Max Tegmark is a Swedish-American physicist and cosmologist. He is a physics professor at MIT and the scientific director of the Foundational Questions Institute. He is also a co-founder of the Future of Life Institute and a supporter of the effective altruism movement, and has received donations from Elon Musk to investigate existential risk from advanced AI.
Tegmark was born in Sweden. While in high school, he and a friend created and sold a word processor written in pure machine code for the Swedish eight-bit computer ABC 80, and a 3D Tetris-like game called Frac. He left Sweden in 1990 after receiving a B.Sc. in physics in from the Royal Institute of Technology. (He had earned a B.A. in economics the previous year at the Stockholm School of Economics.) His first academic venture beyond Scandinavia brought him to California, where he studied physics at the University of California, Berkeley, earning his M.A. in 1992, and PhD in 1994.
His research has focused on cosmology, combining theoretical work with new measurements to place constraints on cosmological models and their free parameters, often in collaboration with experimentalists. He has over 200 publications. He has developed data analysis tools based on information theory and applied them to cosmic microwave background experiments such as COBE, QMAP, WMAP, and to galaxy redshift surveys such as the Las Camanas Redshift Survey, the 2dF Survey and the Sloan Digital Sky Survey.
With Daniel Eisenstein and Wayne Hu, he introduced the idea of using baryon acoustic oscillations as a standard ruler. With Angelica de Oliveira-Costa and Andrew Hamilton, he discovered the anomalous multipole alignment in the WMAP data sometimes referred to as the "axis of evil." With Anthony Aguirre, he developed the cosmological interpretation of quantum mechanics. His year 2000 paper on quantum decoherence of neurons concluded that decoherence seems too rapid for Roger Penrose's "quantum microtubule" model of consciousness to be viable. Tegmark has also formulated the "Ultimate Ensemble theory of everything," whose only postulate is that "all structures that exist mathematically exist also physically." This simple theory, with no free parameters at all, suggests that in those structures complex enough to contain self-aware substructures (SASs), these SASs will subjectively perceive themselves as existing in a physically "real" world. This idea is formalized as the mathematical universe hypothesis, described in his book Our Mathematical Universe.
Tegmark was elected Fellow of the American Physical Society in 2012 for, according to the citation, "his contributions to cosmology, including precision measurements from cosmic microwave background and galaxy clustering data, tests of inflation and gravitation theories, and the development of a new technology for low-frequency radio interferometry."
Tegmark is interviewed in the 2018 documentary on artificial intelligence Do You Trust This Computer? He is also known for his seminal paper on the Mathematical Universe Hypothesis, in which he claims that our physical world is an abstract mathematical structure with an infinite number of initial random conditions. He points to fractals as proof that the equations used to describe all possible mathematical multiverses would fit on a single T-shirt.
Tegmark's latest book, Life 3.0: Living in the Age of Artificial Intelligence, was a best seller.