Re: Ove Interest?

On Thu, 27 Feb 2025 23:21:15 -0500, Frank Krygowski
<frkrygow@sbcglobal.net> wrote:

On 2/27/2025 8:19 PM, John B. wrote:

On Thu, 27 Feb 2025 20:32:10 GMT, cyclintom <cyclintom@yahoo.com>
wrote:
 

On Thu Feb 27 09:39:54 2025 Jeff Liebermann  wrote:

>
Tom claimed to "have an engineering degree" several times.  However,
there's no indication if the degree or diploma he claims to have were
the result of a college education, diploma mill, downloaded from the
interent, or a product of his amazing imagination.
>
Degree in navigation and Chabot College in Hayward
02/09/2021
<https://groups.google.com/g/rec.bicycles.tech/c/_Y1MbXuzvNo/m/o6omSxsfAgAJ>
"general education - Degree in navigation
Tality requested I get a BA so that they could promote me to
department manager
Chabot College - Hayward, CA"
>
08/31/2023
<https://groups.google.com/g/rec.bicycles.tech/c/UlnAtHIZnTg/m/-0rUba4qAgAJ>
"Sailing down the coast I had a sexton ...   It was advantageous to be
able to use the Sexton to tell how far we were off of the coast..."
It's a sextant, not a sexton.

 
Interested how a Sexton (sextant) measure distance from the coast as
it only measures angles :-)

>
ISTM that if one were dealing with a coast that ran east-west and had a
decent chart, you could use a sextant to find that distance. Finding
one's latitude was probably the prime reason sextants were invented.
Once you knew your latitude and that of the coast, the distance is easy
to find. Ask your buddy who claimed to do a lot of sailing.
>

The common use of a Sextant is to find the Latitude by measuring
(traditionally) the  height of the sun above the horizon at noon (by
sun height)..

Knowing one's Longitude - or finding your distance away from a
north-south or other coast - is a different matter. It's a nearly
impossible problem without knowing the precise time, which is why huge
prizes were offered to entice development of accurate chronometers.
>
But if your chart showed the precise locations of two different objects
(e.g. towers) that could be sighted through a sextant, ISTM you could
observe the horizontal angle between them and do some trigonometry to
find your position. That's just a geometry or trig problem.

Marine charts are seldom accurate enough to use points on a chart for
precise navigation, A good friend's favorite anchoring spot at one
site in thru Philippines is something like 100 yard from the water
according to the U.S, chart :-)
--
Cheers,

John B.