Re: [GZG] Space Terrain

On Friday 08 May 2009 16:00:45 Tom B wrote:
> Okay, let's give this its own thread.
>
> As to Asteroids: I know the real ones are thin. However, for all that,
at
> pretty much every Con I attend, there's a game with large, dangerous
> asteroids. So my reference in the prior thread to 'asteroid racers'
was
> from popular usage, rather than realistic space simulation. You could
> substitute 'racers who race around buoys and such' (there was a
stargate
> SG-1 episode in the late seasons that focused around a spaceship race
that
> included a close run around the sun and navigating a field of armed
> range-capable mines).
>
> So, asteroids should probably really be: Not present on the game table
in
> numbers or a small hull scrubbbing effect that persists throughout the
> game.
>
>
> Nebula: Indy brings them up, but my understanding was they were not
very
> dense either - not much real risk or damage unlike how they got
portrayed
> in Wrath of Khan. Aren't they pretty diffuse in real life?

Very diffuse. What you normally see in Hubble/Spitzer images are
composites of different wavelengths portrayed as false colour.
Keep in mind, the same images often show stars in the middle of
the nebulua - they'd be 100's of lightyears inside the gas clouds,
and yet you can still see them.

I've seen it mentioned that most nebulae would actually be invisible
to the naked eye when up close. I don't know how true this is, and
probably depends on the amount of sunlight.

On very dark nights, it is possible to see the Milky Way with the
naked eye, but that's not going to affect space combat.

> Rings: Indy mentioned rings. What's a realistic estimation of ring
> densities? How often do you see asteroids big enough to feature as an
FT
> obstacle in a ring system? What sort of on-map separation would be at
all
> close to reality?

I believe they're very small particles, but as I said in my other
email, I've never seen good images. They might count as a 'wall'
that blocks/limits sensors.

> Planets can be done, moons can be done (though I doubt both on the
same
> board without an MU of at least 10K km). Gravity can be very cool
(Can-Am I
> at ECC had a nice planet and some awesome gravity and proved that I
have
> done Titan's Turn....). How small of an entity could reasonably
generate FT
> visible gravitational effects? The moon should be 3" at 1000 km per MU
> according to the link I just visited that was posted in the other
> discussion. How much smaller can you get? (Yes, this is a density
function,
> but how small and dense could you get for a moon or small planetoid?)

If that's my page, then Mercury is at the very limit of noticeability.
The moons of Saturn/Jupiter are smaller. However, this assumes
1"=1000km.
I chose that scale to be able to fit a planet plus gravity well onto
a table where it would be the focus of the board, but not cover all of
it.

Assume a rock 3000km in diameter, made of pure iron (7.8g/cc), the
surface
gravity would be about similar to Mercury. Another page on my site
(which requires Java) allows you to play with this:

http://www.glendale.org.uk/traveller/planetstats.html

Phobos (moon of Mars) has an escape velocity of 10 metres per second.
An olympic athlete can run fast enough to achieve escape velocity.
That's slight enough to be ignored by most scales in FT, though could
be fun to model for a specific engagement (where a 'ship' is something
like the pods in 2001, with very low thrust).

> Black Hole: What sorts of gravitation would  you get from a black
hole?
> Could one be put on an FT map and have any part of the map be playable
by
> FT fleets at 1000 km/mu or 10000 km/mu?

Of course. You could have a black hole which is playable at 1km/mu!
It would just be a very small black hole :-)

If the Earth was squashed into a black hole, the gravity effects
would be the same as on my chart, as long as you stayed outside
the original diameter of the planet. Since black holing the Earth
shrinks it down to only a few kilometres, you can get a lot closer
than this, so the gravity effects go up dramatically.

You could use them to perform very sharp turns, if you survive
tidal forces.

Black holes may have a large amount of matter falling into them,
and a lot of nasty radiation coming out.

> Pulsar: In SFB, a pulsar used to emanate damaging waves your shields
helped
> thin out. Is this at all reasonable? Could a reasonable bit of space
> terrain be done with some mechanic like this?

Pulsar's often rotate with periods measured in seconds (or less), so
any arc they sweep out will cover the entire table many times each
turn.

> Sphereworld or Ringworld: Planet plus? Could make one of these the
subject
> of an attack or boarding.

The Smoke Ring is another weirdness. 

> Minefield: How best to represent this in FT terms? Contact mines?
X-ray
> laser mines pumped by a bomb? Something else?

You'd want to mine near something important, though not sure how
they'd work.

> Stargate/Jumpgate: Could constitute 'space terrain' for navigation
purposes
> and also have other effects (possible gravity effects even) when
activated.
>
> Nav buoys: Possible objective. Or useful during races as markers.

Very big spaceships or space stations might count. Several asteroids
could have been artificially placed in close proximity, as a base
for something.

> Gas giant atmospheres: Are these viable? How deep? What sort of impact
> would flying through one or trying to hide in one have? They used to
> feature a lot in Traveller for fuel skimming and ambushes. How
reasonable
> is any of that?

If you look at my chart, at the surface of Jupiter, you're being
pulled 20" into the planet every turn. Saturn is a more sedate 9"/turn.
Either way, if you're hitting the atmosphere at orbital velocities
it's probably going to hurt.

>From what I've heard, the visibility in some layers of Jupiter's
atmosphere is clear out to 1000s of km. You may be getting close
to how nebulae are portrayed in SF.

B5 had at least one episode with combat inside Jupiter's atmosphere.

Not sure what a cometary tail would be like.

-- 
Be seeing you,			       http://www.glendale.org.uk
Sam.			    Mail/IM (Jabber): sam@glendale.org.uk 
_______________________________________________
Gzg-l mailing list
Gzg-l@lists.csua.berkeley.edu
http://lists.csua.berkeley.edu/mailman/listinfo/gzg-l