Gravitational waves are real, and scientists have detected them. In the video above, PBS Space Time explains the discovery by researchers at the Laser Interferometer Gravitational-Wave Observatory (LIGO). From the New York Times:
A team of physicists who can now count themselves as astronomers announced on Thursday that they had heard and recorded the sound of two black holes colliding a billion light-years away, a fleeting chirp that fulfilled the last prophecy of Einstein’s general theory of relativity.
That faint rising tone, physicists say, is the first direct evidence of gravitational waves, the ripples in the fabric of space-time that Einstein predicted a century ago (Listen to it here.). And it is a ringing (pun intended) confirmation of the nature of black holes, the bottomless gravitational pits from which not even light can escape, which were the most foreboding (and unwelcome) part of his theory.
More generally, it means that scientists have finally tapped into the deepest register of physical reality, where the weirdest and wildest implications of Einstein’s universe become manifest.
Below, NASA's animated simulation of the black holes merging and releasing the gravitational radiation (background here):
above image credits: R. Hurt/Caltech-JPL Read the rest
Based on UPI photographer Arthur Sasse's famous photo taken on March 14, 1951, Albert Einstein's 72nd birthday. GIF source: Psychedelicacies (via Imaginary Foundation) Read the rest
History has shown us that even some of the greatest scientific luminaries, towering figures such as the naturalist Charles Darwin, the twice-Nobel-Laureate chemist Linus Pauling, and the embodiment of genius — Albert Einstein — have made some serious blunders.
On Being has a nice little archive of rare audio clips from Albert Einstein, speaking on various subjects, including what it means to be American, E=MC^2, Gandhi, and "The common language of science."
Einstein: In His Own Voice
((Photo: Einstein sitting on the front steps of his home in Princeton, wearing his fuzzy slippers. Photo courtesy of Gillett Griffin.) )
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This is a letter, written by Albert Einstein, in which he explains the details of a now-famous test of the theory of relativity—an experiment that involves measuring how the Sun's gravity alters the path of starlight traveling towards Earth.
There's a couple of important things to bring up here. First, this sheet of paper is a really handy reminder to test everything—even the work of geniuses. This test had to be performed during a full solar eclipse. Besides that stipulation there was also, you know, the existence of World War I getting in the way. So while Einstein wrote this letter in 1913, nobody carried out and documented the test until 1919.
And that wasn't the end of it. This is the fun thing about science. We might think Einstein is an awfully smart guy. And we might trust the character of Sir Arthur Eddington, who performed the 1919 test. But a hypothesis and a single confirmation of that hypothesis, is not enough to prove even Einstein right. Einstein's theory of relativity rests on several different tests, each carried out by multiple teams, over many years, using increasingly accurate tools. As late as the 1960s and 1970s, this test was still being done with the understanding that Einstein's predictions hadn't yet been verified.
Also very important: Understanding what the hell Einstein's theory of relativity is all about to begin with. For a great in-a-nutshell explanation that puts Einstein into historical context while actually making sense, I recommend checking out the short videos at Einstein Light. Read the rest
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Tonight, at the American Museum of Natural History in New York City, Neil deGrasse Tyson hosts a roundtable debate on Einstein's Theory of Relativity, its discontents, and how likely the theory is to stand the test of time.
You're all familiar with the recent drama in this department—data from the OPERA experiment in Italy that purported to find neutrinos moving faster than the speed of light. That has since turned out to be the result of a faulty GPS system, but it's not the only challenge to Einstein, and some of those questions can't be discounted nearly as easily.
The debate—which features scientists from UCLA, CERN, Boston University, the MITRE Center, the University of Bologna, and Louisiana State University—starts at 7:30 pm Eastern. You can watch the whole thing in the live stream embedded above.
You can also participate in the debate by tweeting questions to deGrasse Tyson and the panel. You can do that by tagging your question with the hashtag #AsimovDebate. Read the rest