- Daniel Gonzalez Kappa
- BBC news world
If we took a few minutes to think about what quantum physics is, what would you say?
Many people will answer that these are complex formulas that explain very complex processes related to subatomic particles, gravity, energy, the movement of galaxies, black holes, and everything related to space-time and the size of the universe.
Like Albert Einstein. And this is not going to be a contrived answer.
After all, the father of the theory of relativity laid the foundations of statistical physics and quantum mechanics, which are part of modern physics, very different from the physics proposed by Isaac Newton centuries ago.
But there is a less explored branch that does not require you to go far to understand what it is.
In fact, he is here on our planet, among us.
Iraqi-British theoretical physicist Jim Al Khalili raised it in 2015 with a question during a conference: what if the quantum world plays an important role in the functioning of a living cell?
Can such a tiny thing help us understand why we are alive?
For years, the scientific community has been adamant that biology is such a complex science that it has nothing to do with the quantum world.
An idea that today is considered erroneous. In fact, quantum mechanics plays such an important role in biological processes that it is vital for plant photosynthesis or cellular respiration.
This branch of science is known as quantum biology.
And understanding this will open the door to countless answers and ideas that we don’t fully understand yet, whether it’s understanding how mutations work, creating new drugs, or improving quantum computing.
“To some extent, we are solving an important mystery,” Vladimiro Mujica, a chemist at the Central University of Venezuela and a PhD in quantum chemistry from Uppsala University in Sweden, told BBC Mundo.
Recently, Arizona State University, where Mujica currently works, received a $1 million grant from the Keck Foundation, along with UCLA and Northwestern University in Chicago, to study quantum biology over the next three years.
The idea is to understand as much of the scope of this branch as possible, which will revolutionize how we understand the connection between quantum processes and life itself.
But what is quantum biology?
Let’s start from the very beginning. Quantum mechanics:
Modern physics is mainly based on two sections that study the theory of relativity and the quantum world. The first studies such areas as the movement of galaxies and planets; the second studies atomic and subatomic systems, which are so small that we cannot see them with the naked eye.
Huge world and tiny world.
The obvious side is that chemistry, biology and biochemistry are part of matter. And this matter is made up of atoms and molecules.
So, if quantum physics studies this atomic world, it also describes biology.
“Biological processes are actually quantum systems because (quantum) physics describes the behavior of matter on a microscopic level,” says Mujica.
This is a very simple conclusion. But it wasn’t always so obvious.
And there is a good reason for this: biological processes are actually very complex. Quantum systems, on the other hand, need “stability,” which scientists call wave coherence.
The conclusion of the scientific community then was that biological processes are so “noisy” that they do not show this stability. In fact, they were destroying the sequence.
And that is why, throughout the 20th century, scientists separated quantum mechanics from biology. They didn’t pay much attention to him.
But maybe something was missing that the scientists didn’t quite understand or didn’t quite understand. Perhaps there was a method where all this was applied in biological processes.
We already know that matter is made up of particles. Some of these are protons and neutrons, while others are known as elementary particles such as electrons and photons.
These particles work at the biological level. For example, photosynthesis in plants is carried out by the transfer of electrons in molecules.
But there is a problem: how this electron moves. If we had a light bulb, the electron would pass through a copper wire that would get very hot and turn on the light.
But plants do not have this copper wire. In fact, according to Mujica, there are “bad” energy conductors in biology, and a sudden increase in temperature can lead to the complete death of a cell.
So the electron would need something that scientists can’t understand. A simple process that doesn’t require too much energy to allow the particle to move without killing the cell.
This process really exists, and it is called the tunnel effect.
Example: If we have a tennis ball on one side of the court and we need to move it to the other side, we simply toss it from one end to the other.
But if there is a very high wall in the middle of the court, the ball must be thrown very high and over the wall, otherwise it will bounce. This is how classical physics works.
But in quantum physics, things are different. If the tennis ball were actually an electron, then it could go through the wall instead of through it. And this happens because the particles move in the form of waves.
The tunnel effect is like “opening a hole in the barrier and slipping through”. And the advantage is that it is so simple and so cheap that it is used by biological systems to use as little energy as possible.
Scientists call these events “non-trivial”. This is how quantum mechanics changes biological processes.
This is not new. Physicists such as the Austrian Erwin Schrödinger were already tackling this and other topics in quantum physics in the first half of the 20th century, thus paving the way for new discoveries.
But the tunnel effect is not the only quantum mechanism at work in biological processes.
There are others, such as the direction in which a particle spins, called spin. And all these effects act differently at different stages of biological processes.
For example, photosynthesis occurs in three stages. First, it is the capture of a photon (a particle that carries electromagnetic radiation, such as sunlight) by a plant.
Second, electrons absorb the energy of photons and go to a higher energy state by passing through molecules and relying on tunneling.
Finally, the electron is used for a chemical reaction that releases oxygen. And this is what allows beings like humans to breathe.
At all these stages, quantum mechanics is present.
Now imagine that the electron rotates around its axis, and that this movement can be to the right or to the left. Depending on the direction of the spin, the electron will go through the tunnel or not.
To simplify, imagine a screw that, once inserted into a groove, can only be screwed in correctly. And if you try the other way around, it will either not work, or you will damage it.
This is called chirality, from the Greek kheir, which means hand. When an object is chiral, it has another object that is a reflection, like a right hand with a left hand.
This means that rotation goes hand in hand with chirality.
“So now you have a privileged mechanism that protects the e-vehicle from any external noise. Thus, an effect that should not have been important now,” sums up Mujica.
And understanding this is very important for science. We now know that tunneling, rotation, and chirality are not only related to photosynthesis, but also to protein synthesis, to the way organisms breathe, or to communication between neurons.
Even in mutations, transformations of genetic material that occur as a result of a random change in a molecule in our body.
But then what is it for?
Scientists are simply trying to understand the true dimension of quantum biology. After all, for a long time it was considered unimportant, and only about ten years ago this scientific direction began to re-emerge.
One area that could benefit from this is pharmacology, where chirality plays an important role.
Quantum computing is different. “At the moment we are trying to find good systems for quantum processing,” says Mujica. “There are already quantum computers, but they are very limited. They are very advanced and extremely expensive toys,” he adds.
But many of these applications will not see the light of day in the three years Mujica and his colleagues spend studying quantum biology. They see it more as a science that will have significant long-term implications.
It is now clear what a crucial role quantum physics plays in helping us understand the very important biological processes that make life possible.
So it’s not so much a search for other planets, but a deep study of what we have on our own planet.