As I mentioned in an earlier post, many of the chemical reactions that are vital to life as we know it require quantum mechanics to proceed. Many of the machines that make up living creatures function by exploiting QM in some way.
Progress is being made in tracking down how exactly this happens in specific cases. This scientific american article discusses some recent experimental work showing how the mechanisms of photosynthesis exploit QM to enhance the efficiency of converting sunlight to chemical energy.
Here’s a quote from the introductory segment in Nature:
… the observation of electronic coherences in such a complex system is remarkable. Assuming that the effect is general — that similar coherences occur in many different natural light-harvesting systems, and are observed at non-cryogenic temperatures — we may find that nature, through its evolutionary algorithm, has settled on an inherently quantum-mechanical process for the critical mechanism of efficient light harvesting. This is an interesting lesson to be considered when designing artificial systems for this purpose.
Here’s a link to the actual Nature article. You need a subscription to Nature to see it.
What I find most interesting about the article isn’t the underlying science. It has been known for a long time that photosynthesis involves processes that have to be described using QM (as are lots of other important processes like catalysis via enzymes). What’s interesting to me is that the scientists involved are starting to bridge the chasm between the field of quantum chemistry (which is usually how these types of things are described) and quantum computing (which has historically been a separate island from quantum chemistry).
BTW I was going to do a bit about how the non-photosynthetic plant & animal scientific community was “sceptical” of the photosynthetic plants’ claims to be quantum computers, containing irate statements from representatives of various communities, such as the holoparasitic plants (can’t do photosynthesis)… good piece for the Onion. I think I have too much real work to do though.