A short history of nearly everything - Bill Bryson [81]
Since the supercollider debacle particle physicists have set their sights a little lower, but even comparatively modest projects can be quite breathtakingly costly when compared with, well, almost anything. A proposed neutrino observatory at the old Homestake Mine in Lead, South Dakota, would cost $500 million to build—this in a mine that is already dug—before you even look at the annual running costs. There would also be $281 million of “general conversion costs.” A particle accelerator at Fermilab in Illinois, meanwhile, cost $260 million merely to refit.
Particle physics, in short, is a hugely expensive enterprise—but it is a productive one. Today the particle count is well over 150, with a further 100 or so suspected, but unfortunately, in the words of Richard Feynman, “it is very difficult to understand the relationships of all these particles, and what nature wants them for, or what the connections are from one to another.” Inevitably each time we manage to unlock a box, we find that there is another locked box inside. Some people think there are particles called tachyons, which can travel faster than the speed of light. Others long to find gravitons—the seat of gravity. At what point we reach the irreducible bottom is not easy to say. Carl Sagan in Cosmos raised the possibility that if you traveled downward into an electron, you might find that it contained a universe of its own, recalling all those science fiction stories of the fifties. “Within it, organized into the local equivalent of galaxies and smaller structures, are an immense number of other, much tinier elementary particles, which are themselves universes at the next level and so on forever—an infinite downward regression, universes within universes, endlessly. And upward as well.”
For most of us it is a world that surpasses understanding. To read even an elementary guide to particle physics nowadays you must now find your way through lexical thickets such as this: “The charged pion and antipion decay respectively into a muon plus antineutrino and an antimuon plus neutrino with an average lifetime of 2.603 x 10-8 seconds, the neutral pion decays into two photons with an average lifetime of about 0.8 x 10-16 seconds, and the muon and antimuon decay respectively into . . .” And so it runs on—and this from a book for the general reader by one of the (normally) most lucid of interpreters, Steven Weinberg.
In the 1960s, in an attempt to bring just a little simplicity to matters, the Caltech physicist Murray Gell-Mann invented a new class of particles, essentially, in the words of Steven Weinberg, “to restore some economy to the multitude of hadrons”—a collective term used by physicists for protons, neutrons, and other particles governed by the strong nuclear force. Gell-Mann's theory was that all hadrons were made up of still smaller, even more fundamental particles. His colleague Richard Feynman wanted to call these new basic particles partons, as in Dolly, but was overruled. Instead they became known as quarks.
Gell-Mann took the name from a line in Finnegans Wake: “Three quarks for Muster Mark!” (Discriminating physicists rhyme the word with storks, not larks, even though the latter is almost certainly the pronunciation Joyce had in mind.) The fundamental simplicity of quarks was not long lived. As they became better understood it was necessary to introduce subdivisions. Although quarks are much too small to have color or taste or any other physical characteristics we would recognize, they became clumped into six categories—up, down, strange, charm, top, and bottom—which physicists oddly refer to as their “flavors,” and these are further divided into the colors red, green, and blue. (One suspects that it was not altogether coincidental that these terms were first applied in California during the age of psychedelia.)
Eventually out of all this emerged what is called the Standard