James P. Hogan’s 1980 Thrice Upon a Time is a standalone time travel novel. Of a sort.
American-born Murdock is summoned to the ancestral castle in Scotland by his grandfather Sir Charles. Sir Charles wishes to demonstrate a scientific breakthrough: discovery of radiation that propagates back through time. What’s more, he has devised a means to use this tau radiation to send messages as well.
How prudent that might be depends on which model of time is correct.
(spoilers for a 37-year-old book that seems to have been out of print for over a decade)
At first, results seem to indicate that there are a myriad of branching universes. Causality is preserved by the many worlds hypothesis. Or is it? Further investigation invalidates this simple, comforting model. It is possible to send messages back to one’s own past and thus change that past. The changes then propagate forward in time, rewriting history in the process.
Although the process is limited by the need to have a tau communicator at both ends (so inadvertently preventing the invention of inter-temporal communication), the implications are still daunting. After all, minor changes can have profound results: for example, re-running history could change who won a major lottery1. It’s fine for Murdock and Sir Charles to carry out small scale experiments — probably — but there seem to be no circumstances that could justify making dramatic changes to the recent past.
Enter the bugophants. Across the world, massive objects too tiny to see burrow their way through barriers, from walls and mirrors, even into people’s extremities. Thus far there have been no fatalities but that is just a matter of time. A cutting-edge experimental fusion generator has revealed a previously overlooked gap in human models of high density, high temperature matter. What was supposed to be a straightforward power generation system has instead been creating tiny black holes. By the time the dots are connected, there are two million black holes within the Earth and (contrary to Hawking’s model) they will grow fast enough to eventually consume the planet. Which would be bad.
Sir Charles and his nephew have the means to save the world, provided Murdock’s new girlfriend Anne Patterson can write the software needed to reprogram past versions of Sir Charles’ machine to convey messages far more complex than the early designs were intended to manage. If she succeeds, the world will be saved.
The cost? Murdoch and Anne’s first encounter was a “meet-cute” involving an adorable kitten. What are the odds that specific moment will be repeated?
And what are the odds that the world, having been saved, will stay saved?
I wish I had reread this before I wrote Did We ALL Write a Book About Space Elevators? Why Unfortunate Coincidences Happen in Science Fiction for Tor.com because Thrice Upon a Time has its own twin. Gregory Benford’s Timescape also examined inter-temporal communication. Benford being a physicist, he declined to invent a new plot-enabling radiation; he used Feinberg’s tachyons. However, the general result, a device that could send messages back to last Tuesday, is much the same. Hogan’s novel was first published in March of 1980, while Timescape came out in July 1980. The publications were essentially back to back. Given the vagaries of book publication schedules, there’s no obvious way to determine who finished writing their book first. Benford might have found himself trumped by Hogan purely because his publisher delayed his book until a more propitious time of year. If only he had had one of his own devices to warn a past-Benford …
Still, Timescape won the 1981 Nebula, the 1980 British Science Fiction Award, and the 1981 John W. Campbell Memorial Award for Best Science Fiction Novel, and Pocket Books used the title for their SF imprint. Plus, Timescape is still in print. As for the Hogan: evidently no recent edition. The prior appearance of Thrice Upon a Time seems to have done the Benford no great damage.
It does seem odd that a world would face not one but two unrelated global scale crises in the course of just one novel (minor spoiler). One gets the impression that Sir Charles will face a future filled with temporal tweaks to keep the planet safe and intact. I suspect that the novel was plotted this way to save the romance plot, which was broken by the first crisis, Only a second rewrite of the universe’s recent history could repair the romance.
It’s probably for the best that the protagonists did not spend too much time thinking about the implications of their discovery. Since tau radiation is produced naturally all the time, it follows that history is continually evolving. Large scale events seem likely to be stable, but the daily moments we think we remember? Those appear likely to be less stable from version to version. Which explains where the socks went and why you are sure you remembered to set the alarm clock.
This is early Hogan, long before he embraced AIDS denial, Velikovskyism, and holocaust denial. There are occasional hints of the crank to come, such as fulminations about the deplorable state of a British society in which the underclasses have too much influence, with the result that most technological progress in the UK is thanks to Europe and various corporations2. For the most part those can be dismissed as just the usual sort of small‑l libertarian mutterings about the dangers of labour unions3. On a more positive note, the novel shares with Hogan’s debut Inherit the Stars the same interest in the scientific process. The scene in which the flaw in current models of micro-black-holes is uncovered was unexpectedly reminiscent of Feynman’s demonstration of temperature effects on space-shuttle O‑rings.
The prose is of a sufficient grade of neutronium to stop neutrinos dead in their tracks. Readers looking for mellifluous prose should not pick up Hogan. Hogan did not do beautiful words.
Thrice Upon a Time is out of print.
1: The novel uses the lottery as one example. Rewrites could also replace one infant by another, by changing which sperm reaches a particular egg.
2: The novel is set in 2009. Unlike a lot of 1980s-era novels set in 2009, space colonies have not yet materialized, although the characters hope recent developments will facilitate space settlements in another generation or so.
3: The fulminations do suggest that Hogan wrote at least portions of his book before Margaret Thatcher’s 1979 election .