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Frame Dragging by Earth Reconfirmed
smooth wombat writes "After 11 years of watching the movements of two Earth-orbiting satellites, researchers found each is dragged by about 6 feet (2 meters) every year because the very fabric of space is twisted by our whirling world.
The results, announced today, are much more precise than preliminary findings published by the same group in the late 1990s.
The researchers say their result is 99 percent of the predicted drag, with an error of up to 10 percent. The details are reported in the Oct. 21 issue of the journal Nature."
I thought it had to do with some new rendering techinique in HL2.... then i realized it was just boring old space-time stuff...
Hmmm witty sig or funny sig? Maybe elitest techy sig!
....I can't find the @!#% TV remote. Time to diet, I guess.
Table-ized A.I.
Hmmm... I read this earlier because CNN jumped on it, but there are questions (noted in the Nature article) about its actual accuracy. There's some concern that the original gravity field maps that this method used weren't accurate enough.
This is a good step forward, but I think until we call the frame dragging prediction confirmed we should wait to see what Gravity Probe B comes up with.
Alito: A vote for Alito is a punch in the eye to put that bitch back in her place!
-HJ
Comment removed based on user account deletion
You're thinking of NASA's Gravity Probe B. That one isn't finished yet.
This idea of this drag was originally proposed by Einstein. Almost fifty years ago, the idea of how to experimentally verify this effect was proposed; however, it required the launch of a very accurate gyroscope. That gyroscope, which is the center-piece of the longest running NASA project ever, was just recently launched into space. More info about it (Gravity Probe-B) and a good description of this drag can be found at http://einstein.stanford.edu. Yes, the article is describing a different project than GP-B; however, it references the skeptism that the folks at GP-B have expressed at this latest experiment, and the GP-B folks are considered the experts in the field. Check out their site, it's fascinating.
From the CNN article:
"Ciufolini's team analyzed millions of laser signals bounced off two satellites, called LAGEOS and LAGEOS 2. Both are highly reflective spheres not designed to do any work of their own. They look like 2-foot-diameter (0.6m) golf balls and contain no batteries or electronics."
Space Balls?
Basically (acc. to the theory of relativity), gravity is not really a pull from one object to the other. What it is is a distortion in the fabric of space-time. What does this mean? Well think about a sheet stretched out very flat. On this sheeta are a number of very light objects. Now think of a lead weight placed in the center of the sheet. The sheet will bend into an inverted cone shape and all the items will slide towards the weight. Ta Da! Gravity!
Gravity is an extremely pervasive force. While it is the weakest of the defined forces, it permeates every area of our universe and, overall, has the largest impact. It is even powerfull enough to warp light. Again, just think of light as travelling along the surface of the sheet, the depression in the middle will warp the ligh as it travels.
What this article is describing is a secondary gravitational effect. Now, not only does this lead weight cause things to fall towards it, but if the lead weight was spinning, it will create another path/pull of gravity. In the sheet example. think of the lead weight as shaped like a corkscrew. Now imagine what would happen if you started turning that corkscrew. Not only would the sheet be weighed down in that area but it would also become wrapped around the corkscrew, causing further twisting in the fabric of the sheet. This is the effect that is currently trying to be proved.
Black holes are essentially very very very heavy weights. They create an extremely big "depression" in the fabric of the sheet. Many black holes also spin on their axis, much as the earth does. This spinning again distorts the sheet but, given how heavy the black hole is, it causes very large distortions.
This is all predicted by the theory of relativity. For this theory to be considered valid, it must make certain predictions that can be (eventually) proven. If this experiment is, in fact, true then this is yet another proof that relativity is the real deal. And there you have it.
Actually, now that I think about it. This pattern that they describe with the black hole looks exactly like a spiral galaxy (ie. the milky way) - with large "waves" coming out on all sides. It has been theorized that there is an enormous black hole at the center of the galaxy - could this be evidence of it?
Stupids mods... this should be funny, not informative. "Chicken" ... "Sanders" ... "Fred" ... it's obviously a joke.
A real 'clucker' of a joke, in fact.
Not posting anonymous, so that I can receive the karmic flogging I deserve for making this meta-comment.
HSJ$$*&#^!#+++ATH0
NO CARRIER
If backward time travel is possible, it does not seem it would have any adverse effects. Physics does not care about your lineage. Assuming you shot your ancestor, the bullet would not mystically stop and the particles that make up your body would not mystically disappear.
It does not matter that you would not be born to go back in time. Physics does not care about you as a being. If your particles exist in a certain configuration at a certain time in the past, it does not matter that the original cause no longer exists. Physics does not care about timelines. It only cares about the instant immediately preceding the event. Only people care about unbroken chains of cause and effect, not physics.
All the confusion comes from people creating paradoxes by ignoring deterministic physics laws and imposing stupid irrelevancies.
it's really a sad state of affairs when a glorified weblog isn't able to report news faster than a multibillion dollar media corporation with reporters stationed all over the globe.
No, this is different, Gravity Probe B is a separate project, this was an Italian research group who used freely avaliable data from the past 11 years of the two LAGEOS satelites, who's orbital paths have been monitored for that time. Space.com has a good summary, and so does New Scientist
In the future, we will all be very smart or very stupid.
From the CNN article: Black holes [are] typically much more massive than Earth.