It’s the year 2120. You feel no hunger, no cold, no heat, no pain. There’s no need to eat or to take medicine, though you can if you like. You are beautiful, intelligent, and charismatic, as are your friends, co-workers, lovers. Though the economy is fiercely competitive, retirement is not far off. You do not fear death. Look out your office window and you see sunlit spires towering over tree-lined boulevards. ... At least this is what you think you see. In fact, you live and work in virtual reality. Your city amounts to racks of computer hardware and the pipes that cool them. And you are not "you" in the traditional sense: You are an "em," a robotic brain emulation created by scanning a particular human brain and uploading it to a computer. On the upside, you process information 1,000 times faster than a human. On the downside, you inhabit a robotic body, and you stand roughly two millimeters tall. ... This is the world Robin Hanson is sketching out to a room of baffled undergraduates at George Mason University on a bright April morning. To illustrate his point, he projects an image of an enormous futuristic city alongside clip art of a human castaway cowering on a tiny desert island. His message is clear: The future belongs to "ems." ... This may sound more like science fiction than scholarship, but that’s part of the point. Hanson is an economist with a background in physics and engineering; a Silicon Valley veteran determined to promote his theories in an academy he finds deeply flawed; a doggedly rational thinker prone to intentionally provocative ideas that test the limits of what typically passes as scholarship. Those ideas have been mocked, memed, and marveled at — often all at once. ... Hanson, deeply skeptical of conventional intellectual discourse, argues that academics have abdicated their societal responsibilities by ignoring more speculative work.