Introduction to translation:
Over hundreds of years of philosophical and scientific thought, no one has been able to understand the mystery of consciousness, this very ordinary, very strange state, in which you realize that you are the one who is reading this now, and that you are the one who is talking to this person standing in front of you with the knowledge that there is a separation between you and between him.
Recently, some hypotheses have emerged from the quantum world to explain the possibility of explaining the phenomenon of consciousness as the result of complex quantum processes. In this article, we present one of the most recent of these hypotheses.
Translation material:
The mere mention of the term "quantum consciousness" in the minds of most physicists is amazed and trembling, as it seems to provoke mysterious and interesting reflections on the landmarks of the modern era, and if the new hypothesis about quantum consciousness is proven correct, then this means that quantum effects do indeed play an important role in the process of human consciousness. .
In late 2015, physicist Matthew Fisher of the University of California sparked attention about his paper in the Annals of Physics suggesting that the spins of phosphorous atoms could act as primitive qubits in the brain, which It will enable the brain to function like a quantum computer.
Ten years ago, many scientists rejected Fisher's hypothesis as nonsense, yet this hypothesis managed to get some physicists excited, led by the famous mathematician and cosmologist Roger Penrose, who suggested in 1989 that mysterious protein structures called microtubules played a role important in shaping human consciousness by exploiting quantitative influences.
Microtubules played an important role in shaping human consciousness by exploiting quantitative influences
While some researchers, such as the American philosopher Patricia Churchland at the University of California, Patricia Churchland, argue that such an idea might seem plausible to some extent, Fisher's hypothesis faces the same daunting obstacle that microtubules previously faced, a phenomenon called quantum decoherence ).
For example, quantum computers depend on the behavior of infinitesimal atoms that form infinitesimal units called “qubits” or “quantum bits.” When building these computers, you will need to link several qubits together through a property called quantum entanglement.
But the problem is that these entangled qubits are in a fragile state, so they must be far from any noise that may reach them from the surrounding environment, because just one photon collision with a qubit would be enough to decoherence the entire system, which in turn destroys entanglement and erases the properties of the entanglement. Quantum of the system.
Imagine that it is very difficult to perform quantitative manipulation in a very tight (and extremely cold) laboratory environment, let alone our brains, which are such a warm, humid environment that it is impossible to maintain coherence for long periods.
However, over the past decade, evidence has increased that some biological systems use quantum mechanics, such as photosynthesis, in which quantum effects play a role to help plants convert sunlight into energy, and scientists have also noted that migratory birds have a "quantum compass." It enables it to exploit the magnetic fields in the earth to move, as well as the human sense of smell, which has roots related to quantum mechanics.
Fisher's idea of quantum processing in the human brain in general fits well with this emerging field of quantum biology, which he calls "quantum neuroscience", through which he develops complex hypotheses that include nuclear physics, organic chemistry, neuroscience, and biology.
While many have questioned Fisher's hypothesis, some researchers have decided to turn their attention to this hypothesis by giving it a chance to reflect.
Commenting on this, John Preskill, a physicist at the California Institute of Technology, wrote: “Those who have read Fisher’s paper will inevitably realize that this old man is not as crazy as most of the scientific community has described him. The very important questions.
One of the scientists who became suspicious of Fisher's hypothesis was Senthel Toddry, a physicist at the Massachusetts Institute of Technology and a longtime friend of Fisher's.
Toddry saw that Fischer reformulated the central question: “Do quantitative processes actually occur in the brain?”, and that this method of formulation helped test the hypothesis, and about this he says: “The assumption that existed at the time in all scientific circles rejected the possibility of a quantum information processing process In the brain, until Fischer came to point out that there was only one loophole in that assumption, so we were looking forward to the next step to see if he could plug that loophole.”
Indeed, Fischer began assembling a team to conduct lab tests to provide a definitive answer to this question.
Fischer came from a pioneering family in the field of physics. His father, the distinguished physicist at the University of Maryland, "Michael Fisher", received many honors and awards throughout his life for his work in statistical physics.
His brother, Daniel Fisher, is an applied physicist at Stanford University who specializes in evolutionary dynamics, and Matthew Fisher followed in their footsteps and achieved remarkable success in physics by receiving the 2015 Oliver Buckley Prize for his research on quantum phase transitions (the Oliver Buckley Prize is a prize An annual award by the American Physical Society in recognition and encouragement of outstanding theoretical or experimental contributions to the field of physics.
Depression and the beginning of discovering the facts
In the midst of these successes, Fischer decided to move away from the field of physics and everything related to biology, chemistry, neuroscience, and quantum physics because of his suffering with depression.
Fisher vividly remembers the day in February 1986, when he woke up feeling so numb and exhausted as if he had not slept in a week.
The extra sleep didn't help him improve, adjusting his diet and exercising didn't help, and blood tests showed he was fine and no problem, but he was still depressed for two whole years, describing this period: "Every time I woke up I had a headache. Half of my body is sweeping across my entire body without mercy."
It got so bad that he contemplated suicide, but the birth of his first daughter saved him from these thoughts and gave him a reason to continue fighting this depression.
In the end, he found a psychiatrist who prescribed an appropriate treatment for him and his condition began to improve and the pain gradually subsided, and within nine months hope emerged from the womb of suffering and he began to feel reborn.
His experience with depression convinced him that drugs had cured him, but he was surprised to discover that neuroscientists understand so little about the exact mechanisms behind how the human brain works.
This piqued his curiosity, and given his expertise in quantum mechanics, he found himself pondering the possibility that quantum processes might have a role in the human brain.
So he decided to dedicate his time to learning more about this topic, using his previous experience with antidepressants as a starting point.
Fisher noticed that almost all psychotropic drugs are made of complex molecules, so he decided to focus on the simplest type of element, lithium, which appears in the form of a ball of electrons surrounding the nucleus.
Focusing on the fact that lithium available in pharmacies is often a common isotope called lithium-7, Fisher's conclusion leads him to the question: Can a different isotope such as lithium-6, which is rarer, give the same results?
In theory, the results should be identical, because the two isotopes are chemically identical and the difference between them only in the number of neutrons in the nucleus, but in practice experiments have proven that the effect of the two isotopes is completely different.
In 1986, scientists at Cornell University of America studied the effects of the two isotopes on the behavior of pregnant mice by conducting a study in which they divided mice into three groups. The first group was provided with "lithium-7", and the second group with "lithium-6", and the third group did not receive anything. To compare the results.
Once the young mice were born, the scientists noticed that the mice that received lithium-6 showed significantly stronger maternal behaviors than the mice that received lithium-7 and the group that provided them with none.
These results surprised Fisher, who believed that the secret might lie in the spin of the nucleus, which is a quantitative characteristic that affects the duration of each atom's stay in a state of coherence, that is, in isolation from its environment. disengagement.
Based on the fact that “lithium-7” differs from “lithium-6” in the number of neutrons, they are certainly also different in the spin, and thus “lithium-7” decays too quickly for quantum realization to occur, while “lithium-6” remains Entangled longer.
Fisher then discovered two substances that are similar in all important aspects except for spin, which may completely alter their effects on behavior, and considered this a remarkable indication that quantum processes may indeed play an effective role in cognitive processes.
However, moving from an interesting new hypothesis to trying to prove the fact that quantum processes play a role in the brain is a risk, as the brain needs a mechanism to store quantum information in qubits (qubits) for a period of time long enough to intertwine the different qubits, and this must Synapsis has some chemically feasible way to influence how neurons are stimulated in some way, as well as some means to transmit quantum information stored in qubits scattered throughout the brain.
The problem is that this is difficult to achieve. Over the course of his five years of research, Fischer has identified only one sure element that can store quantum information in the brain: phosphorous atoms, the only biological element other than hydrogen that has a spin that is low enough to allow longer periods of bonding. , but provided that phosphorous is linked to calcium ions to extend the bonding periods of its atoms and form groups, because phosphorous alone cannot form stable qubits.
Evidence for the presence of qubits in the brain
In 1975, Cornell University scientist Aaron Posen noticed strange clumps of calcium and phosphorous atoms in X-rays of bones. He drew a model of these clusters consisting of nine calcium atoms and six phosphorous atoms, which scientists later called “Posner molecules” in his honor.
And in the 2000s, these clumps appeared again when scientists ran a model simulating bone growth in an artificial fluid and observed these clumps floating on the fluid.
Subsequent experiments found evidence of similar clumps in the body, which made Fischer believe that Posner molecules could act as natural qubits in the brain as well.
That's the big picture, but as always the greatest danger lies in the little details that Fisher has spent the past few years crafting.
When following the processes that occur in the cell, we will find that they begin with a chemical compound called pyrophosphate, which consists of two phosphate molecules linked together, and each molecule consists of a phosphorous atom surrounded by several oxygen atoms with a zero spin.
The interaction between the spins of the phosphate molecules causes them to become entangled in four different ways: Three of them make the net spin equal to one and are called the "triplet state", in which the entanglement is very weak.
As for the fourth possibility, the spin result in it is zero, which is the single state in which entanglement achieves the highest possible degree, and this is critical in quantum computing (such as ordinary computing, quantum computing needs a language consisting of zeros and ones ).
Next, the enzymes untangle the crosslinked phosphate molecules into two free phosphate ions, which, paradoxically, remain quantitatively cross-linked even after their separation.
Fischer believes that this process occurs more quickly in the monomeric state, and these ions in turn combine with calcium ions and oxygen atoms to form Posner molecules.
Because calcium or oxygen atoms do not have a nucleus spin, this keeps the total spin result equal to half, and this helps in prolonging the bonding times, and we conclude from this that the function of these clusters or assemblies revolves around protecting the entangled pairs from external interference, It makes it easier for them to maintain bonding for much longer periods that can last almost hours, days or even weeks (which our friend is trying to prove).
In this way, the synapses can be distributed over relatively long distances in the brain, affecting the release of neurotransmitters and the stimulation of the synapses (or synapses) of cells, which we consider an amazing and frightening process that occurs in the human brain.
Researchers working in the field of quantum biology are fascinated by Fisher's proposal, for example Alexandra Olaya Castro, a physicist at University College London who commented on Fisher's hypothesis: "It's a well-studied hypothesis, and although it doesn't give you clear answers, it raises questions that might Later it leads us to a method that helps us test certain steps in the hypothesis."
“Fischer is a theoretical physicist who has proposed specific molecules and specific mechanisms, looking at all ways to explain how these mechanisms might affect the brain activity, and this makes it possible to conduct experimental tests.”
empirical test of the theory
Physicist Matthew Fisher of the University of California
Experimental testing is what Fisher is trying to do now. He decided to take a vacation where he joined researchers from Stanford University to repeat the experiment of pregnant mice that took place in 1986, because he finds that the initial results of this study were disappointing due to its lack of information, but he At the same time, he believes that repeating the study with a protocol closer to the original 1986 experiment will make the results more conclusive.
Fischer has applied for funding to conduct more in-depth experiments in quantum chemistry with a small group of scientists in different disciplines and from different universities, and Fischer's main concern now is to investigate whether calcium phosphate does indeed form stable Posner molecules, and whether it can The spinning of the phosphorous nuclei creates entanglement between these molecules for long periods.
But even Peterhur and Olaya Castro are skeptical about Fischer's last assumption about the long-term entanglement of molecules, and about this Olaya Castro says: "To be frank, I think it is highly unlikely that there will be long entanglement periods, because the longest time period related to biochemical activities did not exceed seconds, That's a very long time, by the way" (neurons store information for a maximum of microseconds).
Hoare also agrees with this point of view, and sees that bonding can last at best for only one second. Longer, I think Posner molecules don't do that, but I'm curious to see how it goes."
On the other hand, other scientists believe that there is no need to use quantitative processes to explain the function of the brain, for example, Paul Thaggard, a philosopher in neuroscience at the University of Waterloo in Canada, who stated to the magazine "New Scientist", expressing his objection to Fisher's hypothesis, saying: "The evidence is growing about the possibility of explaining everything about the mind by studying the interactions between neurons, and there is no need for quantitative manipulations here.”
Many aspects of Fisher's hypothesis require closer examination, so he hopes to be able to run experiments to achieve this.
This may lead us to some important questions such as: Are the structures of Posner molecules the same?
To what extent can the spindles of the nuclei be isolated?
Most of all, what if all these experiments prove his hypothesis wrong?
Is it time to abandon the idea of quantum consciousness altogether?
In the end, Fischer resolves the controversy around these questions, declaring: "I think that if it does not work with the spin of the phosphorous nucleus in quantum manipulation, then quantum mechanics will not have an effective effect on the processes of perception for a long time, so the most important thing now is to try to reach a decisive conclusion controversy."
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This article was translated from The Atlantic and does not necessarily represent the Meydan website.
Translation: Somaya Zaher.