Wirt Atmar wrote:
In 1964, Richard Feynman, in a lecture to students at Cornell that's
available
on YouTube, explained the standard procedure that has been adopted by
experimental physics in this manner:
"How would we look for a new law? In general we look for a new law by the
following process. First, we guess it. (laughter) Then we... Don't
laugh. That's
the damned truth. Then we compute the consequences of the guess... to
see if
this is right, to see if this law we guessed is right, to see what it
would
imply. And then we compare those computation results to nature. Or we
say to
compare it to experiment, or to experience. Compare it directly with
observations to see if it works.
"If it disagrees with experiment, it's wrong. In that simple statement
is the
key to science. It doesn't make a difference how beautiful your guess
is. It
doesn't make a difference how smart you are, who made the guess or
what his name
is... (laughter) If it disagrees with experiment, it's wrong. That's
all there
is to it."
-- http://www.youtube.com/watch?v=F5Cwbt6RY
In physics, the model comes first, not afterwards, and that small
difference
underlies the whole of the success that physics has had in explaining the
mechanics of the world that surrounds us.
I agree with much of what you cited and in large parts also with David
Anderson's crusade against hypothesis testing and for multi-model
inference (although it isn't exactly a new topic). However, I'm really
tired of hearing about the physics envy cultivated among so many
ecologist. Especially the last paragraph expresses this whole notion
well: if only ecologists had used such and such an approach, as
physicists did, we would by now have the same set of conclusive and
stringent laws and would be able to successfully construct ecosystems
from scratch. In reality, ecology has had loads of rigorous scientists,
bright minds and multi-model inference but the signal to noise ratio in
our system is completely different from the systems explored in physics.
If you were to be a good scientist as Feynman suggest and come up with
detailed theories/laws in ecology, build models based on them, make
predictions and try to validate them on data from the real world, you
would always have to reject them because you can always find an
ecological system that will violate your predictions. I still believe
that this would be the right way to progress in ecology but I think it
is folly to expect the same "clean" results as in physics. A good point
in case is the unified neutral theory of biodiversity. Hubbell came up
with a theory, built a mathematical machinery according to this theory
and validated his predictions on empirical data. Then people tried to
apply his theory and predictions to other systems and soon failures to
explain an acceptable level of variation in certain systems became
apparent. According to Feynman then the theory is "wrong and that's all
there is to it". I, in contrast, believe that we have to take into
consideration the low signal to noise ratio in our systems and the
staggering number of more or less equally important factors that govern
them, plus the multitude of feedback loops and time lags before passing
such harsh judgments about ecology. AND I don't believe that switching
from hypotheses tests to multi-model inference will get us to a set of
conclusive and stringent laws as they exist in physics any time soon.
But I do believe that the described way is the right path to advance
ecology.
Volker
--
--------------------------------------
Volker Bahn
Department of Biology
McGill University
Stewart Biol. Bldg. W3/5
1205 ave Docteur Penfield
Montreal, QC, H3A 1B1
Canada
t: (514) 398-6428
f: (514) 398-5069
[EMAIL PROTECTED]
www.volkerbahn.com
Lat-Long:
45.50285, -73.5814
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