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Quantum Coherence Found Fueling Photosynthesis
Gaygirlie writes "Ars Technica has posted an interesting article about new findings regarding quantum physics and photosynthesis. Their excerpt for the article: 'Physicists have found the strongest evidence yet of quantum effects fueling photosynthesis. Multiple experiments in recent years have suggested as much, but it has been hard to be sure. Quantum effects were clearly present in the light-harvesting antenna proteins of plant cells, but their precise role in processing incoming photons remained unclear.' Here's a little background info for those unaware of what coherence and quantum coherence are."
I've seen some comments stating that 'meh photoelectric effect nothing new to see here'. While it is true that emission/absorption is subject to quantum mechanics, specifically the photo-electric effect being governed by the work function hf = phi - eV, with hf = hc/lambda, phi being the work-function of the material, and eV being the 'escape velocity' of the electrons; the point being that energy emitted/absorbed must satisfy the above relationship, otherwise the photo-electric effect does not work.
What I believe this study is saying is that 'antennae' structures can act as a single quantum mechanical unit (the coherence) so that the incoming insolar radiation has more paths for electron conduction, since the transfer of energy/conduction of electrons is limited to the quantization by the work function, i.e., charge quantization limits the specific wavelengths/frequencies/energies of incoming photons that the plant can use to harvest energy, so in effect the evolution of these 'antennae' structures over time allows for a coherent systems that can act as single particles, with the different permutations of antennas allowing for vastly more permutations of allowed incoming wavelengths to satisfy the Schrodinger eqn (probably not dirac since these are most likely not relativistic interactions, at least the effects are negligible).
I deal more with relativity and QED/QCD, but that's my interpretation of the article.
'We are trying to prove ourselves wrong as quickly as possible, because only in that way can we find progress.' RPF
Any evolved system will use all possible inputs to its fitness function, simply because there isn't any mechanism of focusing. Unlike human design, which is all about making known mechanisms work and all but those mechanism are ignored, and even actively avoided. When early researchers used solid-state electronics to make genetic algorithms, often the "solution" only worked on the specific hardware circuit it was learnt on (not supposedly identical copies), because it relied on otherwise-undefined race conditions in the silicon.
So don't be surprised if quantum effects are also used by your brain cells ... and by your anal sphincter.
The way people often describe quantum decoherence is that an "observation" occurs that "collapses the wave function" and causes a superposition to converge to a single classical state. But I really think that's a misleading explanation. For one thing, surely the same phenomena occurred long before there were any intelligent observers, and secondly, scientists have observed things in states of quantum superposition WITHOUT causing decoherence.
The way think of it (as a total amateur in the area) is that rather than the wave function representing probabilities of states, it represents the degrees to which something is in all of those states. An "observation" is just like many other interactions with the environment that change those probabilities (or degrees of state).
Then there's the question of why subatomic particles (and some larger things) can be in states of quantum superposition, while larger things cannot. Penrose had a suggestion here. It's gravity. The more massive you are, the less your superimposed states can diverge from one another. Even a planet is in a state of superposition, but all of those states overlap so much relative to the dimensions of the object that you cannot distinguish them.