Artificial General Intelligence (AGI), as opposed to simple AI, is artificial intelligence that can achieve a broad range of goals, even learning from past experience. Instead of being deterministically programmed to be good a chess, for instance, an AGI may be able to learn about and succeed at a myriad of games. Advanced AGIs could do even more. Tegmark also discusses “human-level” AGI: “the ability to accomplish any goal at least as well as humans” (52).

Short for “cosmic apocalypse,” this refers to the ultimate destruction of the entire observable universe. This will likely be tens of billions of years in the future and will bring an end to all life, regardless of advancement or intelligence. In Chapter 6, Tegmark discusses five different cosmocalyptic scenarios.

This refers to any physical material that is constituted by atoms or subatomic parts. Tegmark speculates that, at the upper limits of technologically advanced superintelligence, baryonic matter will be the only resource necessary because technology will be able to rearrange the parts of the atoms at will. All physical material will ultimately be rearrangeable into different material.