Post by Paul B. AndersenThe ONLY VALID TIME FOR HUMANS is the one shown in the main page of
BIPM, and count 86,400 seconds for an earthly day.
And that time is UTC.
It is 86,400 seconds in a _mean_ solar day.
https://www.bipm.org/en/
All the public and private institutions in the ENTIRE WORLD agree with
this time, and it has happened for more than 100 years. For the last 50
years, the use of atomic clocks made it more precise, and digital
networks made it available worldwide for the last 25 years (baseband
fiber optics transmissions). Since 2002, sustained (as comparison and
distribution) by networks of satellite's GNSS.
Relativists, go home!
You do know that UTC clocks are _not_ synchronous in
the ground frame, don't you? Or don't you?
UTC clocks are synchronous in the ECI frame.
That means that if you have two UTC clocks at different
longitude and connect them with an optic fibre, then,
measured with the two UTC clocks, the light will use different
time to go between the clocks in the two opposite directions.
This phenomenon is well known, and is built into the software
of the digital networks that keep the TAI and UTC clocks synchronous.
So you see, Richard, relativity is in everyday, practical use
in the real world.
Each day has 86,400 seconds and each new day has its own.
I.e. the calendar is in days, not seconds.
Some days are longer or short than others,
if so briefly, and there are either extras or
they're lost, as with regards to that seconds
have an abstract definition of always being
of constant duration.
The minutiae for minutes and then secondae for
2'nd minutes, is where the words come from,
that anyways the modern SI unit the second or 1s,
is not considered useful on all milieu's as with
regards to clock seconds and calendar seconds as
with regards to the constant monotone increasing
aspect of events in time and their measurement.
The, ground stations update the GPS satellites
their corrections not the other way around, as
the GPS satellites in their orbits are much
more in the milieu of the gravitational waves
as with regards to that thusly the ground stations
can measure the changes in the ephemeris from the
clocks of the satellites, as with regards to the
relativistic formulas for clock drift, and, the
equivalence principle, and acceleration in co-moving
frames, and, acceleration in non-co-moving frames,
and, not the equivalence principle, as with regards
to aether theory, if in different words as the old
one has been all denounced and fools don't know it
on its own merits.