“We are brothers and sisters of our machines,” the technology historian George Dyson once remarked. Sibling relations are notoriously fraught, and so it is with our technological kin. We love our machines—not just because they’re useful to us, but because we find them companionable and even beautiful. In a well-built machine, we see some of our deepest aspirations take form: the desire to understand the world and its workings, the desire to turn nature’s power to our own purposes, the desire to add something new and of our own fashioning to the cosmos, the desire to be awed and amazed. An ingenious machine is a source of wonder and of pride.

But machines are ugly too, and we sense in them a threat to things we hold dear. Machines may be a conduit of human power, but that power has usually been wielded by the industrialists and financiers who own the contraptions, not the people paid to operate them. Machines are cold and mindless, and in their obedience to scripted routines we see an image of society’s darker possibilities. If machines bring something human to the alien cosmos, they also bring something alien to the human world.