“The Great Pyramid was a fractal resonator for the entire Earth. It is designed according to the proportions of the cosmic temple, the natural pattern that blends the two fundamental principles of creation. The pyramid has golden ratio, pi, the base of natural logarithms, the precise length of the year and the dimensions of the Earth built into its geometry. It demonstrates…. As John Michell has pointed out in his wonderful little book, City of Revelation, ‘Above all, the Great Pyramid is a monument to the art of ‘squaring the circle”.” ― Alison Charlotte Primrose
Explore the mysteries of ancient civilizations by enrolling in the free Unified Science Course at ResonanceScience.org
Photographer unknown: comment for credit
Causality is one of those difficult scientific topics that can easily stray into the realm of philosophy. Science’s relationship with the concept started out simply enough: an event causes another event later in time. That had been the standard understanding of the scientific community up until quantum mechanics was introduced. Then, with the introduction of the famous “spooky action at a distance” that is a side effect of the concept of quantum entanglement, scientists began to question that simple interpretation of causality
Now, researchers at the Université Libre de Bruxelles (ULB) and the University of Oxford have come up with a theory that further challenges that standard view of causality as a linear progress from cause to effect. In their new theoretical structure, cause and effect can sometimes take place in cycles, with the effect actually causing the cause.
Quantum entanglement. Credit: Physics Department, HKUST
The quantum realm itself as it is currently understood is inherently messy. There is no true understanding of things at that scale, which can be thought of better as a set of mathematical probabilities rather than actualities. These probabilities do not exactly lend themselves well to the idea of a definite cause and effect interaction between events either.
The researchers further muddied the waters using a tool known as a unitary transformation. Simply put, a unitary transformation is a fudge used to solve some of the math that is necessary to understand complex quantum systems. Using it makes solving the famous Schrodinger equation achievable using real computers.
UT video discussing some of the more interesting implications of quantum theory.
To give a more complete explanation requires delving a bit into the “space” that quantum mechanics operates in. In quantum mechanics, time is simply another dimension that must be accounted for similarly to how the usual three dimensions of what we think of as linear space are accounted for. Physicists usually use another mathematical tool called a Hamiltonian to solve Schrodinger’s equation.
A Hamiltonian, though a mathematical concept, is often time dependent. However, it is also the part of the equation that is changed when a unitary transformation is introduced. As part of that action, it is possible to eliminate the time dependency of the Hamiltonian, to make it such that, instead of requiring time to go a certain direction (i.e. for action and reaction to take place linearly), the model turns more into a circle than a straight line, with action causing reaction and reaction causing action.
Video describing unitary transformations using advanced linear algebra.
Credit: Umesh V. Vazirani / Cal Berkeley
If this isn’t all confusing enough, there are some extremely difficult to conceive of implications of this model (and to be clear, from a macro level, it is just a model). One important facet is that this finding has little to no relevance to every day cause and effect. The causes and effects that would be cyclical in this framework “are not local in spacetime”, according to the press release from ULB, so they are unlikely to have any impact on day to day life.
Even if it doesn’t have any everyday impact now, this framework could hint at a combined theory of quantum mechanics and general relativity that has been the most sought after prize in physics for decades. If that synthesis is ever fully realized, there will be more implications for everyday life than just the existential questions of whether we are actually in control of our own actions or not.
“I believe that scientific knowledge has fractal properties, that no matter how much we learn, whatever is left, however small it may seem, is just as infinitely complex as the whole was to start with. That, I think, is the secret of the Universe.” – Isaac Asimov
The word fractal has become increasingly popular, although the concept started more than two centuries ago in the 17th century with prominent and prolific mathematician and philosopher Gottfried Wilhelm Leibnitz. Leibnitz is believed to have addressed for the first time the notion of recursive self-similarity, and it wasn’t until 1960 that the concept was formally stabilized both theoretically and practically, through the mathematical development and computerized visualizations by Benoit Mandelbrot, who settled on the name “fractal”.
Fractals are defined mainly by three characteristics:
- Self-similarity: identical or very similar shapes and forms at all scales.
- Iteration: a recursive relationship limited only by computer capacity. With sufficiently high performance, the iterations could be infinite. This allows for very detailed shapes at every scale, that modify with respect to the first iteration, manifesting the original shape at some levels of iteration. Because of this, fractals may have emergent properties, which make them a suitable tool for complex systems.
- Fractal dimension, or fractional dimensions: describes the counter-intuitive notion that a measured length changes with the length of the measuring stick used; it quantifies how the number of scaled measuring sticks required to measure, for example, a coastline, changes with the scale applied to the stick.
The fractal dimension of a curve can be explained intuitively thinking of a fractal line as an object too detailed to be one-dimensional, but too simple to be two-dimensional.7
Although fractals now-a-days are commonly used for the macroscopic regime such as the branches of a tree, a broccoli, blood vessels and many others, for the first time physicists at MIT have discovered fractal-like patterns in a quantum material. The material is neodymium nickel oxide or NdNiO3, a rare earth nickelate that conduces electricity or acts as an insulator, depending on its temperature. It also presents inhomogeneous magnetism: domains or regions with a specific magnetic orientation that vary in size and shape throughout the material. The material exhibits this peculiar electronic and magnetic behavior as a result of quantum, atomic-scale effects, and for this reason it is called a quantum material.
The researchers had to design a very special X-ray-focusing lens in order to map the size, shape, and orientation of magnetic domains point by point at different temperatures, confirming that the material formed magnetic domains below a certain critical temperature. Above this temperature, the domains disappeared erasing the magnetic order. Nevertheless, if they cooled the sample back to below the critical temperature, the magnetic domains reappeared almost in the same place as before! This means that the system has memory, which was very unexpected. One could have a system robust against external perturbations, even if subjected to heat, such that the information is not lost.
Secondly, after mapping the material’s magnetic domains and measuring the size of each domain, the researchers counted the number of domains of a given size and plotted their number as a function of size. The resulting distribution showed the same pattern again and again, no matter what range of domain size they focused on. They found that these magnetic patterns have a fractal nature!
“It was completely unexpected — it was serendipity.”
– Riccardo Comin, Assistant Professor of Physics at MIT.
Because the material acts as an insulator or conductor depending on the temperature, scientists are exploring neodymium nickel oxide for neuromorphic devices — devices that mimic biological neurons. Here, temperature would play the role of voltage in the biological system, which is active or inactive depending on the voltage that it receives. Another potential application is resilient, magnetic data storage devices.
A study has found that adolescents who frequently use cannabis may experience a decline in Intelligence Quotient (IQ) over time. The findings of the research provide further insight into the harmful neurological and cognitive effects of frequent cannabis use on young people.
The paper, led by researchers at RCSI University of Medicine and Health Sciences, is published in Psychological Medicine.
The results revealed that there were declines of approximately 2 IQ points over time in those who use cannabis frequently compared to those who didn’t use cannabis. Further analysis suggested that this decline in IQ points was primarily related to reduction in verbal IQ.
The research involved systematic review and statistical analysis on seven longitudinal studies involving 808 young people who used cannabis at least weekly for a minimum of 6 months and 5308 young people who did not use cannabis. In order to be included in the analysis each study had to have a baseline IQ score prior to starting cannabis use and another IQ score at follow-up. The young people were followed up until age 18 on average although one study followed the young people until age 38.
“Previous research tells us that young people who use cannabis frequently have worse outcomes in life than their peers and are at increased risk for serious mental illnesses like schizophrenia. Loss of IQ points early in life could have significant effects on performance in school and college and later employment prospects,” commented senior author on the paper Professor Mary Cannon, Professor of Psychiatric Epidemiology and Youth Mental Health, RCSI.
“Cannabis use during youth is of great concern as the developing brain may be particularly susceptible to harm during this period. The findings of this study help us to further understand this important public health issue,” said Dr Emmet Power, Clinical Research Fellow at RCSI and first author on the study.
The study was carried out by researchers from the Department of Psychiatry, RCSI and Beaumont Hospital, Dublin (Prof Mary Cannon, Dr Emmet Power, Sophie Sabherwal, Dr Colm Healy, Dr Aisling O’Neill and Professor David Cotter).
The research was funded by a YouLead Collaborative Doctoral Award from the Health Research Board (Ireland) and a European Research Council Consolidator Award.
A team of researchers from Germany, Italy and Hungary has tested a theory that suggests gravity is the force behind quantum collapse and has found no evidence to support it. In their paper published in the journal Nature Physics, the researchers describe underground experiments they conducted to test the impact of gravity on wave functions and what their work showed them. Myungshik Kim, with Imperial College London has published a News & Views piece in the same issue, outlining the work by the team and the implications of their results.
Quantum physics suggests that the state of an object depends on its properties and the way it is measured by an observer; the thought experiment involving Schrödinger’s cat is perhaps the most famous example. But the theory is not universally accepted—physicists have wrangled for many years over the notion, with some arguing that it seems a bit too anthropocentric to be real. Behind the theory is the concept of waveform collapse, by which the observation of a particle, as an example, makes it collapse. To help make sense of the idea, some physicists have suggested that the force behind waveform collapse is not a person taking a look at a particle, but gravity. They suggest that gravitational fields exist outside of quantum theory and resist being forced into awkward combinations such as superpositions. A gravitational fieldforced to do so soon collapses, taking the particle with it. In this new effort, the researchers devised an experiment to test this theory in a physical sense.
The experiment consisted of building a small crystal detector made from germanium and using it to detect gamma and X-ray emissions from protons in the nuclei of the germanium. But before running the experiment, they wrapped the detector in lead and dropped it into a facility 1.4 kilometers below ground level at the Gran Sasso National Laboratory in Italy to prevent as much extraneous radiation from reaching the sensor as possible. After two months of testing, the team recorded far fewer photon hits than theory would suggest—indicating that the particles were not collapsing due to gravity, as theory had suggested.
In one of the University of Sheffield’s physics labs, a few hundred photosynthetic bacteria were nestled between two mirrors positioned less than a micrometer apart. Physicist David Coles and his colleagues were zapping the microbe-filled cavity with white light, which bounced around the cells in a way the team could tune by adjusting the distance between the mirrors. According to results published in 2017, this intricate setup caused photons of light to physically interact with the photosynthetic machinery in a handful of those cells, in a way the team could modify by tweaking the experimental setup.1
That the researchers could control a cell’s interaction with light like this was an achievement in itself. But a more surprising interpretation of the findings came the following year. When Coles and several collaborators reanalyzed the data, they found evidence that the nature of the interaction between the bacteria and the photons of light was much weirder than the original analysis had suggested. “It seemed an inescapable conclusion to us that indirectly what [we were] really witnessing was quantum entanglement,” says University of Oxford physicist Vlatko Vedral, a coauthor on both papers.
Quantum entanglement refers to the states of two or more particles being interdependent, regardless of the distance separating them. It’s one of many counterintuitive features of the subatomic landscape, in which particles such as electrons and photons behave as both particles and waves simultaneously, occupy multiple positions and states at once, and traverse apparently impermeable barriers. Processes at this scale are captured in the complex mathematical language of quantum mechanics, and frequently produce effects that appear to defy common sense. (See Glossary: Quantum Terminology infographic.) It was using this language that Vedral and colleagues had detected signatures of entanglement between photons and bacteria in data from the Sheffield experiment.
Researchers have demonstrated entanglement many times in inanimate objects—in 2017, scientists reported they’d managed to maintain this interdependence between pairs of photons separated by 1,200 kilometers. But if Vedral and colleagues’ proposal that the phenomenon was taking place in bacteria is correct, the study could mark the first time entanglement has been observed inside a living organism, and add to a growing body of evidence that quantum effects are not as unusual in biology as once believed.2
That quantum phenomena might be observable in the messy world of living systems is historically a fringe idea. While quantum theories accurately describe the behavior of the individual particles making up all matter, scientists have long presumed that the mass action of billions of particles jostling around at ambient temperature drowns out any weird quantum effects and is better explained by the more familiar rules of classical mechanics formulated by Isaac Newton and others. Indeed, researchers studying quantum phenomena often isolate particles at temperatures approaching absolute zero—at which almost all particle motion grinds to a halt—just to quash the background noise.
“The warmer the environment is, the more busy and noisy it is, the quicker these quantum effects disappear,” says University of Surrey theoretical physicist Jim Al-Khalili, who coauthored a 2014 book called Life on the Edge that brought so-called quantum biology to a lay audience. “So it’s almost ridiculous, counterintuitive, that they should persist inside cells. And yet, if they do—and there’s a lot of evidence suggesting that in certain phenomena they do—then life must be doing something special.”
Al-Khalili and Vedral are part of an expanding group of scientists now arguing that effects of the quantum world may be central to explaining some of biology’s greatest puzzles—from the efficiency of enzyme catalysis to avian navigation to human consciousness—and could even be subject to natural selection.
“The whole field is trying to prove a point,” says Chiara Marletto, a University of Oxford physicist who collaborated with Coles and Vedral on the bacteria-entanglement paper. “That is to say, not only does quantum theory apply to these [biological systems], but it’s possible to test whether these [systems] are harnessing quantum physics to perform their functions.”
Enzyme Catalysis: A Tunnel Through the Barrier
Traditional theories of enzyme catalysis hold that the proteins speed up reactions by lowering the activation energy. But some researchers argue that a quantum trick known as tunneling also plays a role, and that the structure of enzymes’ active sites might have evolved to take advantage of this phenomenon.
Quantum effects in biology’s fundamental reactions
By the mid-1980s, University of California, Berkeley, biochemist Judith Klinman was convinced that the traditional explanation of enzyme catalysis was incomplete. Contemporary theories held that enzymes interact with substrates on the basis of shape and classical mechanics, physically bringing together substrates at their active sites and stabilizing transition states of molecular structure to accelerate reaction rates up to a trillionfold or more. But Klinman had been getting odd results from in vitro experiments with an enzyme extracted from yeast.
In catalyzing the oxidation of benzyl alcohol to benzaldehyde, the alcohol dehydrogenase enzyme shifts a hydrogen atom from one position to another. Unexpectedly, when Klinman and her colleagues replaced specific hydrogen atoms in the substrate with the heavier isotopes deuterium and tritium, the reaction drastically slowed down. Although classical explanations of enzyme catalysis allowed for modest isotope effects, they couldn’t account for the large drop in rate Klinman observed. “What we saw were deviations from the existing theories,” she says.
Her team kept investigating, and, in 1989, published an explanation building on ideas already circulating among enzyme researchers: that catalysis involves a quantum trick called tunneling.3 Quantum tunneling is like kicking a football through a hill, explains Al-Khalili—where the football is an electron or another particle, and the hill is an energy barrier preventing a reaction from happening. “In the classical world you have to kick it hard enough to get it up the hill and down the other side,” he says. “In the quantum world, you don’t have to. It can go halfway up, disappear, and reappear on the other side.”
Klinman’s team posited in this and later papers that, during the catalysis of benzyl alcohol oxidation and many other reactions, hydrogen transfer takes place with assistance from tunneling. This helps explain why deuterium and tritium often hold reactions up—heavier particles are worse at tunneling, and can make tunneling harder for other particles in the same molecule. The effects observed by Klinman’s group have since been replicated by other labs for multiple enzymes and provide some of the strongest evidence for quantum effects in biological systems, Al-Khalili says. (See infographic.)
But while it’s now generally accepted that tunneling occurs in biological catalysis, researchers are divided on how much it matters—and whether it might be subject to natural selection. Chemist Richard Finke at Colorado State University, for example, showed that some reactions exhibit isotope effects to a similar degree whether or not an enzyme is present, suggesting that it’s unlikely that enzymes are particularly adapted to enhance tunneling effects in the reactions they catalyze.4 It’s also unclear how much tunneling speeds up reactions; some researchers argue that the effect generally contributes no more than a small boost to processes governed primarily by classical mechanics.
Klinman says she thinks that tunneling in enzymes is far more fundamental. “Our view is that enzymes create very precise and compact active site structures” that promote tunneling, she says. During catalysis, for example, enzymes change conformation in a way that can bring hydrogen donor and acceptor sites close enough—within about 0.27 nanometers of each other—to facilitate tunneling, she notes.
Her group has pursued the idea by mutating enzymes’ active sites and observing how reaction rates and isotope effects change in vitro. Earlier this year, for example, the team created a version of soybean lipoxygenase that slightly mispositions its substrates in a way that should make hydrogen tunneling unfavorable. Compared with the wild type, the mutant enzyme’s catalytic power is four orders of magnitude lower, and it’s much more sensitive to the replacement of hydrogen with deuterium.5
Researchers are still quantifying tunneling’s role in catalysis, and Klinman emphasizes the importance of using multiple methods, including mutagenesis and computational modeling, to understand exactly how proteins speed up reactions. Experimental evolution of enzymes, in which researchers repeatedly select proteins to increase their catalytic power, could also offer insight into tunneling’s contribution—although at least one recent attempt to do this was inconclusive. Last year, a team that evolved an enzyme catalyzing a reaction involving hydrogen transfer reported that quantum tunneling was “not observed to significantly change” across the evolutionary process.6
The debate mirrors an ongoing conversation about the functional importance of quantum phenomena in another of Earth’s critical biological processes, photosynthesis. While Vedral and colleagues are investigating whether bacteria’s photosynthetic machinery becomes entangled with photons, other groups have been studying how another quantum effect could help maximize the efficiency of photosynthetic energy transfer.
During the light-harvesting reaction in plants and some microbes, photons excite electrons contained in chlorophyll molecules to create entities called excitons. These excitons are then transferred from chlorophyll molecule to chlorophyll molecule until they reach the reaction center—a cluster of proteins where their energy can be captured and stored.
Excitons can lose energy as they’re transferred, meaning that the more roundabout their routes are among the chlorophyll molecules, the less energy reaches the reaction center. Physicists suggested decades ago that this wastefulness could be averted if the transfer process was quantum coherent. That is, if excitons could travel like waves rather than particles, they could simultaneously try out all paths to the reaction center and take only the most efficient route. (See illustration.)
In 2007, a team led by chemists Graham Fleming of the University of California, Berkeley, and Robert Blankenship of Washington University in St. Louis claimed to have observed quantum coherence in complexes of chlorophyll molecules extracted from green sulfur bacteria, photosynthetic microbes often found in the deep ocean where light availability is low. The researchers used a technique that analyzes the energy absorbed and emitted by a sample, and detected a signal called quantum beating—oscillations they interpreted as evidence of coherence—in complexes cooled to 77 Kelvin. Over the next few years, they and other groups replicated the results at ambient temperatures,8 and extended the findings to chlorophyll complexes from marine algae9 and spinach.10
Whether these results reflect a meaningful quantum contribution to energy transfer in photosynthesis is up for debate. In 2017, for example, researchers in Germany took another look at green sulfur bacteria and reported that the coherence effect lasted less than 60 femtoseconds (0.00006 nanoseconds)—too brief to aid energy transfer to the reaction center.11 But last year, another group argued that there are multiple types of coherence in chlorophyll complexes, and some do appear to last long enough to be useful in photosynthesis.12 Other scientists point to hints that some bacteria can switch coherence effects on or off by producing different forms of a key light-harvesting protein.13 Such findings have reignited speculation that, like enzymes, photosynthetic machinery might have evolved to exploit quantum phenomena.
Coherence effects in photosynthesis are now a well-accepted phenomenon, says Blankenship. As is the case for tunneling in enzymes, “the most relevant discussion at this point is whether they really have an effect on [the] efficiency of the system or some other aspect of it that gives a real biological benefit. I think the jury’s still out.”
Quantum explanations for puzzles in animal biology
Every winter, European robins in the northern part of the continent migrate hundreds of kilometers south to the Mediterranean. It’s a navigational feat made possible by magnetoreception—specifically, the birds’ ability to detect the direction of the Earth’s magnetic field. But early attempts to explain this sixth sense, including the proposal that birds rely on internal magnetite crystals, failed to garner experimental support.
By the late 1990s, the problem had caught the eye of Thorsten Ritz, then a graduate student working on quantum effects in photosynthesis under the supervision of the late biophysicist Klaus Schulten at the University of Illinois at Urbana-Champaign. He became particularly interested in cryptochrome, a light-sensitive protein found in the retinas of birds for which there’s now “good evidence” of a role in magnetoreception, says Ritz, who has since moved to the University of California, Irvine. So in 2000, focusing on this protein and building on Schulten’s earlier theoretical work, Ritz, Schulten, and another Illinois colleague published what would come to be known as the radical-pair model to explain how magnetoreception might operate.14
The researchers proposed that reactions in the cryptochrome protein generate a pair of radicals—molecules that each have a lone electron. The behavior of those electrons, which can be quantumly entangled with each other, is sensitive to the alignment of weak magnetic fields such as the Earth’s. Changes in the alignment of this pair relative to the magnetic field could theoretically trigger downstream chemical reactions, allowing the information to be somehow transmitted to the brain. (See illustration.)
The hypothesis generated a handful of predictions that Ritz went on to test in collaboration with the biologists who first described magnetoreception in robins, Roswitha and Wolfgang Wiltschko. In a study published in 2004, for example, the team exposed robins to magnetic fields oscillating at frequencies and angles that the model predicted would disrupt the radical pair’s sensitivity to the Earth’s magnetic field—and effectively knocked out the birds’ ability to navigate.15
The idea has taken off since then, with growing theoretical support. And two 2018 studies of the molecular properties and expression patterns of one version of cryptochrome, Cry4, point to the protein as a likely candidate magnetoreceptor in zebra finches16 and European robins.17
More work is needed to determine whether or not avian magnetoreception really works this way, and to reveal if entanglement between the electrons of the radical pair is important. Scientists also don’t fully understand how cryptochrome could communicate magnetic field information to the brain, says Ritz. Meanwhile, his group is focused on mutagenesis experiments, which could help unravel cryptochrome’s magnetosensitivity. Last fall, University of Oxford chemist Peter Hore and biologist Henrik Mouritsen of the University of Oldenburg in Germany won European funding for QuantumBirds, a project with similar aims.
Magnetoreception isn’t the only puzzle in animal sensory biology that’s generated interest among quantum physicists; another scientifically mysterious sense that researchers hope to help crack is olfaction. The traditional theory—that odorant molecules fit into protein receptors on olfactory neurons to trigger smells—faces the challenge that some molecules with almost identical shapes have completely different odors, while others with different stereochemistry smell alike.
In the mid-1990s, University College London (UCL) biophysicist Luca Turin, now a respected perfume critic, proposed that olfactory receptors might be sensitive not just to shape, but to the frequencies of vibrating bonds in odorant molecules.18 He argued that when an odorant binds to a receptor, if its bonds are vibrating at a certain frequency they can facilitate the quantum tunneling of electrons within that receptor. This transfer of electrons, according to his model, triggers a signaling cascade in the olfactory neuron that ultimately sends an impulse to the brain.
Experimental evidence for the idea is still elusive, says Jenny Brookes, a UCL physicist who has formulated the problem mathematically to show that it’s theoretically feasible. “But that’s partly why it’s quite exciting.” In recent years, researchers have looked for isotope effects similar to the ones found in enzyme function. If tunneling plays a substantial role, odorant molecules containing heavier hydrogen isotopes should smell different from normal versions due to the lower vibration frequencies of their bonds.
The findings are mixed. In 2013, Turin’s group reported that humans can distinguish between odorants containing different isotopes.19 Two years later, other researchers failed to reproduce the results and called the theory “implausible.”20 But the idea didn’t go out of fashion. In 2016, another team reported that honey bees can differentiate odors with different isotopes,21 while a recent theoretical study presents a suite of new predictions to help test the model’s validity.22
Theoretical work is also driving interest in quantum biological explanations with far less experimental support. For example, some researchers have speculated that the coherence effects posited to play a role in photosynthesis could also contribute to such widespread biological phenomena as vision and cellular respiration. Others have suggested that proton tunneling could promote spontaneous mutations in DNA, although theoretical work by Al-Khalili and colleagues suggest this isn’t terribly likely, at least for the adenine-thymine base pairs they modeled.23
Perhaps the most extreme extension of quantum physics to the animal kingdom is the idea that weird quantum effects might play a role in the human brain. University of California, Santa Barbara, physicist Matthew Fisher has argued that neurons possess molecular machinery capable of behaving like a quantum computer, which instead of using bits of 0s or 1s operates with qubits, units of information that can have states of both 0 and 1 simultaneously.24
The brain’s qubits, Fisher proposed, are encoded in the states of phosphate ions inside Posner molecules, clusters of phosphate and calcium found in bone and possibly within certain cells’ mitochondria. Recent theoretical work by his team argues that the states of phosphate ions in different Posner molecules could be entangled with one another for hours or even days, and may therefore be able to perform rapid and complex computations.25 Fisher recently received funding to set up an international collaboration, called QuBrain, to look for these effects experimentally. Many neuroscientists have expressed skepticism that the project will turn up positive results.
Putting quantum biology to work
Most ideas in quantum biology are still driven more by theory than by experimental support, but a number of researchers are now trying to close the gap. Vedral’s team plans to collect more data on bacterial entanglement later this year, and physicist Simon Gröblacher of Delft University of Technology in the Netherlands has proposed carrying out entanglement experiments with tardigrades. In 2017, Al-Khalili and his Life on the Edge coauthor, University of Surrey biologist Johnjoe McFadden, helped establish a doctoral training center for quantum biology to encourage interdisciplinary crosstalk and advance research efforts. Among the wider community of scientists and research funders, “now you’re not considered completely mad if you say you’re studying quantum mechanics in biology,” McFadden says. “It’s just considered a little bit wacky.”
Researchers who spoke to The Scientist also emphasize that, whether or not the theorized mechanisms garner experimental support, the speculation in quantum biology is itself valuable. “As we miniaturize our technology, we have a wealth of information in the biological world from which to draw inspiration,” says theoretical physicist and quantum computing researcher Adriana Marais, head of innovation at tech company SAP Africa. “This is a fantastic opportunity to investigate what life is, but also to learn lessons on how to engineer processes at this microscale in an optimal way.”
Real-world applications encompass technologies from more-efficient solar cells to new classes of biosensors. Last year, one group proposed a design for a “biomimetic nose,” based partly on the quantum theory of olfaction, to detect tiny concentrations of odorants.26 And Hore and others have highlighted the radical-pair mechanism that may underlie magnetoreception for use in devices to sense weak magnetic fields.
“We can use the information we gain to design systems on these principles,” says Ritz, “even if it turns out that that’s not how birds do it.”
- D. Coles et al., “A nanophotonic structure containing living photosynthetic bacteria,” Small, doi:10.1002/smll.201701777, 2017.
- C. Marletto et al., “Entanglement between living bacteria and quantized light witnessed by Rabi splitting,” J Phys Commun, 2:101001, 2018.
- Y. Cha et al., “Hydrogen tunneling in enzyme reactions,” Science, 243:1325–30, 1989.
- K.M. Doll et al., “The first experimental test of the hypothesis that enzymes have evolved to enhance hydrogen tunneling,” J Am Chem Soc, 125:10877–84, 2003.
- S. Hu et al., “Biophysical characterization of a disabled double mutant of soybean lipoxygenase: The ‘undoing’ of precise substrate positioning relative to metal cofactor and an identified dynamical network,” J Am Chem Soc, 141:1555–67, 2019.
- N.-S. Hong et al., “The evolution of multiple active site configurations in a designed enzyme,” Nat Commun, 9:3900, 2018.
- G.S. Engel et al., “Evidence for wavelike energy transfer through quantum coherence in photosynthetic systems,” Nature, 446:782–86, 2007.
- G. Panitchayangkoon et al., “Long-lived quantum coherence in photosynthetic complexes at physiological temperature,” PNAS, 107:12766–70, 2010.
- E. Collini et al., “Coherently wired light-harvesting in photosynthetic marine algae at ambient temperature,” Nature, 463:644–47, 2010.
- T.R. Calhoun et al., “Quantum coherence enabled determination of the energy landscape in light-harvesting complex II,” J Phys Chem B, 113:16291–95, 2009.
- H.-G. Duan et al., “Nature does not rely on long-lived electronic quantum coherence for photosynthetic energy transfer,” PNAS, 114:8493–98, 2017.
- E. Thyrhaug et al., “Identification and characterization of diverse coherences in the Fenna–Matthews–Olson complex,” Nat Chem, 10:780–86, 2018.
- S.J. Harrop et al., “Single-residue insertion switches the quaternary structure and exciton states of cryptophyte light-harvesting proteins,” PNAS, 111:E2666–75, 2014.
- T. Ritz et al., “A model for photoreceptor-based magnetoreception in birds,” Biophys J, 78:707–18, 2000.
- T. Ritz et al., “Resonance effects indicate a radical-pair mechanism for avian magnetic compass,” Nature, 429:177–80, 2004.
- A. Pinzon-Rodriguez et al., “Expression patterns of cryptochrome genes in avian retina suggest involvement of Cry4 in light-dependent magnetoreception,” J Roy Soc Int, doi:10.1098/rsif.2018.0058, 2018.
- A. Günther et al., “Double-cone localization and seasonal expression pattern suggest a role in magnetoreception for European robin cryptochrome 4,” Curr Biol, 28: 211–23.E4, 2018.
- L. Turin, “A spectroscopic mechanism for primary olfactory reception,” Chem Senses, 21:773–91, 1996.
- S. Gane et al., “Molecular vibration-sensing component in human olfaction,” PLOS ONE, 8:e55780, 2013.
- E. Block et al., “Implausibility of the vibrational theory of olfaction,” PNAS, 112:E2766–74, 2015.
- M. Paoli et al., “Differential odour coding of isotopomers in the honeybee brain,” Sci Rep, 6:21893, 2016.
- A. Tirandaz et al., “Validity examination of the dissipative quantum model of olfaction,” Sci Rep, 7:4432, 2017.
- A.D. Godbeer et al., “Modelling proton tunnelling in the adenine–thymine base pair,” Phys Chem Chem Phys, 17:13034–44, 2015.
- M.P.A. Fisher, “Quantum cognition: The possibility of processing with nuclear spins in the brain,” Ann Phys, 362:593–602, 2015.
- M.W. Swift et al., “Posner molecules: from atomic structure to nuclear spins,” Phys Chem Chem Phys, 20:12373–80, 2018.
- A. Patil et al., “A quantum biomimetic electronic nose sensor,” Sci Rep, 8:128, 2018.
Clarification (June 25): This story has been updated to clarify that, in quantum tunneling, there is a very brief lag time before a particle traversing a barrier appears on the other side. The Scientist regrets any confusion.
A new paper suggests that the mysterious X17 subatomic particle is indicative of a fifth force of nature.
Physicists have long known of four fundamental forces of nature: gravity, electromagnetism, the strong nuclear force, and the weak nuclear force.
Now, they might have evidence of a fifth force.
The discovery of a fifth force of nature could help explain the mystery of dark matter, which is proposed to make up around 85 percent of the universe’s mass. It could also pave the way for a unified fifth force theory, one that joins together electromagnetic, strong and weak nuclear forces as “manifestations of one grander, more fundamental force,” as theoretical physicist Jonathan Feng put it in 2016.
The new findings build upon a study published in 2016 that offered the first hint of a fifth force.
In 2015, a team of physicists at Hungary’s Institute for Nuclear Research was looking for “dark photons,” which are hypothetical particles believed to “carry” dark matter. To catch a glimpse of these strange forces at work, the team used a particle accelerator to shoot particles through a vacuum tube at high speeds. The goal was to observe the way isotopes decay after thrust into high-energy states — anomalies in the way particles behave could suggest the presence of unknown forces.
So, the team closely watched the radioactive decay of beryllium-8, an unstable isotope. When the particles from beryllium-8 decayed, the team observed unexpected light emissions: The electrons and positrons from the unstable isotope tended to burst away from each other at exactly 140 degrees. This shouldn’t have happened, according to the law of conservation of energy. The results suggested that an unknown particle was created in the decay.
A new type of boson
A team of researchers at the University of California, Irvine (UCI), proposed that the unknown particle was not a dark photon, but rather a boson — specifically, a “protophobic X boson,” which would be indicative of a fifth fundamental force. In simple terms, bosons are particles in quantum mechanics that carry energy, and function as the “glue” that holds matter together and controls the interactions between physical forces.
As Big Think’s Robby Berman wrote in 2016:
“[In] the Standard Model of Physics, each of the four fundamental forces has a boson to go with it – the strong force has gluons, the electromagnetic force is carried by particles of light, or photons, and the weak force is carried by W and Z bosons. The new boson proposed by the UCI researchers is unlike others and as such may point to a new force. The new boson has the intriguing characteristic of interacting only with electrons and neutrons at short distances, while electromagnetic forces normally act on protons and electrons.”
The X17 particle
In the new paper, published on the preprint archive arXiv, the Hungarian team observed similar evidence for a new boson, which they refer to as the X17 particle, as its mass is calculated to be about 17 megaelectronvolts. This time, however, the observations come from the decay of an isotope of helium.
“This feature is similar to the anomaly observed in 8Be, and seems to be in agreement with the X17 boson decay scenario,” the researchers wrote in their paper. “We are expecting more, independent experimental results to come for the X17 particle in the coming years.”
A ‘revolutionary’ discovery
The discovery of a fifth force of nature would provide a glimpse into the “dark sector”, which in general describes yet-unobservable forces that can’t readily be described by the Standard Model. Strangely, the subatomic particles in this hidden layer of our universe hardly interact with the more observable particles of the Standard Model.
A fifth force could scientists better understand how these two layers coexist.
“If true, it’s revolutionary,” Weng said in 2016. “For decades, we’ve known of four fundamental forces: gravitation, electromagnetism, and the strong and weak nuclear forces. If confirmed by further experiments, this discovery of a possible fifth force would completely change our understanding of the universe, with consequences for the unification of forces and dark matter.”
Simon El’evich Shnol is a biophysicist, and a historian of Soviet science.
He is a professor at Physics Department of Moscow State University and a member of Russian Academy of Natural Sciences. His fields of interest are the oscillatory processes in biology, the theory of evolution, chronobiology, and the history of science. He has mentored many successful scientists, including Anatoly Zhabotinsky.One of the famous provisions of ibn-i arab. Shnol notices this in his experiments in the lab. Every moment of life is different and has a personality of itself, God is creating a brand new moment from the time to time.