The SelfStandardization musing (6 April 2002) reminded me of Frederik Pohl's The Gold at the Starbow's End, a cover story in Analog science-fiction magazine several decades ago. In brief, a small group of smart people are deliberately sent on a pointless interstellar voyage, designed to isolate them from others. Left to their own devices and not knowing what's impossible, they come up with some great discoveries and save the world. A cute, hugely improbable, well-written yarn.

But in the version as originally published Pohl made a couple of major technical goofs, which ^z as a snotty-nosed teenage ur-physicist couldn't resist pointing out in a Letter to the Editor. And decades later, a snotty-nosed almost-pentagenarian ^z (yes, I have a bad cold at the moment ... sniff) hasn't forgotten. Specifically:

• The "starbow" of the title was described as a rainbow-like ring around the equator of the sky, seen from a spaceship traveling almost at the speed of light and created by relativistic red- and blue-shifting of starlight. Sorry! The author ignored aberration of light, the same phenomenon that makes rain mostly strike from the front when one runs or drives through a storm. Any "starbow" in real life would appear as a small circle in the forward direction — but it would be muddied, probably beyond recognition, by infrared and ultraviolet light shifted into the visible spectrum. The magazine's cover painting was wrong too.
• A key plot element in the story was a message, purportedly containing an encyclopædic collection of fantastic technological secrets, and purportedly impossible to decode by an unenlightened civilization such as ours. The author described it as Gödel encoded. He made the mistake of showing it explicitly in the text. (Gödel encoding consists of writing a string of symbols as a particular type of large integer.) Sorry! The numerical value that Pohl put into his story may have seemed large to him, since it was thousands of digits long — but it was trivially small, far too little to contain more than a few words of information. Worse yet, Pohl didn't know how easy it is to compute the beginning of a Gödelized string, via modular arithmetic. And so another of his plot devices collapsed.

"Picky, picky," you may say. Yes — but part of the game that sf authors and readers play with one another is to avoid such slipskis, or to take pride in spotting them. Pohl later corrected these errors, as much as he could, in the published edition of the novel. The result was a better story.

TopicLiterature - TopicScience - TopicPersonalHistory - 2002-05-05

(corrected on 18 November 2002, thanks to a tip-off by an anonymous reader — I had mistakenly written "Fritz Leiber" instead of "Frederik Pohl" throughout the above — oops! — ^z)

(correlates: ReaderAsPerformer, MakeYourOwnWeather, ProdesseQuamConspici, ...)