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Re: From Science New, and more
James R. Cunningham wrote:
Sean Carroll wrote:
True, I suppose. What they fail to mention is that 'most scientists' --
including, I might emphasise, the Alvarezes -- are in completely
unrelated fields of specialisation and know as little (or less) about
dinosaurs as (than) the general, non-scientifically-educated public.
True, but then on the other hand, some in our field are not into physics
or math and seem to have no concept of the amount of energy released.
Which is why collaboration among scientists of different fields to do
interdisciplinary problems is important. But there is a danger in
relying to heavily on one side of the matter. How many physicists,
chemists, botanists, and other scientists have stumbled on something in
their own field that just happened to relate, time-wise, to the K-T
extinctions and lost all sense of objectivity in boldly announcing that
they have 'explained' those extinctions?
The only way to explain a phenomenon like mass extinction is to
understand its pattern throughout natural history, and the only way to
understand the extinction of dinosaurs is to have a grasp of the greater
biological, ecological, and geological picture in which dinosaurs lived,
died and evolved. Understanding the amount of energy released by a
bolide impact may be enough to let you create an idealised mathematical
model *suggesting* that such an impact *might hypothetically* have
contributed to a particular extinction, but that hypothesis then has to
be integrated into the knowledge we already possess about various
relevant fields: the way that dinosaurs lived, the patterns of
extinction among dinosaurs and their contemporaries, the historical
pattern of extinctions throughout geological time, and the observable
statistical tendencies of evolution in various populations, among other
things. Only then can the hypothesis be considered 'tested'. Too often
scientists, seduced by the popularity and grand scope of the subject,
get tunnel vision and think of just one minor aspect as if it were the
solution to everything.
People like the Alvarezes who come in from a distant field like
chemistry or astrophysics convinced that they have 'solved the mystery'
are inherently at a disadvantage in this process of integration and
testing of the hypothesis, because they have learned a different
constellation of facts in their field than the constellation that is
relevant to the subject. They may understand some things related to both
their field *and* the K-T extinctions, like the concentration of
iridium, but they also know a lot of other things that are unrelated to
the K-T extinctions through which they are interpreting that knowledge,
and fail to know a lot of things that *are* relevant, like the
historical pattern of large and small extinctions throughout the Mesozoic.
People who are actively studying dinosaurs and specialise in them have a
far greater chance of having the right toolbox, with all the relevant
knowledge and method bearing on the problem, to make a sober, unbiased
(or, at the least, with the type of biases that are cancelled out by the
opposite biases of others in the field) assessment of the bolide-impact
model in the view of *all* the relevant evidence, including especially
the historical and ecological patterns that physical scientists are most
likely to be completely ignorant about, and determine whether it passes
enough tests to be a workable model of the most important aspects of the
The statement of physicists that a bolide impact could release enough
energy to cause extinction, coupled with the statement of geologists
that there is a crater for such an impact at about the K-T boundary in
age, is enough to put the bolide-impact-as-cause-of-the-K-T-extinctions
hypothesis on the ballot, as it were, and open to serious investigation.
It is *NOT* enough to verify the hypothesis and make it acceptable for
use as a 'standard model' without significant challengers. That can only
be done by bringing to bear biological, ecological, and historical
evidence that dinosaur scientists have easy access to, but that are
foreign and unfamiliar to astrophysicists, for example.
In point of fact, I believe this larger picture renders the
direct-causation hypothesis rather silly and at best makes bolide
impacts a minor contributing factor to the K-T and other mass
extinctions. I find it hard to take such a direct causal 'explanation'
of extinctions seriously when no one has yet produced any evidence that
I know of that it would be possible for a planet-wide biological
community to ever exist *without* rare quasiperiodic mass extinction
events; why are we accepting an explanation of a phenomenon as
'generally accepted truth' when it has not even been established that
the phenomenon *needs* an explanation? It may very well be that trying
to explain why a particularly large extinction took place at 65 Ma and
not 75 or 55 Ma is barking up the wromg tree completely, tantamount to
trying to explain why an electron jumps energy levels at one particular
time as opposed to another: it just happens once in a while,
statistically, and if it had happened at a different time we'd be trying
to 'explain' why the dinosaurs all went extinct 45 million or 130
million years ago.
Regardless, I think that the appropriate perspective leaves the
bolide-cause hypothesis as at best one of several seriously contending
models for what happened at the end of the Cretaceous, not yet anything
approaching a comprehensive, widely-tested hypothesis (or a 'standard
accepted fact', if you will), like the dinosaurian origin of birds or
the monophyletic nature of the Dinosauria. And among the very people who
have the broadest range of tools necessary to evaluate the hypothesis
(dinosaur scientists) one finds the widest controversy on the topic,
while among those likely to have tunnel-vision and proprietary interest
in a particular ad hoc hypothesis (scientists from other fields) one
finds the more common 'acceptance' of the hypothesis as an 'agreed
fact'. I think this is strong evidence, if not downright proof, that the
body of evidence supporting the hypothesis (though it may be clearly
significant) is far less decisive than it is generally supposed,
especially by the commercial media (who have no interest whatsoever in
scientific rigour but will print any hypothesis eagerly as long as it's
sensational and simplistic enough).
What should be relevant is what *dinosaur* scientists believe, not what some mythically monolithic 'most scientists' believe.
Then, perhaps it would be wise for some *dinosaur* scientists to take a
few more physics courses.
Indeed, that's beyond dispute. I never said that strongly divergent
specialisation was a *good* thing, just that it exists. Any attempt by a
scientist to systematically acquaint him or herself with the basics of
as many fields as possible is highly commendable.
No offense intended to those who disagree
with the asteroid concept and also have a quantitive feel for the
I'm hardly untutoured in physics, not that I would say I have a direct
intuitive feel for bolide impact energies. But I *do* have an intuitive
feel for the pattern of speciation and extinction throughout the course
of biological life, and I can't help but think any attempt to explain
one specific instance (or 2 or 6 specific instances) of mass extinction
in terms of bolide impacts while completely ignoring the probable
continuity in large and small extinction patterns within a nonlinear,
semifractally organised biosphere is just ramming one's head against a
brick wall and declaring 'It will fall if only I hit enough individual
bricks with enough brute force!' Perhaps it would be better to forget
the physics of impulse and momentum for a moment and look for a way to
topple the *whole* wall.
How could this *possibly* follow? It's based only on assumption: A
bolide hit 65 million years ago, therefore it probably killed the
Well, as you no doubt know, that isn't the assumption the conclusion is
In point of fact, I *don't* know that. I saw no other evidence in that
NYT article, which is part of my point: the media ignores what is
significant scientifically speaking, and prints vague platitudes and
wild speculations from scientists as gospel to be assumed. Maybe we'd
have already had a solution to the K-T problem strong enough to be a
standard accepted truth if not for the fact that this is the kind of
crappy pseudo-scientific, unverifiable fluff that most people get when
they read about 'science' in the media.
On a lighter note, in the thread 'Re: JP4 a GO!', firstname.lastname@example.org
> JP2: This time they made the raptors actually eat a _lot_ of people,
> and instead of one T.rex there was two. Good old logic, 2 is better
> than 1.
Gotta agree with that logic. Compare the best scene in the 1st movie,
Gennaro's demise, with the best in the 2nd movie, Eddie's extinction.
Which do YOU think is grander and more wicked, a shaken-not-stirred
spinal column or a snapped-like-a-twig one? ;)
> And as if that wasnt enough, T.rex had to go beserk around L.A.
Actually, it was San Diego. And I know I'm in the minority but I still
love and revere that scene, though it's way too short and the end is way
too anticlimactic. In fact, I still love both the 2nd book and the 2nd
movie, no matter what anyone says.
> i think they'd really win the prize if they had added thousands of
> japanese people running in the streets screaming, but since this is a
> hollywood movie the japanese was exchanged with cars crashing;)
But they *did* show a group of Japanese tourists, just before the Rex
eats that tall whiny white dude. In fact, I've read that the one is
shouting in Japanese, 'I left Tokyo to get AWAY from this!!' ;)