Everything felt possible at Transhuman Visions 2014, a conference in February billed as a forum for visionaries to "describe our fast-approaching, brilliant, and bizarre future." Inside an old waterfront military depot in San Francisco's Fort Mason Center, young entrepreneurs hawked experimental smart drugs and coffee made with a special kind of butter they said provided cognitive enhancements. A woman offered online therapy sessions, and a middle-aged conventioneer wore an electrode array that displayed his brain waves on a monitor as multicolor patterns.

On stage, a speaker with a shaved head and a thick, black beard held forth on DIY sensory augmentation. A group called Science for the Masses, he said, was developing a pill that would soon allow humans to perceive the near-infrared spectrum