Liste des Groupes | Revenir à p relativity |
rhertz <hertz778@gmail.com> wrote:And in the meantime in the real world -
On Fri, 18 Oct 2024 19:40:13 +0000, J. J. Lodder wrote:Yes, and FYA, Clarke foresaw -manned- space travel.
>rhertz <hertz778@gmail.com> wrote:>
<snip>
>>THE USE OF TRANSPONDERS HAS BEEN OF COMMON USE IN SPACECRAFTS, ROCKETS,
DEEP SPACE SONDES, ETC., SINCE THE SPAGE AGE COMMENCED, AND IS UNRELATED
TO SHAPIRO'S DELAY. IT'S A MATTER OF COMMON SENSE IN RADIO ENGINEERING.
>Not really, the first sats didn't have one.>
The point is that having transponders in interplanetary probes
reduces the uncertainty in positions of all bodies
at least a thousandfold, to typically hundreds of meters.
So while you are still whining about what may have been wrong
with the original Shapiro experiment (nothing)
correctly taking gravitational delays into account
has long since been a routine engieering matter
in interplanetary navigation.
>
There just is no way to ignore it
and still arrive at correct orbit predictions,
>
Jan
For Christ's Sake, Jan!. Stop posting things of which you don't know!
>
The use of transponders in satellites has been a dreamed solution for
communications, since 1945 (at least), when Arthur C. Clark INVENTED the
geostationary satellite communications!
>
He foresaw the use of 3 geosynchronous satellites, at about 36,000 Km,
to cover ALL the international communications. In 1963, Syncom was the
world's first geostationary satellite.
Those geo-stationary satellites would have to be manned,
because a maintenance crew would be needed
to plug in a spare when a radio tube burned out.
[snip irelevancies about history space travel, yes we all know]
And back to the point:
You whine about a popularised account of Shapiro's radar measurements
of planetary distances. (and relativistic delays that were a by-product)
All this from almost 60 years ago.
It has completely escaped your notice that in the meantime
measurements in the solar system have increased more than a thousandfold
in accuracy,
Les messages affichés proviennent d'usenet.