How do plants turn sunlight into energy? The question is incredibly important: just about every form of life on earth, and certainly the life of every human being, depends upon their ability to do it. Even if you do not choose to eat a strictly plant-based diet (and here are a number of reasons from the ancient philosopher Plutarch to choose a plant-based diet, and here are some more from the ancient poet Ovid), every animal (or fish) that you choose to consume for food depends (at some point in its food chain) on the ability of plants to turn sunlight into energy.
Recently, Edward J. O'Reilly and Alexandra Olaya-Castro of the Department of Physics and Astronomy at University College London published a scientific paper discussing their research into the transformation of light into energy by plants. Why might professors from a department of physics and astronomy be interested in such a subject? Because these professors are interested in the intersection of quantum physics and biomolecular processes, and because evidence suggests that plants' ability to transform light into energy involves quantum phenomena!
Entitled "Non-classicality of the molecular vibrations assisting exciton energy transfer at room temperature," the article published in Nature Communications on January 09, 2014, concludes that studies conducted on cyanobacteria, cryptophyte algae, and higher plants reveal that "light harvesting" complexes inside plants, algae and cyanobacteria utilize a form of vibrational energy transfer that involve quantum behavior (Nat. Commun. 5:3012. doi: 10.1038/ncomms 4012 (2014)). While it sounds as though scientists are still investigating the exact role these "non-trivial" quantum phenomena play in the process, the research presented by Drs. O'Reilly and Olaya-Castro suggests that these non-classical vibrations enhance the efficiency of the light collection and energy transfer that takes place during this critical photosynthetic transformation upon which just about all life on earth depends.
The term "non-classical" refers to the fact that evidence from experiments conducted as early as 1800 had started to reveal fundamental flaws in "classical physics" (also known as "classical mechanics" or "Newtonian physics"). By the early decades of the twentieth century, enough evidence had accumulated to cause some physicists to realize that an entirely new form of physics was necessary to explain the evidence: the theory that began to take shape to explain these often-bizarre experimental results is now called "quantum theory" or "quantum physics" or "quantum mechanics."
In their outstanding book Quantum Enigma: Physics Encounters Consciousness (Second Edition), Professors Bruce Rosenblum and Fred Kuttner of the University of California at Santa Cruz provide what they call a "rough summary" of quantum theory:
Quantum theory tells that the observation of an object can instantaneously influence the behavior of another greatly distant object -- even if no physical force connects the two. These are the influences Einstein rejected as "spooky actions," but they have now been demonstrated to exist. Quantum theory also tells us that an object can be in two places at the same time. Its existence at the particular place where it happens to be found becomes an actuality only upon its observation. Quantum theory thus denies the existence of a physically real world independent of its observation. 7.
These assertions are more than startling -- they are actually staggering in their implications. Interested readers are urged to obtain Quantum Enigma to explore the subject in greater depth.
In terms of the light-harvesting complexes in plants (and algae and bacteria), the recent paper first provides evidence to rule out classical explanations for the vibrational behavior observed, and then discusses evidence that the non-classical vibrations assist in efficient energy transfer. They demonstrate that the vibrations of the excitons involved in the light-harvesting process demonstrate superposition: that is to say, the vibration of the excitons demonstrates non-classicality in that particles enter a state in which they exist on different levels of vibration simultaneously. Or, as the authors of the new report put it:
[. . .] at times when Q(t) is negative -- that is, t=0.2ps -- the regularized quasi-probability solution Pw(α) at this time exhibits negatives, which rules out any classical description of the same phenomena. [. . .] In short, non-classicality of the collective mode quasi-resonant with the excitonic transition arises through the transient formation of exciton-vibration states.
(That certainly sheds some light on the subject!)
More discussion of the quantum aspects of this vital biological process can be found on this page of University College London's Department of Physics and Astronomy website.
As stated previously, the implications of quantum physics upon our entire understanding of the universe are profound and staggering. At a very fundamental level, quantum theory appears to undermine the "ideology of materialism" that informs almost everything students are taught in most school classrooms, from kindergarten through graduate school. One way of interpreting the final sentence in the Rosenblum and Kuttner quotation above (in which they declare that "Quantum theory thus denies the existence of a physically real world independent of its observation") is by concluding that the universe (in some way) arises from consciousness, rather than the conventionally-taught materialist position which basically declares that consciousness arises from the universe (that our consciousness is dependent upon the physical structures of our brains, for example).
The fact that plants appear to be exhibiting quantum behavior on a very fundamental level -- that in fact their very survival is dependent upon quantum behavior, and thus that our very survival is dependent upon quantum behavior -- adds a whole new layer of profundity to the staggering implications of quantum theory.
We have already seen (from the Rosenblum and Kuttner quotation above, and more evidence is presented in their book) that quantum physics relates very intimately to the question of consciousness -- that quantum phenomena in some sense depend upon consciousness. The fact that plants appear to depend upon quantum phenomena is thus especially intriguing, given the fact that plants are directly involved in most of the methods of altering human consciousness (from the fruit of the vine, to the fermentation of beer, to coffee, tea, and more powerful plants such as ganja, opium, peyote or ayahuasca).
The new research presented by Drs. O'Reilly and Olaya-Castro clearly has enormous implications. They should be commended for their work, and encouraged to continue to explore the ways in which plants and other life forms use and depend upon quantum phenomena.