Far out cosmology: LIGO finds waves? third time (Introduction)

by David Turell @, Friday, June 02, 2017, 22:48 (2729 days ago) @ David Turell

From two colliding black holes:

https://cosmosmagazine.com/space/black-hole-collision-reveals-clues-to-early-cosmos

"Scientists have observed one of the most powerful astronomical events ever seen — the collision of two giant black holes to form an even larger black hole.

"It’s the third time since 2015 that such a collision has been observed via an instrument called LIGO (Laser Interferometer Gravitational-wave Observatory), which consists of a pair of detectors, one in Hanford, Washington, USA, and the other in Livingston, Louisiana, each designed to measure gravitational waves from distant cosmological events.

"Gravitational waves are ripples in the fabric of space, created by movements of massive objects.

“Normally we don’t think of space as having any properties at all, so it’s counterintuitive,” says Michael Landry, director of LIGO’s Hanford observatory. Nevertheless, he says, Einstein’s theory of general relativity predicts that space can expand, contract, or vibrate, thereby distorting the medium in which we all live.

"Such waves can be measured, he adds, because the distortions they produce look like changes in the length of any object they pass through. Landry compares it to stretching the canvas of a painting. “If I stretch the medium, the painting gets distorted,” he says.

"In this case, what LIGO saw were the rapidly vibrating distortions produced as the two black holes spiraled toward each other before merging, releasing as much energy in the form of gravitational waves as would be produced if two stars the size of the Sun were converted from mass into energy in about one-third of a second. Once the collision was complete, the new black hole had a mass about 50 times that of the Sun.

***

" Careful computer modeling, she adds, shows that the signals detected by LIGO contain the “gravitational fingerprints” of black holes whose spins did not align with their orbit.

“'This favors the theory that these two black holes formed separately then paired up, rather than being formed from the collapse of two already paired stars,” she says."

Comment: Einstein is again confirmed. Space-time is a fabric that can ripple.


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