万物简史 第229期:马斯特-马克的夸克(1)
11 Muster Mark's Quarks 第十一章 马斯特马克的夸克 IN 1911, A British scientist named C. T. R. Wilson was studying cloud formations by tramping regularly to the summit of Ben Nevis, 1911年，一位名叫C.T.R.威尔逊的英国科学家经常
万物简史 第230期:马斯特-马克的夸克(2)
As physicists built bigger and more ambitious machines, 随着物理学家建造越来越大、越来越雄心勃勃的机器， they began to find or postulate particles or particle families seemingly without number: 他们开始或推断出似乎永无
万物简史 第231期:马斯特-马克的夸克(3)
Particles can come into being and be gone again in as little as 0.000000000000000000000001 second (10-24). Even the most sluggish of unstable particles hang around for no more than 0.0000001 second (10-7). 粒子可以在短达0.000 000 000 000 000 0
万物简史 第232期:马斯特-马克的夸克(4)
CERN, the European Organization for Nuclear Research, is like a little city. Straddling the border of France and Switzerland, it employs three thousand people and occupies a site that is measured in square miles. CERN boasts a string of magnets that
万物简史 第233期:马斯特-马克的夸克(5)
The intention of the collider was to let scientists probe the ultimate nature of matter, as it is always put, by re-creating as nearly as possible the conditions in the universe during its first ten thousand billionths of a second. The plan was to fl
万物简史 第234期:马斯特-马克的夸克(6)
Particle physics, in short, is a hugely expensive enterprisebut 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 underst
万物简史 第235期:马斯特-马克的夸克(7)
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 seco
万物简史 第236期:马斯特-马克的夸克(8)
Although quarks are much too small to have color or taste or any other physical characteristics we would recognize, they became clumped into six categoriesup, down, strange, charm, top, and bottomwhich physicists oddly refer to as their flavors, and
万物简史 第237期:马斯特-马克的夸克(9)
It is all, as you can see, just a little unwieldy, but it is the simplest model that can explain all that happens in the world of particles. Most particle physicists feel, as Leon Lederman remarked in a 1985 PBS documentary, that the Standard Model l
万物简史 第238期:马斯特-马克的夸克(10)
In an attempt to draw everything together, physicists have come up with something called superstring theory. This postulates that all those little things like quarks and leptons that we had previously thought of as particles are actually stringsvibra
万物简史 第239期:马斯特-马克的夸克(11)
String theory has further spawned something called M theory, which incorporates surfaces known as membranesor simply branes to the hipper souls of the world of physics. I'm afraid this is the stop on the knowledge highway where most of us must get of
万物简史 第240期:马斯特-马克的夸克(12)
Almost at once the Bogdanov paper excited debate among physicists as to whether it was twaddle, a work of genius, or a hoax. Scientifically, it's clearly more or less complete nonsense, Columbia University physicist Peter Woit told the New York Times
万物简史 第241期:马斯特-马克的夸克(13)
Hubble realized that this could be expressed with a simple equation, Ho = v/d (where Ho is the constant, v is the recessional velocity of a flying galaxy, andd its distance away from us). Ho has been known ever since as the Hubble constant and the wh
万物简史 第242期:马斯特-马克的夸克(14)
This would mean that the universe was only half the size and age that Sandage believedten billion years. Matters took a further lurch into uncertainty when in 1994 a team from the Carnegie Observatories in California, using measures from the Hubble s
万物简史 第243期:马斯特-马克的夸克(15)
The difficulty in making final determinations is that there are often acres of room for interpretation. Imagine standing in a field at night and trying to decide how far away two distant electric lights are. Using fairly straightforward tools of astr
