From: Brian D Williams (talon57@well.com)
Date: Wed Feb 17 1999 - 09:36:05 MST
From: EvMick@aol.com
>Actually I do beleive that dinosaurs are pretty much as they are
>portrayed to be. Big walking appetites that lived millions of
>years ago.
>I still can't quiet understand the size differential between those
>early dino's...the early (giant) mammals...and today's critters.
>Why should giantism have been the norm (?) then as compared to
>now? There must have been a LOT of giants given the small amount
>of critters that manage to get fossilized...else we would have
>little or no record.
Actually, according to the Yucatan impact theory, all land
creatures larger than about 50 pounds went extinct. So I guess we
could say the asteroid selected for smallness. While the mammals
then came to dominate, they had a completely different body plan,
(warm blooded and all) which in many ways is more efficient. The
evolving predators, including us, selected for speed rather than
size. It is known that such things as mammoths and giant sloths
existed here in the america's till man arrived.
> Is it true that strength increases as the square and weight as
>the cube? I beleive that is why Howard Hughe's flying boat....The
>Spruce Goose...was at the tippy tip of the envelope for large
>aircraft of it's day, until the materials used in AirCraft
>production had improved allowing such large aircraft as the C5 and
>the 747. Wasn't this strength of weight ratio one of the reasons
>that Zepplins lost their dominance?
The Hindenberg disaster was largely responsible for this I think,
that and the fact that airplanes were faster/more cost efficient.
>I'm puzzled...and like a dog with a bone...I keep chewing.
No problem there, so do I.
Brian
Member, Extropy Institute
www.extropy.org
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