maybe the best account and video of first LIGO gravity wave 2015.09.14: The New Yorker: Rich Murray 2016.02.11
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maybe the best account and video of first LIGO gravity wave 2015.09.14: The New Yorker: Rich Murray 2016.02.11
 
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maybe the best account and video of first LIGO gravity wave 2015.09.14: The New Yorker: Rich Murray 2016.02.11
http://rmforall.blogspot.com/2016/02/maybe-best-account-and-video-of-first.html [ about 1 minute video, time slowed down about 100X -- the two black holes spiral around each other, making 11 half-turns before merging suddenly the black holes are invisible, so we see their twisted space-time showing highly distorted swirling views of their far away galactic background -- this happened 1.3 billion years away ( 1.3 billion years ago -- our nearest neighbor galaxy Andromeda is about 2.2 million lightyears away ( 2.2 million years old from us -- our galaxy is about 0.1 million lightyears wide... ] TODAY 10:30 AM Gravitational Waves Exist: The Inside Story of How Scientists Finally Found Them BY NICOLA TWILLEY "Just over a billion years ago, many millions of galaxies from here, a pair of black holes collided. They had been circling each other for aeons, in a sort of mating dance, gathering pace with each orbit, hurtling closer and closer. By the time they were a few hundred miles apart, they were whipping around at nearly the speed of light, releasing great shudders of gravitational energy. Space and time became distorted, like water at a rolling boil. In the fraction of a second that it took for the black holes to finally merge, they radiated a hundred times more energy than all the stars in the universe combined. They formed a new black hole, sixty-two times as heavy as our sun and almost as wide across as the state of Maine. As it smoothed itself out, assuming the shape of a slightly flattened sphere, a few last quivers of energy escaped. Then space and time became silent again." [ Another source says they reached a top speed of half the speed of light as they merged... ] "On Sunday, September 13th, Effler spent the day at the Livingston site with a colleague, finishing a battery of last-minute tests. “We yelled, we vibrated things with shakers, we tapped on things, we introduced magnetic radiation, we did all kinds of things,” she said. “And, of course, everything was taking longer than it was supposed to.” At four in the morning, with one test still left to do — a simulation of a truck driver hitting his brakes nearby — they decided to pack it in. They drove home, leaving the instrument to gather data in peace. The signal arrived not long after, at 4:50 A.M. local time, passing through the two detectors within seven milliseconds of each other. [ In Louisiana and in Oregon, 1,865 miles apart ] It was four days before the start of Advanced LIGO’s first official run." "Since the September 14th detection, LIGO has continued to observe candidate signals, although none are quite as dramatic as the first event. “The reason we are making all this fuss is because of the big guy,” Weiss said. “But we’re very happy that there are other, smaller ones, because it says this is not some unique, crazy, cuckoo effect.” "These sites are separated by 3,002 kilometers (1,865 miles). Since gravitational waves are expected to travel at the speed of light, this distance corresponds to a difference in gravitational wave arrival times of up to ten milliseconds." "After an equivalent of approximately 75 trips down the 4 km length to the far mirrors and back again, the two separate beams leave the arms and recombine at the beam splitter." "Based on current models of astronomical events, and the predictions of the general theory of relativity, gravitational waves that originate tens of millions of light years from Earth are expected to distort the 4 kilometer mirror spacing by about 10E−18 m, less than one-thousandth the charge diameter of a proton. Equivalently, this is a relative change in distance of approximately one part in 10E 21. A typical event which might cause a detection event would be the late stage inspiral and merger of two 10 solar mass black holes, not necessarily located in the Milky Way galaxy, which is expected to result in a very specific sequence of signals often summarized by the slogan chirp, burst, quasi-normal mode ringing, exponential decay." "One black hole was about 36 times the mass of the Sun, and the other was about 29 solar masses. As they spiraled inexorably into one another, they merged into a single, more-massive gravitational sink in space-time that weighed 62 solar masses, the LIGO team estimates." [ So, 3 solar masses was radiated away as invisible gravitational energy -- about 5 % conversion of mass into pure energy... ] ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College to unsubscribe http://redfish.com/mailman/listinfo/friam_redfish.com |
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