Appendix
Presentation Speech by Professor Nils Palsternacka of the Royal Swedish Academy of Sciences
(Translation from the Swedish text)
Your Majesties, Your Royal Highnesses, Ladies and Gentlemen,
That you see me standing before you is a tribute to the photopigments in your eyes that capture light. That we are all feeling pleasantly warm, despite the chilly weather outside in the streets of Stockholm, is by grace of leaves in Carboniferous forests that captured sunlight with their photo-synthetic pigments and left us a residue of coal and oil. These are simple examples of how the interaction of radiation and matter underpins life on earth. In the late nineteen forties, a deep physical understanding of this interaction was achieved by Feynman and Schwinger, and by 1970 it seemed to most physicists that this was a finished chapter and that exploration of fundamentals had moved on either to a more cosmic scale or to events deeper within atoms. Yet there was a surprise in store.
The Solvay Conference is an event of great importance in the physics calendar. At the 1972 gathering, well into an afternoon session, a cry was heard from the back of the hall. Heads turned to see Richard Feynman holding a bundle of papers aloft in his hand. 'Magic!' he cried, and advanced to the front, and, apologising to the speaker, seized the stage. In five minutes of intense, gesticulating argument he explained how a problem that had long baffled him had been solved by a young researcher named Michael Beard.
The Solvay 'magic moment' has of course gone down in history, and it is not hard to see why the ideas in Beard's paper appealed so strongly to Feynman. They showed how certain diagrams that described the interaction of light with matter obey a new kind of subtle symmetry that greatly simplifies calculations. In popular perception, quantum mechanics describes the very small; and indeed it is true that only very small systems can easily maintain coherence, in the sense that they preserve their isolation from the environment. Yet Beard's theory revealed that the events that take place when radiation interacts with matter propagate coherently over a large scale compared to the size of atoms; furthermore, the manner of their propagation resembles the flow diagram for a complicated system, the sort of picture an engineer might give of the workings of an oil refinery, say, or of the logical steps in a computer program. This has transformed our understanding of the photoelectric effect to such an extent that we now speak of the Beard-Einstein Conflation, a spine-tingling hyphenation for any physicist, placing Beard's work proudly in a lineage originating from Einstein's revolutionary 1905 paper.
With his genius for popularisation, Feynman contrived a party trick to demonstrate the principles behind the Conflation. This requires six belts or straps that are interwoven in an attractive pattern. Six people then take two free ends each and hold the knot out for inspection. Anyone may verify that a very intractable knot has been created and there is no hope of untying it unless the participants release their ends. Next the participants perform a sort of country-dance pirouette with a neighbour, an operation that seems to increase the intractability of the knot. But then, at a signal, all the participants pull, and to the amazement of the gathering the belts fall apart. Feynman's Plaid has become a favourite with all physics lecturers, and there is probably no physics undergraduate who has not participated in it, and in some cases met his or her future spouse in the happy melee.
Here we see the topological essence of Michael Beard's conception: the action of the group (the exceptional Lie group E8, one of the bulkier residents of the Platonic realm) that disentangles and choreographs the complicated interactions between light and matter, unfolding them into a succession of logical steps. It is the interplay of these operations that constitutes the essential magic, the wave of the enchanter's wand, and it brings to mind Einstein's description of Bohr's atomic theory as the highest form of musicality in the sphere of thought. In the words of the philosopher Francis Bacon:
The sweetest and best Harmony is, when every Part or Instrument, is not heard by itself, but a Conflation of them all.
Professor Michael Beard, you have been awarded this year's Nobel Prize in Physics for your profound contribution to our understanding of the interaction of matter and electromagnetic radiation. It is an honour for me to convey the warmest congratulations of the Royal Swedish Academy of Sciences. I now ask you to step forward to receive your Nobel Prize from the hands of His Majesty the King.
Ian McEwan
