[time-nuts] Optical link connects atomic clocks over 1400 km of fibre

Poul-Henning Kamp phk at phk.freebsd.dk
Thu Aug 25 04:25:49 EDT 2016

In message <1057836989.2088307.1472104857885.JavaMail.yahoo at mail.yahoo.com>, Br
uce Griffiths writes:

>You'd need a rather thick copper jacket to shield effectively
>against the 50Hz magnetic field.

As in: A good-sized fraction of the wavelength if I recall :-)

Electric fields are so much easier...

One interesting thing here is that across distances like this,
there would be significant longitudal currents in such a shield.

Not as bad as metal spanning the Mississippi, but getting there.

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.

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