From: swf@tools3teradata.com (Stan Friesen)
Newsgroups: talk.origins
Subject: Re: Velikovsky, Einstein, and Cohen
Date: 14 Dec 92 21:33:07 GMT
Distribution: world
Organization: NCR Teradata Database Business Unit

In article <169@fedfil.UUCP>, news@fedfil.UUCP (news) writes:
|> ^What others?
|> 
|> Articles I've seen in newspaper and magazine accounts which, due to space
|> limitations, I cannot always keep...  The Avon Field Guide to Dinosaurs.

Oh, just lovely, such *reliable* sources, NOT!
If the Avon Guide is the little pink pocket size, it is a piece of trash.

|> ^Infallible, hardly!  In fact it is generally considered relatively *crude*.
|> 
|> McGowan gives an idea of just how crude it is, i.e. real and predicted weights
|> for an elephant were around 5.5 and 6.5 tons.  At that rate, the 180 ton figure
|> might be brought down to something over 140 tons.  He still wouldn't begin
|> to make it in our world.

Yep, it is *that* far off for somehting we know as well as the Elephant.

|> ^In particular its accuracy is limited to the accuracy of the model.
|> ^And just how accurate do you think a model based on *one* *leg* is going to
|> ^be?  (At the time McGowan wrote his book, only one leg from the ultrasaur
|> ^has been exhumed, so that was all that was available for analysis).
|> 
|> I remember reading that collar bones, ribs, and other bones were uncovered
|> in the late 70's.  McGowan's book is dated 1991.  What exactly are you
|> talking about?

I may have been confused about exactly which parts were dug up first.
But this does not change the fact that McGowan's analysis is based on old data.
After you factor in the lead time, and preparation time, for a popular science
book, you get a book that was probably mostly written mid-80's

|> ^Try reading some actual journal articles on dinosaur weight estimates, and you
|> ^will see that they are generally considered to have about a 30% (or higher)
|> ^confidence bound.  This is *very* crude, little more than order of magnitude.
|> 
|> 30% Off from 180 tones is still 120 tons and more.  He still can't make it.
|> Bill Kazmaier at that size would be able to lift less than half his weight
|> off the ground, and Kaz is the most powerful creature his size or larger, lb.
|> for lb. imaginable.  What are you talking about?

"or higher"

|> ^, and there have been several
|> ^significant advances in *technique* since then
|> 
|> Archimedes' technique could not be improved upon, assuming you have a good
|> idea as to the general shape and size of the creature involved, which we do.

Which we *don't*.  One of the *main* problems with Archimedean weight estimates
for dinosaurs is how *little* we know about thier actual shape.  There is, right
off, at least a 30% variation in *volume* between various models of dinosaurs
known from *complete* skeletons (such as Allosaurus, Stegosaurus, Tyranosaurus).

If there is that much room for disagreement on body shape when we know the whole
skeleton, think how *much* more uncertainty there is with only part of the
skeleton available.

[Now, admittedly the largest of the body size estimates are based on older, "fat"
models, and are thus almost certainly wrong - unfortunately, McGowan seems to
have used exactly these older, fat, models, so his weight estimates are almost
certainly all high].
|> 
|> 
|> -- 
|> Ted Holden
|> HTE

-- 
sarima@teradata.com			(formerly tdatirv!sarima)
  or
Stanley.Friesen@ElSegundoCA.ncr.com
Newsgroups: talk.origins