[geocentrism] Re: Geosynchronous/Geostationary satellites
- From: "Neil Robertson" <nroberts@xxxxxxxxxxxxxxxxxx>
- To: <geocentrism@xxxxxxxxxxxxx>
- Date: Thu, 28 Oct 2004 15:02:48 +1000
Gary,
>
> So you're NGR. You're a diplomatic sort, for sure. "...would appear to
> be
> inappropriate."
Just my humble attempt to steer you away from potential difficulty.
> For the record, the only instructions I ever got was a warning early on
> from
> the BA himself not to attack other people, only their ideas. If there
> were
> any instructions to completely obliterate the Bible and any logic derived
> therefrom from all BA posts, the BA himself did not say that.
Yes, the BA is very strict on the attacking ideas and not people principle
and will ban people who step out of line in that regard. He is very fair in
this and will ban friend and foe alike if they break that basic rule. There
is a FAQ link on that site that gives you the basic rules for the forum and
from memory I don't think it specifically states that religion is not an
acceptable topic.
You would be aware however that peoples religious and political views are
generally deeply held and when they collide with opposing views friction is
the usual result. This is particularly the case with the internet as you
only have disembodied voices without the usual feedback we get with face to
face communication. Misunderstandings occur and mischief is not unknown due
to the anonymity that the internet appears to provide. In view of this the
discussion of religion and politics is generally frowned upon on the BA
forums and the BA himself has mentioned this a few times in his posts.
Whilst your post in that thread mentioned geocentrism your question was
specifically about the bibles support for that view and nothing to do with
the scientific nature of the arguement. As such it was against the general
thrust of the board which is all about the science of astronomy and related
matters. It was also against the spirit of the thread as was pointed out a
little later by the threads originator.
I have learnt from experience that it is adviseable to shy away from topics
which will cause disharmony and of course there are a number of sites that
discuss religion and politics in a vigourous manner if that is what you
seek.
>>
>> > I think I am beginning to see this figure eight now, though it is a
> tough
>> > one to visualize.
>
> What do you think of Jack's bringing up the analemma? It is interesting,
> I'd say, but I don't know enough about the analemma to compare it to the
> figure eight of the satellites.
Yes the analemma is an interesting effect. I remember reading all about it
some years ago in the Sky and Telescope magazine I have subscribed to for
many years. They had a poster you could buy of the Suns passage in the sky
photographed over a year by some amature astronomer. It was the first I had
heard of the effect and I almost purchased the poster. I have been meaning
to take a photo myself but I don't think I am that organised to stick it out
for a whole year.
The effect is caused by a similar situation to the satelites orbit but for
slightly different reasons. As I have mentioned previously the satellite
situation comes about because its orbit is inclined to the earths equator
and its orbit is elliptical. The earths orbit around the Sun is elliptical
like the satellites but is only very slightly inclined to the Suns equator
so that aspect does not contribute to the up down motion of the Sun. Instead
that is caused by the earths 23.5 degree axial tilt. I touched on this
briefly in my response to Pillips query concerning the fixed path of the
stars and the up down motion of the Sun over a yearly period.
All facinating stuff. If you wish to read more about this you can go to this
site www.analemma.com which has all the info (diagrams calculations movies
charts etc) that you are ever likely to need on the subject.
>
>I would surmise by this that there is no perfectly steady geostationary
>satellites, right?
Well it depends on how technical you want to be. Would you accept movement
of 1mm either way or a metre or ten metres or a killometre or ten
killometres. In a technical sense these are not stationary but you would
never know the difference from the earths surface and they would still be
steady enough for the job that were required to do.
>You make it sound like it's a hit or miss proposition
> when launching the geostationary satellites. I imagine each one costs a
> monumental amount of money. How could they keep sending them up there if
> they weren't achieving purposeful objectives? Are they really so
> helpless
> as to the final location of their satellite orbits?
>
If the earth was perfectly spherical and of uniform density and there were
no other objects in the universe to peturb the satellites orbit a perfect
orbit could be achieved. Such ideal conditions do not exist and the
technicians play with the cards that they are dealt. As I have stated
previously they calculate the orbits based on their knowledge of orbital
mechanics and place the satellites in a position to remain as stationary as
possible over as long a period as possible. These satellites will not stay
exactly in position because of the factors I have spoken of in previous
posts. The satellites carry fuel so that thrusters can periodically nudge
them back into position but they can not carry an inexhustible supply of
fuel and eventually the satellite will be unuseable because of the drift.
Such satellites have about a 5 year lifespan and then they are replaced.
The satellite business is expensive I have seen figures of $1 billion all
up costs for a geostationary satellite so the business is not something you
would take up lightly. They charge an arm and a leg for the satellite use
though and they would not do it if it was not profitable.
> And what advantage for the geostationary satellites, is there? I mean, if
> the regular geosynchronous satellites have a continental sized
> "footprint",
> what could be better than that? Why would they even attempt to make them
> geostationary in the first place?
>
They try to make them geostationary because that is the ideal situation.
They can't help the fact that things beyond their control play havoc with
their work. Not perfectly geostationary is fine however as I have previously
stated as long as the drift is kept within acceptable bounds.
> I've been wondering the following for awhile. Aren't there any
> geosynchronous satellites orbiting at a latitude flatly and parallel with
> the equator? You made it sound like these do not exist. But why would
> any
> orbit off the equator automatically mean an orbit inclined to the equator?
> A satellite could be 22,200 miles from, say, the Tropic of Cancer just as
> well as the equator, couldn't it? Why wouldn't a flat orbit there be
> geo-stationary only higher in the sky?
>
They do not exist. You have to remember Gary that a small object orbits a
larger object because of its speed and the gravitational attraction between
them. That gravitational attraction acts towards the centres of the objects
and satellites will always orbit the centre of the earth. Regardless of how
you try to set up the orbit the satellite would always be pulled into an
orbit that is around the centre of the earth.
I hope once again that I have been of assistance.
Neil.
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