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TexasTowelie

(111,643 posts)
Fri Sep 23, 2016, 04:10 AM Sep 2016

Here’s What Happens When Two Black Holes Collide



Last September, a small chirp rattled a pair of L-shaped antennas for the first time. That’s the sound you hear when there’s a ripple in the fabric of space and time – a gravitational wave. The wave is caused by two black holes colliding, circling each other at half the speed of sound, tugging at the space and time around them.

This December, scientists heard the chirp again, confirming Albert Einstein’s Theory of Relativity for the second time in recorded history.

David Reitze played a key role in the discovery. He’s the executive director of the Laser Interferometer Gravitational-Wave Observatory (LIGO), which operates the antennas in Louisiana and Washington state that picked up the waves.

“On a fundamental scale it changes the way we look at the universe,” he says. “So it’s a new kind of astronomy. And I think everybody can get excited about that.”

Read more: http://www.texasstandard.org/stories/heres-what-happens-when-two-black-holes-collide/
21 replies = new reply since forum marked as read
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Here’s What Happens When Two Black Holes Collide (Original Post) TexasTowelie Sep 2016 OP
Such a bombastic event, and such a low-key sound-signal. :D DetlefK Sep 2016 #1
Gravity is so weak that it takes a monster event to travel so far and punch through all the noise Bernardo de La Paz Sep 2016 #6
Sounds like a Skype message chirp. Helen Borg Sep 2016 #2
Half the speed of sound? krispos42 Sep 2016 #3
I suspect that it is the speed of light. TexasTowelie Sep 2016 #4
The black holes circle each other like leaves circling a drain, so half the speed of sound Bernardo de La Paz Sep 2016 #7
No, it's the speed of light caraher Sep 2016 #9
"This December" Gruenemann Sep 2016 #15
I only read the article caraher Sep 2016 #16
The video notes half the speed of light. Beartracks Sep 2016 #12
I thought this was a set up of Trump joke. nt msanthrope Sep 2016 #5
K&R!!!!!!!!!!!!!!!!!!!!! burrowowl Sep 2016 #8
Turned out it was just a lab tech who had eaten at Chipotle's. nt Bozvotros Sep 2016 #10
Gravitational Waves Explaination cpwm17 Sep 2016 #11
That is really good - thanks! Kind of Blue Sep 2016 #14
This sucks.... Spitfire of ATJ Sep 2016 #13
So if these two events were detected only months apart, closeupready Sep 2016 #17
As Lawrence Krauss says.... AlbertCat Sep 2016 #18
Very Interesting, thank you for posting! ScienceIsGood Sep 2016 #19
You're welcome TexasTowelie Sep 2016 #20
Thank you, I was a member years ago. This election brought me back. ScienceIsGood Sep 2016 #21

Bernardo de La Paz

(48,870 posts)
6. Gravity is so weak that it takes a monster event to travel so far and punch through all the noise
Fri Sep 23, 2016, 07:10 AM
Sep 2016

There is so much gravitational noise that only big events punch through. And the distances are so far that the signal dissipates and weakens by time we get it. Then gravity is fundamentally so weak that it takes huge detectors.

Bernardo de La Paz

(48,870 posts)
7. The black holes circle each other like leaves circling a drain, so half the speed of sound
Fri Sep 23, 2016, 07:12 AM
Sep 2016

... for the black hole movement, approximately 350 miles per hour.

The gravity waves travel at the speed of light, I'm pretty sure.

caraher

(6,277 posts)
9. No, it's the speed of light
Fri Sep 23, 2016, 09:32 PM
Sep 2016

The orbital period in those final moments is measured in seconds... 350 MPH is basically stationary, when you look at the size of the orbits of these bodies about their center of mass.

Plus 700 MPH is the speed of sound, in air, at sea level. The speed of sound depends on the physical medium, and there is no physical relevance of the speed of sound in air (basically nitrogen) at standard temperature and pressure, for black holes moving out in space.

The whole article is badly written, so I forgive anyone confused by it... the December detection is the second direct gravitational wave detection. That is not at all, even remotely, the same as "confirming Albert Einstein’s Theory of Relativity for the second time in recorded history." The author probably couldn't even tell you *which* theory of relativity this would confirm (general relativity). Even had the author said "second confirmation of Einstein's prediction of gravitational waves" most knowledgeable physicists would consider that dead wrong; Taylor and Hulse received a Nobel for observations performed decades ago that were pretty much universally taken to confirm gravitational waves. The difference is they didn't detect the waves themselves, they observed the waves indirectly by looking at energy loss in fast-rotating binary systems.

Gruenemann

(975 posts)
15. "This December"
Tue Sep 27, 2016, 10:56 AM
Sep 2016

Text reads "This December", which would certainly be a disturbance in the space-time continuum. Audio implies it was this September.

Thanks for explaining the "speed of sound" effup.

caraher

(6,277 posts)
16. I only read the article
Tue Sep 27, 2016, 11:28 AM
Sep 2016

I have a former student on the LIGO team and I know they saw two events in fall 2015, one that they wrote up in the big paper and a second one. I don't remember whether it was in September or December.

But I'm pretty sure December 2016 is wrong!

 

closeupready

(29,503 posts)
17. So if these two events were detected only months apart,
Tue Sep 27, 2016, 11:55 PM
Sep 2016

it stands to reason that black holes are colliding all over the place, all the time, right?

I mean, yet another set of data showing how absolutely mindblowingly MASSIVE the universe is.

 

AlbertCat

(17,505 posts)
18. As Lawrence Krauss says....
Thu Sep 29, 2016, 11:59 AM
Sep 2016

The universe is very big and very old and amazing coincidences happen all the time.

TexasTowelie

(111,643 posts)
20. You're welcome
Fri Sep 30, 2016, 10:35 PM
Sep 2016

and welcome to DU!

I think that you will find a lot of interesting articles in the Science Group so please enjoy.

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