Laboratories are not usually where people go looking for proof of a soul, yet a growing group of high profile scientists is trying to drag that question under the fluorescent lights. From speculative physics to neurosurgeons who say they have glimpsed an afterlife, the effort to test the soul is shifting from theology to data, even as the evidence remains fragmentary and fiercely contested. At the center of the latest debate is a Harvard astrophysicist who has outlined a stark experiment that, in theory, could show whether consciousness survives the shutdown of the brain.
I find that tension revealing: the more precisely researchers map neurons and quantum fields, the harder it becomes to ignore the possibility that something about us might not be reducible to firing synapses. Yet the same methods that make a “chilling test” imaginable also expose how fragile and uncertain most claims about the soul still are.
The Harvard physicist who wants to trap a soul in data
The most provocative current proposal comes from Harvard Prof Avi Loeb, an astrophysicist better known for studying black holes and interstellar objects than for weighing metaphysics. Loeb has argued that if the human mind is fully encoded in the brain’s roughly one quadrillion synapses, then in principle a sufficiently detailed scan could capture that information pattern at the moment of death and track whether anything about it persists. In his thought experiment, the existence of the human soul stops being a purely philosophical claim and becomes a question about whether a specific configuration of information can survive the collapse of the biological hardware that hosts it, a possibility he frames in starkly empirical terms in a recent discussion of what those synapses encode.
Loeb’s scenario is deliberately unsettling. He imagines monitoring a dying brain at extreme resolution, then comparing the information content before and after clinical death to see whether any identifiable pattern appears to “leak” into the environment or reappear elsewhere. In a follow up description of the same idea, he frames it bluntly as an attempt to see whether science can show that human souls exist, presenting the proposal as a chilling experiment that would either detect such a transfer or fail to find any trace at all. For now it remains hypothetical, but it captures a broader shift: some physicists are increasingly willing to treat the soul as an information problem, not just a religious one.
From 21 grams to fifth dimensions: earlier attempts to pin the soul down
Loeb is not the first scientist to try to drag the soul onto a lab scale. In 1907, physician Duncan MacDougall famously placed dying patients on a specially constructed bed that functioned as a scale, hoping to detect a sudden loss of mass at the instant of death. MacDougall hypothesized that souls have physical weight and reported that one body lost about 21.3 grams, roughly three quarters of an ounce, which he treated as the mass of the soul in what became known as the 21 grams experiment. Later reviews of his work note that he used a tiny sample of human subjects and that his measurements were inconsistent, but the idea that the soul might literally be weighed has lingered in popular culture.
Modern assessments of MacDougall’s project are far less romantic. A detailed overview of the 21 grams experiment points out that small sample sizes and uncontrolled variables make any claimed “measurable weight loss upon death” unreliable, and later critics have noted that bodily processes at the point of death, such as air leaving the lungs or fluids shifting, can easily explain minor changes in weight. That skepticism has not stopped other theorists from reaching for more exotic frameworks. Another Harvard physicist, Lisa Randall, has been cited as entertaining the idea that the soul could be associated with a fifth dimensional space, a notion linked to her work on extra dimensions that extend ideas from Einstein’s theory of relativity, a view described in a profile of Another such Harvard voice.
The neurosurgeon who says his brain died and something else woke up
If physicists like Loeb and Lisa Randall approach the soul as an information or dimensional puzzle, neurosurgeon Eben Alexander III approaches it as a survivor. Eben Alexander III, MD, spent 15 years on the faculty at Harvard Medical School, operating on brains and teaching that consciousness arises from neural activity. In a widely discussed account of his illness, he describes falling into a coma after a severe infection and later arguing that his cortex was so compromised that his vivid experiences during that period could not have been generated by normal brain function, a claim he has elaborated in a detailed paper on near-death experiences and the mind body debate.
Before his illness, Alexander has said he could not reconcile his knowledge of neuroscience with any belief in heaven, God, or the soul, but after his coma he reversed that stance and presented his story as evidence that consciousness can exist independent of the brain. A description of his book notes that before he underwent his journey he was a skeptic, and that he later framed his recovery as a case for an afterlife involving God and a personal soul. Promotional material for the same work describes it as a scientist’s case for the afterlife, noting that thousands of people have reported similar near death experiences and that Alexander, a neurosurgeon, returned from his coma convinced that he had come back from another realm, a framing that underpins the narrative of Thousands of such accounts.
Critics have pushed back hard, pointing out that coma is not the same as brain death and that residual activity could still generate intense experiences. An overview of his book notes that Proof of Heaven: A Neurosurgeon’s Journey into the Afterlife is a New York Times bestselling autobiographical account of his coma, and that some reviewers have questioned his interpretation of an induced coma as brain death, a key claim in Proof of Heaven. Yet Alexander has doubled down, arguing in a later interview that we know a tremendous amount about the brain and its workings, including evidence that it is not the producer of consciousness but more like a filter, a position he links to his week long coma in November 2008 in a discussion of what he has learned since.
Biocentrism and the claim that death is an illusion
While Alexander leans on personal experience, American scientist Robert Lanza, MD, tries to build a more formal theory. Lanza has argued that consciousness is a fundamental property of the universe and that what we call death is not the end of that awareness but a shift in perspective. In one discussion, he explains that biocentrism is an ethical system based on the idea that all living things have value and should be respected, and that death, in this view, is not simply the cessation of bodily functions, a stance he outlines while describing Lanza’s broader philosophy.
Lanza has expanded that argument in work based on The Grand Biocentric Design, written with Matej Pavsic and published by BenBella Books in 2020, where he contends that the reality of the soul is supported by the idea that consciousness exists independent of the body. In a summary of that project, he and Matej Pavsic are presented as co authors who argue that the soul exists independent of the body and that biocentrism offers evidence that it continues after physical death, a claim laid out in material Based on that book. Supporters sometimes go further, insisting that this is no faith or religion but an actual fact, and urging readers to say the word QUORA without moving their mouths as a way to notice that inner speech does not depend on visible motion, an argument used to claim that death is change, not ending, in a discussion of whether Its claims hold up.
More from Morning Overview