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Re: PLEUROCOELOUS VERTEBRAE IN SAUROPODS



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[the / was indeed missing, 1/(1/r1+1/r2), oops]

> too), but a basic dino model would include
>
> Russ Andersson
> Autonomous Effects
> engineering lurker...
>
> [ I think the above is reasonably good, but probably a bit too
>   simplistic for anything but very rough calculations.  First off, all
>   of the thermal conductivities (the reciprocals of the thermal
>   resistances) are dependent upon temperature (though I suspect this
>   is a small effect for physiologically reasonable temperatures).
>   Bigger neglected effects are a) metabolic heat production isn't
>   necessarily constant -- it will vary with activity levels, gut
>   loading and probably temperature.  The ambient temperature isn't
>   fixed.  Finally, no mention is made of the variable current source
>   provided by solar (and to a much lesser extent indirect solar)
>   radiation.  But it's a good start, and I'll allow such messages
>   because I think people should have some understanding of the basic
>   physics before they try to conclude anything about the not so basic
>   biology. -- MR ]

The operative word was "basic" --- I intentionally kept it simple.
I just wanted to show people how you could go about setting up these
models--not at all hard per se--the hard part is getting the raw
data. Assuming people know a little electical analysis, they can
leverage it to thermal modeling as well. Some posts had
lead me to suspect that there was a bit much talk about thermal
effects without a clue as to the underlying theory.

The things you mentioned are all easy to model. Personally
I'd tend to include respirated air too, as well wind-induced
effects. (Did dinosaurs sweat?) Another thing I wonder about is
to what extent people are familiar with the phase lag between
the daylight and temperature cycles. It also impacts thermal
strategies. However, I think you can construct some pretty
nice models easily using the electrical analogs, and maybe
get some kitchen science numbers to feed them. Then, you can
generate complete thermal profiles either by hand, using general
packages such as MACSYMA or Mathematica, or easily with the
help of widely available engineering tools such as SPICE and
its offspring.

                                        Russ Andersson




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