On Sat, 27 Aug 2011, Onno Meyer wrote:
Johannes wrote:
What about pebbles instead of sand? That should not make dunes, and
propably you get less friction too.
Hello Johannes,
I want to go with the rules and stay reasonably realistic. What
is the terrain VE152 type for a stretch of pebbles? Hard? Open?
Broken?
Open says packed sand is covered, while larger rocks are likely
broken.
I would interpret everything as open, where you can easily drive in a
straight line, and broken everything, where you have specific terrain
features, that require you you to either slow down, or move around.
So for ordinary cars, fist sized stones would be still open, while if the
stones start to get larger then head sized it becomes broken.
Johannes wrote in another mail:
Sorry, did overlook that you have mentioned pebbles already. But as gravel
roads show, pebbles are not the worst ground for wheels at least, i guess
also for skids. Especially if you have roughly spherical pebbles.
You won't get round pebbles without plenty of water and wind, I
think. The alternative for dry worlds is Mars-style dust.
You'd need something that rolls the stones around a lot, preferably
slowly. On top of my head, i know no good alternative to water either. If
you have some open water on the planet, or even if you had it in the past,
and strong tidal forces (like if the planet is actually a moon of a gas
giant), you could have had in the past a very large flat coast, where
tidal forces did grind stones flat. Then tectonic changes did get the
ocean away. (If you have a very small shallow ocenan, you could even have
all it's coasts as one big pebble desert)
So you likely will not get it with a hydrographics 0 world, but with
hydrographics 1 or 2 i would consider it plausible, and most of the world
will still give the look and feel of a desert world.
AFAIK there is an other way to get round stones. A volcano throws lave
into the air, and it freezes solid before it hit's the ground. I have
heared only about large ones, and they are rare, but then the large ones
are more noteworthy. I have no idea of how to get only small ones, or of a
natrual process that filters the small ones from the large ones though.
If you have very brittle stones , you propably don't need them to be all
that spherical to get a similar effect. If stones are wedged together,
then they will break rather then giving much resistence to the land ship.
You'd need an explaination, why they have not turned to sand already
though.
Propably there also is an ideal stone size, that behaves pebble like
enough, that it does not build dunes, but for large skids behaves just
like sand.
One mans groundfloor is an other mans earthmissle
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Johannes Trimmel
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