The Age of Em

Summary

The book explores the implications of a future world in which researchers have not created artificial general intelligence but have learned to scan human brains and run them as software, producing emulated people who soon outnumber biological humans.

There have been three human eras so far, based on foraging, farming, and industry. The next era is likely to arise from artificial intelligence in the form of brain emulations, sometime in the next century or so. This book paints a detailed picture of this new era.

— The Age of Em

The book's main scenario proposes that sometime in roughly the next century, human brains will be scanned at "fine enough spatial and chemical resolution," and combined with good enough models of how brain cells process signals, "to create a cell-by-cell dynamically executable model of the full brain in artificial hardware, a model whose signal input-output behavior is usefully close to that of the original brain."

Hanson calls this a "baseline" scenario built by applying "today's standard academic consensus science" to the em premise. In it, ems live mostly in a few hot, dense cities and work largely in virtual reality. Cheap copying drives em wages to near subsistence. A typical em runs about a thousand times faster than a human, and most are short-lived "spurs" copied for one task. The economy might double monthly, so the era could last an objective year or two yet feel like millennia to ems. Biological humans retire on their investments in the em economy.