In 1974, a young physicist named Jacob Bekenstein made an unusual career move. Two years after completing a doctoral thesis at Princeton that would eventually reshape modern physics, he immigrated to Israel and took a position at Ben Gurion University in Beersheba, the youngest university in the country. The thesis had proposed something that most of his colleagues considered foolhardy: that black holes possess entropy, and that this entropy is proportional not to their volume but to the area of their event horizon. Stephen Hawking thought it was wrong. He set out to disprove it and ended up confirming it instead. The consequences of that confirmation have not finished arriving.

Bekenstein’s insight, refined over four decades at Ben Gurion and then the Hebrew University of Jerusalem, seeded one of the deepest ideas in modern physics: the holographic principle. All the information contained within a volume of space, the principle states, can be fully described by data encoded on the surface enclosing it. The three dimensional world you see around you may be, in some precise and mathematical sense, a projection from a two dimensional boundary. Reality is a hologram, and the seed of the proof was planted in the Negev.

This matters because it reopens a question that physics spent most of the twentieth century trying to close.

Are we living on an atom?

The intuition is ancient. When Rutherford and Bohr revealed the structure of the atom, the resemblance to a miniature solar system was immediately striking. Electrons orbiting a nucleus. Planets orbiting a star. The analogy invited an irresistible speculation: perhaps the pattern nests infinitely, every atom a universe, every universe an atom in something incomprehensibly larger.

Physics closed the door firmly. The planetary model turned out to be wrong. Electrons do not orbit nuclei the way planets orbit stars. They exist as probability clouds governed by quantum mechanics, and quantum mechanics bears no resemblance to gravity at planetary scales. The forces are different. The mathematics is different. The apparent symmetry between an atom and a solar system was dismissed as a coincidence of illustration, not a feature of nature.

And here is the editorial point that physicists are reluctant to make plainly: it is physics itself that keeps reopening the door.

The holographic principle undermines the very basis on which the question was dismissed. The dismissal rested on the assumption that small things and large things obey fundamentally different rules, that quantum mechanics and gravity occupy separate kingdoms with no structural overlap. Bekenstein’s entropy formula was the first crack. If the information content of a region of space depends on its boundary rather than its volume, then our intuitions about what is inside and what is outside, what is small and what is large, are unreliable at the deepest level. The map is not smaller than the territory. The map is the territory, viewed from a surface we cannot see.

There is a second crack, and it is more recent. In 2020, Franco Vazza, an astrophysicist at the University of Bologna, and Alberto Feletti, a neurosurgeon at the University of Verona, published a quantitative comparison of the cosmic web, the large scale structure of galaxy clusters and filaments, with the neuronal network of the human brain. The two systems are separated by more than 27 orders of magnitude in scale. They should have nothing in common. But the statistical properties of their networks, the distribution of nodes, the clustering of connections, the spectral density of their fluctuations, were remarkably similar. The authors were careful not to claim that the universe is a brain. What they demonstrated was that certain patterns of organisation recur at scales so different that the recurrence demands explanation rather than dismissal.

This is the pattern that ought to trouble anyone who believes the atom question is settled. Every generation of physics produces a result that complicates the neat separation between scales. Bekenstein showed that information does not respect volume. The holographic principle showed that dimensionality itself may be emergent rather than fundamental. Vazza and Feletti showed that structural complexity recurs across 27 orders of magnitude without any known mechanism to enforce the repetition. None of this proves that we live on an atom. But it dissolves the confidence with which the idea was dismissed, and confidence was the only thing holding the door shut.

The honest position is not that the question is naive. It is that the question is unanswerable with the physics we currently possess, and that the physics we currently possess keeps producing results that make the question harder to set aside. A universe whose information is encoded on a boundary, whose large scale structure mirrors its smallest biological networks, whose fundamental dimensionality may be a projection rather than a given, is not a universe in which nested scales can be ruled out by appeal to the difference between quantum mechanics and gravity. That difference may itself be an artefact of the projection.

Bekenstein died in 2015, of a heart attack, in Helsinki. He was there to give a lecture. He had spent 41 years in Israel, and the entropy formula that bears his name alongside Hawking’s was the work of a lifetime conducted almost entirely at Israeli institutions. The question he helped to frame remains open, written on a surface we are only beginning to learn how to read.