Much of chemistry is about bonds, but sometimes it can also be about anti-bonds. It is also true that the simplest of molecules can have quite subtle properties. Thus most undergraduate courses in chemistry deal with how to describe the bonding in the diatomics of the first row of the periodic table. Often, only the series C2 to F2 is covered, so as to take into account the paramagnetism of dioxygen, and the triple bonded nature of dinitrogen (but never mentioning the strongest bond in the universe!). Rarely is diberyllium mentioned, and yet by its strangeness, it can also teach us a lot of chemistry.
Archive for January, 2011
Shorter is higher: the strange case of diberyllium.
Friday, January 21st, 2011Is there a difference between a scientific blog and scientific journal?
Friday, January 14th, 2011In my blogroll, I link to Tim Gowers’ blog. He is a very eminent mathematician, and so it is interesting to see what motivates him to write a blog about mathematics. This latest post goes a large way to explaining why. He starts by speculating about the features of some piece of research that might render it conventionally unpublishable, highlighting two reasons; (1) it is not original and (2) it does not lead anywhere conclusive. He then goes on to show how either outcome might nevertheless be useful to someone, even if unpublishable conventionally. The rest of his post then concentrates on the cap-set problem in pure mathematics. It boils down to the observation that the community as a whole might often spot something that individual might have a blind spot for. Or, that others may in turn be inspired by lines of research which had apparently led nowhere for the original poster. Tim of course is favoured by having often 80+ comments appended to each of his posts!
A comparison of left and right handed DNA double-helix models.
Saturday, January 1st, 2011When Watson and Crick (WC) constructed their famous 3D model for DNA, they had to decide whether to make the double helix left or right handed. They chose a right-handed turn, on the grounds that their attempts at left-handed models all “violated permissible van der Waals contacts“. No details of what these might have been were given in their original full article (or the particular base-pairs which led to the observation). This follow-up to my earlier post explores this aspect, using a computer model.