Re: The birth of General Relativity


"Tom Potter" <tdp1001@xxxxxxxxx> wrote in message
news:ab693d2b-db19-4cc8-bb27-52c4c93024f4@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
On Oct 7, 4:36 pm, Eric Gisse <jowr...@xxxxxxxxx> wrote:
Tom Potterwrote:

[...]

The best GPS receivers can,
by using the methods addressed above,
reduce the uncertainty in time to about one nanosecond,
which amounts to a sphere of uncertainty of about one foot.

....and uncorrected clock drift is measured in tens of nanoseconds per
day. Welcome to why GR is used in the GPS.

I am surprised to see that my pal Eric Gisse
is ignorant of the fact that atomic clocks DO NOT drift
"in tens of nanoseconds per day. "

Sure they do. Some gain, some lose. Where the bigot Goose goes wrong
is in thinking his religion has something to do with it and can convince
someone else of his stupidity. GPS is accurate to 90 feet, uncorrected.
Modern combine harvesters are accurate to an inch using differential GPS.
That's quite simple, a local receiver obtains its GPS position and transmits
the difference between that and its actual position. The moving receiver
then adds its GPS position to the offset it obtains from the fixed local
receiver and thus knows its position exactly.


.

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