Nice discussion of astronomical timekeeping

Enjoy:
http://www.gresham.ac.uk/event.asp?PageId=4&EventId=850
--
Dave

On Feb 3, 8:17*pm, Dave Typinski wrote:
Enjoy:

Not a single mention of how, back in the days of temperature-
compensated pendulum clocks, astronomers used the transits of stars,
instead of the Sun, to provide an accurate measure of time not
affected by the Equation of Time since it depended on the Earth's
rotation alone.

Did Oriel get to him, or what?

John Savard

On Feb 4, 6:34*am, Quadibloc wrote:
On Feb 3, 8:17*pm, Dave Typinski wrote:

Enjoy:

Not a single mention of how, back in the days of temperature-
compensated pendulum clocks, astronomers used the transits of stars,
instead of the Sun, to provide an accurate measure of time not
affected by the Equation of Time since it depended on the Earth's
rotation alone.

Did Oriel get to him, or what?

There _is_ a discussion of sidereal time in the talk, but apparently
nothing about how stellar transits were an important fundamental
standard of timekeeping for many years, which I consider quite an
omission.

John Savard

Quadibloc wrote:

On Feb 4, 6:34*am, Quadibloc wrote:
On Feb 3, 8:17*pm, Dave Typinski wrote:

Enjoy:

Not a single mention of how, back in the days of temperature-
compensated pendulum clocks, astronomers used the transits of stars,
instead of the Sun, to provide an accurate measure of time not
affected by the Equation of Time since it depended on the Earth's
rotation alone.

Did Oriel get to him, or what?

There _is_ a discussion of sidereal time in the talk, but apparently
nothing about how stellar transits were an important fundamental
standard of timekeeping for many years, which I consider quite an
omission.

That's a good point, John. Mention of it would have made the lecture
that much better.

I thought the discussion of the SR & GR corrections in the GPS were
quite good; better than I've seen elsewhere.
--
Dave