[meteorite-list] Space.com's Top 5 Cosmic Myths - #4

From: David Weir <dgweir_at_meteoritecentral.com>
Date: Thu Apr 22 09:53:34 2004
Message-ID: <3DFA5596.F7B76CB1_at_earthlink.net>

Hello List,

Every time this subject comes up (often it seems) I remember a post by
Russ Kempton that makes even more sense to my way of thinking.

--------------begin quote----------------------

Compression is correct - but - compression is motion,
motion produces friction and thus heat. And, you are
right -- it's not just semantics. It identifies a process
making it a wonderful teaching model.

As the air (gas) molecules are compressed, they move.
Any "gas" that suddenly has to move (compression) has
more and more molecules banging into each other - heat
from friction.

The causal relationship is:

Compression/motion
Motion/friction
Friction/heat

What happens afterwards is a complex process called
gas dynamic drag which deals with the thermal effects of
gas in motion. Ultimately the resultant heat is partitioned
away from the meteoroid through ablation.

-------------------end quote---------------------

David
Received on Fri 13 Dec 2002 04:48:06 PM PST