"The ambiguity of the apple"

Alan Garner remembers Alan Turing (Guardian):

He was stocky, barrel-chested, with a high-pitched, donnish voice and the aerodynamics of a brick. He was funny and witty and he talked endlessly, but I understood very little of what he was saying, and it became clear that he ran in order to think. He seemed to be obsessed by mathematics and biology. That much I could work out.

We had one thing in common: a fascination with Disney's Snow White and the Seven Dwarfs, especially the transformation of the Wicked Queen into the Witch. He used to go over the scene in detail, dwelling on the ambiguity of the apple, red on one side, green on the other, one of which gave death. We had both been traumatised by Walt.

Also an appealing piece in Nature News, casting doubt on the claim (which I missed at the time) that cows are magnetic:

Three years ago, Hynek Burda, a zoologist at the University of Duisburg-Essen, Germany, and his colleagues added cattle to the magnetic family with a paper in Proceedings of the National Academy of Sciences. The team used data from Google Earth to show that domestic cattle seem to prefer to align their bodies along Earth’s magnetic field lines¹, and showed a similar phenomenon in field observations of deer. [...] Burda and his colleagues reanalysed the replication attempt by Jelinek and his colleagues⁴. Burda says that half of the Jelinek team's data should be excluded because some of the pastures are on slopes or near high-voltage power lines, for example, or because the images are too poor to make out cattle, or appear to contain hay bales or sheep instead. “One half of their data is just noise,” says Burda.

I wonder if Lydia Davis reads Nature News.