I was convinced that something good would come of my newfound addiction, and yesterday something did. Someone from SoapBoxxer pointed me toward this study about the newly discovered relationship between photosynthesis and quantum mechanics. It seems that researchers at Berkeley (yay!) have discovered a possible reason for plants' uncannily efficient use of sunlight (they're able to convert upwards of 90% of absorbed light into energy, whereas most solar panels haven't even come close to 50% efficiency yet). For a long time, how exactly they managed this was a mystery, but it seems like we've got a possible explanation now.
"We have obtained the first direct evidence that remarkably long-lived wavelike electronic quantum coherence plays an important part in energy transfer processes during photosynthesis,” said Graham Fleming, the principal investigator for the study. “This wavelike characteristic can explain the extreme efficiency of the energy transfer because it enables the system to simultaneously sample all the potential energy pathways and choose the most efficient one."
I can't stress enough how cool this is. Apparently the pigment molecules that are responsible for making the initial conversion of light energy to usable energy have a unique (so far--more on that in a bit) ability to momentarily "pause" the energy in a superposition and simultaneously explore all the possible ways the energy can be utilized. When it finds the most efficient way to utilize it, the wave function collapses into that state, and the energy gets passed on. The researchers on the project are careful to stress
For this reason, the transfer of electronic coherence between excitons during relaxation has usually been ignored. By demonstrating that the energy transfer process does involve electronic coherence and that this coherence is much stronger than we would ever have expected, we have shown that the process can be much more efficient than the classical view could explain. However, we still don’t know to what degree photosynthesis benefits from these quantum effects.
Obviously, I'm not a physicist (though reading about this stuff makes Columbia's MA in the Philosophical Foundations of Physics look mighty tempting), but it seems pretty clear that this adaptation is at least partially responsible for the very high efficiency of photosynthetic plants. Now, I'd like to take this idea a step further. What follows is PURE speculation on my part--I know there is at least one physicist in the audience, so PLEASE correct me if anything I say makes no sense.
I've discussed free will at some length on this blog, but I've spent very little time on Libertarianism (basically the view that we have free will in the traditional, robust, alternative possibilities sense). I've been dismissive of it as a viable philosophical position mostly because I haven't been able to see any scientifically plausible way that it could be true--most people who argue for it these days do so through an appeal to quantum mechanics, but are unable to describe how the brain might inherit the indeterminacy inherent in QM without also inheriting the randomness. This is a problem, of course, because random actions are no freer than determined ones--in order for us to really be "free" in a Libertarian sense, we have to be able to choose from multiple different paths without that choice being a random one.
Now the speculation: if chlorophyll can do this, why not the brain? If these researchers are correct, plants have evolved a mechanism to explore multiple quantum states at the same time before collapsing into the most beneficial one--what if our brains are doing something similar? Obviously, the mechanism would need to be far more complex than that involved in photosynthesis (making a rational choice doesn't seem to be just a matter of collapsing into the lowest energy state), but still: this research seems to lay some exciting groundwork for further exploration of the biological utilization of quantum mechanics. If our brains were somehow able to do something similar to this, it could potentially allow for quantum indeterminacy without quantum randomness--all possible quantum states would be open to us (indeterminacy), but which state we "collapsed" into would be dictated by something other than chance (not randomness). I'm very excited to see where this goes.