[time-nuts] Plate Tectonics was: GPS Antenna on Tower.
brooke at pacific.net
Tue Jun 20 20:48:59 EDT 2017
I have a web page devoted to finding true North.
There are many ways. Here's on that uses the north star.
The first step is to sight the North Star (assuming you are in the Northern hemisphere.
But the North star currently is at:
dec: +89°15' 51"
R.A.: 2h 31m 49s
This means that when the sidereal time is 2h 31m 49s it's exactly North and then again after 12:00:00 hours sidereal
time pass it's again exactly North. Any star can be used with this method, but the closer the star is to 90 deg dec
the better from a geometry perspective.
> One thing I still haven't understood is, how these transit instruments
> were "calibrated" and placed exactly on a north-south line.
>>> All fascinating stuff....
> Attila Kinali
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