See...? Everything is improved by adding cats!
A University of Western Australia (UWA) boffin who played a major part in Australia's contribution to finding gravitational waves reckons detectors can get a lot more sensitive. UWA Professor David Blair, who discussed how quantum noise can interfere with gravitational wave detection with Vulture South in 2011, has supervised …
Wednesday 13th April 2016 09:33 GMT Anonymous Coward
Wednesday 13th April 2016 10:25 GMT cray74
I wonder how they sort out all the noise. At sensitivity equal to 1/10,000th the diameter a proton, stray atoms in a vacuum chamber bumping the apparatus must be an issue.
Do they shock isolate the bathrooms? One office chili cookoff at the LIGO facility could seriously pollute (har) the data.
Wednesday 13th April 2016 12:51 GMT John Mangan
Re: Noise Filtering
There are a whole array of isolation mechanisms. There are passive items like lead/rubber stacks, the mirrors are suspended on fine 'wires' to filter higher frequency noise. There are feedback mechanisms using laser beam sidebands to further reduce noise.
On top of that although the impression given is that a laser beam enters the arm, reflects at the end and then exits these arms are actually Fabry-Perot cavities and the light bounces back and forth 'a lot'. The reflectivity of the mirrors define the 'finesse' of the cavity and the 'finesse' also defines the frequency response to gravitational waves. So one photon hitting a bump isn't going to be a big deal.
There are also baffles along the tubes to ensure that scattered light doesn't get to re-enter the beam and (almost certainly) a whole host of other enhancements that weren't even thought of when I left the field nearly three decades ago.
Wednesday 13th April 2016 20:54 GMT JeffyPoooh
Re: Noise Filtering
cray74 "I wonder how they sort out all the noise?"
There are some very nice audio samples of the raw Advanced LIGO audio signal available on-line. The raw signals are dominated by all sorts of artifacts, such as the 'Violin Mode' oscillation of the suspension strings. They do a lot of filtering with the usual Signal Processing tricks. That's after spending millions on the isolation hardware.
Wednesday 13th April 2016 18:05 GMT Anonymous Coward
Wednesday 13th April 2016 19:12 GMT cray74
1/7th of a "tsunami-like wave" is almost certainly a "tsunami-like wave".
Or you could say, "It's almost an order of magnitude improvement."
But more to the point, not every large engineering improvement is accomplished in single giant leaps. Incrementalism works, too. A few percent here, a few percent there, and then the next generation of runners has shaved off a minute from the mile, or an hour from a marathon, or LIGO's watching the gravity waves of binary neutron stars rather than just spotting super giant black holes colliding.
Wednesday 13th April 2016 20:23 GMT ma1010
Wednesday 13th April 2016 21:02 GMT Stoneshop
Well, the gravitational force* between two bodies** is proportional to the product of their masses*** over the square of their distance****. So it would require two stadiums, the matter they are filled with, and also depends on the distance between them. A gravitational wave, as I understand it*****, is the variation in force due to matter shifting and/or being destroyed.
This suggests the Roundhouse Kick as the preferred unit.
* So, Norrises
** Say, Fred Astaire and Ginger Rogers
*** Jubs squared
**** Brontosauruses squared