On Sun, Mar 23, 2025 at 3:14 PM Alan Grayson <[email protected]> wrote:
> > > On Sunday, March 23, 2025 at 1:06:06 PM UTC-6 John Clark wrote: > > *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>* > > > What do you mean by L shaped, if there are two separate detectors? AG > There’s an L-shaped detector in Louisiana, and another one in Washington state, Both Detectors have two arms and both arms are 2 1/2 miles long. John K Clark 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/95dc35bf-ae36-496d-9fbd-859e230b0f35n%40googlegroups.com > <https://groups.google.com/d/msgid/everything-list/95dc35bf-ae36-496d-9fbd-859e230b0f35n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- 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/CAJPayv0Hviv-dm8f%3DyuEtKOrzQe0RBkRWHbgQd%2BZH26S824VRg%40mail.gmail.com.
