> What about an ADEV/TDEV plot of the pulsar J0437-4715? Very boring. It's a straight line from top left to bottom right. :-)
See page 5 of this: http://arxiv.org/pdf/1004.0115.pdf Jim Palfreyman On 29 July 2016 at 17:33, Azelio Boriani <azelio.bori...@gmail.com> wrote: > What about an ADEV/TDEV plot of the pulsar J0437-4715? > > On Fri, Jul 29, 2016 at 12:39 AM, Jim Palfreyman <jim77...@gmail.com> > wrote: > > Hi All, > > > > Tom gave me a nudge to look here - I hadn't been following this thread. > > > > For those that don't know, I study pulsars and so the way we measure what > > pulsars do could be relevant to this discussion. > > > > First, I have never heard of a Q measure when referencing a pulsar. I > think > > the key here is that it's not resonating as such. Rotating yes, > resonating > > no. > > > > Pulsars spin and slow down due to giving off energy (magnetic dipole > > radiation). So in the pulsar world we mainly refer to spin frequency (F0) > > and frequency derivative (F1). With some of the younger and more > "erratic" > > pulsars, F2 (and further) can be modelled. > > > > Here's some data on the Vela pulsar (hot off the presses - measured just > > now): > > > > F0 11.1867488542579 > > F1 -1.55859177352837e-11 > > F2 1.23776878287221e-21 > > > > Vela is young and erratic. Millisecond pulsars are outstanding clocks. > > Here's the data for J0437-4715 - one of the most stable pulsars we know > > about: > > > > F0 173.6879458121843 > > F1 -1.728361E-15 > > > > I'm sure the "Q" of Vela would be pretty decent - but I can tell you now, > > as a time-keeper, she's useless. > > > > > > Jim Palfreyman > > > > > > > > On 28 July 2016 at 20:50, Tony Finch <d...@dotat.at> wrote: > > > >> Neville Michie <namic...@gmail.com> wrote: > >> > >> > The conical pendulum has a simple form of a weight on a string, > instead > >> > of oscillating in one plane as a conventional pendulum, it swings > around > >> > in a circular orbit in the horizontal plane. It has a definite > resonant > >> > frequency. > >> > >> I don't think it does have a resonant frequency, any more than the Earth > >> does: the angular velocity of the pendulum is sqrt(g/h) where h is the > >> height of the pendulum; give it more energy, it swings higher, so h is > >> smaller, so the frequency is higher. > >> > >> Tony. > >> -- > >> f.anthony.n.finch <d...@dotat.at> http://dotat.at/ - I xn--zr8h > >> punycode > >> South Thames, Dover: Southwesterly 5 or 6. Slight or moderate. Rain or > >> showers. Good, occasionally poor. > >> _______________________________________________ > >> time-nuts mailing list -- time-nuts@febo.com > >> To unsubscribe, go to > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> and follow the instructions there. > >> > > _______________________________________________ > > time-nuts mailing list -- time-nuts@febo.com > > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.