The LIGO interferometer - how do you get a signal?

[Daecon]

And we've seen better trolls.

[Professional Strawman]

Yep, they all can't figure out how an Interferometer works.

[Strange]

Just in case any readers think that Professional Trollman has some sort of point, the question is not haw an interferometer works. That is, of course, very well understood.

 

The question is about the subtlety of how LIGO, specifically, works. This is acknowledged in both sources linked in post 3. For example:

 

Today I am addressing a question that many professional physicists fully don't understand! I wrote a little while ago about how light and gravitational waves will stretch out as the Universe expands (this is called redshift). If an object is coming towards us, its light is compressed (and this is called blueshift). Basically, if objects are moving, light and gravitational waves will experience a Doppler effect. I have also written about how a passing gravitational wave will stretch and compress space in perpendicular directions. When you put these two facts together, you come to the conclusion that the light inside the arms of LIGO is also be stretched and compressed by a gravitational wave. So, how can we use this light to measure gravitational waves when the light itself is affected by the gravitational wave?

 

I doubt that Professor Troll is too stupid to understand this. But presumably he has some sort of chip on his shoulder that make him feel the need to try and put others down. Which, as always with trolls, just makes him look rather pathetic.

[Professional Strawman]

The question is about the subtlety of how LIGO, specifically, works.

 

Michelson be rolling in his grave right now.

So, how can we use this light to measure gravitational waves when the light itself is affected by the gravitational wave?

 

That's a question for a Miss Universe pageant. All of us know the answer to that silly question (except some Physicists of course). Why do you ask such questions here? Ask them in Trash. Or Speculation, silly!

Edited July 31, 2016 by Professional Strawman

[Mordred]

The problem is Strawman you don't understand Swansorts question in the first place.

 

Instead of trying to understand it. You assume you do then insult our members instead of posting a scientific discussion. We don't mind members disagreeing however we do require that they defend their viewpoints with a scientific discussion.

 

I have yet to see that on your posts this thread. Quite frankly if you cannot discuss things scientifically or follow the forum rules...

 

Take yourself elsewhere. We dont need members who cannot follow rules or cannot contribute to a discussion without resorting to insult.

 

You haven't offered a single scientific post this entire thread.

 

Instead you post mere attempts to insult rather childish. We dont need your garbage here.

 

edit just noticed you are already banned

Edited July 31, 2016 by Mordred

[Klingoln]

You would never see anything. So if the light stretches as the distance between the test

masses change, why does the phase of the light change?

 

Clearly, this nonsense belongs in Trash.

[imatfaal]

!

Moderator Note

 

 

 

Clearly, this nonsense belongs in Trash.

 

Klingoln - or perhaps I should say Professional Strawman - you have been banned; both of you. Please stop trolling now.

 

[Enthalpy]

A computation of the effect of a gravitational wave on the light in an interferometer is in Chap 1.4 (Pdf p18/149) of

"Seismic Isolation for the Test Masses of the VIRGO Gravitational Wave Antenna" by Claudio Casciano.