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Star's Black Hole Encounter Puts Einstein's Theory of Gravity To the Test (sciencemag.org)
An anonymous reader quotes a report from Science Magazine: For more than 20 years, a team of astronomers has tracked a single star whipping around the supermassive black hole at the center of our galaxy at up to 25 million kilometers per hour, or 3% of the speed of light. Now, the team says the close encounter has put Albert Einstein's theory of gravity to its most rigorous test yet for massive objects, with the light from the star stretched in a way not prescribed by Newtonian gravity. In a study announced today, the team says it has detected a distinctive indicator of Einstein's general theory of relativity called "gravitational redshift," in which the star's light loses energy because of the black hole's intense gravity. The star, called S2, is unremarkable apart from a highly elliptical orbit that takes it within 20 billion kilometers, or 17 light-hours, of the Milky Way's central black hole -- closer than any other known star. A team led by Reinhard Genzel at the Max Planck Institute for Extraterrestrial Physics (MPE) in Garching, Germany, has been tracking S2 since the 1990s, first with the European Southern Observatory's (ESO's) 3.6-meter New Technology Telescope in Chile's Atacama Desert and later with ESO's Very Large Telescope (VLT), made up of four 8-meter instruments. Ghez's team at UCLA also began to observe the star around the same time with the twin 10-meter Keck telescopes in Hawaii. In a paper published today in Astronomy & Astrophysics, Genzel's group reports seeing the combined action of the relativistic effects, with the black hole's gravity redshifting S2's radial velocity by 200 kilometers per second, a small fraction of its overall speed. The results match closely with the predictions of relativity and are inconsistent with Newtonian gravity.
You suck black hole
Because this story also arrived here yesterday. At least this post has more info.
Not long ago, it was impossible to see stars at this distance. Now adaptive optics have improved the resolution so much that they are able to track stars at the center of the galaxy. This is through all the intervening dust and closer stars obstructing the view. I have trouble getting a good image of Saturn due to atmospheric turbulence, and these guys are imaging the center of the galaxy. Well done.
Wasn't this story posted yesterday?
That Newtonian gravity is imprecise is already well known, milions of people who use GPS, Glonass or Galileo already use the general relativity calculations in practice. It is far more interesting to know how the results compare to alternative theories of gravity, like for example Verlinde's: https://en.wikipedia.org/wiki/...
Actually it's closer to a peak of 240k/s if you look at table 3. Though the gravitational gradient must not be too large given the massive size of the black hole in question here, it would be amazing If it were possible to see a close pass stretch a star into a ribbon and watch as it is torn apart. As it is the star must deform considerably under those enormous fields.
Where's the goatse guy now that he could be topical at least once?
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
Not unexpected though. And more egg in the face of those in trendy circles where questioning Einstein (from a well of ignorance) has become fashionable.
He may be a star, but his hole sure ain't black.
Red shift.
There is nothing wrong with questioning Einstein. While his theories are highly successful, they are not the end of physics.
What's more, questioning conventional wisdom helps understand it.
No. This experiment was specifically designed to test General Relativity. If anyone else wants their theory tested, they should propose a testable outcome unique to their theory, then design an experiment to perform the appropriate measurements, and finally convince enough people that this experiment has enough scientific potential to secure funding.
Meta-studies that use data gathered from other experiments are notorious for producing poor quality results. At best they should be used as a basis for securing funding for a proper study. This whole idea of trying to infer other things from study data is why there are now a lot of proposals to publish the intent of an experiment before performing it to reduce the occurrences of p-hacking and other statistical nonsense.
My own experience has been the opposite. When I do a test or look for data to prove/test my own ideas, no matter how hard I try I can't completely get away from confirmation bias. I suppose if I tried hard enough, I could end up with reverse confirmation bias - designing the experiment and looking at the data in a way designed to prove the opposite. That's still bias.
When I look at results from people who were NOT trying to test my pet theory, who were collecting the data for an unrelated reason, I can both find surprising facts I wasn't looking for and have a degree of confidence that the experiment and data weren't subconsciously (or conciously) biased, because the people collecting the data weren't even interested in the question I'm considering.
Having said all of that, isolating variables is a real thing.
What's really cool is that this star passes about as close to a black hole as the Voyager probes are from Earth right now. Can you imaging what it would look like if it were that close to our own solar system? What effect would its mass have on our solar system?
https://voyager.jpl.nasa.gov/m...
It is easier to build strong children than to repair broken men. -Frederick Douglass
I'm just happy to see the sort of science that makes accurate predictions (to multiple significant figures!) make headlines for once.
Socialism: a lie told by totalitarians and believed by fools.
The story sped across the internet so fast it got redshifted and it being posted 24 hours late on slashdot shows that due to it's relativistic nature Slashdot actually is running approximately 24 hours behind other parts of the internet.
Tell me, does having you head up your ass help you live in the world?
Fascism: An authoritarian and nationalistic right-wing system of government and social organization. See also: NAZI's
S2 has about 14 solar masses, but it passes relatively close to the galaxy's central black hole (about 4x the distance from our sun to Neptune). Its orbital period is just 16 years despite having a semi-major axis about 970x that of the Earth (about 32x bigger than Neptune's orbit). The Max-Planck Institute for Extraterrestrial Physics put together an animation of the previous decade of observations (1992-2013). You can see how it whips around the black hole at closest approach.
"Momentarilly" means for a short time, not in a short time. The word you want is "presently".
Really, dude. Check a dictionary before you embarrass yourself by posting uninformed nonsense like this.
Whooosh. --- joke going over your head.
Agent K: A *person* is smart. People are dumb, stupid, panicky animals, and you know it.
When I look at results from people who were NOT trying to test my pet theory, who were collecting the data for an unrelated reason, I can both find surprising facts I wasn't looking for and have a degree of confidence that the experiment and data weren't subconsciously (or conciously) biased
Except now you are dredging the data and no matter what, 5% of pet theories are confirmed within a few standard deviations in such a case,
"His name was James Damore."
Oh? Someone designed an experiment that involved putting a star into an orbit around our central black hole in our galaxy? How did they do that?
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.