Satellite To Test Relatively

dude_from_munich writes "Einstein proposed in 1916 that space and time form a structure that can be curved by the presence of a body. Scientists are finally planning to put Einstein's theory of relativity to test after a project delay of 44 years."

Comments

Relatively speaking.

[p4ul13]

First post; but only because I'm moving slower than you.

A quick look at TFA quickly shows....

[Jonas the Bold]

That this is exactly the same as this story.

I sure hope...

[Anonymous Coward]

...that it tests relatively well!

What if it fails

[squiggleslash]

Supposed the experiment runs exactly as planned, there are no apparent flaws with any of the equipment, no problems with the theory behind the experiment... and the results contradict the theory of relativity.

What happens then?

Re:What if it fails

[lambent]

We finally get an excuse to throw that einstein bastard out on his ear. I don't know about you, but i'm getting pretty tired of that know-it-all being right ALL the freaking time.

Re:What if it fails

[AS400 Hacker]

Buildings collapse, bridges fall, the earth crashes into the sun.

Shit like that.

Redundant experiment.

[c.r.o.c.o]

As /. keeps prooving several times every day, time warps happen all the time.

This is just one example, but I'm sure many more can be found without launching the probe...

Eddington's proof

[jedigeek]

As usual the BBC's article is scant on details. There's no mention of Arthur Eddington's (1919) proof of relativity which proved gravity caused light to bend. However,

http://www.sciencedaily.com/releases/2004/04/040 40 5091215.htm

Is more interesting.

Re:fuzzy math?

[q-the-impaler]

I suppose they meant 2004 - 1959 (since that is when the experiment was proposed)

Of course GTR has been confirmed many times

[aminorex]

The article as phrased suggests that GTR is hitherto unconfirmed by observational data. That is not the case: The aspects of the General Theory of Relativity which are addressed by this experiment are consistent with experimental data for the perihelion of Mercury which actually predated and motivated the General Theory, and are confirmed every day by gravitational lensing effects used very practically by astronomers, as recently reported here on slashdot.

It's a popular Senior or Graduate physics exercise to design experiments demonstrating GTR -- and a somewhat more ambitious exercise to perform them. This one is notably primarily for being bloody expensive and having blown it's schedule by such a honking big margin.

Re:Of course GTR has been confirmed many times

[PurpleFloyd]

Not only has it been confirmed many times, but it's even been confirmed by satellite. Take a look here for an interesting article which explains how the GPS satellite system must correct for relativity, and how it does so (and in doing so verifies the time-dialation postulate of Einstein's theories).

Of course, the GPS system is not anywhere near the first proof of this or many other relativistic phenomena; atomic clocks on board jetliners can test whether gravity affects the speed of a clock (it does) and other phenomena. Another example is found in cosmic rays; many short-lived particles, formed in the Earth's upper atmosphere when high-energy rays hit the atoms in air, would be unobservable if not for time dialation; "common sense" predicts that they would decay only a few meters from their starting position, but relativity tells us that since the particles are moving extremely fast, their decay rate will be slowed enormously from our frame of reference, and the particles will still be observable from the ground.

If you know where to look, proofs of general and special relativity are all around us. All you need in most cases is an atomic clock or good cloud chamber, yours for not more than a few million dollars.

Re:Of course GTR has been confirmed many times

[Alsee]

cloud chamber, yours for not more than a few million dollars

How to Build a Cloud Chamber

You can probably scavenge common felt and tape and a slide projector etc for free. You can buy pure (not 70%) isopropyl alcohol for about $7.60, and Dry Ice for probably $20 or less. I can pick up dry ice locally for $10. The issue with dry ice is that it will only last a day or so unless you get a huge block. I had a $40 block last 3 or 4 days.

Dry Ice is a real blast for parties, but at -109.3F / -78.5C you freeze-burn yourself pretty badly, and the pure Carbon Dioxide gas can be a minor hazard. Safety page here. With gloves, ordinary ventilation, and basic common sence you should be fine.

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