Posted on 10/22/2004 1:19:26 AM PDT by familyop
WASHINGTON (Reuters) - Einstein was right -- again. Satellites that have been pulled slightly off their orbits show that the Earth is indeed twisting the fabric of space-time as it rotates, scientists said on Thursday.
They said their findings are the first to directly measure and prove an important aspect of Albert Einstein's General Theory of Relativity -- that a rotating body warps and twists the "fabric" that combines the three dimensions of space and the fourth dimension of time.
"As the Earth turns, it is actually twisting space-time with it. Near Earth, the twisting is greater," said Michael Salamon, a physicist at NASA in Washington.
"This twisting of space-time, which is also referred to as frame-dragging, has never been directly observed before," Salamon told reporters in a telephone briefing.
"This is the first real, solid, direct evidence we have for the twisting of space-time caused by the spinning of a rotating body."
Erricos Pavlis of the Joint Center for Earth System Technology at NASA and the University of Maryland and colleagues observed two satellites orbiting the Earth and found that they did shift as the planet pulled on space.
"We measured the distance from the Earth to the satellite with the accuracy of millimeters," Pavlis said. Their research was reported in the journal Nature.
The Laser Geodynamics Satellite I or LAGEOS I, a NASA spacecraft, and LAGEOS II, a joint NASA/Italian Space Agency satellite, are basically hunks of metal covered with reflectors that make them easy to follow and measure from the ground.
Their butterfly-shaped orbits are meant to simulate the movement of a spinning gyroscope. Einstein's theory predicts that a nearby spinning body -- such as the Earth -- will pull on space and cause a gyroscope to shift slightly on its axis.
There is no proof that some other force is not acting on the satellites, Pavlis said, but it is unlikely.
"It would have to be a very smart force to exactly mimic general relativity," he said.
"We have eliminated all of the forces that we do know -- tidal forces, et cetera and so forth, as well as gravitational model errors."
Pavlis likens the effect to a spoon twisting in a jar of molasses.
"Similarly, as the Earth rotates, it pulls space-time in its vicinity around itself. This will shift the orbits of satellites near Earth," he said.
Salamon said indirect evidence has been seen of frame-dragging, but this is the first direct measurement.
In April, NASA launched Gravity Probe B, a probe carrying four gyroscopes, which the scientists say should prove Einstein's theory with even higher accuracy when its results are reported next year.
Absolutely amazing. When I was 19, I was more interested in drinking beer and flirtin' with the girlies.
Suppose we orbit Al Gore, will that cause a big enough warp?
Sorry, I was just looking at the Victoria Secret web site....what did you say?
Well, when Einstein was 19, there wasn't really much else to do with your spare time besides think.
So did Einstein, and he didn't do too well in school. Apparently. he was quite a womanizer.
I'm amazed at how many of Einstein's theories are still being verified. Gravitational lensing, and Bose-Einstein condensates come to mind as recent ones.
Show me the pictures.
WEEKLY HIGHLIGHTS FOR 8 OCTOBER 2004:
GRAVITY PROBE B MISSION UPDATE
http://einstein.stanford.edu/highlights/hlindexmain.html
Well sure. Once Einstein screwed the rest of us 19-year-olds by being born first so he could discover general relativity, there wasn't much else for us to do.
Well, I certainly feel better now. But actually, the story about Einstein doing poorly in school is a myth. Einstein had high marks the whole time...but his school reversed the grading system (1 was best, 5 was worst...then 5 became best and 1 became worst). The apparent dive in Einstein's schooling was actually a mistake in interpretation.
Great! So when do we get to go back in time?
I've got an ex-wife I want to leave at the altar.
The other great physicist of the 20th century, Richard Feynman, wa also a womanizer.
"Let's do the Time Warp..."
Why, thanks. I have been putting in extra effort lately.
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