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 <[email protected]> wrote: > Neville Michie <[email protected]> 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 <[email protected]> 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 -- [email protected] > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
