Quark•Hunters Are Rewarded Corey the Logical Choice
NEWS NOBEL PHYSICS------NOBEL CHEMISTRY------Quark•hunters are rewarded Corey the Washington Inelastic scattering produced, as ex THE Nobel physics prize committee this pected, a complex mess of new particles, logical choice year took what may be the final step in its but Friedman, Kendall and Taylor found London curiously unchronological recognition of that the statistical properties of this mess THIS year's Nobel prize in chemistry has the experimental discoveries that have behaved in a relatively simple way at been awarded to Elias Corey of Harvard established, over the past few decades, the higher energies. This 'scaling' of the University, Massachusetts, for his con generally accepted standard model of results of deep inelastic scattering ( deep tributions to synthetic organic chemistry. elementary particle physics. The winners, because the more energetic electrons were Corey is widely credited by chemists as Jerome Friedman and Henry Kendall of able to penetrate further into the proton) having played a key part in transforming the Massachusetts Institute of Technology did not have any immediate interpreta organic synthesis from something resemb and Richard Taylor of the Stanford Linear tion, but it struck some theoretical physi ling a 'black art' to a discipline founded Accelerator Center {SLAC), collaborated cists, in particular James Bjorken and firmly on logic. That he has won the prize in 1967 on electron-proton scattering Richard Feynmann, as a clue to some alone rather than sharing it is itself a testa studies at SLAC that demonstrated the underlying simplicity in proton structure. ment to his position in the field and the existence of smaller particles inside the Feynmann realized that scaling made pervasive influence of his ideas. proton. Murray Gell-Mann, a co-inventor sense if, at high energies, the electrons Over the past three decades, Corey has with George Zweig of these subparticles, were interacting with individual subunits devised synthetic routes to more than 100 named quarks, won the physics prize in of the proton rather than with its consti natural products, many of which have 1969, but, for reasons the secretive tuents as a whole. He called the subunits found wide use in medicine and industry. Swedes are unlikely to reveal, it has taken partons, and argued that the results of He is perhaps best known for leading the another 21 years for the experimental deep inelastic scattering showed that the group that in 1969 made the first synthetic work that substantiated Gell-Mann's partons moved rather freely inside the prostaglandins, molecules involved in the hypothesis to be similarly rewarded. protons. This seemed to be at odds with regulation of among other things blood Although the results obtained by Fried Gell-Mann's theory, because his quarks pressure and the heart. But it was not so man, Kendall and Taylor turned out to had to be strongly interacting. At the same much his prolific output that attracted the be of fundamental importance, their ex time, according to Bjorken, there were Nobel Committee as his strictly logical periment was originally seen as a long doubts about the reality of the scaling approach to complex syntheses. shot at best, a waste of accelerator time at laws, and also alternative explanations for In the 1950s, at the start of his career, worst. When it came on-line in 1966, the them that involved not proton substruc organic synthesis was largely a trial Stanford Linear Accelerator was mostly ture but new dynamical effects in the and-error pursuit. Progress was being devoted to studies of elastic electron electron-proton interaction. made in understanding the mechanisms of scattering, in which the aim was to record The programme of deep inelastic organic reactions and in developing useful the deflections and energy losses of elec scattering studies was to continue for reagents, but synthetic chemists still ana trons bounced off protons. Inelastic many years, accumulating results that lysed target molecules case by case. scattering experiments, which Friedman, allowed different explanations to be dis In the absence of general rules, the Kendall and Taylor decided to pursue, tinguished. On the theoretical front prevailing approach was to identify a poss were referred to by some as "beam it was eventually realized that, at suffici ible starting subunit (a readily available surveys": an electron was slammed into ently high energies, quarks could theoret reagent, for example) within the structure the protons at high energy to create a ically behave at close range as if they were of the target molecule. The problem then shower of new particles, and the debris free particles, but still be inextricably became how to manipulate the subunit so was examined to see if any useful second bound up inside the proton. as to generate the full structure. ary beams (of muons, for example) By the mid-1970s, quarks had become This approach led to some notable suc could be extracted. real particles, not abstractions. And in the cesses, such as Robert Woodward's heroic The standard wisdom at the time was long run the success of the quark model synthesis of chlorophyll, one of the that the mess of debris created by inelastic put physics on the road towards unification achievements that earned him the Nobel scattering was too complex to be under mania, the goal of which is to assemble all prize in chemistry in 1965. Yet by and stood in a way that would shed light on the forces of nature into some single, all large, chemical manipulations were still the inner structure, if there were any, of encompassing model . deployed in an ad hoc fashion , a practice the proton. Elastic scattering, the modern This year's physics award, in conjunc that remained the norm until the 1960s version of Rutherford's famous experi tion with that of two years ago, when when Corey began working on sesquiter ment in which he scattered alpha particles Leon Lederman, Melvin Schwartz and penes, a family of natural products whose off atoms to show the presence of small, Jack Steinberger were made Nobel laure structures were void of obvious starting dense, electrically charged atomic nuclei, ates for their discovery of neutrinos in subunits. was instead thought to be the way to probe the early 1960s, corrects an omission that Corey reasoned that to devise logical the proton. But the first round of results elementary particle physicists had long synthetic routes to such molecules, it was from elastic scattering experiments noted. In contrast, the 1983 discovery of necessary to work backwards from the end showed nothing of interest, indicating the W and Z particles, crucial to unifica product, disconnecting chemical structure only that the proton seemed to be a tion of the weak and electromagnetic for until one obtained a set of simple precur smooth, structureless distribution of ces, was promptly recognized when Carlo sors. In seminal papers published in 1967 charge. In retrospect, this was inevitable. Rubbia and Simon van der Meer won the and 1968, Corey wove his ideas into a Elastic scattering could have picked up the physics prize the following year. general synthetic strategy, coining the existence of a hard core to the proton, as With most notable particle discoveries term 'retrosynthetic' analysis to describe in the Rutherford experiment, but now rewarded, it may be that physicists it. charged quarks moving rapidly about will have to find the top quark or the Put crudely, the analysis involves sub inside the proton would, to the passing electroweak Higgs boson before the jecting the target molecule of the synthesis electron, be indistinguishable from a Nobel will come their way again. to a series of stepwise dissections, accord smooth charge distribution. David Lindley ing to a set of simple rules bearing on the 698 NATURE · VOL 34 7 · 25 OCTOBER 1990 © 1990 Nature Publishing Group