Highly cool. Cosma Shalizi notes that plants think:
Posted by DeLong at January 22, 2004 01:46 PM | TrackBackThree-Toed Sloth: The Secret life of Plants: An extremely interesting paper has now made its public appearance:
David Peak, Jevin D. West, Susanna M. Messinger, and Keith A. Mott, "Evidence for complex, collective dynamics and emergent, distributed computation in plants", Proceedings of the National Academy of Sciences 101 (2004): 918--922: Abstract: It has been suggested that some biological processes are equivalent to computation, but quantitative evidence for that view is weak. Plants must solve the problem of adjusting stomatal apertures to allow sufficient CO2 uptake for photosynthesis while preventing excessive water loss. Under some conditions, stomatal apertures become synchronized into patches that exhibit richly complicated dynamics, similar to behaviors found in cellular automata that perform computational tasks. Using sequences of chlorophyll fluorescence images from leaves of Xanthium strumarium L. (cocklebur), we quantified spatial and temporal correlations in stomatal dynamics. Our values are statistically indistinguishable from those of the same correlations found in the dynamics of automata that compute. These results are consistent with the proposition that a plant solves its optimal gas exchange problem through an emergent, distributed computation performed by its leaves.
Not so fast,
the headline should say:
Plants That Compute! (sort of)
And computation is not a form of thought?
Posted by: Brad DeLong on January 22, 2004 03:10 PMWell, depends on what you define as "think." an emergent property that solves a difficult math problem (looks like a differential eqn in this case) is not thinking in my book. if it were, does that mean the cellular automata he refers to also think? maybe i need to read the paper.
Posted by: heet on January 22, 2004 03:53 PMI used to go around telling people that president Bush had the intelligence of a potted plant.
Looks like I was wrong.
Posted by: Kuas on January 22, 2004 03:57 PM... and so does your car's air conditioner.
Posted by: Leopold on January 22, 2004 04:00 PMguess Mathematica thinks....it computes...
rt
I'm not so sure. I just fired up Mathematica... It just sits there...
Now the system of me + Mathematica can think, yes, much better in some ways than me by myself...
Posted by: Brad DeLong on January 22, 2004 06:17 PMBecause a physical process can be precisely described and correlated to the structure and operations of a formal model, this does not mean that the formal properites of the model determine the physical process. That would be to put the cart before the horse, or, in other words, to commit what Whitehead called the fallacy of misplaced concreteness. On the other hand, physical processes of sufficient complexity in the interactions of their elements and the maintenance of their boundary constraints can develop emergent properties that would seem to mimic formal computations. These would be brains or brain-analogs. Otherwise one would be reverting to the Aristotelian notion that plants have nutritive souls.
Posted by: john c. halasz on January 22, 2004 09:14 PM>> And computation is not a form of thought?
Whoa!! (that's the spelling I gleaned from Dilbert)
Of course computation is a form of thought?
-- but which way are you trying to have us to make the intellectual leap, logically? We know silicon computers can compute and it should be no great surprise therefore that plants can compute, although yes it is nice to see this shown in a controlled experiment. Whether thought is a form of computation is another matter entirely. I'm not even sure I believe (or even understand as a practical matter) Turing's thesis--
I am a "materialist" but their is no a-priori reason why a material Turing machine (as opposed to the mathematical concept used as a theoretical tool) would need to have a finite control device. This is related only tangentially to quantum computation which as usually understood does not change the class of computable functions.
Posted by: CSTAR on January 23, 2004 07:53 AM>> Mathematica... It just sits there...
Huh? What version do you have? Gee even firing up an ancient version of xcalc, it does more than than that! Yeah, it sits there, sure, but all sorts of processes are going on in the background. Unless of course your computer crashes when you start up mathematica.. :)
I never liked mathematica. WHy don't you talk to your colleague Richard Fateman in CS.?
Posted by: CSTAR on January 23, 2004 08:07 AMTurings thesis? Turings thesis? We don't know no Turings thesis!
I meant Church's thesis.
Posted by: CSTAR on January 23, 2004 10:23 AM