Re: Depth of Atmosphere in SJ Query

Well this (gravity/atmosphere) is a topic where SJ is totally 
inconsistent. Thus you can do just whatever you want.

Page 7 of the Concordance says that the atmosphere gradually thins out the 
higher you go.

Me, I'd go for the standard model of gravity and air, except when it comes 
to Spelljammers (which are powered by magic afterall). Never fix what 
isn't broken, and planets work just fine the way they are.



On Tue, 22 Aug 2006, Dreamer wrote:

> OK, I need to try and work out what the depth of atmosphere is on
> the various sized bodies in SJ.
>
> I'm assuming that the atmosphere stays the same pressure all the
> way to the edge of the gravity field, when it suddenly drops to
> zero?
>
> This can get more complex if bodies are irregularly shaped, like
> a globe with some immense mountains - I'd expect the mountains to
> have atmosphere, rather than be sticking out of the gravity field
> and hence lack atmosphere.
>
> Maybe I am missing some obvious reference, but the time to get
> out of a planet's "gravity well" table on page 51 of CoAS seems
> an obvious place to start, which seems to be the irrelevant of
> your SR:
>
> Size       Class  Diameter      Time
> Fine         A     <10mls       10 rounds (1 turn)
> Diminutive   B      10-100mls   2 turns
> Tiny         C     100-1Kmls    2 turns
> Small        D      1K-4Kmls    3 turns
> Medium       E      4K-10kmls   4 turns [Earth-sized]
> Large        F     10K-40Kmls   6 turns
> Huge         G     40K-100Kmls  12 turns
> Gargantuan   H    100K-1Mmls    24 turns (4 hrs)
> Colossal     I      1M-10Mmls   48 turns (8 hrs)
> Amazing      J     10Mmls+      96 turns (16 hrs)
>
> These are of course the pre-3rdEd one minute rounds and ten
> minute turns.
>
> I've said that it takes a SJ ship a little more than 8 minutes to
> freefall from the edge of the atmosphere to sea level on an
> Earth-like world (Isis, in Maj Space).  Presumably that is at
> terminal velocity in one atmosphere pressure all the way.
>
> We did some calculations about a beanstalk to orbit from an
> Earth-like world, a while back, and something like 16 miles of
> atmosphere seems to stick in my memory.
>
> Thoughts?
>
> Help?
>
> -- 
> Dreamer
> dreamer@??????.?????.??.uk
> http://www.romsys.demon.co.uk/
>
> ********************************************************************
> The D&D Homepage: http://www.wizards.com/dnd
> The Spelljammer Homepage: http://www.spelljammer.org
> To unsubscribe, send email to LISTSERV@??????.???????.com
> with UNSUB SPELLJAMMER-L in the body of the message.
>