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Old January 11th 05, 05:41 AM
E. Telly Kelly
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In article , EvolBob
wrote:

For example the Andromeda galaxy is 2 million light years (LY), and a quasar
is about 8,000 million LY's distant, yet a star map to get to these and
other places in the Universe has to show where they are now. The simplest
way around this quandary could be to have faster than light drives that act
as time machines that displaced the same light year distance per year in
time traveled backwards.


Thanks for the response, Robert...

Actually, I'm going on the "if you've got nearly infinite power and can
go fast enough, it doesn't matter" school of astrogation, here.

That is, if you keep the nose of your ship pointed at where your target
APPEARS to be, you can treat your path as a straight line, even though
you'll actually be following a curve.

And actually, it might not be all that big a curve, if you're in , say,
Kim Kinnison'e "Dauntless"... Consider an incredibly sloppy,
back-of-an-envelope calculation:

Andromeda and Milky Way galaxies approaching each other @ 250,000 mph...
....or a bit under 2.2 * 10^9 miles/year.

So, in the 2,000,000 years that it took the light to from the AG to
reach us, the two galaxies have moved some:

4.4*10^15 miles closer together.

1 Light year ... call it 5.9 *10^12 miles

So if I'm remembering my highschool math right, the two galaxies are
almost 750 LY closer together than they appear to us. That's what...
0.0375%...?

So, if we're talking a ship that can travel between the two galaxies in
weeks or months, then I really think that we can just use the next
local galaxy, which is moving more or less towards us, as a directional
baseline and distance outward from the center of the galaxy that you're
in, as a pretty fair "Tennessee windage" locator.

snippage

Regards
Robert

"E. Telly Kelly" wrote in message
...
Hi, all.

I'm writing a story where, for a tthrowaway bit, a character gives a
coordinate position for the Sol system. My thought was to try to come
up with some sort of external coordinate system where a point from the
geometrical center of the milky way to the same point in the Andromeda
Galaxy (as the nearest large object) would be the zero degree line and
distance outward and north/south deviation from that center point would
complete the description. I've tried, but can't find anything that
would help me do this. (Obviously, since the Andromeda galaxy isn't in
the plane of the equator of the Milky Way, I'm assuming that the zero
degree line is the intersection of the plane of the Milky Way's
equator with the plane that has both galaxies' centers as points in
it.)

I can find the Andromeda Galaxy's direction from Earth, but can't find
anything that will tell me (a non-astronomer/non-mathematician) how the
three points (Earth and galactic centers) stand in relation to each
other.

Can anyone point me in the right direction to find this out? I realize
that this is, as said earlier, just going to be used in one line in the
story, but I'd really like to be able to make it *sound* believable.

I will be grateful for any assistance.