Monday Science Links

This week's science:

• Jennifer at Cocktail Party Physics posts on martial arts injuries and blood spatters: Jim fractured his wrist this past week when he agreed to hold six pine boards while his instructor attempted to break them with a kick. Apparently, the instructor missed the central target area and the full force of his kick landed off to the side, so all that kinetic energy (or should one say momentum? Terminology can be so confusing!) went into Jim's wrist instead of into the board...But he's the curious sort, so he emailed me asking if I knew anything about what went on from a physics standpoint to bring about his injury. I've done lecture/demos on the topic, focusing on broad concepts as opposed to specific calculations, so I knew a little, even though I never featured board-breaking in any of my lectures. Frankly, I've never understood the point of such an exercise. I'm an adherent of the Bruce Lee philosophy, immortalized in Enter the Dragon: "Boards don't hit back."Except in the strictest physics sense, they kinda do.


• Jennifer (a different one) at Mind the Gap posts on the stories of science: When you strip away the formal scientific record, all that is left are the stories of the people who were part of creating it. Of course some scientists write autobiographies, but our collective library of scientific tales is primarily a verbal one: pub stories, rumors, speculations, fading memories, back-stabbing mutterings, second-hand accounts and urban myth.


• What is this, Jennifer week? The one at The Infinite Sphere posts on looking for white nose syndrome: The first room in the cave is a large, open canyon with a very steep scree slope at the bottom. A small canyon at the side of the room leads further into the cave. This particular cave is extremely large and complicated. It consists of an interlocking maze of rooms, canyons, pits, crawls, and other obstacles. In the winter, due to the geology of this section of the cave, cold air is trapped in this entire section making the temperatures drop to around 4-5 C (37 F), which is extremely unusual for caves in the southeast. Typically caves are around 13.3 C (56 F) all year round. That's the kinds of winter temperatures gray bats (Myotis grisescens) require. Around 1.5 million gray bats hibernate in the cave.


• Jenni- er, Darren at Tetrapod Zoology posts on Britain's lost lynxes and wildcats: Conventionally it's been thought that, within recent history, the British Isles have only ever been home to a single small cat species, and this is Felis silvestris, the species most usually referred to (in Britain) as the Scottish wildcat. Of course, this name is entirely inappropriate given that the present restriction of the wildcat to Scotland is an artefact of human persecution: until very recently, the wildcat occurred across essentially the whole of Britain (even occuring in Ireland during the Holocene (Sommer & Benecke 2006), contrary to conventional wisdom).


• Pamela at Star Stryder posts on watching the summer skies: In general, I guess I’m a winter kind of girl. I’m a winter kind of girl who wants to give her students some things to go out and look at this summer. I need to change my ways, and add the summer skies to my memory. it’s not like the summer doesn’t have a huge wealth of objects to offer. Sagittarius is on the rise and this celestial teapot contains not only the center of the galaxy, but also nebulae, clusters, and dark patches.

Enjoy!