*Correction: the two LIGO installations are in Louisiana and Washington state. not Oregon as I originally said. * *John K Clark See what's on my new list at Extropolis <https://groups.google.com/g/extropolis>* n0w e3b
On Sun, Mar 23, 2025 at 2:47 PM John Clark <[email protected]> wrote: > On Sun, Mar 23, 2025 at 2:36 PM Alan Grayson <[email protected]> > wrote: > > >> *>> LIGO is able to measure the distance between two mirrors 2 1/2 miles >> apart to an accuracy of 1/10,000 the width of a proton. And you need that >> sort of accuracy if you want to detect gravitational waves. They achieve >> this astounding level of precision by measuring the interference effects >> between two laser beams. * >> >> >> >> *> So they measure an interference pattern. How do they know it's a >> gravitational wave? AG* >> > > *LIGO is L shaped with each leg being 2 1/2 miles long, theory says > gravitational waves should shrink the distance between one leg at the same > time it's expanding the distance in the other leg, nothing else could do > that. And to make sure they have two identical facilities, one in Louisiana > and the other in Oregon, if it's a gravitational wave then the two > detectors should measure the same thing at almost the same time because > gravitational waves move at the speed of light, any slight delay between > the two can help them figure out the direction the gravitational wave is > coming from. * > > *John K Clark See what's on my new list at Extropolis > <https://groups.google.com/g/extropolis>* > e3b >> >> >> -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/CAJPayv0wx2qDqC3McJWtF2NVCHTTc6FQEtwqRVFtxA2rSxYY6w%40mail.gmail.com.
