Quantum physics is often described as “counterintuitive”. And it’s no wonder: after all, a theory that speaks of atoms that pass through “walls” like ghosts, particles distant from each other that communicate as if by telepathy, and elements that exist in more than one place at the same time, meeting to the laws of classical physics that we know, it sounds strange to say the least. Most scientists believe, however, that their oddities are restricted to the microscopic world – that of atoms, electrons and protons –, but that they would not affect the visible world of large and living things. That’s not what it says, however, in a relatively new area of ​​science: quantum biology.
There is a caveat here: when we talk about atoms passing through “walls” (more precisely, the phenomenon known as tunnel effect), particles that communicate by “telepathy” (quantum entanglement) and objects capable of performing more than one state at the same time ( superposition), this has nothing to do with supernatural phenomena. Indeed, the term “quantum” has become popular with mystics, but practices like “quantum therapy” and “quantum diet” are unscientific and have nothing to do with actual quantum physics.
Well then. What “quantum biologists” (actually, there is not even an official way to call scholars in the field) believe is that the phenomena that happen in the microworld and are described by quantum physics do have consequences in the macroscopic world, governed by the laws of classical Newtonian physics. More specifically, they would have consequences in the living world. They would leave a “quantum signature” on it.
The reader may ask: but isn’t this obvious? If we are all made up of atoms, it is to be expected that what happens in the microscopic world will have an impact on the world we can see. After all, “biology is like applied chemistry, and chemistry is like applied physics, so isn’t it all physics when you get to the fundamentals of things?” rhetorically asks molecular genetics professor Johnjoe McFadden and theoretical physicist Jim Al-Khalili in the book “Life on the Edge: The Coming of Age of Quantum Biology” [A vida na fronteira: a chegada da era da biologia quântica]from 2014.
And it’s true. If biology ultimately involves the interaction between atoms, then the rules of the quantum world must indeed operate at the smallest scales of living organisms, the authors claim. But what science says so far is that these rules operate only at these scales, but they do not generate relevant effects in the world we see. We cannot walk through walls nor can we be in two places at once, even though the particles inside us are capable of it. Why is there this boundary between the visible universe and the universe we know exists on the smallest scales?
The evidence in favor of quantum biology indicates that quantum phenomena cross this boundary and not only have an impact on the living world, but that impact is not trivial. There are indications of quantum phenomena such as superposition and tunnel effect in various biological processes, from photosynthesis to the functioning of enzymes. A study published in “Nature” in 2004 showed that the robin, when migrating across the planet, does so as if its retina “used” quantum entanglement between electrons to guide itself from the Earth’s magnetic field. The bird, by the way, ended up becoming the poster boy for quantum biology.
There is no irrefutable proof that quantum biology does not exist, and that is enough for science. The problem is that we also don’t have instruments with enough technology to obtain irrefutable proof that it exists. This is because one of the biggest challenges in quantum physics is precisely measurement. We know that quantum objects do weird things, but the moment we look at them, they lose this character and start to behave like any other classical object, that is, governed by the rules of classical physics. Submitting a quantum property to a scientific instrument, such as pointing in many directions simultaneously, implies transforming it into a conventional property – pointing in a single direction.
That’s where Brazilian quantum engineer Clarice Aiello comes in, 39, leader of the Center for Quantum Biology at the University of California at Los Angeles, UCLA. Its objective is to use the technologies of quantum physics to build instruments that allow quantum experimentation and measurement in biology. “When quantum objects start to interact with each other, an uncontrolled reaction takes place that kills that quantum character,” she explains. “Everything that starts quantum dies classical. That’s why we live in a classical world. And hence the discomfort that quantum mechanics causes us in the beginning.”
As it is easy to kill this quantum character in any object, the engineering challenge is to find ways to make the quantum system as protected as possible. This includes, for example, keeping quantum chips at very low temperatures to decrease the thermal energy of interaction, and using vacuum chambers to avoid collision between atoms. “Even the most perfect quantum computer will die classical. It will only give us quantum information before that time of thermalization and losing its quantum character”, says Aiello.
That’s why quantum biology can also be confusing, when it proposes that quantum phenomena are happening at room temperature and with important consequences for the biological functioning of things. “Although, in biology, this quantum character also ends up being “pulled” by classical behavior in a very short time, quantum phenomena still manage to have an influence and change biological systems”, highlights the engineer.
It is worth saying that short time, in the quantum world, is really short. In the case, for example, of the capture of energy from the sun by plants in the process of photosynthesis, this time is on the order of one picosecond, which is equivalent to 10-12 seconds, or a trillionth of a second. In the case of the quantum property studied by Aiello, the spins of electrons, things are slower – they take from a billionth to a millionth of a second. “In other words, if quantum phenomena actually happen there, that means that quantum biology can survive for a microsecond – which, believe me, is enough to macroscopically change, for example, chemical reactions.”
For the scientist, there is no doubt that quantum phenomena have an influence on the living world, whether in cell culture, drosophila or the squirrel that visits her daily on the balcony of her house and that appeared when we were talking by video call. Many experiments have already been done on a chemical scale, in protein solutions, and quantum phenomena were present there. “But the next step is confirmation in a behavioral experiment, and there’s a lot between a protein and a Drosophila.”
In practice, his work involves lying down and crawling on the floor to build something that doesn’t exist anywhere in the world, a kind of microscope with coils – quite different from the microscopes we usually see in biology laboratories. “It’s a big optical table, with a lot of mirrors and lasers, whose function is to help us look inside a cell. Around the biological sample, we place coils that are the source of the magnetic field. Our idea is to look to what happens in the cell and control that by changing the magnetic field.”
It’s a risky bet, but it can be revolutionary. Aiello believes that quantum biology is today where quantum computing was 20 years ago, and today no one doubts its potential. “Everyone is starting from scratch, which is a great opportunity for Brazil”, emphasizes the engineer, who established a partnership with Instituto D’Or de Ensino Pesquisa (Idor) to develop the area in the country. “We need to train interdisciplinary scientists to work in this field today and plan where we want to be in the future.”
And although for Aiello everything that looks like magic is unexplained science, she doesn’t rule out the possibility that, in this still distant future, we can talk about “quantum healing” – not in the esoteric sense of fashion. “If we understand how quantum phenomena affect chemical reactions in the body, maybe 50 years from now we will be able to direct them to treat diseases, in the same way that drugs do, but controlling endogenous quantum behavior (that is, that does not need manipulation) that seem to exist in living things. Today, however, this is just science fiction.”
For now, what we have are many fundamental questions and, as McFadden and Al-Khalili put it, “the mystery of how quantum weirdness manages to survive in hot, wet, messy living bodies.”
*
Clarice Cudischevitch is a journalist, coordinator of the Ciência Fundamental blog and communication manager at Instituto Serrapilheira.
Subscribe to the Instituto Serrapilheira newsletter to keep up with more news from the institute and from the Ciência Fundamental blog.
