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Arthur T Knackerbracket has found the following story:
Testing general relativity is a fraught business. The theory has proven to be so robust that anyone who thinks it's wrong gets slapped around by reality in a pretty serious way. The tests that we apply are also limited by our environment, in that we can only look at gravity with precision where it's rather weak: in the lab, or by tracking the motion of planets. That's a whole range of scales and forces, but it doesn't cover where it might truly matter, which is right next to a black hole.
Observing orbits around a black hole would take a career's worth of measurements and, frankly, who has the time? It is also a rare benefactor who will fund a couple of decades worth of telescope time. Luckily, telescopes have been collecting data for a while, and some of that happens to include the vicinity of some black holes. Recently, some scientists decided to dig up the data and test general relativity in the vicinity of a supermassive black hole.
At the center of our galaxy, there lies a black hole, which like the Rabbit of Caerbannog, fiercely devours unwary wanderers. Nevertheless, there are a few foolhardy stars that orbit close to the rabbit black hole. These stars have orbits of just a couple of decades, and they experience rather large gravitational forces. So, astronomers expect that accurate observations of these stars might pick out deviations from general relativity.
Luckily, the Keck telescopes have been gathering data from the heavens for about 25 years, and over that time, they have turned their unblinking eyes towards the galactic center on numerous occasions. Each time, the observations were performed a bit differently. For instance, the telescopes were upgraded with adaptive optics in 2005, and some of the observations focused on obtaining spectral data rather than imaging. These latter data contain orbital velocity data, because the motion of the star causes a doppler shift in the observed colors of light.
All of this data was combined in a consistent way to map out the orbital positions and velocities of two stars. This is quite an achievement, because for each observation, the telescope is pointing in a slightly different direction, using different exposure times, and accounting for other slight differences. Although other telescopes also have data available, the public records were not detailed enough to allow the scientists to process the data in a consistent way. This is a pity, because, the data set consists of about 100 observations from just these two telescopes. Imagine what might have been obtained if more telescopes had accessible data?
After all of this, what have we learned? General relativity is still right, and it predicted the stellar motion accurately. These measurements tested general relativity in a way that was distinct from all previous ones—in high gravitational fields over long periods of time. In particular, the new measurements helped to put boundaries on extensions to general relativity that follow a kind of modified Newtonian dynamics model. In these models, there is a distance at which a new force becomes apparent, and that force has some unknown characteristic strength. So, astronomers are looking for a consistent distance at which there is a noticeable deviation from predictions. However, the measurements tell us that for any distance that is relevant to the orbit of these stars, a new force would have zero strength.
Or, more precisely, a new force would have a strength that is so small that we cannot yet measure it. Conclusion: general relativity wins again.
-- submitted from IRC
(Score: 2, Informative) by Anonymous Coward on Monday June 05 2017, @07:50PM (8 children)
The media and science-popularizers treat Einstein like he popped into existence from some other dimension, delivering unto us The Word. The truth of the matter is that the man was a product of exactly his times, and his work would not have been perfected—let alone even made possible—without the direct and indirect contributions of a huge number of people.
For instance, there's a reason that an Einstein could come to be only after a Riemann, or a Michelson or a Morley, etc.
(Score: 3, Insightful) by pvanhoof on Monday June 05 2017, @08:00PM (2 children)
I believe at the time of writing his most important papers, he was together with Mileva Marić. As I understood history, she often double checked his work.
(Score: 0) by Anonymous Coward on Tuesday June 06 2017, @04:46AM (1 child)
There is literally 0 evidence of this. Arguably there is less than 0 since there is substantial evidence to the contrary. In particular Maric failed out of university after being unable to achieve the necessary 4/6 on her final examinations - scoring a 2.5 in, you guessed it, mathematics. She then took it again and failed again without improving. She then gave up. And now she's supposed to be double checking Einstein's work which were, almost entirely, based around advanced theoretic applications in the field Maric failed out of? This is called revisionist history to try to support a political agenda.
(Score: 0) by Anonymous Coward on Tuesday June 06 2017, @12:50PM
Depends on which paper you are talking about. General Relativity, yes, that's very heavy mathematics. Special Relativity, there's mathematically nothing more advanced that basic vector algebra (there exist more advanced formulations, but those came later). The breakthrough in Special Relativity was in the concepts, not in the mathematics (indeed, most of the formulas themselves were already known from Lorentz aether theory; there's a reason the transformations are known as "Lorentz transformations", not "Einstein transformations"). If she knew enough mathematics to be admitted to university, I guess it should have been sufficient for cross-checking that paper.
And of course, Maric (or anyone else) having cross-checked Einstein's work would in no way devalue Einstein's contribution. Just because you can comprehend something doesn't mean you could have come up with it to begin with. And yes, I'm a physicist, I know what I talk about.
Note that I have no idea whether or not she did cross-check Einstein's work. All I say is that if she did, that doesn't detract the slightest bit from Einstein's achievements.
(Score: 0) by Anonymous Coward on Monday June 05 2017, @08:04PM (1 child)
I am sure without Einstein, another would have stepped up.
(Score: 2) by Arik on Monday June 05 2017, @08:16PM
Well, turned up at least. Steins do not, in my experience, step.
If laughter is the best medicine, who are the best doctors?
(Score: 2, Interesting) by Anonymous Coward on Tuesday June 06 2017, @04:56AM (1 child)
Nobody is saying he didn't build off the shoulders of giants. Relativity is, in effect, a direct result of the Michelson-Morley experiment. [wikipedia.org]
However, at the same time - he was not just a product of his times. Michelson-Morley was 1887 when Einstein was 8 years old. Einstein's first paper on relativity would not be published for about 2 decades. His 'big picture' paper coming 3 decades after Michelson-Morley. There was an entire generation of scientists that had the opportunity to discover relativity. They failed. Though the math is complex, it's workable for more or less any mathematician. In my opinion what really made Einstein unique was his creativity. The whole concept of relativity is absurd, and I think it's this absurdity that kept it from being considered for so long. There's a physics joke that all the scientists of the time were trying to explain why light could be seen as moving at identical rates from differing perspectives - and Einstein simply assumed it! For an educated and intelligent man to even imagine that the universe twists itself around into multiple asynchronous 'perspectives' with time as just yet another dimension of movement is phenomenal and something that requires the mind of a mathematician and the creativity of a child - a rare mix indeed!
(Score: 2) by aristarchus on Tuesday June 06 2017, @08:39PM
Nice trick, if you can pull it off. Is the even more specialler Relativity? In my own experience, being 1887 is no piece of cake. Of course, it gets better after that.
(Score: 2) by FatPhil on Tuesday June 06 2017, @07:54AM
However, it's a tightly interwoven nest of mathematical and scientific progress, noone succeeds alone.
Great minds discuss ideas; average minds discuss events; small minds discuss people; the smallest discuss themselves