I have just two quibbles with this New Yorker article on the Large Hadron Collider to which Scott Aaronson directed my attention. First, throughout her informative story, Elizabeth Kolbert consistently abbreviates “Large Hadron Collider” as “L.H.C.” I’ve yet to see anybody in the physics community use the periods when they write “LHC.” Is this some official policy which we, the project’s website and the rest of the Internet just are too lazy to follow? Or are these strange little dots the product of a New Yorker in-house style guide demanding their presence based on some holier-than-Sinai rule about tiny ink specks? If the latter is the case, the foolish prescriptivist responsible needs an introduction to my friend the clue-by-four.
My second and marginally more serious complaint involves the following passage from page five:
String theory posits that the universe is composed of tiny strands of energy, which vibrate at different frequencies, creating what appear to be different particles. In its most popular form, string theory demands the existence of seven dimensions beyond the usual fourâ€”three in space and one in timeâ€”that weâ€™re familiar with. Supersymmetry, meanwhile, which is often referred to by the acronym SUSY (pronounced soo-see), holds that every particle has a â€œsuperpartnerâ€ with a different spin, spin here being understood not as it is in everyday life but as a fixed property of a particle that determines some of its basic characteristics. Under the naming system thatâ€™s been devised for these hypothetical superpartners, the counterpart of a quark would be a squark, and that of a photon a photino. (The superpartner of the as yet undiscovered Higgs would be a Higgsino.) It has been proposed that these â€œsuperparticlesâ€ could account for the dark matter that physicists estimate makes up nearly a quarter of the universe.
No, I’m not going to complain that squark is far too undignified a term for a fundamental constituent of reality. My concern here is with the final sentence, and in particular with Kolbert’s choice of words stating that dark matter “makes up nearly a quarter of the universe”. The problem is more a sin of omission than of commission: while correct, this statement by itself is likely to leave the impression that normal, non-dark matter makes up three-quarters of everything with the dark portion filling out what’s left. In reality, the situation is very different.
According to our best current understanding, about 22% of the stuff in the Universe is dark matter. The large majority of the rest, 74% of the total, is not ordinary matter but rather dark energy, a quintessential something-or-other which fills space with remarkable uniformity and pushes everything apart, accelerating the expansion of the Universe faster and faster.
That which we so arrogantly call “normal” matter — four or five percent of the total — is what’s left. Most of it is hydrogen and helium floating in interstellar gas clouds. Then come the ionized gases in stars, neutrinos zipping through space (almost massless individually, but there’s sure a heck of a lot of them) and, finally, clocking in at less than one twentieth of one percent of the total, is everything heavier than helium.
Kind of throws a wrench in the works for the claim that the Universe was “designed for life,” doesn’t it? If all the Cosmos were a cake for Zeus, dark energy would be the fluffy chocolate pastry itself, dark matter would be the ice cream in between the cake layers, and all the elements of which the complexity of life is made constitute the merest candy sprinkle. The Universe was, it appears, “designed” for dark energy if it was designed at all, with dark matter an interesting elaboration and star-stuff like ourselves a small distraction.