Edition: Millennium, 2000
Review number: 1467
Gregory Benford is an author whose writing I like, but I have never got round to reading much of his work. Timescape is a classic science fiction, not quite about time travel but considering how history might be affected by the possibility of sending messages to the past. Half of the novel is set in San Diego in 1963, and half in Cambridge in 1998, with chapters more or less alternating between the two settings. (The dates were clearly chosen to that the novel appeared halfway between the two.)
In 1998, the world is experiencing a massive environmental catastrophe caused by mutations in oceanic plankton induced by the indiscriminate use of certain chemicals in agriculture. Physicists in Cambridge are investigating tachyons, sub-atomic particles which travel faster than the speed of light, and it occurs to one of them that it would be possible to send some kind of message to the past by sending a beam of tachyons to the point in space where the Earth once was, and interfering with physics experiments being carried out at the time when the Earth was at that position (direct detection of the tachyons being impossible, as technology wouldn't be in a position to pick them up at that point). The early sixties were chosen as a target because experiments which can be affected by beams of tachyons were beginning to be studied then.
Some people divide the science fiction genre into "hard" and "soft" writing. Hard SF is concerned with science: it views the genre almost as a way to carry out an informal discussion of more less speculative ideas, usually in physics, in a fictional setting. Soft SF is more often interested in the social aspects of science and technology, centring on culture. It is perhaps something of an outmoded way to view the genre, which seems to be more simply speculative in nature (i.e. centred around "what if" ideas) than anything else, where science fiction elements (such as space travel) are not simply props to a story which doesn't depend on them except as part of the background.
If the distinction has any meaning, then Gregory Benford has usually been regarded as a hard science fiction writer, partly because he is also a physics professor, and partly because he is also concerned to get the science in his stories as compatible with known fact (and interesting fact-based speculation) as possible. Most of the physics in Timescape is based on what was known, or what at least seemed plausible in 1980, including what is quite likely to be the earliest mention of dark matter in a science fiction novel. The exception to this is the tachyons, which physicists still generally doubt could possibly exist. How they could behave if they did exist has been the subject of a certain amount of speculation, and Benford builds in part on this. And of course, tachyons are needed for the central plot device in Timescape of sending the message back in time, even if this violation of causality is one of the main reasons that their existence is considered unlikely. Benford has a rather convoluted but clever and interesting mechanism to get out of this trap, which I will not give away.
At the same time, Benford is able to write well enough to avoid the major criticism often levelled at hard SF writers, that they neglect important aspects of the story such as characterisation because of their overwhelming interest in the scientific idea. In Timescape, the reader does care about the characters in both timelines, and the background is believable - possibly in part because the setting is the physics research community which Benford is a member of in real life. It all works well, and the end product is a fascinating novel - at least, I think it would be to anyone interested in the physics. My rating - 9/10.