Einstein Passes New Tests

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Everything I need to know I learned through Googling.

We have to keep taking tests after we die?

I better start studying.

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I have a blood test scheduled for next Monday. I guess I better start studying too. :roll:

PS - Astronomy Magazine has some good articles on Einstein in the Feb. 05' issue.



(edit to add PS)

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It's just one of those damn things of which there are many few. -- Dan Blocker

Couldn't have passed the tests. There is no variable G and the binary pulsar doesn't have a misalinged accretion disk.
8)

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Neptune- The original Dark Matter.

The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth

Tensor wrote:

Had to do a double-take there - thought I was on the 'Huygens' thread in ATM =D>

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By asking questions we sometimes get the wrong answers, from wrong answers we learn to ask the right questions.

(emphasis mine)

I thought that gravitational waves have never been detected, which Gravity Probe B was supposed to remedy.

From the article (I hope fair use?):
So it's maybe an indirect test, and not actually seeing the wave come by?
Which LIGO would do.

I don't know if the physics relating orbital shrinking to gravity waves leaves no room for alternative explanations, but I can think of one:

A giant cat sits outside the orbit and swats the pulsars with its front paw each time... oops, should take this to ATM. :wink:

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Ken

Visit the BAUT Team Page
BOINCview: Network control
and a superior UI!

Yeah, wonder how do they infer that.

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What brings us together is stronger than what pulls us apart

I think the GR prediction is that gravitational waves would carry away energy from the binary pulsar thus causing the orbits to shrink. The results from this test showed the orbit is shrinking by 7 millimeters a day in accordance with the GR prediction. This would seem to be evidence that gravitational waves are real and behave as GR predicts.

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"A mystic is a person who is puzzled before the obvious but who understands the nonexistent." -- Elbert Hubbard

Gravity Probe B is looking for two effects. First, how much the earth warps space and time and second, the amount of frame dragging the spin of the earth causes.

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Neptune- The original Dark Matter.

The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth

Correct. The study of this new binary pulsar is simply a higher precision version of the work the pulsar PSR 1939 + 16 that led to the 1993 Nobel in Physics. Read Joseph Taylor's Nobel lecture for a description of the comparison of the observed decrease in rotation rate with the theoretical prediction from GR (energy loss through gravitational radiation).

While all of these observations and tests are extremely compelling, they are still not a direct observation of gravitational radiation. There is still a minutely small chance that there is another explanation for the energy loss. That's why detectors like LIGO have been built for final confirmation. Still, most physicists would say the pulsar work demonstrates the existence of gravitational radiation and the validity of GR. It certainly works for me.

edit (corrected Taylor's first name, although my initial error is still quoted below. Alas).

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"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind." - William Thompson, 1st Baron Lord Kelvin

"If it was so, it might be, and if it were so, it would be, but as it isn't, it ain't. That's logic!" - Tweedledee

This isn't right. This isn't even wrong. - Wolfgang Pauli

Sorry about that. I just couldn't help myself.

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Neptune- The original Dark Matter.

The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth

Now I see they explain that in the article. Number one rule: read the linked stuff carefully before posting. ops:

Thanks anyway.

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What brings us together is stronger than what pulls us apart

Strangely enough, I actually have Taylor's paper sitting in front of me for unrelated reasons. To see just how accurate GR's predictions are in the case of PSR 1939 + 16 are astounding.

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"The plan does not involve mayonaise."
"... I knew there was a catch."

You can't take the sky from me.

Yeah, I was amazed that the graphs of the prediction and the observations are virtually the same. (the first few years are a bit off, but I think they didn't really have good enough data at that point).

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Neptune- The original Dark Matter.

The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth

Of course the amazing thing is that the analysis of this new binary pulsar improves what was an already compelling comparison in 1993. I know I've linked to it many times before, but forgive me if I direct people once again to the Particle Data Group's review of Experimental Tests of Gravitational Theory. It's intended for physicists and astronomers, so some may find it hard going, but its summary of the current state of tests of GR (complete with references to the original papers) is useful.

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"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind." - William Thompson, 1st Baron Lord Kelvin

"If it was so, it might be, and if it were so, it would be, but as it isn't, it ain't. That's logic!" - Tweedledee

This isn't right. This isn't even wrong. - Wolfgang Pauli

Forgive you????? Thank you. More people should be directed to it. I think I bookmarked that the first time you posted it.

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Some try to tell me, thoughts they cannot defend,... - Moody Blues.

Neptune- The original Dark Matter.

The author feels that this technique of deliberately lying will actually make it easier for you to learn the ideas. - Donald Knuth