A breakthrough new discovery observes the spooky world of the quantum at work inside our own cells, potentially solving one of the mysteries of science while confirming the quantum world remains as elusive as ever with far reaching implications for everything from technology to biology.
There are few concepts that have a hold on the public imagination like the weird nature of the quantum world. The strange behavior of subatomic particles, once described by Einstein as “spooky,” appears in everything from pop culture (Christopher Nolan’s time-travel twister Tenet) to philosophy (the many worlds hypothesis) to almost every field of actual science, physics to biology.
The average person probably can’t explain this quantum world in detail, much less recite any applicable equations, but everyone understands there’s a tantalizing mystery to explore: The idea that the world doesn’t work the way we think it does on the surface. That there is a deeper level to reality where everything is very different than it seems at first glance.
The classic thought experiment illustrating how radically different this world works comes from one of the founders of the original quantum theory, Erwin Schrodinger and his infamous cat. At a basic level, the quantum world operates on probabilities, a switch is not simply on or off, instead it can be both (at least for a time).
Schrodinger’s Cat imagines a poor feline in a sealed box, nothing can get in or out, we cannot see in or out, or make any measurements. The box contains the cat and a poison gas canister. The canister is triggered by a quantum switch. The equations that describe the behavior of the switch indicate it can literally be on or off at the same time, meaning the cat is both dead and alive at the same time.
The cat then persists in this superimposed state of being alive and dead until we open the box and look inside.
Interestingly, even though his work is considered one of the most important scientific accomplishments of the 20th century, Schrodinger, just like Einstein, wasn’t happy with the implications of his own theories. “I don’t like it, and I’m sorry I ever had anything to do with it,” he said plainly.
In fact, he created the famous cat to illustrate the absurdity of the outcome. Cats can’t be both dead and alive in the real world. How can they be in the quantum? Why does the quantum world contain this level of uncertainty?
Werner Heisenberg was a contemporary of Schrodinger’s who formulated the eponymous uncertainty principle: The more we know about the location of a subatomic particle the less we know about its velocity (technically momentum). The more we know about the momentum, the less we know about the position.
It doesn’t seem to make much sense, but thousands of experiments performed over the last century have confirmed refined versions of Schrodinger’s and Heisenberg’s theories, and no one really knows why. Like many things in life, we just know that it’s real and it works.
In fact, it works so well technology companies such as IBM and Google are busy building quantum computers in perhaps the next phase of our digital revolution. The idea is to turn the unusual nature of quantum supposition (the cat being dead and alive at the same time) into computational power.
The idea itself has been a long time coming: Paul Benioff first suggested the potential for a quantum computer in the early 1980’s, taking Alan Turing’s work into the quantum realm.
Today, we actually have preliminary quantum computers. They come in a variety of forms, but the most popular model replaces the traditional on/off circuit with a quantum circuit. In a regular computer, a bit represents the on or off state of a single circuit, a 1 for on and a 0 for off. In quantum circuits, the qubit is both on and off until it’s measured.
The percentage chance of it being on or off is based on the behavior before the measurement, meaning we can get information about these quantum states from the final state and use that information in our calculations. If this seems impossible, consider a non-quantum analogy: Sound hits our ear as a single wave, all sounds are translated into a single beat in our eardrum. Our brain then un-entangles the different waves and we experience each sound distinctly. The mathematics of this is called a Fourier transform. We extract information about the constituent parts from a single point on the wave. It’s not quantum by any means, but it shows that, in mathematics, we can create many meanings from one signal.
Back to quantum computers, the qubit means more computing power from each on and off switch. The question now is when quantum computers will achieve supremacy over electronic transistors. In October 2019, a processor created in conjunction with Google AI was reported to have done that, calculating 3,000,000 times as fast as the world’s most powerful computer. While none of these quantum computers are in widespread usage yet, we can certainly expect more achievements in the near future.
In the meantime, this fuzzy world of the quantum, the ability to take advantage of calculations that occur only in the quantum realm, has intrigued researchers even the field of biology, our own brains and bodies.
In 1989, famed physicist and collaborator with Stephen Hawking, Sir Roger Penrose proposed a radical theory that our minds are essentially quantum computers. The Emperor’s New Mind: Concerning Computers, Minds and The Laws of Physics put forth the concept that our consciousness cannot be modelled by a traditional computer.
Traditional computers operate according to principles established by Alan Turing. Essentially, they process instructions. The instructions are applied on the input, in sequence: Take A and B and make AB, take AB and make A and B. Computers today use electrical circuits to manage the process, but early experiments in the late 1800’s by Charles Babbage showed it could be done purely mechanically. Before transistors, we used vacuum tubes. Penrose demonstrated how it could be done with something mundane as even billiard balls.
As a result, he felt that consciousness required something else, more mysterious and unpredictable. He turned to the quantum. While Penrose’s ideas are considered flawed in the scientific community, the idea itself remains an intriguing example of what lies just beyond our understanding. (The book itself is excellent as well, serving mostly as a well-written overview of physics and mathematics.)
In 2000, Johnjoe McFadden, published Quantum Evolution: The New Science of Life. McFadden’s idea was perhaps even more stunning than Penrose: He sought to explain the origin of life as a quantum calculation, evolution as quantum computer. Specifically, he was responding to the oft-repeated notion that there simply wasn’t enough time for life to evolve. He accepted that random combinations of chemicals could produce the building blocks of an early cell, but felt that the sheer numbers didn’t work. Instead, McFadden believed the quantum world held the answer: Much like quantum computers can take advantage of calculations performed before a measurement is made, he posited that evolution could do the same.
Like Penrose, McFadden’s ideas weren’t exactly well received and are largely discredited in the scientific community. The common thread to both objections is pretty simple: Quantum processes are very difficult to maintain. We use the term “measurement,” but the bar to interfere with quantum action is much, much lower. The effects occur on such a small scale that a collision with a regular molecule, something far too small for us to easily conceive, is enough to constitute a measurement.
Returning to the cat in Schrodinger’s famous thought experiment, it makes sense in theory, but in practice you cannot build a box entirely sealed off from the outside world and a switch that triggers a poison canister from a quantum state. In the real world, the quantum switch would be affected by everything around it. Therefore, expecting the human mind to maintain a quantum state or evolution to occur at the quantum scale in the topsy turvy world of the primordial Earth is too much to ask.
Or is it? For the first time ever, scientists at the University of Tokyo have observed human cells reacting to quantum effects. Their journey started with the behavior of migratory birds, specifically whether they can see the Earth’s magnetic field to guide their journey.
It has long been believed this is the case and that something in their visual system enables them to actually see magnetism, but no one has been able to prove it, perhaps until now. The team at the University of Tokyo used a special microscope sensitive to faint flashes of light to observe a culture of human cells to see if they responded dynamically to changes in the magnetic field.
Inside both plant and animal cells are special proteins known as cryptochromes. These proteins are sensitive to blue light. It is believed that they are capable of absorbing an incoming photon of light, and then transferring the energy by changing their shape. The process remains poorly understood, but it is thought to underlie the natural response to the day-night cycle and ability to detect a magnetic field.
In this case, the researchers bathed the cryptochrome containing cells in blue light to cause them to fluoresce (glow) weakly. Then, they swept a magnetic field across the cells and looked for a response. They found that when the field passed over the cells, the intensity of the glow dipped by approximately 3.5%.
Why is this the case?
The answer lies in the quantum realm. A magnetic field can influence the properties of an electron, that’s actually how magnets work. Normally, the electrons in a piece of metal (or anything else for that matter) point in all sorts of different directions, cancelling each other out. A magnetic field can cause them all to point in a single direction, producing the familiar effect.
Inside our cells, an electron in the outer shell of an atom becomes entangled with another electron in a second atom as a result of the magnetic field (interestly the idea was first proposed by Klaus Schulten in 1975). The two electrons, called a radical pair, remain separate, but the entanglement means that certain properties, in this case their spin, will correspond even if they are far apart. Think of it as a tiny, tiny little piece of a magnet.
Of course, from the point of view of an electron, a cell is a crazy place and this entanglement will be fleeting. In the parlance we used earlier, a measurement will be made to break the quantum state, but the radical pair should last long enough to affect the way the atoms in the cell behave.
The researchers believe the changes in fluorescence are caused by the formation and degradation of these radical pairs under the influence of the magnetic field. As a result, biophysicist Jonathan Woodward says, “We think we have extremely strong evidence that we’ve observed a purely quantum mechanical process affecting chemical activity at the cellular level.” Adding, “The joyous thing about this research is to see that the relationship between the spins of two individual electrons can have a major effect on biology.”
In short, we now have evidence that chemical processes in our bodies take advantage of quantum effects. While this shouldn’t imply that Penrose and McFadden are correct, it’s almost inconceivable that nature only uses this ability in the single instance of detecting an electrical field. Translation: The mysteries of the quantum world are now inextricably bound up in the mysteries of ourselves, and there is a lot more to discover.