[time-nuts] NPR Story I heard this morning

[Bob Bownes]

But won't the doppler effect change as the Cs atoms fall down the gravity
well? :)


On Tue, Nov 4, 2014 at 3:14 PM, Attila Kinali <attila at kinali.ch> wrote:

> On Mon, 3 Nov 2014 11:54:41 -0800
> Peter Monta <pmonta at gmail.com> wrote:
>
> > Sorry if this is a bit off-topic.  I'd like a simple, clear explanation
> for
> > the layman that drills down on exactly how the current definitional
> scheme
> > can be realized to arbitrary precision.  For example, assume that we must
> > go off-earth at some point to get a better timescale.  How fuzzy is the
> > solar potential ("soloid")?
>
> It will be done as usual: As soon as they can reliably measure an
> systematic
> effect that is impossible to cancel out, they will redefine or ammend the
> definition of the second to account for this issue.
>
> And going by the presentations given at EFTF this year, there is quite
> some interest in precision gravity measurements in the time/frequency
> community. And yes, they use the same basic phyiscs as their atomic clocks
> :-)
> (one apporach is to let Cs atoms fall down a tube and measure their
> acceleration using doppler shift of the hyperfine transitions line)
>
>                         Attila Kinali
>
> --
> I pity people who can't find laughter or at least some bit of amusement in
> the little doings of the day. I believe I could find something ridiculous
> even in the saddest moment, if necessary. It has nothing to do with being
> superficial. It's a matter of joy in life.
>                         -- Sophie Scholl
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
>