Bruce, a question about An Optimized Application

Mike Hewson
Mike Hewson
Moderator
Joined: 1 Dec 05
Posts: 6,170
Credit: 130,144,045
RAC: 20,038

RE: RE: Actually I'll

Message 23731 in response to message 23730

Quote:
Quote:
Actually I'll share some interesting stuff I found while browsing the presentations....
Cheers, Mike.

Thanks for taking the time to review the presentations, this is very interesting information! I was wondering how much "good" triple-coincidence time data they were collecting, because the intruments are so incredibly sensitive they pick up the very least bit of earthly background noise. In fact, imho, the sensitivity is such and the planet is so noisey that a space-based instrument seems probably best (and I know one is planned eventually).

Updates like yours are encouraging, and certainly keep up my interest in the project! :)


Quite right! Ultimately space is the place to be!
( What 'good' really means is that the 'dark port' of the interferometer has been held at an interference fringe minimum by the active use of the incredible control system of the whole array. One then takes the signals used in that system to perhaps deduce the flexing/distortion of spacetime induced by a passing gravitational wave propagating through the entire LIGO. The poorer alternative is to not do that control effort, but measure the light fluctuation at that port..... )
Anyhows, what makes the project not entirely hopeless here on Earth - given that we are looking for alterations in spacetime of the order of 10 to the power of minus 21 while using instruments, wavelengths, noises etc all far larger than that - is that most 'background' is incoherent. This means that many non-astronomical influences like the 'shot noise' of a laser, or thermal movements of the atoms in the mirrors do not have a preference with respect to the direction of the effect of scientific interest. A good analogy is the seaside where there is a lot of slosh, froth, wind, waves and spray etc.... but if you watch for long enough ( much, much longer than these 'obvious' disturbances ) the tide comes and goes. In other words averaging smears away such temporary upsets and allows trends to be observed. Another helpful method is to 'park' the noise in less critical parts of the observed data. So if you have some noise component that blurs a region of particular interest ( technically in the power vs. frequency spectrum ) then one can cleverly design widgets to interact physically with the detector parts to channel energy away into other 'modes'. So you ask the tenor to sing just as hard but in the baritone range! In addition, if you can't do that, then make the noise well defined, 'narrow', well studied, and understood - hence you can confidently subtract it away from the data. Another expectation is that widely separated detectors ought not suffer identical patterns of incidental noise - like a tree being felled in the Louisiana woods, or a brushfire in Washington State - so comparison between sites ( with simultaneously locked interferometers ) is quite valuable. Another trick is to get the chalk and pencil out and make a well educated guess as to what sort of signal ought to be heard for some given astronomical phenomenon, and then search for that in all the hubbub.
Cheers, Mike.

I have made this letter longer than usual because I lack the time to make it shorter. Blaise Pascal

rbpeake
rbpeake
Joined: 18 Jan 05
Posts: 247
Credit: 219,857,449
RAC: 8,697

RE: ...and then search for

Message 23732 in response to message 23731

Quote:
...and then search for that in all the hubbub.
Cheers, Mike.


Thanks for the wonderful explanation! I guess our computers are searching for the faint gravitational wave "song" in amongst the furious noise of the hurricane...

Again, I really appreciate your time in making these clear explanations. :)

JardaM
JardaM
Joined: 21 Mar 05
Posts: 9
Credit: 2,553,158
RAC: 1

Back to the original name of

Back to the original name of this thread.
Albert v.4.50 has shown up.
Bruce, could you kindly explain what level of optimization did you implement? This might be quite important for akosf.

rbpeake
rbpeake
Joined: 18 Jan 05
Posts: 247
Credit: 219,857,449
RAC: 8,697

The new 4.50 Albert is in

Message 23734 in response to message 23733

The new 4.50 Albert is in beta test currently. Akosf said he is starting to "work some black magic" on it. :)

Wurgl (speak^Wcrunching for Special: Off-Topic)
Wurgl (speak^Wc...
Joined: 11 Feb 05
Posts: 321
Credit: 140,550,008
RAC: 0

RE: The new 4.50 Albert is

Message 23735 in response to message 23734

Quote:
The new 4.50 Albert is in beta test currently. Akosf said he is starting to "work some black magic" on it. :)

Personally I prefer white magic, but Hungary may have a different tradition :-)

Akos Fekete
Akos Fekete
Joined: 13 Nov 05
Posts: 561
Credit: 4,527,270
RAC: 0

RE: RE: The new 4.50

Message 23736 in response to message 23735

Quote:
Quote:
The new 4.50 Albert is in beta test currently. Akosf said he is starting to "work some black magic" on it. :)
Personally I prefer white magic, but Hungary may have a different tradition :-)

Hey! White magic is boring,
but I have some magic words for you... ;-)

Comment viewing options

Select your preferred way to display the comments and click "Save settings" to activate your changes.