--- title: Spacetime Is Doomed --- "Spacetime is doomed." borrows the phrase from the physicist Nima Arkani-Hamed, and he means it almost literally: that space and time are not the fundamental stage on which reality plays out, but a late, local construction — and that the deepest theories of physics will have to be written in some other language entirely. ## Two roads to one conclusion Hoffman reaches the claim from two directions at once. From **perception**: on the , spacetime is the "desktop" and objects are the "icons" — a fitness-tuned interface, not a window onto what is real. From **physics**: a number of physicists argue, for entirely independent reasons, that spacetime is not fundamental. Hoffman's distinctive move is to claim these are the same discovery seen from two sides, and to treat it as a prediction his theory makes: "if ITP is right, then space-time is doomed... the very predicates of space and time are almost surely the wrong predicates to describe objective reality." ## The amplituhedron The physics he leans on most is the **amplituhedron** of Nima Arkani-Hamed and Jaroslav Trnka — a geometric object whose "volume" yields the probabilities of particle scattering *directly*, without invoking space, time, or locality at any step in the calculation. To its discoverers this hints that spacetime and locality are emergent rather than built in, which is the source of Arkani-Hamed's much-quoted slogan. It is worth being clear about the status of this: the amplituhedron is so far defined for a specific, simplified ("toy") quantum theory — planar 𝒩 = 4 super-Yang-Mills — rather than for the real world; it is a beautiful and suggestive result, not yet a theory of our universe. And Arkani-Hamed, while he does say "spacetime is doomed," does not endorse Hoffman's further step. ## Deriving spacetime from consciousness That further step is Hoffman's bold conjecture: that the very combinatorial objects physicists find at the root of scattering amplitudes — "decorated permutations," the faces of the amplituhedron — fall out of the dynamics of networks of . The chain he proposes runs: the Markov dynamics of conscious agents → their communicating classes → decorated permutations → the amplituhedron → scattering amplitudes — so that, in his words, "a particle is... a projection of the dynamics of a communicating class of conscious agents to a face of an amplituhedron" (from his 2023 paper "Fusions of Consciousness"). In still more recent work he argues that even the arrow of time is "an artifact of projection" from a deeper, timeless dynamics. This is the most speculative frontier of his whole program — openly unfinished, offered as a falsifiable direction of research rather than an established result. ## Kant, updated Hoffman notes a philosophical ancestor. Kant argued that space and time are forms the mind imposes on experience, not features of things as they are in themselves. Hoffman claims to arrive at a similar place — but, he says, "as a theorem that follows from evolutionary game theory" rather than from philosophy alone. The interface that hides reality is the subject of ; the evolutionary argument beneath it, . ## Sources & talks A conference lecture making the case in full: Hoffman and Stephen Wolfram on what might replace spacetime: **More:** Hoffman with the physicist Brian Keating, ["Spacetime is DOOMED!"](https://www.youtube.com/watch?v=v_3Hwbn-Clc). **Primary sources:** Hoffman, Prakash & Prentner, ["Fusions of Consciousness," ](https://doi.org/10.3390/e25010129)[*Entropy*](https://doi.org/10.3390/e25010129)[ 25(1):129 (2023)](https://doi.org/10.3390/e25010129) · Arkani-Hamed & Trnka, "The Amplituhedron," *JHEP* (2014) · and *The Case Against Reality* (W. W. Norton, 2019).