I recently read this article from Reuters
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.
© Reuters 2004. All Rights Reserved.
And I got this response
Yes, the implication of this is that time travel is possible. What you must understand, however, is that time travel is only possible in one direction--forward in time. There is an upper limit as to what velocity an object can travel at: the speed of light, designated c in physics texts. If an object possesses mass, it cannot travel at c, only massless particles can do this. As a particle approaches c, time relative to it proceeds much slower than a particle nearly at rest. By traveling at high speeds, you can slow down the rate of time relative to you, but you can not travel back in time, as your post appears to imply. In fact, one of the biggest hurdles that supersymmetric string theory had to overcome was the problem of the theorized existence of a tachyon, a particle that could travel faster than light, and thus, backward through time. In a new formulation of string theory, this problem was solved through by the use of additional dimensions. This is where six dimensional Calabi-Yau shapes come into play, but we'll leave that for another day.
If you want to study more on the subject, study the "Twin Paradox" on Google. Also look up the concept of time dilation.
How Credible is the response?
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.
© Reuters 2004. All Rights Reserved.
And I got this response
Yes, the implication of this is that time travel is possible. What you must understand, however, is that time travel is only possible in one direction--forward in time. There is an upper limit as to what velocity an object can travel at: the speed of light, designated c in physics texts. If an object possesses mass, it cannot travel at c, only massless particles can do this. As a particle approaches c, time relative to it proceeds much slower than a particle nearly at rest. By traveling at high speeds, you can slow down the rate of time relative to you, but you can not travel back in time, as your post appears to imply. In fact, one of the biggest hurdles that supersymmetric string theory had to overcome was the problem of the theorized existence of a tachyon, a particle that could travel faster than light, and thus, backward through time. In a new formulation of string theory, this problem was solved through by the use of additional dimensions. This is where six dimensional Calabi-Yau shapes come into play, but we'll leave that for another day.
If you want to study more on the subject, study the "Twin Paradox" on Google. Also look up the concept of time dilation.
How Credible is the response?
