‘Mimsy Were The Borogoves’ by Henry Kuttner and C. L. Moore
At least that is how H&C credit the story in The Ascent Of Wonder. It was originally published under the pseudonym Lewis Padgett and their failure to mention this makes their introduction very confusing as it addresses itself solely to Kuttner. Although we are told that “all their stories under whatever byline were jointly created – the Padgett name was used for stories that were most strongly Kuttner’s” (122), we are not told that the Padgett name was used for this very story. Which would have been helpful.
As befits its classic status, ‘Mimsy Were The Borogoves’ gets a pretty comphrehensive Wikipedia entry which points towards an online version. It also reminds us that the story was the inspiration for The Last Mimzy, a film that no one in the UK could take seriously since it is playground slang for a vagina.
Anyway, a couple of million years hence a bloke called Unthahorsten sends some educational toys back in time. One gets found by Charles Dodgeson’s Alice, the other gets found by a young boy in Forties America. These impressionable kids use this future tech to access a world the adults cannot see because their brains are conditoned to Euclidean geometry. It is a nice idea but, as with ‘The Best Monkey’ by Daniel Abraham, I didn’t like or believe the way it was told.