Message boards : Science : LIGO-Australia Proposed
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*** if two LIGOs haven't observed anything yet, ***
There aren´t only 2 detectors but thereof 4 (Geo660 and Virgo too) and the japanese one coming soon in operation as the 5th. All they are in a belt on the north half of the globe.
My point of view is: As long as there is no proven evidence of GW by more than one of these detectors, it is irresponsible to install a 6th detector, as they realy can´t be paid just from our pocket money. To make plans, also detailed plans, for the days just after the advent of that proven evidence is fine, so one can start off immediately.
We are searching now for 6 years for this waves without success, with detectors that have the neccessary proven sensitivity to find something valuable. The only result now, that has been concluded is, that neutronstars are obviosly more precisely ballshaped than allowed by theoretical calculations. At minimum 2 detectors become upgraded to 10 fold sensitivity just now. By schedule they will start the testphase in the next year and come to regular operation one year later (2014). To check, whether there are GW or no and to take basic measurements, the existig 5 detectors are more than sufficient.
Of course, if there would be found no GWs or theire strenght is engraving lower than expected, that would be very spectacular and a strong indicator for some sort of new physics.
|ID: 115675 · Reply Quote|
Again, as I understand it (correct me if I'm wrong), the original plan for LIGO Astralia was this:
"the LIGO Laboratory decided to explore the
option of shifting one of the Advanced LIGO detectors
from the US to a southern hemisphere location"
quoted from here.
|ID: 115677 · Reply Quote|
...with detectors that have the neccessary proven sensitivity to find something valuable
That is not quite the case. While it is true that upper bounds have been placed on certain models - the neutron star asymmetries that you refer to - alas that's not a detection per se. Which is the rub ...... and bear in mind that the detectors aren't equivalent for a host of arcane reasons.
The trouble is that gravitational waves are a leading edge hypothesis involving 'first use technology', so 'proven' is somewhat of a tail-chasing argument. I really should dig out those late 90's studies for reference here. The precise reason for making predictions back then was to defray the very issue you have raised now. Specifically it was anticipated that a 'scorecard' would be desired. So while we are all gunned up to get a GW detection - because that would be new, cool, interesting etc - Nature may not actually provide us with one. But if they don't exist, then we have discovered a novelty indeed.
What I should add is that the experience with early resonant bar detectors - Joseph Weber at al - induced considerable caution within the field as to what ought be claimed, expected or touted as a detection. Again the extremely low order of the effect is the prime issue.
( edit ) To be exact : NOT detecting certain gravitational wave patterns from neutron stars with 'mountains' is also consistent with
- gravitational waves NOT existing, PLUS
- neutron star asymmetries of a degree constrained by other factors
( edit ) Certainly the Einstein Telescope has prior gravitational wave detection as an absolute prerequisite for it's construction. All of these projects are worth a bucket of someone's money, so it is all the more important to be clear about expectations.
"I have made this letter longer than usual, because I lack the time to make it short." - Blaise Pascal
|ID: 115678 · Reply Quote|
If you will permit a digression on the significance/detection issue ...
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