The makers of Brainstorm (1983) spent more than a decade transferring the revolutionary concept of an "empathy machine" from page to screen, only for the famously troubled production to be met with critical and commercial indifference on release. But since 1984 the film has continued to inspire viewers to imagine possibilities for the future. As a result, Brainstorm now seems less like a fixed piece of film history than an idea in evolution. The screen...