Learning from nature is an idea as old as mythology — but until now, no one has imagined that the natural world has anything to teach us about the quantum world.
Before the twentieth century, biology and physics rarely crossed paths. Biological systems were often seen as too complex to be penetrable with mathematical methods. After all, how could a set of differential equations or physical principles shed light on something as complex as a living being?
In the early twentieth century, with the advent of more powerful microscopes and techniques, researchers began to delve more deeply into possible physical and mathematical descriptions of microscopic biological systems. Some famous examples (among many) include Turing patterns and morphogenesis, and Schrödinger’s lecture series and book ‘What is Life?’, [1992)] in which he predicted several of the functional features of DNA. [ What is Life? (Cambridge Univ. Press, 2008).] The pace of progress in this field is now rapid, and many branches of physics and mathematics have found applications in biology; from the statistical methods used in bioinformatics, to the mechanical and factory-like properties observed at the microscale within cells.[ Quantum Aspects of Life (Imperial College Press, Quantum mechanics and biology. Biophys. J. 2, 207–215 (1962).]
This progress leads naturally to the question:
Can quantum mechanics play a role in biology?
In many ways it is clear that it already does. Every chemical process relies on quantum mechanics. However, in many ways quantum mechanics is still a concept alien to biology, especially on a scale that can have a physiological impact.[ Some quantum weirdness in physiology. Proc. Natl Acad. Sci. USA 106,17247–17248 (2009)].
Recent technological progress in physics in harnessing quantum mechanics for information processing and encryption puts the question in a different light:
Are there any biological systems that use quantum mechanics to perform a task that either cannot be done classically, or can do that task more efficiently than even the best classical equivalent?
In other words, do some organisms take advantage of quantum mechanics to gain an advantage over their competitors?
Many attempts to find examples of such phenomenon have been met with fierce criticism by both physicists and biologists. [Tegmark, M. Importance of quantum decoherence in brain processes. Phys. Rev. E 61, 4194–4206 (2000)][Penrose–Hameroff orchestrated objective-reduction proposal for human consciousness is not biologically feasible. Phys. Rev. E 80, 021912 (2009)]. , , , &
However, over the past decade a range of experiments have suggested that there may be some cases in which quantum mechanics is harnessed for a biological advantage.
In what form do these quantum effects usually appear?
In quantum information, arguably the most important quantum effect is that quantum bits can exist in superpositions whereas classical bits cannot. In quantum biology, the role of quantum effects can be subtle. However, we may consider a biological system that exploits coherent superpositions of states for some practical purpose to be the clearest example of functional quantum biology. [Neill Lambert, Yueh-Nan Chen, Yuan-Chung Cheng, Che-Ming Li, Guang-Yin Chen & Franco Nori; Quantum biology: Nature Physics 9,10–18(2013) doi:10.1038/nphys2474]
Are we ready for quantum biology?
In Life on the Edge, Jim Al-Khalili and Johnjoe McFadden argue quantum effects are decisive in biology – but this challenging idea needs more proof.
FOR 15 years, theoretical physicist Jim Al-Khalili and molecular geneticist Johnjoe McFadden have been discussing how quantum physics, the science of the incredibly small, might affect biology.
Quantum physics and biology have long been regarded as unrelated disciplines, describing nature at the inanimate microlevel on the one hand and living species on the other hand. Over the past decades the life sciences have succeeded in providing ever more and refined explanations of macroscopic phenomena that were based on an improved understanding of molecular structures and mechanisms. Simultaneously, quantum physics, originally rooted in a world-view of quantum coherences, entanglement, and other nonclassical effects, has been heading toward systems of increasing complexity.
While in the days of Darwin and Mendel the life sciences were mainly focusing on botany or zoology, modern biology, pharmacology, and medicine are deeply rooted in a growing understanding of molecular interactions and organic information processing.
Quantum physics, on the other hand, was initially centered on microscopic phenomena with photons, electrons, and atoms. But objects of increasing complexity have attracted a growing scientific interest, and since the size scales of both physics and the life sciences have approached each other, it is now very natural to ask: what is the role of quantum physics in and for biology?
Erwin Schrödinger, most famous for his wave equation for nonrelativistic quantum mechanics, already ventured across the disciplines in his lecture series “What is life?” (Schrödinger, 1944). He anticipated a molecular basis for human heredity, which was later confirmed to be the DNA molecule (Watson and Crick, 1953). Since the early days of quantum physics, its influence on biology has always been present in a reductionist sense: quantum physics and electrodynamics shape all molecules and thus determine molecular recognition, the workings of proteins, and DNA. Also van der Waals forces, discrete molecular orbitals, and the stability of matter: all this is quantum physics and a natural basis for life and everything we see.
But even 100 years after its development, quantum physics is still a conceptually challenging model of nature: it is often acclaimed to be the most precisely verified theory of nature and yet its common interpretation stands in discrepancy to our classical, i.e., prequantum, world-view, and our natural ideas about reality or space-time. Is there a transition between quantum physics and our everyday world? And how will the life sciences then fit into the picture—with objects covering anything from molecules up to elephants, mammoth trees, or the human brain?
Still half a century ago, the topic had some rather skeptical reviews (Longuet-Higgins, 1962). But experimental advances have raised a new awareness and several recent reviews (e.g., Abbot et al., 2008) sketch a more optimistic picture that may be overoptimistic in some aspects.
[Quantum physics meets biology: Markus Arndt, Thomas Juffmann, and Vlatko Vedral. HFSP J. 2009 Dec; 3(6): 386–400. Published online 2009 Nov 9. doi: 10.2976/1.3244985 PMCID: PMC2839811]
What is Quantum Mechanics ? The weird world of quantum mechanics.
Quantum mechanics is the science of the very small: the body of scientific principles that explains the behaviour of matter and its interactions with energy on the scale of atoms and subatomic particles.
Quantum mechanics starts with the simple idea that energy does not come in just any amount; it comes in discrete chunks, called quanta. But deeper into the theory, some truly surprising – and useful – effects crop up
Superposition: A particle exists in a number of possible states or locations simultaneously – strictly, an electron might be in the tip of your finger and in the furthest corner of the Universe at the same time. It is only when we observe the particle that it ‘chooses’ one particular state.
Entanglement: Two particles can become entangled so that their properties depend on each other – no matter how far apart they get. Under quantum rules, no matter how far apart an “entangled” pair of particles gets, each seems to “know” what the other is up to – they can even seem to pass information to one another faster than the speed of light. A measurement of one seems to affect the measurement of the other instantaneously – an idea even Einstein called “spooky”.
Tunnelling: A particle can break through an energy barrier, seeming to disappear on one side of it and reappear on the other. Lots of modern electronics and imaging depends on this effect.
Experiments suggest this is going on within single molecules in birds’ eyes, and John Morton of University College London explained that the way birds sense it could be stranger still.
“You could think about that as… a kind of ‘heads-up display’ like what pilots have: an image of the magnetic field… imprinted on top of the image that they see around them,” he said.
The idea continues to be somewhat controversial – as is the one that your nose might be doing a bit of quantum biology.
Most smell researchers think the way that we smell has to do only with the shapes of odour molecules matching those of receptors in our noses.
But Dr Turin ( Luca Turin of the Fleming Institute in Greece) believes that the way smell molecules wiggle and vibrate is responsible – thanks to the quantum effect called tunnelling. The idea holds that electrons in the receptors in our noses disappear on one side of a smell molecule and reappear on the other, leaving a little bit of energy behind in the process.
A paper published in Plos One this shows that people can tell the difference between two molecules of identical shape but with different vibrations, suggesting that shape is not the only thing at work. Simon Gane, a researcher at the Royal National Throat, Nose and Ear Hospital and lead author of the Plos One paper, said that the tiny receptors in our noses are what are called G-protein coupled receptors. “They’re a sub-family of the receptors we have on all cells in our body – they’re the targets of most drug development,” he explained. “What if – and this is a very big if – there’s a major form of receptor-drug interaction that we’re just not noticing because we’re not looking for a quantum effect? That would have profound implications for drug development, design and discovery.”
What intrigues all these researchers is how much more quantum trickery may be out there in nature.
“Are these three fields the tip of the iceberg, or is there actually no iceberg underneath?” asked Dr Turin. “We just don’t know. And we won’t know until we go and look.”
Jim Al-Khalili of the University of Surrey is investigating whether tunnelling occurs during mutations to our DNA – a question that may be relevant to the evolution of life itself, or cancer research.
He told the BBC: “If quantum tunnelling is an important mechanism in mutations, is quantum mechanics going to somehow answer some of the questions about how a cell becomes cancerous?”
“And suddenly you think, ‘Wow!’ Quantum mechanics is not just a crazy side issue or a fringe field where some people are looking at some cranky ideas. If it really might help answer some of the very big questions in science, then it’s hugely important.”
Classical physics explains matter and energy on a scale familiar to human experience, including the behaviour of astronomical bodies. It remains the key to measurement for much of modern science and technology. However, towards the end of the 19th century, scientists discovered phenomena in both the large (macro) and the small (micro) worlds that classical physics could not explain. As Thomas Kuhn explains in his analysis of the philosophy of science, The Structure of Scientific Revolutions, coming to terms with these limitations led to two major revolutions in physics which created a shift in the original scientific paradigm: the theory of relativity and the development of quantum mechanics.
In this sense, the word ‘quantum’ means the minimum amount of any physical entity involved in an interaction. Certain characteristics of matter can take only discrete values.
Light behaves in some respects like particles and in other respects like waves.
Matter—particles such as electrons and atoms—exhibits wavelike behaviour too. Some light sources, including neon lights, give off only certain discrete frequencies of light. Quantum mechanics shows that light, along with all other forms of electromagnetic radiation, comes in discrete units, called photons, and predicts its energies, colours, and spectral intensities.
Some aspects of quantum mechanics can seem counterintuitive or even paradoxical, because they describe behaviour quite different from that seen at larger length scales. In the words of Richard Feynman, quantum mechanics deals with “nature as She is – absurd”. For example, the uncertainty principle of quantum mechanics means that the more closely one pins down one measurement (such as the position of a particle), the less precise another measurement pertaining to the same particle (such as its momentum) must become.
- At Massachusetts Institute of Technology, Mass., U.S.A., Daniel Nocera and his colleagues have produced an
artificial leaf made mostly of silicon, nickel and cobalt. The leaf is the size of a playing card, and it is about ten times more efficient than a natural leaf and can operate continuously for about 45 hours.When the layered leaf is exposed to light and water simultaneously, a silicon junction captures incoming photons and energizes the cobalt-based oxygen evolving complex at one end and a nickel, molybdenum and zinc alloy at the other. Together, they split the water touching the device and produce hydrogen that can be put into storage. Oxygen is released from the cobalt side of the leaf, and hydrogen gas from the nickel-molybdenum-zinc side. Separating the two sides while the gases are produced would produce ample hydrogen for fuel cells.Previously, platinum was the catalyst of choice for creating the electrolytic effect, but the nickel-molybdenum-zinc alloy performs more than adequately while being much less expensive.
Consequences of the light being quantised
Why Ultraviolet Light can cause sunburn but visible or infrared light cannot ?
The relationship between the frequency of electromagnetic radiation and the energy of each individual photon is why ultraviolet light can cause sunburn, but visible or infrared light cannot. A photon of ultraviolet light will deliver a high amount of energy – enough to contribute to cellular damage such as occurs in a sunburn. A photon of infrared light will deliver a lower amount of energy – only enough to warm one’s skin. So, an infrared lamp can warm a large surface, perhaps large enough to keep people comfortable in a cold room, but it cannot give anyone a sunburn.
All photons of the same frequency have identical energy, and all photons of different frequencies have proportionally different energies. However, although the energy imparted by photons is invariant at any given frequency, the initial energy state of the electrons in a photoelectric device prior to absorption of light is not necessarily uniform. Anomalous results may occur in the case of individual electrons. For instance, an electron that was already excited above the equilibrium level of the photoelectric device might be ejected when it absorbed uncharacteristically low frequency illumination. Statistically, however, the characteristic behaviour of a photoelectric device will reflect the behaviour of the vast majority of its electrons, which will be at their equilibrium level. This point is helpful in comprehending the distinction between the study of individual particles in quantum dynamics and the study of massed particles in classical physics.
For years biologists have been wary of applying the strange world of quantum mechanics, where particles can be in two places at once or connected over huge distances, to their own field. But it can help to explain some amazing natural phenomena we take for granted.
Every year, around about this time, thousands of European robins, Erithacus rubecula, escape the oncoming harsh Scandinavian winter and head south to the warmer Mediterranean coasts. How they find their way unerringly on this 2,000-mile journey is one of the true wonders of the natural world. For unlike many other species of migratory birds, marine animals and even insects, they do not rely on landmarks, ocean currents, the position of the sun or a built-in star map. Instead, they are among a select group of animals that use a remarkable navigation sense – remarkable for two reasons.
The first is that they are able to detect tiny variations in the direction of the Earth’s magnetic field – astonishing in itself, given that this magnetic field is 100 times weaker than even that of a measly fridge magnet. The second is that robins seem to be able to “see” the Earth’s magnetic field via a process that even Albert Einstein referred to as “spooky”. The birds’ in-built compass appears to make use of one of the strangest features of quantum mechanics.
Over the past few years, the European robin, and its quantum “sixth sense”, has emerged as the pin-up for a new field of research, one that brings together the wonderfully complex and messy living world and the counter-intuitive, ethereal but strangely orderly world of atoms and elementary particles in a collision of disciplines that is as astonishing and unexpected as it is exciting.
Welcome to the new science of quantum biology.
Most people have probably heard of quantum mechanics, even if they don’t really know what it is about. Certainly, the idea that it is a baffling and difficult scientific theory understood by just a tiny minority of smart physicists and chemists has become part of popular culture. Quantum mechanics describes a reality on the tiniest scales that is, famously, very weird indeed; a world in which particles can exist in two or more places at once, spread themselves out like ghostly waves, tunnel through impenetrable barriers and even possess instantaneous connections that stretch across vast distances.
But despite this bizarre description of the basic building blocks of the universe, quantum mechanics has been part of all our lives for a century. Its mathematical formulation was completed in the mid-1920s and has given us a remarkably complete account of the world of atoms and their even smaller constituents, the fundamental particles that make up our physical reality. For example, the ability of quantum mechanics to describe the way that electrons arrange themselves within atoms underpins the whole of chemistry, material science and electronics; and is at the very heart of most of the technological advances of the past half-century. Without the success of the equations of quantum mechanics in describing how electrons move through materials such as semiconductors we would not have developed the silicon transistor and, later, the microchip and the modern computer.
However, if quantum mechanics can so beautifully and accurately describe the behaviour of atoms with all their accompanying weirdness, then why aren’t all the objects we see around us, including us – which are after all only made up of these atoms – also able to be in two place at once, pass through impenetrable barriers or communicate instantaneously across space?
One obvious difference is that the quantum rules apply to single particles or systems consisting of just a handful of atoms, whereas much larger objects consist of trillions of atoms bound together in mind-boggling variety and complexity. Somehow, in ways we are only now beginning to understand, most of the quantum weirdness washes away ever more quickly the bigger the system is, until we end up with the everyday objects that obey the familiar rules of what physicists call the “classical world”.
In fact, when we want to detect the delicate quantum effects in everyday-size objects we have to go to extraordinary lengths to do so – freezing them to within a whisker of absolute zero and performing experiments in near-perfect vacuums.
Quantum effects were certainly not expected to play any role inside the warm, wet and messy world of living cells, so most biologists have thus far ignored quantum mechanics completely, preferring their traditional ball-and-stick models of the molecular structures of life.
Meanwhile, physicists have been reluctant to venture into the messy and complex world of the living cell; why should they, when they can test their theories far more cleanly in the controlled environment of the lab where they at least feel they have a chance of understanding what is going on?
Yet, 70 years ago, the Austrian Nobel prize-winning physicist and quantum pioneer, Erwin Schrödinger, suggested in his famous book, What is Life?, that, deep down, some aspects of biology must be based on the rules and orderly world of quantum mechanics. His book inspired a generation of scientists, including the discoverers of the double-helix structure of DNA, Francis Crick and James Watson. Schrödinger proposed that there was something unique about life that distinguishes it from the rest of the non-living world. He suggested that, unlike inanimate matter, living organisms can somehow reach down to the quantum domain and utilise its strange properties in order to operate the extraordinary machinery within living cells.
- Schrödinger’s argument was based on the paradoxical fact that the laws of classical physics, such as those of Newtonian mechanics and thermodynamics, are ultimately based on disorder. Consider a balloon. It is filled with trillions of molecules of air all moving entirely randomly, bumping into one another and the inside wall of the balloon. Each molecule is governed by orderly quantum laws, but when you add up the random motions of all the molecules and average them out, their individual quantum behaviour washes out and you are left with the gas laws that predict, for example, that the balloon will expand by a precise amount when heated. This is because heat energy makes the air molecules move a little bit faster, so that they bump into the walls of the balloon with a bit more force, pushing the walls outward a little bit further. Schrödinger called this kind of law “order from disorder” to reflect the fact that this apparent macroscopic regularity depends on random motion at the level of individual particles.
But what about life? Schrödinger pointed out that many of life’s properties, such as heredity, depend of molecules made of comparatively few particles – certainly too few to benefit from the order-from-disorder rules of thermodynamics. But life was clearly orderly.
Where did this orderliness come from?
Schrödinger suggested that life was based on a novel physical principle whereby its macroscopic order is a reflection of quantum-level order, rather than the molecular disorder that characterises the inanimate world. He called this new principle “order from order”.
But was he right?
Up until a decade or so ago, most biologists would have said no. But as 21st-century biology probes the dynamics of ever-smaller systems – even individual atoms and molecules inside living cells – the signs of quantum mechanical behaviour in the building blocks of life are becoming increasingly apparent. Recent research indicates that some of life’s most fundamental processes do indeed depend on weirdness welling up from the quantum undercurrent of reality.
Here are a few of the most exciting examples.
Enzymes are the workhorses of life. They speed up chemical reactions so that processes that would otherwise take thousands of years proceed in seconds inside living cells. Life would be impossible without them. But how they accelerate chemical reactions by such enormous factors, often more than a trillion-fold, has been an enigma. Experiments over the past few decades, however, have shown that enzymes make use of a remarkable trick called quantum tunnelling to accelerate biochemical reactions. Essentially, the enzyme encourages electrons and protons to vanish from one position in a biomolecule and instantly re-materialise in another, without passing through the gap in between – a kind of quantum teleportation.
[I believe,(although I do not have any proof or reference for it) it might be following the same physics principles, as is followed by an electrons that travels through a wire, when a potential is applied across it. The electron seems to be travelling at light speed although, what happens actually is that, as soon as an electron enters one end of wire, at the same time, at the other end of the wire, an electron which was initially part of wire itself ejects simultaneously.Now the time required for the electron to be ejected depends upon the electric potential applied across and the material of the wire itself.]
Quantum tunnelling (or tunneling) is the quantum-mechanical effect of transitioning through a classically-forbidden energy state. It can be generalized to other types of classically-forbidden transitions as well.
Consider rolling a ball up a hill. If the ball is not given enough velocity, then it will not roll over the hill. This scenario makes sense from the standpoint of classical mechanics, but is an inapplicable restriction in quantum mechanics simply because quantum mechanical objects do not behave like classical objects such as balls. On a quantum scale, objects exhibit wavelike behaviour. For a quantum particle moving against a potential energy “hill”, the wave function describing the particle can extend to the other side of the hill. This wave represents the probability of finding the particle in a certain location, meaning that the particle has the possibility of being detected on the other side of the hill. This behaviour is called tunneling; it is as if the particle has ‘dug’ through the potential hill.
As this is a quantum and non-classical effect, it can generally only be seen in nanoscopic phenomena — where the wave behaviour of particles is more pronounced.
And before you throw your hands up in incredulity, it should be stressed that quantum tunnelling is a very familiar process in the subatomic world and is responsible for such processes as radioactive decay of atoms and even the reason the sun shines (by turning hydrogen into helium through the process of nuclear fusion). Enzymes have made every single biomolecule in your cells and every cell of every living creature on the planet, so they are essential ingredients of life. And they dip into the quantum world to help keep us alive.
Another vital process in biology is of course photosynthesis. Indeed, many would argue that it is the most important biochemical reaction on the planet, responsible for turning light, air, water and a few minerals into grass, trees, grain, apples, forests and, ultimately, the rest of us who eat either the plants or the plant-eaters.
The initiating event is the capture of light energy by a chlorophyll molecule and its conversion into chemical energy that is harnessed to fix carbon dioxide and turn it into plant matter. The process whereby this light energy is transported through the cell has long been a puzzle because it can be so efficient – close to 100% and higher than any artificial energy transport process.
The first step in photosynthesis is the capture of a tiny packet of energy from sunlight that then has to hop through a forest of chlorophyll molecules to makes its way to a structure called the reaction centre where its energy is stored. The problem is understanding how the packet of energy appears to so unerringly find the quickest route through the forest. An ingenious experiment, first carried out in 2007 in Berkley, California, probed what was going on by firing short bursts of laser light at photosynthetic complexes. The research revealed that the energy packet was not hopping haphazardly about, but performing a neat quantum trick. Instead of behaving like a localised particle travelling along a single route, it behaves quantum mechanically, like a spread-out wave, and samples all possible routes at once to find the quickest way.
THE BIRD’S-EYE COMPASS
A third example of quantum trickery in biology – is the mechanism by which birds and other animals make use of the Earth’s magnetic field for navigation. Studies of the European robin suggest that it has an internal chemical compass that utilises an astonishing quantum concept called entanglement, which Einstein dismissed as “spooky action at a distance”. This phenomenon describes how two separated particles can remain instantaneously connected via a weird quantum link. The current best guess is that this takes place inside a protein in the bird’s eye, where quantum entanglement makes a pair of electrons highly sensitive to the angle of orientation of the Earth’s magnetic field, allowing the bird to “see” which way it needs to fly.
The avian magnetic sensor is known to be activated by light striking the bird’s retina. Researchers’ current best guess at a mechanism is that the energy deposited by each incoming photon creates a pair of free radicals. [Ritz, T., Thalau, P., Phillips, J. B., Wiltschko, R. & Wiltschko, W. Nature 429, 177–180 (2004).] — highly reactive molecules, each with an unpaired electron. Each of these unpaired electrons has an intrinsic angular momentum, or spin, that can be reoriented by a magnetic field. As the radicals separate, the unpaired electron on one is primarily influenced by the magnetism of a nearby atomic nucleus, whereas the unpaired electron on the other is further away from the nucleus, and feels only Earth’s magnetic field. The difference in the fields shifts the radical pair between two quantum states with differing chemical reactivity.
“One version of the idea would be that some chemical is synthesized in the bird’s retinal cells when the system is in one state, but not when it’s in the other”, says Simon Benjamin, a physicist at the University of Oxford, UK. “Its concentration reflects Earth’s field orientation.” The feasibility of this idea was demonstrated in 2008 in an artificial photochemical reaction, in which magnetic fields affected the lifetime of a radical pair.[Maeda, K. et al. Nature 453, 387–390 (2008).]
Benjamin and his co-workers have proposed that the two unpaired electrons, being created by the absorption of a single photon, exist in a state of quantum entanglement: a form of coherence in which the orientation of one spin remains correlated with that of the other, no matter how far apart the radicals move. Entanglement is usually quite delicate at ambient temperatures, but the researchers calculate that it is maintained in the avian compass for at least tens of microseconds — much longer than is currently possible in any artificial molecular system. [Gauger, E. M., Rieper, E., Morton, J. J. L., Benjamin, S. C. & Vedral, V. Phys. Rev. Lett. 106, 040503 (2011).]
Reference: The Dawn of Quantum Biology by Philip Ball , Nature, Vol. 474, 16 June 2011, pg 272-274.
This quantum-assisted magnetic sensing could be widespread. Not only birds, but also some insects and even plants show physiological responses to magnetic fields — for example, the growth-inhibiting influence of blue light on the flowering plant Arabidopsis thaliana is moderated by magnetic fields in a way that may also use the radical pair mechanism. [Ahmad, M., Galland, P., Ritz, T., Wiltschko, R. & Wiltschko, W. Planta 225, 615–624 (2007)] But for clinching proof that it works this way, says Benjamin, “we need to understand the basic molecules involved, and then study them in the lab”.
All these quantum effects have come as a big surprise to most scientists who believed that the quantum laws only applied in the microscopic world. All delicate quantum behaviour was thought to be washed away very quickly in bigger objects, such as living cells, containing the turbulent motion of trillions of randomly moving particles. So how does life manage its quantum trickery? Recent research suggests that rather than avoiding molecular storms, life embraces them, rather like the captain of a ship who harnesses turbulent gusts and squalls to maintain his ship upright and on course.
Just as Schrödinger predicted, life seems to be balanced on the boundary between the sensible everyday world of the large and the weird and wonderful quantum world, a discovery that is opening up an exciting new field of 21st-century science.
Reference: You’re powered by quantum mechanics. No, really… http://www.theguardian.com/science/2014/oct/26/youre-powered-by-quantum-mechanics-biology