- The eighteenth problem is set by Professor Jonathan Harrison of the University of Nottingham under the title 'Jocasta's Crime'.
- Compulsory reading:
- Miss Jocasta Jones was walking in a secluded part of a local wood when she was attracted by the barking of her dog to a metal object which looked for all the world like an extremely old and rusty deep freeze. She opened it and found inside it a man, alive, but frozen solid. With some help from Miss Jones the man, who called himself Dum, thawed out. He handed Miss Jones a book, which he said told one how to build a time machine2 and a deep freeze.
- Miss Jones, however, was a very feminine creature, and much more interested in men than in engineering. She fell deeply in love with Dum, and married him. After a decent interval they produced a baby whom, because he was the spitten image of his father, they forenamed Dee.
- When Dee reached maturity, he found the book, which had carefully been put away on a high shelf, out of the reach of children. Following the instructions in it, he built the machine and got inside, taking his father and the book with him, in case he should need some technical assistance on his journey. He pressed the starter button, and, though nothing unusual appeared to happen inside the machine, everything visible through its solitary porthole seemed to start moving in the opposite direction to what it had before, and much more rapidly. The sun rose in the West, and set in the East, backwards day succeeded backwards day, and reverse year followed upon reverse year. The journey was so long that Dee, who had underestimated the amount of food they would need, was reluctantly compelled to make use of his greater youth and strength in order to kill and eat Dum. Eventually Dee arrived at the date which was his preselected destination, and got out. His first act on alighting from the time machine3 had been to blow it up, and everything contained in it, including what little remained of Dum.
- Dee, however, had not been happy in his new environment. The guilt he felt for what he seemed to remember he had done produced a mild attack of paranoia, which was accentuated by the loneliness of his position. He had wandered forlornly about, obsessed with the thought, which even changing his name to Dum could not eradicate, that despite his having destroyed the evidence, the men he now lived with could not fail to discover and severely punish him for his unnatural action. To escape he built the deep freeze, and got inside. He was prudent enough to take with him the book, in case he needed to build himself another time machine4 or deep freeze at an earlier or later date.
- The next thing Dum remembered was being resuscitated by a Miss Jocasta Jones, who had been exercising her dog in the neighbourhood...
- Did Jocasta5 commit a logically possible crime?
See "Harrison (Jonathan) - Report on Analysis 'Problem' no. 18" for a Report.
- Administrative details removed.
- Responses are restricted to 600 words, which is approximately the length of the question!
- Much though I dislike such remarks, this piece does have an underlying sexist tone! “Miss Jones … was a very feminine creature, and much more interested in men than in engineering”. Did the audience chuckle?
- Crime? Can you commit a crime in ignorance of the facts (rather than of the law)?
- And, whose crime is it? The reference is obviously to Oedipus’s mother, of the same name, who married her son.
- But, the criminal in the original story is taken (by Sophocles, though not straightforwardly so, and by Oedipus himself) to be Oedipus – who kills his father and marries his mother, and blinds himself when he finds out what he has done. He did indeed intend to kill his father, though in ignorance that it was his father, and Jocasta was completely innocent of this crime. Also both Oedipus and Jocasta intended to – and indeed did – marry, though equally oblivious of their relationship.
- These quibbles are irrelevant to the main drift of the problem, which is a paradox of a causal loop where someone is their own father. But I see (after writing this footnote) that at least two of the competition entrants also noticed it.
Text Colour Conventions (see disclaimer)
- Blue: Text by me; © Theo Todman, 2019
- Mauve: Text by correspondent(s) or other author(s); © the author(s)