Gravitational wave detection at LIGO

[ivica]

Lawrence M. Krauss 2015-09-25: "Rumor of a gravitational wave detection at LIGO detector. Amazing if true. Will post details if it survives."
John Baez 2016-02-11 gives further links...

[Joy Christian]

Lawrence M. Krauss 2015-09-25: "Rumor of a gravitational wave detection at LIGO detector. Amazing if true. Will post details if it survives."
John Baez 2016-02-11 gives further links...

They are not rumors anymore! Apparently you missed the dramatic live press conference announcement of the detection yesterday.

The gravitational waves have indeed been directly detected for the first time in the history of mankind. Here is the actual published paper in PRL:

http://physics.aps.org/featured-article ... 116.061102

If you look carefully, one of the authors of this historic paper is the son of our very own Jay Yablon! His name is Josh Yablon. See pages 13/16 in the PDF at the above link of the paper, 4th line from the bottom, second from the right, is where you will see his name. Congratulations to Josh and to his proud father Jay. And of course congratulations to the entire LIGO team for accomplishing this seemingly impossible feat. It is a monumental achievement. And let us also not forget Einstein today!

[ivica]

Congratulations to Josh and to his proud father Jay. And of course congratulations to the entire LIGO team for accomplishing this seemingly impossible feat. It is a monumental achievement. And let us also not forget Einstein today!

Ditto!

[thray]

Allow me to add my voice to the chorus of praise for the LIGO team (and Josh Yablon) on this historic occasion. To quote Karl Hess, Einstein was Right!

[FrediFizzx]

If you look carefully, one of the authors of this historic paper is the son of our very own Jay Yablon! His name is Josh Yablon. See pages 13/16 in the PDF at the above link of the paper, 4th line from the bottom, second from the right, is where you will see his name. Congratulations to Josh and to his proud father Jay. And of course congratulations to the entire LIGO team for accomplishing this seemingly impossible feat. It is a monumental achievement. And let us also not forget Einstein today!

Hey Jay, did you know about this all this time from Sept. 2015? Congrats to all. I guess there is also no debate anymore about if black holes exist or not. I wonder what happened to all the poor people in those two "Universes" that merged?

http://arxiv.org/abs/1410.3881

[ivica]

I wonder what Einstein could say about current state of science, society ...

:mrgreen:

[Ben6993]

Two thoughts/questions on this.

1. If the gravitational waves are accepted as existing as a result of the LIGO data does that imply that gravitons should also be accepted as existing? Can't find that explicitly pointed out in the media coverage.

2. Don't really have much of a clue what spacetime nor space and time are, but I don't see why gravitons should be exactly equated with causing vibrations of space/time/spacetime. Agree though to gravitons causing vibrations of something within space/time but not space/time/spacetime itself. That something being a gravitational field, just as photons give rise to an EM field.

[Joy Christian]

Two thoughts/questions on this.

1. If the gravitational waves are accepted as existing as a result of the LIGO data does that imply that gravitons should also be accepted as existing? Can't find that explicitly pointed out in the media coverage.

2. Don't really have much of a clue what spacetime nor space and time are, but I don't see why gravitons should be exactly equated with causing vibrations of space/time/spacetime. Agree though to gravitons causing vibrations of something within space/time but not space/time/spacetime itself. That something being a gravitational field, just as photons give rise to an EM field.

Gravitational waves do not necessitate gravitons. The latter requires additional assumptions for its justification (based on the orthodox interpretation of quantum theory) which Einstein’s generally covariant theory strongly resists. So, No, LIGO data most certainly does not imply that gravitons should be accepted as existing.

By the way, no one knowledgeable doubted the existence of gravitational waves since 1970's, because since then we have had extremely strong indirect evidence for gravitational waves from the timing data of a binary pulsar. One cannot explain this data without the dissipative energy loss accounted for by the gravitational waves.

[Ben6993]

Joy wrote:

Gravitational waves do not necessitate gravitons. The latter requires additional assumptions for its justification (based on the orthodox interpretation of quantum theory) which Einstein’s generally covariant theory strongly resists. So, No, LIGO data most certainly does not imply that gravitons should be accepted as existing.

By the way, no one knowledgeable doubted the existence of gravitational waves since 1970's, because since then we have had extremely strong indirect evidence for gravitational waves from the timing data of a binary pulsar. One cannot explain this data without the dissipative energy loss accounted for by the gravitational waves.

Thanks Joy. You first point confirms what I thought, but could not find elsewhere.
Your second point is interesting and I suppose it makes sense as they would not have built LIGO if they had not strongly expected to find some gravitational waves. I suppose that means that a gravitational wave does not require the existence of a graviton particle nor a graviton field. That's ok for me as I do not equate classical gravitational waves with quantum graviton fields as I see the latter as more narrow in scope.

[Yablon]

If you look carefully, one of the authors of this historic paper is the son of our very own Jay Yablon! His name is Josh Yablon. See pages 13/16 in the PDF at the above link of the paper, 4th line from the bottom, second from the right, is where you will see his name. Congratulations to Josh and to his proud father Jay. And of course congratulations to the entire LIGO team for accomplishing this seemingly impossible feat. It is a monumental achievement. And let us also not forget Einstein today!

Hey Jay, did you know about this all this time from Sept. 2015? Congrats to all. I guess there is also no debate anymore about if black holes exist or not. I wonder what happened to all the poor people in those two "Universes" that merged?

http://arxiv.org/abs/1410.3881

Thanks to Fred and Joy and Thray and ivica and anybody else who had offered congratulations on Joshua's recognition for his role in the LIGO project, as one of the authors of this landmark paper. Joshua should be finishing his doctoral dissertation this year, and we are hopeful that this will give him a bog boost as he starts the next chapter in his life as a physicist who is also the son of a physicist (me) and the grandson of a physicist (his maternal grandfather). And the brother of a chemist (his sister Paula). My psychiatric nurse spouse Deborah keeps all the rocket scientists in our family, sane.

Jay

[thray]

Jay,

What an illustrious lineage! Dissertation sure to go well.

All best,
Tom

[Yablon]

Jay,

What an illustrious lineage! Dissertation sure to go well.

All best,
Tom