[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

RE: science and philosophy




-----Original Message-----
From: Jaime A. Headden [mailto:qilongia@yahoo.com]
Sent: Thursday, September 19, 2002 12:13 AM
To: dinosaur@usc.edu
Cc: dino.hunter@cox.net
Subject: RE: science and philosophy

Traqcy Ford (dino.hunter@cox.net) wrote:

<No one has answered me how can we really 'test' whether or not
Cryptovolans could fly using modern living animals as examples. We can't
can we? So we have to take it on 'faith' it could? Or do we
argue/philosophy/debate over it? Neither side will ever be able to prove
it either way, which is were the 'philosophy' I've been talking about
comes in. Sure, we call it a theory, but to me it's close to the same
thing.>

  No, two people have explicitly explained how one can test volancy: Tom
Holtz and myself. The answer being biomechanical tests. Comparative
anatomy and the Extant Phylogenetic Bracket are procedures within which to
operate in which these tests can be determined to provide the most useful
data and be provided and likelier to be true than not (Occam's Razor).
Paul goes into some detail in his latest book and in PDW on restoring the
shoulder anatomy of theropods and with Per Christiansen on ceratopsid
forelimbs and shoulder, indicating how a limb can operate. Feathers, as
comparative tests show, do not make an animal fly, even a bird. The arms
provide the power, feathers the lift, but feathers will not make the
animal fly on their own, contra proposals about *Longisquama*'s supposed
aeronautical ability. Studies in flying snakes show that the skin flabs
allone (integument) do virtually nothing but impose drag on the snake,
it's the way the snake moves that provides the ability to glide,
essentially a directionally-controlled descent.<<

No, this is all paper work. We CAN NOT physically test this with a LIVING
animal. What you and Tom say can in no way be tested with a living animal or
even a group of living animals because there aren't any.  You are ASSUMMING
this is the way things are but we can't dissect, observe, living breathing
animals. Nature will and does throw us curves and that is what Cryptovolans
is, a curve, which in no way means that it couldn't fly based on the
assumption you and others have said. This seems to be something people can't
understand or get over, just making these arguments in no way makes it true,
we need a living animal to be absolutely sure about things. You can keep
arguing this all you want, but it won't change things. It comes down to he
said/she said thing.

WE CAN NOT test this with living animals.

And until we can anything can work on paper. Believe me I know, I use to
work with engineers and some of the stuff they said would work didn't.


>>Without the, preferrably, 3-d manipulation that Eriksson and
Paul/Christiansen did with ceratopsid limbs, and musucular studies of the
first and of Hucthinson/Garcia and Carranno/Hutchinson, the latter two for
theropod limbs, we can make a set of testable assumptions based on
observable morphology. One can see the relationships of most bones and
infer a relationship that permits a means of restoring the rest. As Novas
and Puerta did with *Unenlagia* (and Paul dissented from) manipulating the
limbs are ideal, but you can do as much with less with careful
observation. My own biomechanical studies is favored by 3D studies, but
often I must make inferences from flat images. Ideally, I would be doing
muscular dissections, and because of this my study is limited to the major
muscles of the jaws and limbs that I have been working with the last few
years.<<

But the computer can not 100% accurately test how dinosaurs move. I hope
when you did your 3d modeling you used how the bones looked and not just
tubes/circles or else your studies will not be accurate.

 >> *Cryptovolans* defies 3D manipulation, but it can be useful to observe
the elbow, shoulder, and wrist joints, articulation of elements, and
determination of ability of flexion. Only then can we assess flight
ability. After that, we can determine performance if the animal appears
likely to fly. Feathers won't cut it by themselves, no matter how big they
are.<<

IF we had a living animal then it can be tested, but alas, we don't.

  Cheers,

=====
Jaime A. Headden<<

Tracy L. Ford
P. O. Box 1171
Poway Ca  92074