Invisibility is perhaps one of the oldest concepts in ancient mythology. Since the advent of recorded history, people who have been alone on a creepy night have been frightened by the invisible spirits of the dead, the souls of the long-departed lurking in the dark. The Greek hero Perseus was able to slay the evil Medusa armed with the helmet of invisibility. Military generals have dreamed of an invisibility cloaking device. Being invisible, one could easily penetrate enemy lines and capture the enemy by surprise. Criminals could use invisibility to pull off spectacular robberies. Invisibility played a central part in Plato’s theory of ethics and morality. In his philosophical masterpiece, The Republic, Plato recounts the myth of the ring of Gyges. The poor but honest shepherd Gyges of Lydia enters a hidden cave and finds a tomb containing a corpse wearing a golden ring. Gyges discovers that this golden ring has the magical power to make him invisible. Soon this poor shepherd is i
Teleportation, or the ability to transport a person or object instantly from one place to another, is a technology that could change the course of civilization and alter the destiny of nations. It could irrevocably alter the rules of warfare: armies could teleport troops behind enemy lines or simply teleport the enemy’s leadership and capture them. Today’s transportation system—from cars and ships to airplanes and railroads, and all the many industries that service these systems—would become obsolete; we could simply teleport ourselves to work and our goods to market. Vacations would become effortless, as we teleport ourselves to our destination. Teleportation would change everything. Teleportation is also part of every magician’s bag of tricks and illusions: pulling rabbits out of a hat, cards out of his or her sleeves, and coins from behind someone’s ear. One of the more ambitious magic tricks of recent times featured an elephant disappearing before the eyes of a startled audien