Physicists Detect Gravitational Waves, Proving Einstein Right

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by mikeash on Thursday February 11, 2016 @11:53AM (#11081306)

Is there any idea how far away these black holes were? It would be interesting to know the volume of space it can potentially detect evens.

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by drx on Thursday February 11, 2016 @12:07PM (#11081383)

TFA says "they had heard and recorded the sound of two black holes colliding a billion light-years away" and "1.2 billion years ago".

And from the paper: "The source lies at a luminosity distance of 410+160-180 Mpcc corresponding to a redshift z=0.09+0.03-0.04.". (https://dcc.ligo.org/LIGO-P150914/public) Which corresponds to 1.337+0.522-0.587 billion ly (or between 750.2 million and 1.859 billion ly).

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by mikeash on Thursday February 11, 2016 @12:14PM (#11081426)

Oops, missed that. Thanks!

Looks like there are roughly three million galaxies within a billion light years. Seems like lots of space for black hole pairs to live in. I suppose over the coming years, these gravity wave observatories will nail down just how common they are.

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by gradi3nt on Thursday February 11, 2016 @03:18PM (#11082869)

So that's wayyyyyyy outside our galaxy? Any idea how many galaxies fit into a 1 billion ly sphere around the milky way? I'm guessing a shit ton, which makes the detection of a bh merger seem more realistic to me.

That's some serious range!

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by jballanc on Thursday February 11, 2016 @03:49PM (#11083129)

It was mentioned during the press conference today that gravitational waves are not affected by interstellar/intergalactic dust the same way light is. In theory, once our detectors are good enough we should be able to use gravitational wave astronomy to peer all the way back to the big bang!

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by nerfhammer on Thursday February 11, 2016 @04:46PM (#11083539)

So, we'll finally be able to hear what god said at the start of the universe?

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by ddalex on Thursday February 11, 2016 @06:11PM (#11084081)

This is a beautiful premise for a mind bending book.

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by mikeash on Thursday February 11, 2016 @07:05PM (#11084381)

I'm sure He either said "let there be light" or "gee, that's funny...."

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by mattmanser on Thursday February 11, 2016 @08:11PM (#11084663)

I'd prefer either "what does this button do?" or "shit, don't press that!".

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by mikeash on Thursday February 11, 2016 @09:36PM (#11084948)

Those are what you get when you figure out how to construct a machine that looks to the future and can hear what God says at the end of the universe.

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by astrodust on Friday February 12, 2016 @10:40AM (#11087928)

"I clicked print and nothing happened!"

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by tossaway1 on Thursday February 11, 2016 @03:24PM (#11082917)

If these waves travel at the speed of light shouldn't the distance and time match up...?

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by drx on Thursday February 11, 2016 @03:42PM (#11083069)

This would be true in a static universe, but, during the 1.2 billion years the waves have been traveling, the universe was experiencing accelerating expansion.

For example, the edge of the observable universe is about 46.5 lightyears away, while the universe is thought to be 13.8 billion years.

https://en.wikipedia.org/wiki/Observable_universe#Misconcept...

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by mehwoot on Thursday February 11, 2016 @05:12PM (#11083723)

is about 46.5 lightyears away

I assume you mean 46.5 billion?

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by drx on Thursday February 11, 2016 @06:01PM (#11084015)

Yeah, thanks! I can't edit it any more, unfortunately.

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by vanattab on Thursday February 11, 2016 @03:41PM (#11083065)

Not if space time it'self is stretching while the light is in transit.

[ Parent | on HN ]

Re:Physicists Detect Gravitational Waves, Proving Einstein R... by xenophonf on Thursday February 11, 2016 @02:11PM (#11082336)

That's around 1/60th the diameter of the observable universe!

[ Parent | on HN ]