Monday Science Links

This week's science:

• Chris at Highly Allochthonous asks how you tell a dinosaur footprint from a hole in the ground?: If they weren't being mentioned all over the place, these things would make a fine geopuzzle; I certainly wouldn't guess that these things were dinosaur tracks. They look much more like potholes to me, and if If I came across this in the field, that would probably be what I'd call them. Which shows how much I know.


• Carl Zimmer at The Loom talks about dinosaurs with feathers: In recent years, dinosaurs have gotten awfully cute. They’re no longer Victorian lumps of saggy muscle. A lot of them are not even frightening. They’re fuzzy, feathery little critters. But, as I’ve written before, cuteness is not what drives paleontologists to hunt for these fossils and spend years poring over them in laboratories.
  


• Darren at Tetrapod Zoology also talks about those little feathery dinosaurs from China: Today sees the formal publication of the bizarre little Chinese maniraptoran theropod Epidexipteryx hui Zhang et al., 2008 from the Daohugou Formation of Ningcheng County, north-eastern China. Unfortunately the publication of this new species is not quite the surprise it should be, as the authors inadvertently submitted their manuscript to the wrong venue a few weeks ago, thereby making the article visible to the whole world some time before it was ready to be published. Anyway, we'll just have to pretend that never happened. Belonging to a recently discovered group called the scansoriopterygids, Epidexipteryx is tiny (less than 20 cm long I think), and very, very weird (Zhang et al. 2008). Its skull is short-snouted with a truncated antorbital fenestra, a nostril positioned in a relatively high position, and strongly procumbent, proportionally large anterior teeth (the teeth get smaller further back). Its arms and hands were very elongate (see figure below, from Zhang et al. 2008).


• Pamela at Star Stryder reassures us that super-massive black holes can only grow so large: So, first, I’d like to say there are two ways to look at this: 1) In reality, 2) in make-believe land. Make-believe land is oh so much more fun. So, lets imagine that somehow we are able to grow a very large blackhole in isolation. Then, using imaginary technology (we are in fantasy land, afterall), we throw a star at the supermassive blackhole (SMBH) so that it’s goes on a straight, uninterrupted path toward the SMBH. So straight, so perfect, infact, that if we could watch we’d see it hit on a line connecting the star’s center of mass with the SMBH’s center of mass. Now, the SMBH will simply slurp up this perfectly thrown star. Burp. No more star and no accretion disk. Now, If you, using your super duper, impossible, imaginary technology could throw a star with dead on aim over and over every second across all the epochs of time, you could pretty much build a SMBH as big as you wanted.


• Sean at Cosmic Variance takes on explaining quantum mechanics at the macro level: One of the annoying/fascinating things about quantum mechanics is the fact the world doesn’t seem to be quantum-mechanical. When you look at something, it seems to have a location, not a superposition of all possible locations; when it travels from one place to another, it seems to take a path, not a sum over all paths. This frustration was expressed by no lesser a person than Albert Einstein, quoted by Abraham Pais, quoted in turn by David Mermin in a lovely article entitled “Is the Moon There when Nobody Looks?“: I recall that during one walk Einstein suddenly stopped, turned to me and asked whether I really believed that the moon exists only when I looked at it. The conventional quantum-mechanical answer would be “Sure, the moon exists when you’re not looking at it. But there is no such thing as `the position of the moon’ when you are not looking at it.”.

Enjoy!