[Bill S (OP)]

Worth a look, I think.

http://www.nature.com/news/ligo-black-hole-echoes-hint-at-general-relativity-breakdown-1.21135?WT.ec_id=NEWS-20161215&spMailingID=52998738&spUserID=MjgzNDMxNjU2ODIS1&spJobID=1063046368&spReportId=MTA2MzA0NjM2OAS2

[yor_on]

So cool Bill, a very nice extract.
=

Not discussing implications though, just the fact that we've seemed to measure a 'gravitational wave'. That was needed.

[jeffreyH]

Interesting.

[evan_au]

the three black-hole mergers so far captured by LIGO

It's amazing how quickly a stunning discovery like gravitational waves becomes "ho-hum".
The first one got great coverage in the general press, the second one was mentioned in the scientific press, but I hadn't heard about the third event.

Physicists have predicted that Einstein’s hugely successful theory could break down in extreme scenarios, such as at the centre of black holes

Einstein knew that his theory broke down at the center of black holes, as it predicted a gravitational singularity.

Over the past century, physicists trying to combine quantum theory and general relativity discovered that these combined theories break down near the event horizon.

So this might shed a bit of evidence about what really happens at the event horizon, and so point to a merger of quantum theory and general relativity, in this strong-field environment near a black hole.

[Bill S (OP)]

It's amazing how quickly a stunning discovery like gravitational waves becomes "ho-hum".
The first one got great coverage in the general press, the second one was mentioned in the scientific press, but I hadn't heard about the third event.

But, had you heard the echoes? []

[jeffreyH]

The echoes could indicate something else entirely.

[evan_au]

Maybe I wasn't quite so out-of-date...
Wikipedia still lists only 2 detected gravitational wave events that have been officially announced:
https://en.wikipedia.org/wiki/List_of_gravitational_wave_observations

[timey]

LIGO...  What are the probabilities?

http://www.nature.com/news/ligo-black-hole-echoes-hint-at-general-relativity-breakdown-1.21135?WT.ec_id=NEWS-20161215&spMailingID=52998738&spUserID=MjgzNDMxNjU2ODIS1&spJobID=1063046368&spReportId=MTA2MzA0NjM2OAS2

In a universe that is not only expanding, but is currently accelerating in this expansion, it strikes me as peculiar that LIGO is detecting these black hole mergers.

It is understood that there is thought to be a black hole in the centre of most galaxies, and it is also understood how there are thought to be rouge black holes that are not associated with galaxies...

Clearly LIGO are detecting the black hole that is not associated with a galaxy.

What I find peculiar under the premise of this accelerated expansion, is the fact that these huge masses that I would have thought, under the premise of accelerated expansion to be far flung apart from each other, are in fact observed to be merging as mass clumping together...

Any thoughts?

[jeffreyH]

These black hole pairs should arise from binary star systems within galaxies. Both stars having enough mass to collapse into a black hole when all their fuel is exhausted. Think of it like a solar system with two suns. The dynamics of the system will be inherently unstable. Which is what ultimately causes the black hole merger.

[yor_on]

You know, reading 'Afshordi’s team set up a simple model in which the black hole is surrounded by mirrored walls, rather than just a conventional event horizon, and applied to it properties of each of the three black-hole mergers so far captured by LIGO. This revealed what the precise time interval between repeated echoes should have been if the black holes have any structure at their event horizons — around 0.1 seconds, 0.2 seconds and 0.3 seconds. And when they looked at the LIGO data, they found that the release of gravitational waves in all three mergers was followed by successive echoes at exactly those intervals.' doesn't make me feel totally comforted about the existence of that 'firewall'

[timey]

LIGO...  What are the probabilities?

http://www.nature.com/news/ligo-black-hole-echoes-hint-at-general-relativity-breakdown-1.21135?WT.ec_id=NEWS-20161215&spMailingID=52998738&spUserID=MjgzNDMxNjU2ODIS1&spJobID=1063046368&spReportId=MTA2MzA0NjM2OAS2

In a universe that is not only expanding, but is currently accelerating in this expansion, it strikes me as peculiar that LIGO is detecting these black hole mergers.

It is understood that there is thought to be a black hole in the centre of most galaxies, and it is also understood how there are thought to be rouge black holes that are not associated with galaxies...

Clearly LIGO are detecting the black hole that is not associated with a galaxy.

What I find peculiar under the premise of this accelerated expansion, is the fact that these huge masses that I would have thought, under the premise of accelerated expansion to be far flung apart from each other, are in fact observed to be merging as mass clumping together...

Any thoughts?

This post was made as an independent discussion from the topic of this thread... I do not understand why my post has been moved here.  It is not directly relevant to the OP.... Therefore I shall continue the discussion of the topic that is relevant to this post back on its own thread here, thank you:

http://www.thenakedscientists.com/forum/index.php?topic=69399.0