Hal, at one point shortly after their discovery in the late 60’s, Pulsars were considered as a possible primary frequency standard. Then atomic clocks became more amenable as lab standards.
As to time-nut measurements on pulsars, check this out: https://arxiv.org/abs/0909.1054 Millisecond and binary pulsars are the most stable astronomical standards of frequency. They can be applied to solving a number of problems in astronomy and time-keeping metrology including the search for a stochastic gravitational wave background in the early universe, testing general relativity, and establishing a new time-scale. The full exploration of pulsar properties requires that proper unbiased estimates of spin and orbital parameters of the pulsar be obtained. These estimates depend essentially on the random noise components present in pulsar timing residuals. The instrumental white noise has predictable statistical properties and makes no harm for interpretation of timing observations, while the astrophysical/geophysical low-frequency noise corrupts them, thus, reducing the quality of tests of general relativity and decreasing the stability of the pulsar time scale. > On Jun 2, 2020, at 6:00 PM, Tom Van Baak <t...@leapsecond.com> wrote: > > Hal, > > This will keep you busy for an hour: > > "Listening for Gravitational Waves Using Pulsars" > https://www.nasa.gov/feature/jpl/listening-for-gravitational-waves-using-pulsars > > "Spotting gravitational waves using pulsar ticks" > https://www.pnas.org/content/pnas/113/32/8878.full.pdf > > "Detection of Gravitational Waves using Pulsar Timing" > https://arxiv.org/abs/1004.3602 > https://arxiv.org/pdf/1004.3602.pdf > > "Pulsar timing arrays: the promise of gravitational wave detection" > https://iopscience.iop.org/article/10.1088/0034-4885/78/12/124901/ampdf > > "Pulsars could reveal nanohertz gravitational waves within 10 years" > https://physicsworld.com/a/pulsars-could-reveal-nanohertz-gravitational-waves-within-10-years/ > > "The local nanohertz gravitational-wave landscape from supermassive black > hole binaries" > https://www.nature.com/articles/s41550-017-0299-6.epdf > > "Gravitational Wave detection & data analysis for Pulsar Timing Arrays" > https://local.strw.leidenuniv.nl/events/phdtheses/haasteren/thesis.pdf > > /tvb > > >> On 6/2/2020 2:49 PM, Hal Murray wrote: >> I watched the video of an astronomy talk yesterday. (Info below. I thought >> it was good.) >> >> During the Q&A, the speaker discussed the possible options for detecting >> different wavelengths of gravity waves. >> >> For very long wavelengths, she mentioned the possibility of watching pulsars. >> >> Has anybody seen any discussion of the numbers? Is this anywhere near >> possible? >> >> >> >> >> A Sharper Image: Seeing Colliding Galaxies with Adaptive Optics >> https://www.youtube.com/watch?v=stAGLke6XDU >> >From Oct 2018 >> >> > > > _______________________________________________ > time-nuts mailing list -- time-nuts@lists.febo.com > To unsubscribe, go to > http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.