10 February 2010

Chlorophyll as quantum computer

Marginal Revolution | Tyler Cowen | Department of !

Yesterday I read this:
While physicists struggle to get quantum computers to function at cryogenic temperatures, other researchers are saying that humble algae and bacteria may have been performing quantum calculations at life-friendly temperatures for billions of years.

The evidence comes from a study of how energy travels across the light-harvesting molecules involved in photosynthesis. The work has culminated this week in the extraordinary announcement that these molecules in a marine alga may exploit quantum processes at room temperature to transfer energy without loss. Physicists had previously ruled out quantum processes, arguing that they could not persist for long enough at such temperatures to achieve anything useful.
Roger Penrose is now on related points looking more credible.
Hmmmmmm. Good news for Penrose indeed.

I always liked his consciousness-as-quantum-effect theory, but I never found it that convincing.  It always seemed very hand-wavy to me:  there may be these nano-sized neural structures, and they may allow quantum something or other to occur, and that something or other resolves the mind-body problem.  I sort of want it to be true, but none of the Penrose I ever read was sound enough to move me out of the Mysterian camp.

I think this is going to have bigger effects on quantum computing than philosophy of mind, at least in the next decade or so.


  1. Consciousness and self awareness are properties of human beings which are living/thinking biological systems. The only way to produce consciousness or self-awareness in an artificially intelligent system is to add biological components to create a "hybrid" system consisting of biological life integrated with artificially intelligent components. The biological component would account for any level of consciousness or self-awareness in the hybrid system - not any AI hardware components. Of course, except for humans, the level of consciousness, understanding and self-awareness in other living things does not attain to the degree as in humans which accounts for our higher intelligence. Trying to duplicate consciousness and self-awareness of the spirit/soul of a man inside some hardware -- a man made machine –- is folly and a waste of research dollars. AI should stick to duplicating intelligent behavior like vision or diagnosing illnesses, which are intelligent processes that can be simulated by the execution of operational AI computer algorithms or artificial neural networks.

  2. Well I'm a part of the looks-like-a-duck school of AI. I don't care that our systems actually achieve intelligence, only that they behave similarly to intelligent beings, so I agree that it's easiest to stick to duplicating intelligent behavior.

    But I think you are flatly wrong to assert that the only way to achieve "real" intelligence is with the hybridization of biological components. One of the sticking points when it comes to understanding consciousness is that both living things and everything else, including artificial machines, are made of the same physical stuff. Materialistic dualism has been pretty roundly rejected. There's only one type of matter with which to work. Some matter is apparently conscious, but the vast majority isn't. Why?

    We do not know whether that's because of some special arrangement of the matter in animal brains. It may be something intrinsically biological that enables matter to become conscious, but it may be something else that can be duplicated in an artificial system. You can't just assert that it in order for a system to be conscious then it must have matter that is derived from a living thing.

    The quantum effects noted in chlorophyll would be useful for quantum computing research entirely unrelated to consciousness. From the cursory New Scientist summary linked above, it seems that the organism being studied is solving a shortest path problem in constant time, which has any number of revolutionary applications.