On Fri, Dec 19, 2008 at 3:04 AM, bfranchuk at jetnet.ab.ca
<bfranchuk at jetnet.ab.ca> wrote:
Ethan Dicks wrote:
So many ways to tell time in the modern era.
This is a huge change
from a few centuries ago, when a marked stick was close enough.
Nope ... Looks out side, it is dark but is it after midight yet? Hard to
tell with this candle what notch my sundial stick is at.
There were also time-keeping candles - obviously the size and
composition of the candles will affect burn rate, but for acceptable
levels of accuracy of the time, burning calibrated candles would
suffice for whatever hours you happened to be awake after sunset (we
take electric light completely for granted after 100+ years of it, but
formerly, there was a lot more rising and sleeping with the sun going
on than now).
While you don't get time as accurate as moden
clocks
sundial and moondials are still interesting time telling devices.
Yes they are. I've only ever fiddled a little bit with telling time
by the moon, but I did build a sundial at Pole - it was easy - the
normal calculations all cancel out (think of "tangent of 90 degrees"),
and I effectively made what looks like a dartboard, divided into 24
equal-angle slices. Piece of cake (or is that pi?)
One of these days, I should make a sundial for 40N (Columbus, OH). It
would be a nice accompaniment to all of my newfangled clocks.
-ethan