J.D. Bernal: “The Analytic Theory of Point Systems”

J.D. Bernal is a pretty established name in the field of materials science and crystallography. I first learned about him when I came across his seminal  1959 Nature paper “A Geometrical Approach to the Structure of Liquids”

( http://www.nature.com/nature/journal/v183/n4655/pdf/183141a0.pdf, Nature subscription is needed to read the whole paper) which discusses the random closed pack sphere model.  Also, searching his name as the author Nature database returns 72 hits which is pretty remarkable. Obviously I did not filter out the pure research letters from other entries.

Anyway, his first achievement seems to be his quaternion based analysis of crystallographic groups.  Despite the importance of the paper (or essay if you will), it was never published. Before the advent of the internet, in 1981, it was made available through Alan MacKay of Birkbeck College, University of London.  After an e-mail inquiry, Prof. MacKay informed me that IUCR has finally made it publicly available through their website. You can reach it from the link; http://www.iucr.org/education/teaching-resources/bernal-essay

The primitive typing format makes it a tough read, so in near future I hope to decipher and rework the details and re-type everything in Latex and make it available for those who are interested.

Slayer as a mnemonic device!

Now, this is could easily be my most stupid post that has appeared here, yet I can`t resist it. The term “Killing Fields” refer to two different things. Mathematically, a Killing Field is a vector field which generates isometries(therefore preserves the metric structure) on a pseudo-Riemannian Manifold. For the layman terms, it is an abstract mathematical construct invented by the 19 century German mathematician Wilhelm Karl Joseph Killing. It is also the name of a famous 1984 movie with 3 oscars. Lastly, it is a song with pathetic lyrics(great drumming though) by the trash metal band Slayer from their 1994 album “Divine Intervention” . I don`t watch the movie often, yet the song perennially resides in my IPOD. Whenever I listen to it, a certain view pops to my mind in which Tom Araya(Singer/Bassist) and Kerry King(Guitarist) is battling with differential geometry books to master the subject! And it brilliantly works as a visual mnemonic device for me to remember the pertinent differential geometric concepts (although I rarely need them). Apparently the more wide-stretching/illogical connections you make, the better is your memory response.