Perhaps "equation of longitude"? Dan Uza
On Wed, Mar 13, 2019, 20:50 Julian Lush <julian.l...@hotmail.co.uk> wrote: > How about longitude adjustment? > > Julian Lush > 72 Bromfelde Road, London SW4 6PR > 020 7622 9497 07815 637706 > ------------------------------ > *From:* sundial <sundial-boun...@uni-koeln.de> on behalf of Frank King < > f...@cl.cam.ac.uk> > *Sent:* 13 March 2019 12:29 > *To:* Dan-George Uza > *Cc:* Sundial List > *Subject:* Re: dischrony > > Dear All, > > I have a mild distaste for "correction" since > it implies something is wrong. In particular > 'local mean time' and 'local mean time-zone time' > are both correct, but different, times. One is > offset from the other but this offset is in no > sense a correction! > > To me "offset" is neutral. > > There are, of course, many many different > times in current use. Here are just a few: > > TAI, UTC, UT1, UT2, GMT, GST, GPS time > > None of these is wrong but each is offset > from all the others. > > Sometimes the offset is constant such as > the difference between TAI and GPS time > > Sometimes the offset changes infrequently, > such as the difference between TAI and UTC > (which changes only when there is a leap > second). > > Sometimes the offset changes continuously, > such as the difference between GST (sidereal > time) and GMT. > > This suggests that the word 'constant' is > not generally appropriate and is why I am > not keen on the Italian "costante locale". > > This is actually a false assertion when > referring to local mean time versus local > time-zone time because in most places the > reference time zone is shifted 15 degrees > backwards and forwards at the whim of > legislators! The offset is not constant! > > Dan-George asks: > > how would you translate the Italian > "foro gnomonico" > > In English, this translates literally as > "gnomonic hole" but this would be a bad > translation! It generally refers to the > hole in the roof (or possibly a side wall) > of a cathedral or large church that lets > in the sun so as to cast an image of the > sun on the floor. > > The best English equivalent is "aperture > nodus" but that isn't quite the same thing. > An aperture nodus provides a spot of light > on the dial plate, not an image of the sun. > > The French "oeilleton" is more challenging! > In English, this translates literally as > "eye-cap" which I think of as something > for medical use, for washing your eyes. > > I rather suspect that the French also use > this to mean aperture nodus but I should > like confirmation. > > Frank > > Frank King > Cambridge, U.K. > > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > >
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