Max Tegmark

Physicist; president and co-founder of the Future of Life Institute (organiser of the 2023 pause letter and 2025 superintelligence statement)

MIT / Future of Life Institute

Safety researchers

Tegmark is the MIT physicist whose institute organised the famous 2023 'pause' letter and the 2025 call to ban superintelligence outright. His group's analysis put the chance of losing control of a superintelligence at 90%, and he wants companies forced to publish that number the way Manhattan Project physicists calculated the odds of igniting the atmosphere.

Their number

90%

A paper with MIT students found "a 90% probability that a highly advanced AI would pose an existential threat" (reported by The Guardian, May 10, 2025). Tegmark: "The companies building super-intelligence need to also calculate the Compton constant, the probability that we will lose control over it... It's not enough to say 'we feel good about it'. They have to calculate the percentage."
Source

On timing

Treats superintelligence as a near-term possibility that labs are actively racing toward; FLI's 2025 statement demands a prohibition until 'broad scientific consensus that it will be done safely and controllably' (October 2025).

Source

What they call for

  • Prohibition on developing superintelligence until safety consensus and public buy in
  • 6 month pause on training beyond GPT 4 (2023)
  • Labs to compute and publish a 'Compton constant' for loss of control
  • International agreement on AI red lines
  • Safety standards like those for drugs and aviation

In their own words

  • FLI open letter: "We call on all AI labs to immediately pause for at least 6 months the training of AI systems more powerful than GPT-4."

    22 March 2023

    Source

  • "The companies building super-intelligence need to also calculate the Compton constant, the probability that we will lose control over it."

    10 May 2025

    Source

  • FLI Statement on Superintelligence: "We call for a prohibition on the development of superintelligence, not lifted before there is (1) broad scientific consensus that it will be done safely and controllably, and (2) strong public buy-in."

    22 October 2025

    Source

Signed

  • FLI pause letter 2023 (organiser)
  • CAIS extinction statement 2023
  • Global Call for AI Red Lines 2025
  • FLI Statement on Superintelligence 2025 (organiser)

Last verified 1 September 2026

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