Still going with the Twitter #weirdscifacts! They’re getting much harder to find, so if you have any to suggest, please let me know!
508. Aug 03: Swede held for attempting to build nuclear reactor in his kitchen. Note the word “attempting”. He almost certainly wouldn’t have made a working reactor, and he seems to have had no nefarious plans. He isn’t the first to try, though! (h/t @sciencecomedian)
509. Aug 04: Hymenoepimecis argyraphaga — the wasp that makes zombie spiders! (classic post by @nerdychristie) This fact was inspired by the fact that the wasp/spider conflict is central to Nick Mamatas’ novel Sensation, that I recently reviewed.
510. Aug 05: Fossil find shows Velociraptor eating another dinosaur. Of course, it’s not weird that Velociraptor ate dinosaurs, but it is very unusual for it to be fossilized essentially in the act! (h/t @anatotitan)
511. Aug 06: Turning wood into bones??!! (h/t @AndreaKuszewski)
512. Aug 07: The Vegas hotel that acts as a death ray to pool-goers! The hotel, with its massive concave mirrored surface, acts as a crude focusing reflector.
513. Aug 08: A billion-year-old piece of North America traced back to Antarctica. (via @physorg_com)
514. Aug 09: Curious attempts to build anti-gravity devices. Though there is no evidence of the existence of anti-gravity, much less any clear path to generating it, lots of people have made a big fuss over trying to create it. Some have been sincere, some less so! (by @jenlucpiquant)
Skulls in the Stars 
I just thought to ask about this —
Cats and rattlesnake eyes have vertical pupils.
Goats and some octopi have rectangular pupils.
Cuttlefish have pupils shaped like a keyhole.
Moray eels have weirdly sort-of crescent-shaped pupils.
There’s some reason to think that natural selection has produced these pupil shapes. But what is being selected? Why would it be useful to have a wider aperture in one direction than another?
Presumably this isn’t important in low light, when for example cats have round pupils.
When the light intensity is high enough to get enough light with a smaller pupil, what optical difference does it make to have it still wide in some directions? Cats have vertical pupils, and goats basicly have horizontal pupils then. But they tend to carry their heads differently….
Interesting question! I’ll have to look into the origins of these pupil shapes, because off the top of my head I don’t know.