[LEAPSECS] Nit-pick: SI second
Paul Sheer
p at 2038bug.com
Wed Feb 9 18:58:51 EST 2011
Since the velocity of the atomic clock causes relativistic dilation,
surely it is not the altitude-above-sea-level, but the radial distance
from the earths axis that we are talking about???
I.e. surely both latitude and altitude affect the ceasium? I mean the
velocity of the atomic clock as it stands in the lab is dictated by the
earth rotation times the radial distance from the earths rotational
axis?
???
-paul
On Thu, 2011-02-10 at 00:24 +0100, Magnus Danielson wrote:
> On 07/02/11 20:10, Tom Van Baak wrote:
> >> It is also why TAI's rate was adjusted in the 1990's to compensate for
> >> the red-shifted data that had been collected at NIST in Boulder, since
> >> it sits at about 5400' (1700m) above sea level (as well as other
> >> facilities not at sea level).
> >>
> >> Warner
> >
> > Are you sure you aren't confusing red shift (which has been
> > a known factor since the 60's) with blackbody shift (which
> > only arose in the 90's as clocks hit the 1e-15 level)?
>
> These are distinct in the face of SI. The nit-picker could find all the
> material needed in
>
> http://www.bipm.org/utils/common/pdf/si_brochure_8_en.pdf
>
More information about the LEAPSECS
mailing list