Humans are made of quantum particles, and quantum effects do operate within our bodies at the molecular level. But the kind of entanglement you’re probably imagining, two people sharing a mysterious instantaneous connection, has no basis in current physics. The human body is far too warm, wet, and complex to maintain the delicate quantum states that entanglement requires. That said, there’s a small but serious line of research exploring whether quantum entanglement might play a role inside individual brains, at scales far smaller than anything we’d notice.
Why Entanglement Breaks Down in Living Things
Quantum entanglement is extraordinarily fragile. When entangled particles interact with their environment, they lose their quantum connection almost instantly in a process called decoherence. In the warm, busy environment of a human body, decoherence happens on timescales between a ten-trillionth and a hundred-quintillionth of a second. For comparison, the fastest processes in your neurons take about a thousandth of a second. That’s a gap of at least ten billion times. Any entangled state involving your neurons or cells would collapse long before it could influence anything meaningful.
A 2024 mathematical proof published in Quanta Magazine confirmed what physicists long suspected: heat destroys entanglement. In any system of interacting particles, there’s always a specific temperature above which entanglement vanishes completely. The human body, at roughly 37°C, is enormously above the near-absolute-zero temperatures where entanglement thrives in laboratory experiments. The proof also showed something interesting: the threshold temperature doesn’t depend on the total number of atoms in a system, only on how nearby atoms interact. But that doesn’t help the case for human entanglement, because the local interactions inside biological tissue are still far too energetic.
The Largest Objects Ever Entangled
To appreciate the scale problem, consider the current records. The largest object observed behaving as a quantum wave was a clump of sodium atoms roughly 8 nanometers across, weighing about 200,000 atomic mass units. That’s comparable in size to a large protein molecule or a small virus. It’s impressive for physics, but it’s vanishingly tiny compared to a human cell, let alone a whole person. And achieving even that required carefully controlled laboratory conditions, not the chaotic interior of a living body.
Some physicists have proposed that gravity itself might set a hard limit on quantum behavior. Roger Penrose has hypothesized that objects above a certain mass can never exist in quantum superposition because gravity forces them into a single definite state. Others, like the physicists behind a theory from 1986, suggest that particles spontaneously lose their quantum properties at random, and in a large system of billions of entangled particles, the collapse of just one would rapidly cascade through the rest. The exact mass limit where quantum behavior becomes impossible remains unknown. It could be as small as a milligram or as large as the Earth, but either way, a human being is well within the range where maintaining whole-body entanglement is not physically plausible.
Quantum Effects That Do Exist in Biology
None of this means quantum physics is irrelevant to life. In a reductionist sense, quantum mechanics shapes every molecule in your body. The stability of your DNA, the way proteins fold, the energy levels that let molecules absorb specific wavelengths of light: all of these are quantum phenomena. Electrons routinely “tunnel” through energy barriers in biological processes, a purely quantum behavior first identified in the 1960s in photosynthetic bacteria. Electron tunneling has since been found in cellular respiration and even electron transport along DNA.
Proton tunneling, where a hydrogen atom passes through a barrier it shouldn’t classically be able to cross, has been confirmed in enzymes that process alcohol. Researchers verified this by swapping hydrogen for deuterium (which is chemically identical but twice as heavy), and the reaction rate changed exactly as quantum tunneling theory predicted.
In photosynthesis, experiments on bacterial light-harvesting complexes revealed that energy moves between molecules through quantum coherence, with the energy spread across several molecules simultaneously rather than hopping from one to the next. This coherence lasted hundreds of femtoseconds (a femtosecond is a millionth of a billionth of a second) and spanned several nanometers. That’s remarkable for a biological system, but it’s still happening at molecular scales and ultrafast timescales, nothing close to the experience of a whole organism.
The Hypothesis About Quantum Processing in the Brain
The most serious scientific proposal for entanglement in humans comes from physicist Matthew Fisher, who published a detailed hypothesis in 2015 about quantum processing in the brain. Fisher identified phosphorus as the only biologically common element whose atomic nucleus could theoretically serve as a quantum bit. The idea centers on phosphate ions and a calcium-phosphate cluster called a Posner molecule, which Fisher argues could shield phosphorus nuclear spins from decoherence long enough for entanglement to persist.
In this model, an enzyme breaks apart a molecule containing two phosphorus atoms, and that chemical reaction entangles the nuclear spins of the two phosphorus atoms. Each phosphorus atom then gets incorporated into a separate Posner molecule, carrying its half of the entangled pair. When two Posner molecules later bind together and dissolve, they release a burst of calcium ions that could trigger neurotransmitter release, potentially influencing whether a neuron fires. The whole chain would represent a kind of quantum computation happening at the chemical level inside brain cells.
A 2022 experiment published in the Journal of Physics Communications used MRI techniques designed to detect a specific quantum signal called zero quantum coherence in the brains of human volunteers at rest. The researchers reported finding experimental indications that entanglement creation occurs as part of physiological and cognitive processes, particularly linked to heartbeat-evoked signals in the brain. This is preliminary work, and the findings are far from settled, but it represents one of the few attempts to look for quantum entanglement signatures in living human tissue.
What This Means for “Entangled People”
If Fisher’s hypothesis is correct, entanglement might play a role in how individual brain cells process information. But this is entanglement between pairs of phosphorus atoms inside one person’s brain, not entanglement between two people. The popular idea that two humans could be quantum entangled, sharing thoughts or feelings across a distance, confuses the physics. Quantum entanglement doesn’t transmit information, feelings, or consciousness. Even in laboratory settings, entangled particles can’t send signals faster than light. Measuring one particle tells you something about its partner, but you can’t control what result you get, so there’s no way to use it as a communication channel.
The gap between “phosphorus atoms might be briefly entangled inside brain chemistry” and “two people are quantumly connected” is enormous. It’s roughly like saying that because your cells use electrical signals, you should be able to power a lightbulb by touching it. The underlying physics is real, but the leap to the macroscopic claim ignores every constraint that governs how that physics actually works.
So the direct answer: quantum entanglement almost certainly operates at the atomic and molecular level inside your body, as it does in all matter. Whether it plays a functional role in brain processing is an open and genuinely interesting scientific question. But two humans being entangled with each other in any meaningful sense is not supported by physics, and the fundamental barriers of heat, complexity, and decoherence make it effectively impossible.