical use of this "part" of existence?
Take all this and combine it with the speculative view of massless particles, i.e. a pure waves whose medium is space/time itself, as the informationrich, faster than speed, "dataway" of souls and you'll get both a bunch of kooks and people who realise that monotheistic religions might have been basically right all along... (some of you might not differ between the two, I know I know lol).
Offtopic but I'll throw it in anyway:
http://www.veritas-ucsb.org/library/origins/quote
For any and all atheists reading this don't worry, be happy
this comment is provided "as is" and without any express or implied legibility or congruity [...]
The idea of relativity is that no frame of reference is "special". Working this out for frames that differ by a constant velocity is pretty straightforward, but the situation with respect to rotation isn't so straightforward. If you spin yourself around you will quickly find that there does seem to be a special frame that doesn't make you dizy, which we call the non-rotating frame. To know that you are spinning, you don't appear to have to measure your rotation relative to anything else.
Einstein had the idea that really, rotation is relative, too, and this apparently special non-rotating frame is really just the frame in which you are not spinning relative to the other bodies in your region of space time. In other words, seen from a different region of the universe, maybe our region of the universe is spinning furiously, but we don't notice it because all the bodies near us are all spinning furiously together.
When you work out the math in the context of general relativity, the implication is that, near a big spinning body, for you to feel like you are not spinning you actually needs to be spinning slightly relative to what would fell like not spinning far away from the body. The effect is called frame-dragging. This experiment tried to measure the frame-dragging effect of the Earth on some extremely precise gyroscopes in orbiting satelites.
There's no reason *not* to be confused by the article. It's a pretty subtle phenomenon, described in an astoundingly sloppy writeup. Hard to believe it took three people to write something which is neither complete nor coherent, and which doesn't even give you enough key words to search for more information.
The Gravity Probe B homepage has a far better introduction to the experiment. (Go to "classroom" -> "story of GPB" for a concise intro.)
http://einstein.stanford.edu/
In short, general relativity predicts that a massive rotating object (like the earth) distorts the space around it in such a way that nearby objects that are locally at rest are actually rotating slightly when compared to distant stars. (Locally at rest means that, for example, if you put some guy in a box with any measurement apparatus he could imagine, his measurements would show that the box isn't rotating.) This doesn't happen in Newtonian physics, and Gravity Probe B should be able to measure it and compare it to what one predicts using GR.
The effect is usually called "frame dragging," or the "Lense-Thirring Effect."
The equation is 40DD=MC2.
Yeah, the earth is somewhat flattened (actually, pear shaped due to Antarctica holding more glaciers than the arctic.) The amount of deformation is so small that the human eye perceives it as perfectly spherical. The Earth is rounder and smoother than a pool ball, for reference.
I'll never make that mistake again, reading the experts' opinions. - Feynman
It seems to me that confirming (or refuting) a key prediction of relativity is a moderately good story, at least.
And the brethren went away edified.
The word 'inconclusive' comes to mind.
Not as often as the word 'hooters'.
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- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
Curiously enough Rudolf Steiner once stated that the laws of physics aren't the same everywhere. According to him they gradually change the further you get away from a certain point in space. He said something like:"Very much like the gravity influence of an object declines the further away you get from it, so do the laws of physics change."
This could be the proof of his statement.
We suffer more in our imagination than in reality. - Seneca
Einstein would probably have been surprised at this particular application of relativity.
No it won't. GR is derived from several axioms - in particular, the assumption that the laws of physics are the same everywhere that they are meaningful. If G Probe B get expected results, then it would back up this assumption, and do disprove Steiner.
1. The experiment agrees with GR and NASA says that GR is right about frame dragging.
2. The experiment doesn't agree with GR and NASA says that it messed up and they'll ask the tax payers for a do over.
This experiment is not legitimate. If they get the result they expect, they'll accept the result. If they don't get the result they expect, they'll just say (rightly) that it was a flawed experiment. We won't get any more validation of GR than we already have. If they really want to validate frame dragging, they need to look for weirdness associated with very large spinning objects, like black holes. If you could study black holes enough to find some behavior along the axis that contradicts classical physics, that would give you some meat to back the concept of frame dragging.
This is precisely what general relativity says.