\tSo far, so good, but the title is also a rather cheesy crystallographic pun because reciprocal space is a real<\/em> thing. Well, actually it\u2019s a weird, imaginary<\/em> thing, a mathematical construct used by X-ray crystallographers to interpret the diffraction patterns of spots that we record from our crystals. In the crystal, the molecules are arranged in orderly rows and columns, stacked like bricks in unit cells<\/em>. The orderliness is the key to strong scattering of the X-rays in the directions allowed by a mathematical rule known as Bragg\u2019s Law<\/a>.<\/p>\n \tBut if you follow the maths\u2014that damnable white rabbit\u2014it takes you down a hole and before you know it you are in reciprocal space<\/em>, where it is the spots of the diffraction pattern that are arrayed in rows and columns. But all the dimensions and angles are inverted \u2013 reciprocated. Crystals with small<\/em> molecules packed into small unit cells create a huge<\/em> reciprocal lattice where the spots are widely separated.<\/p>\n \t \tAnd, oddly enough, that\u2019s where the book discussed in this week\u2019s Fiction Lab<\/a> comes in. As has been mentioned elsewhere<\/a>, on Wednesday evening I railed against the scientific inanities of the plot of \u201cAs she crawled across the table\u201d, a novel based on the creation, in a basement physics lab, of a portal into a parallel universe that wholly absorbed \u2014 metaphorically and sometimes literally \u2014 those who gazed into it. It was a very strange story. I hated it and yet, though I almost dare not admit it, there is a kind of resonance with my own fascination with reciprocal space.<\/p>\n \tAs a protein crystallographer I make occasional visits to reciprocal space, usually to take a look at a strange entity that lurks there known as the Ewald Sphere<\/a>. It\u2019s an absorbing place. But if you make the effort to get acquainted, to get to know the angles and the curves, it will ultimately reward you with a beautiful new molecular structure. It can be hard work, but the exchange is a worthwhile one.<\/p>\n \tAnd such are my aspirations for this blog.<\/p>\n","protected":false},"excerpt":{"rendered":" It’s the name of this blog. But why? Well, in Web2.0-land, a blog (can you hear my teeth grinding?) is quintessentially a space for the reciprocation of views, the exchange of ideas. So far, so good, but the title is … Continue reading ![\"\"](\"http:\/\/farm4.static.flickr.com\/3077\/2852072432_225511c2b4_m.jpg\")
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\nA slice of reciprocal space<\/em><\/p>\n