Time and irreversibility
In Tom Stoppard’s play Arcadia [Stoppard, 1993], the action revolves around the precocious Thomasina, a 13-year-old girl who writes about, and discusses with her tutor Septimus Hodge, the irreversibility of time and chaos, years before these concepts were developed by mathematicians and scientists. An unusual and effective dramatic technique is to interleave action from the years 1809-12 and the present.
Stoppard’s play impacts on audiences in several ways. First, it brings fundamental concepts of time to the attention of the non-scientist in the audience in a way that they can relate to and discuss themselves. Process time is, after all, experienced by everyone. The second impact is to show that thinking about time may be unusual but can be a reasonable activity for non-professional scientists, given enough imagination.
One of the predictions of relativity is that there is a maximum speed, the speed of light, so that no physical object, effect or signal can travel faster than that speed. This is not a significant factor on small distance scales such as over the surface of a planet: light can travel seven times around the world in one second, which means that the ordinary human observer can disregard this limit under normal circumstances.
A significant problem arises for science fiction writers when they have to deal with communication between well-separated planets in different solar systems or even in different parts of our galaxy. This is because conversations would stretch over many years between planets when their separations are measured in light- years (approximately 6 million million miles). This is a clearly inconvenient plot factor in a novel, so many authors, including Asimov, have simply ignored the problem by postulating a short cut referred to as hyperspace. A space ship with hyperspace travel capability, usually referred to as a warp drive or hyperdrive, enters hyperspace near the ship’s point of origin and emerges instantly (as far as the ship’s occupants are concerned) many light year away, close to its destination planet.
A variant approach is taken by Frank Herbert in his Dune novels: the Guild Navigators can ‘fold space’ when under the influence of the spice Melange, and this enables space ships to pass instantly from one part of the galaxy to another. Such a concept can be mathematically described as a wormhole in Einstein’s theory of general relativity.