Gravitational/Scalar Waves

[swansont]

I like the description, it's quaint

 

From reading of Mr Hawkins and his predecessors our thoughts of black holes seem to change with time.

Would you agree it's just one proposed mechanism and may or not be correct?

 

I wonder why 0.2S, when I look at the graph of Ligo's first event it looks closer to about 0.17S, speaking of Ligo's first event leads to it's second captured event that looks nothing like the first, the one we've discussed so far.

 

 

What do you mean by first event?

[DrP]

Yes - our knowledge if definitely growing with time. The models for BHs have change over the last few decades from what I can tell.... we are still learning about them. We are only just about to take a picture of one, so you could say we are in our infancy with what we know. These theoretical physicists do a great job of assembling a picture from the info they have.

 

When I first joined this forum, the thinking was that a BH was a singularity.

[Ant Sinclair]

What do you mean by first event?

I read it here;

 

http://physics.stackexchange.com/questions/262771/why-does-ligos-second-detection-of-gravitational-waves-and-a-black-hole-merger

who is Mr. Hawkins? Please don't say you mean Dr. or Professor Stephen Hawking; accuracy is important and so is politeness.

 

And our ideas and understanding of extreme phenomena which are at high cosmological distances obviously change with each new observation - but I see no huge volte-face.

 

Eyeballing a graph is not a great way to decide on the timing of an event - but frankly who cares; we measured an event and it looked just as we expected for that sort of scenario.

 

The second event was different I believe in that one of the blackholes had considerable spin on its axis at merger and they were both smaller so the detectable finale was spread out over a longer period

How was it determined that the final 200ms of energy output from the merger was responsible for the 'pulse', was it a pulse or a wave, or was it a pulse with waves 'riding' on it or was it a wave with ripples riding on it?

Yes - our knowledge if definitely growing with time. The models for BHs have change over the last few decades from what I can tell.... we are still learning about them. We are only just about to take a picture of one, so you could say we are in our infancy with what we know. These theoretical physicists do a great job of assembling a picture from the info they have.

 

When I first joined this forum, the thinking was that a BH was a singularity.

You're correct there DrP, if the artists by numbers can see the framework correctly a Type4 Civilisation may be within our scope/grasp.

[swansont]

I read it here;

 

http://physics.stackexchange.com/questions/262771/why-does-ligos-second-detection-of-gravitational-waves-and-a-black-hole-merger

 

 

 

And since you read about it elsewhere, it helps to mention that for context for discussion here.

 

That link seems to quite adequately explain why the signals look different.

[Mordred]

I read it here;

 

http://physics.stackexchange.com/questions/262771/why-does-ligos-second-detection-of-gravitational-waves-and-a-black-hole-merger

How was it determined that the final 200ms of energy output from the merger was responsible for the 'pulse', was it a pulse or a wave, or was it a pulse with waves .

Its pulses called chirp that is in the form of quadrapole waves.

 

The chirps result from irregular distance transition changes as the two BHs approach each other in elliptical orbits.

Edited April 12, 2017 by Mordred

[swansont]

 

How was it determined that the final 200ms of energy output from the merger was responsible for the 'pulse', was it a pulse or a wave, or was it a pulse with waves 'riding' on it or was it a wave with ripples riding on it?

 

Pulses are waves. Just of limited duration.

[Ant Sinclair]

Pulses are waves. Just of limited duration.

Would that be just one wave then, a single pulse being a single wave?

 

a single vibration or short burst of sound, electric current, light, or other wave.

"a pulse of gamma rays"

synonyms: burst, blast, spurt, eruption, impulse, surge; informalsplurt

"a dolphin emits short pulses of ultrasound"

[swansont]

Would that be just one wave then, a single pulse being a single wave?

 

a single vibration or short burst of sound, electric current, light, or other wave.

"a pulse of gamma rays"

synonyms: burst, blast, spurt, eruption, impulse, surge; informalsplurt

"a dolphin emits short pulses of ultrasound"

I don't really know what a "single wave" is in this context. As the definitions say, a pulse is a short burst. I had said limited duration. Same thing.

[Strange]

And, specifically, a "chirp" is a signal where the frequency increases with time.

Would you agree it's just one proposed mechanism and may or not be correct?

 

That is always true in science. However, in this case, the waveform matched very precisely the predictions for a signal produced by the merger of two black holes. So, it could be something else that we know nothing about that just happens to look just like something we do know about ... or it could be what it appears to be.

[beecee]

Would you agree it's just one proposed mechanism and may or not be correct?

 

 

That is always true in science. However, in this case, the waveform matched very precisely the predictions for a signal produced by the merger of two black holes. So, it could be something else that we know nothing about that just happens to look just like something we do know about ... or it could be what it appears to be.

Nice answer to a "query" which reminds me of remarks we often see outside of science that tend to deride same by the tired old "Ahh, its only a theory" jibe.