Intercontinental optical clock comparison at 10^-18 · revision history

Revision 2

Accepted · core change · record

Changes against revision 1:

Title · changed
Revision 1: Intercontinental optical clock comparison at 1e-18
Revision 2: Intercontinental optical clock comparison at $10^{-18}$
Plain
Clocks on different continents must be compared to check that they agree, but satellite links are not yet good enough. Height differences also matter, since a clock 1 cm higher runs faster by about one part in $10^{18}$.
Precise · changed · core
Revision 1: Achieve a comparison of optical clocks separated by more than 5000 km with total uncertainty below 1e-18, including link noise and the gravitational redshift (1.1e-18 per cm height), which requires geopotential differences known to $1e3\,\mathrm{cm}^2\,\mathrm{s}^{-2}$.
Revision 2: Achieve a comparison of optical clocks separated by more than 5000 km with total uncertainty below $10^{-18}$, including link noise and the gravitational redshift ($1.1 \times 10^{-18}$ per cm height), which requires geopotential differences known to $10^{3}\,\mathrm{cm}^2\,\mathrm{s}^{-2}$.
Settled by · changed · core
Revision 1: An intercontinental clock comparison via free-space optical satellite link, transportable clocks or fiber, with an uncertainty budget below 1e-18 and agreement with independent geodesy.
Revision 2: An intercontinental clock comparison via free-space optical satellite link, transportable clocks or fiber, with an uncertainty budget below $10^{-18}$ and agreement with independent geodesy.
Kind
well-posed
Answer type
yes-no
References
(empty)
Literature status
open
Status note
(empty)
Posed since
(empty)

Decisions