“Just So Science” – Nature Nanotech Knows

By Elf Eldridge 30/06/2011 1


There’s been quite a bit of talk recently about the biological implications of quantum effects. For those not familiar with quantum phenomena, they describe a set of bizarre properties molecules and light exhibit at very small length scales or at very low temperatures. Things like quantum tunelling, coherence and entanglement which typically are seldom observed in our normal, human world – which incidentally is why we find them so weird! They’re only strange as they don’t contribute to or idea of common sense, because we don’t see them that often. Well, that’s what we thought – new evidence has come to light suggesting that this is not entirely the case.

quantum in Photosynthesis
Quantum in Photosynthesis
Quantum in Birds eye?
Quantum in Bird's eye?
Quantum computing?
Quantum computing?

In fact, it has been shown to be a crucial factor in the efficiency of the light antennae in both photosynthetic plants,  and bacteria. In fact, after the antenna absorb the light, they transfer it into a vibration that’s passed to the chloroplast that eventually uses the energy of the light to create carbohydrates that store the energy. But the weird thing is that the vibrations always take the most efficient route from antennae to chloroplast, and a group from UC Berkley made laser measurements of the vibrations that indicated that the vibrations (or excitons in physics-speak) are all coherent. essentially this means that all the individual vibrations act as part of a larger system, rather than individually. What does that mean? Well it allows the vibration to explore every possible pathway between the antennae and the chloroplast, simultaneously, and then automatically select the most efficient path. And what the researchers showed was that this still occurs at room temperature.

Another example, but this has yet to be proven, may be how birds sense direction and navigate by the earth’s magnetic field. What is known is that birds sense magnetic field when light strikes the light sensitive retina at the backs of their eyes. Several researchers have suggested that the light generates two radicals, each with a different chemical reactivity depending on the strength of the applied  magnetic field. The magnetic field stabilizes one radical preferentially to the other, making it stick around for longer and giving it more chance to react with other things.  These radicals react with other molecules, essentially amplifying the magnetic field and turning it into a chemical signal that the bird can sense.

So what? Well, if we can figure out the specific quantum effects of what is going on in these system we could potentially stabilize the bits in a quantum computer! Just be taking a little advice from biology….

References:

1) P.Ball “The Dawn of Quantum Biology” Nature 474, 272-274 (2011)


One Response to ““Just So Science” – Nature Nanotech Knows”

  • This quantum- coherence must work as the optimal efficiency process in nature for a lot of systems. In this context, the photosysthesis is a fascinating example.