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General Relativity Is At Least 99.95% Right
ultracool writes to mention a ScienceDaily piece on compelling proof of general relativity. A team at the University of Manchester have used three years' worth of data on a pair of pulsars as a litmus test, against which they've benchmarked Einstein's theory. From the article: "Though all the independent tests available in the double pulsar system agree with Einstein's theory, the one that gives the most precise result is the time delay, known as the Shapiro Delay, which the signals suffer as they pass through the curved space-time surrounding the two neutron stars. It is close to 90 millionths of a second and the ratio of the observed and predicted values is 1.0001 +/- 0.0005 - a precision of 0.05%. A number of other relativistic effects predicted by Einstein can also be observed. 'We see that, due to its mass, the fabric of space-time around a pulsar is curved. We also see that the pulsar clock runs slower when it is deeper in the gravitational field of its massive companion, an effect known as "time dilation."'"
Observations that support a theory are nice, but they are not a proof.
If Einstein is the Samuel L. Jackson of science, what would Tesla be comparable to?
Yet, Einstein was dead wrong when it came to god playing dice :)
How can they say anything is 99.95% right, have they never heard of the Cartesian method of doubt. . .
.05%. They are perfectly aware of the lack of knowledge that could be hiding in that .05%, but that .05% defines the limit of our lack of knowledge.
.so all in all I'd say about 1-5% doubt - but you can never know
Yes, that's why they said what they said, i.e. that they have only shown the predictive accuracy of Relativity to a margin of error of
. .
And this makes no sense whatsover, because you are just pulling numbers out of your ass. Yes, it's true that you can never "know," but you can measure and increase the degree of your surity.
KFG
there is no such thing as "fabric of space-time". It's a convenient buzzword but it doesn't mean anything
Of course it means something: it is a summary of the distance and time measurements we make, and can be described in terms of geometrical curvature. If it didn't mean anything, then it wouldn't have any observable consequences.
Things work as if Einstein was right, but there is no evidence that he was right.
You're splitting hairs that don't exist. "Working as if Einstein was right" is "evidence that he was right". It's the only kind of evidence possible.
If you pass a current through a wire it generates a magnetic field. If that field crosses another wire it generates a current in that wire.
That's not necessarily true. A static magnetic field doesn't induce a current in a wire. You might be talking about alternating current, which produces a time-varying magnetic field.
It's exactly as if the magnetic field moved from one wire across the other.
I don't know what you mean by a magnetic field "moving", but certainly the magnetic field of one wire can intersect the position of another wire.
The flaw is that if you wrap both wires through an iron donut all the field is inside the iron - absolutely NO field is detected anywhere around either wire.
Perhaps I'm visualizing the geometry wrong, but your statement appears to be false.
The theory is false, but it is "exactly as if" it were true.
What theory? That the (time-varying) magnetic field produced by one current can induce a current in another wire? That theory is always true. (Of course, you have to take into account induction from other objects which may cancel that current.)
Likewise, Einstein's theory may give correct answers even though nobody actually knows why.
It is not possible to know "why" a theory is true, at least if that theory regards some fundamental phenomenon. It's possible to explain "why" some approximate theory is true by deriving it from a more fundamental one, assuming the more fundamental theory is true.
For one thing, plasma physicists can easily explain a lot of effects in electrical terms, relying on laboratory observations instead of imagined theories.
Nonsense. Plasma physicists use theories just like any other physicist does. Those theories of course are electromagnetic in nature.
Astronomers ignore plasma physics because nobody ever taught it to them.
More nonsense. Plenty of astronomers use plasma physics. What are you, an Alfven plasma cosmology crackpot?
Isn't that (at most) 0.05% the most interesting part?
Obviously, you never had any education about electrodynamics, or you would recognise your example as bullshit.
HI O WISE PRINCE. WHT TOOK U SO DAM LONG?
As a result, the best we can say is that the theory we have put together fits the observed data to a high degree of precision - but that this may be invalidated at any time by new phenomena. See, for example, the progression from Newtonian mechanics to Relativity, or the long-running debate over the nature of light.
Well, no, that's not the "best" we can do. It is quite possible to prove theories to be correct experimentally, if you formulate the theories correctly and then conduct the right kinds of experiments.
The problem is that General Relativity, like most physical theories, was pulled out of a hat and has caught on because it's appealing to physicists. Furthermore, the experiments being conducted to test those theories are chosen rather haphazardly. For those kinds of theories and those kinds of experiments, it is indeed impossible to prove anything