[time-nuts] Re: NPR: Researchers Are One Step Closer To Redefining The Second

[Poul-Henning Kamp]

--------
Magnus Danielson writes:

> A number of different approaches to new SI definition of Hz (was second)
> was put forward, by among others me, and that range from a single
> species to actually use a ensemble of species. The later would have a
> benefit in using the advancement of several species and allow a larger
> range of clock realizations.

In one of his lectures Feynmann mentions that the energy levels of
hydrogen have been calculated to 15 or 16 digits "from first
principles".

As far as I can figure out, that must have happened in the 1970'ies,
which means it was probably done on one of Seymour Cray's designs.

Hydrogen is obviously "the easy one", but even if the calculation
scales to the power of four on the number of particles in the atom,
we should still be well inside current super-computing capacities.

Do you know if anybody has considered that as way to nail the frequencies ?

-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.