NASA to test Einstein's time warp theory

theage.com.au ^ | April 5, 2004 | Richard Macey

[Destro]

NASA puts new spin on old Einstein

By Richard Macey

April 5, 2004

Almost 90 years after Albert Einstein published his theory that space and time are "curved", it is about to be put to a $US850 million ($A1.1 billion) test.

Next Sunday week, if all goes well, a NASA satellite fitted with four tiny gyroscopes will be fired from Vandenberg Air Force Base, California, into a 640-kilometre- high orbit.

The size of ping-pong balls, the gyroscopes will be set rotating, aligned to a star tracked by the satellite's on-board telescope.

If Einstein's theory of relativity is right, the angle at which they spin should gradually drift over the next two years as the satellite orbits.

According to the theory, gravity does not only distort space up and down, left and right, forward and backward but can also make time run slower, so that the tick of a second on a clock may not always take exactly one second.

But Einstein's theory has only been partially verified.

"Until a theory is thoroughly tested," said Stanford University scientists, who helped develop the mission, "we cannot accept it as fact."

NASA said the satellite "will measure how space and time are warped by the presence of the Earth, and, more profoundly, how the Earth's rotation drags space-time around with it".

"These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the universe," the agency said.

First proposed in the 1950s, the satellite, Gravity Probe B, has been funded by NASA since 1964, its design extensively changed to ensure success.

It is arguably "among the most thoroughly researched programs" that NASA has undertaken.

[Destro]

You mean Bush likes to read books on theoretical physics for fun? I thought he went to a business school?

[fire_eye]

If this is really possible, it's a matter of the utmost urgency.

It represents a way to get Scummer and Hitlary out of the galaxy and on their way into a black hole somewhere during our lifetime.

Plus, if the experiment worked on them, we could follow it up with space barges loaded with Islamikazis... Earth would then finally be safe for humans!!

My dream of global social cleansing would become a reality!! (HEY, You hear THAT, all you Demonrat trolls from DU? THIS time, I said ****GLOBAL**** Social Cleansing! Come on, go berserk!!)

[RadioAstronomer]

Pretty cool stuff. This spacecraft is incredibly sophisticated. :-)

[RadioAstronomer]

bttt

[VadeRetro]

For example, I doubt that tidal forces could be re-created in a centrifuge, but if you come across someone who has done so, please let me know, because I would be interested in this information.

My uneducated guess would be that tidal forces are easily observed in a small centrifuge. That is, the forces would be unequal at different ends of an object which is large relative to the centrifuge. (Not all parts of the object are whirling at the same linear velocity.) In a sufficiently large centrifuge (that big space station in Kubrick's 2001), the tidal forces shrink to nothing for human-sized objects. I don't think the tidal forces matter regarding time dilation, though. The equivalence principle amounts to saying, "Gees are gees, however created." What happens in one case happens in all cases.

[new cruelty]

"Scotty, I need warp speed in three minutes or we're all dead!"

That line always cracks me up.

[r9etb]

Why don't they simply put a Timex in a centrifuge and spin it up?

LOL! For what it's worth, the GPS satellites have shown themselves to be a pretty good testing ground for relativity studies.

[Constantine XIII]

For starters, it is a tiny, tiny effect for something as low-mass and slow-turning as the earth. So small in fact that a truck driving down the road several miles away will jostle the machinery enough to throw the whole thing out of whack. In space, no one can hear you drive. :P

Also, the four gyroscopes consist of the most perfect spheres ever made by man. Again, the tiniest deviation could throw off the accuracy of the experiment enough to make it completely worthless.

If this were easy, after all, some one would have done it by now!

[Flightdeck]

I think the reporter misled us a bit here. The goal isn't to repeat the atomic clock flying-around-the-world experiment, it is to test for frame dragging. Supposedly, this is when a massive object rotates fast and pulls the fabric of spacetime with it like a whirlpool. The most extreme example of this is a black hole's event horizon, but given enough time (2 years in this case) even a lightweight earth is supposed to drag spacetime detectably. So, I don't think this can be performed on earth.

This all goes back to the bucket of water. When you spin a bucket, why does the water move up the edges? Answer is supposed to be it's relative motion with respect to absolute spacetime.

[Constantine XIII]

Heck, we can't ever accept any scientific theory as iron-clad fact, since you can't really prove anything right with experiments (though you can for certain prove stuff wrong)

[longshadow]

precessing placemarker

[PatrickHenry]

I see that you finally dragged your frame over here.

[Elsie]

When you spin a bucket, why does the water move up the edges? Answer is supposed to be it's relative motion with respect to absolute spacetime.

I like 'centrifical force' for an answer!

[Flightdeck]

Yes, but what gives rise to that force? That's what stumped every physicist born until Einstein.

[YoSoy2]

"You mean Bush likes to read books on theoretical physics for fun?"

No, I think he misses playing indian and cops-and-robbers in the backyard in Texas. :)

[Destro]

People are way too defensive and kneejerkish on some issues.

[TheLion]

Fox News just had a report on this. They said the price tag so far was about $700 million!

[Doc On The Bay]

The 'Dems would have us believe that "W" never completed Grade School--Harvard MBA Notwithstanding!

Not one in 100 of "W"'s Detractors could Fly--or Has Flown-- Supersonic Jet Interceptor, ( as has "W",) yet the 'Dems PERSIST in Labelling "W" as "Stupid."

Hmmm!

The 'Dem's are in a state of "Cognitive Dissonance" regarding "W".

The 'Dems have SO SERIOUSLY UNDERESTIMATED "W", that they must Promulgate Egregious Lies to Promote their Seriously Compromised Candidate for the Presidency.

John Kerry is--in essence--a "Manchurian Candidate."

His "Post-Vietnam Activities" & his "Socialist/Communist" voting record reflect a Politician Totally "out of touch" with the General Population of America; he Mainly represents the "Privileged Elite," who seem to believe that a "Command Economy," (with the "Elite" in "Command") is the "Proper Fate" of America.

Doc

[Excuse_My_Bellicosity]

I was thinking the same thing. When I was in college, I remember a lecture in my junior-level physics class where the professor was saying that there is a ton of experimental evidence to show that Einstein's Theory of Relativity is true. One example he gave involved the GPS satellites. Every GPS satellite in earth orbit has an atomic clock onboard. The clocks have to compensate for relativity effects because they are orbiting at 18,000 mph relative to us. This disparity in time can be easily measured by atomic clocks, and it coincides precisely with known mathematical theory.

General relativity in the global positioning system.

[Batrachian]

Right, but someone else said that this more recent experiment explains a slightly different aspect of relativity. I don't quite remember the details.