62
" Supersymmetry was (and is) a beautiful mathematical idea. The problem with applying supersymmetry is that it is too good for this world. We simply do not find particles of the sort it predicts. We do not, for example, see particles with the same charge and mass as electrons, but a different amount of spin.
However, symmetry principles that might help to unify fundamental physics are hard to come by, so theoretical physicists do not give up on them easily. Based on previous experience with other forms of symmetry, we have developed a fallback strategy, called spontaneous symmetry breaking. In this approach, we postulate that the fundamental equations of physics have the symmetry, but the stable solutions of these equations do not. The classic example of this phenomenon occurs in an ordinary magnet. In the basic equations that describe the physics of a lump of iron, any direction is equivalent to any other, but the lump becomes a magnet with some definite north-seeking pole. "
― Frank Wilczek , The Lightness of Being: Mass, Ether, and the Unification of Forces
70
" The facts that so impressed Newton-that the planets all orbit in roughly the same plane (the ecliptic) and in the same direction-reflect their role as repositories of angular momentum, spun off as the original gas cloud condensed. Other features reflect the long influence of history, wearing down the rough edges, so to speak. The fact that the same side of our Moon always faces Earth is one such feature: rotation of the Moon would raise powerful tides, which act as friction. Presumably, in the distant past, there was such a rotation, but it has been damped out. (For similar reasons, the length of Earth days is increasing. Geological records, which show daily fluctuations in tidal deposits, indicate that during the Cambrian era, 650 million years ago, days were roughly twenty-one hours long.) "
― Frank Wilczek , A Beautiful Question: Finding Nature's Deep Design
72
" If this idea is right, then the basis of harmony is successful prediction in the early stages of perception. (This process of prediction need not, and usually does not, involve conscious attention.) Such success is experienced as pleasure, or beauty. Conversely, unsuccessful prediction is a source of pain, or ugliness. A corollary is that by expanding our experience, and learning, we can come to hear harmonies that were previously hidden to us, and to remove sources of pain.
Historically, in Western music, the palette of acceptable tone combinations has expanded over time. Individuals can also learn, by exposure, to enjoy tone combinations that at first seem unpleasant. Indeed, if we are built to enjoy learning to make successful predictions, then predictions that come too easily will not yield the greatest possible pleasure, which should also bring in novelty. "
― Frank Wilczek , A Beautiful Question: Finding Nature's Deep Design
74
" A true analysis of the incoming signal as to color must reveal the same information as Newton's prismatic analysis. A true analysis, that is to say, would resolve the incoming signal into its pure spectral components, each having its own independent strength. To report the result of such an analysis, we would need to specify a continuous infinity of numbers, one for the strength of each pure spectral component. Thus space of potential color information is not merely infinite, but infinite-dimensional. Instead, our eyes' projection of this information captures, as Maxwell discovered, just three numbers.
In short: the space of color information is infinite-dimensional, but we perceive, as color, only a three-dimensional surface, onto which those infinite dimensions project. "
― Frank Wilczek , A Beautiful Question: Finding Nature's Deep Design
75
" As Maxwell recognized, if atoms and molecules operated on the same principles as the Solar System, the world would be very different. Every atom would be different from every other, and every atom would change over time. Such a world wouldn't have chemistry as we know it, with definite substances and fixed rules.
It is not immediately obvious what makes atomic systems behave so differently. In both cases we have a massive central body attracting several small ones. The forces in play, gravitational or electrical, are broadly similar-both decrease as the square of the distance. But there are three factors which make the physical outcome very different, giving us stereotyped atoms but individualized solar systems:
1. Whereas planets differ from one another (as do stars), all electrons have exactly the same properties (as do all nuclei of a given element, or more precisely a given isotope).
2. Atoms obey the rules of quantum mechanics.
3. Atoms are starved for energy.
The first item in this explanation begs the question, of course. We're trying to explain why atoms can be the same as each other, and we start off by asserting that some other things, electrons, are all the same as each other! We'll come back to that later.
But having the same parts doesn't guarantee the same outcome, by any means. Even if all planets were the same as one another, and all stars were the same as one another, there would still be many possible designs for solar systems, and they'd all be subject to change.
We've seen how quantum mechanics brings discreteness, and fixed patterns, into the description of continuous objects that obey dynamical equations. It's the story you'll recall, that unfolds in figures 24 (page 172), 25 (page 174), and 26 (page 187), and plate CC.
To close the loop, we need to understand why the electrons in atoms are usually found in just one among their infinite variety of patterns. That's where our third item comes in. The pattern with lowest energy-the so-called ground state-is the one we generally find, because atoms are starved for energy.
Why are atoms starved for energy? Ultimately, it is because the Universe is big, cold, and expanding. Atoms can pass from one pattern to another by emitting light, and losing energy, or absorbing light, and gaining energy. If emission and absorption were balanced, many patterns would be in play. That's what would happen in a hot, closed system. Light emitted at one time would be absorbed later, and a balanced equilibrium would set in. But in a big, cold, expanding Universe, emitted light leaks into vast interstellar spaces, carrying away energy that is not returned.
In this way we find that dynamical equations, which by themselves cannot impose structure, do so through jujitsu (gentle skill), focusing the power of other principles. They guide the constraining powers of quantum mechanics and cosmology. Cosmology explains their poverty of energy, and quantum mechanics shows how poverty of energy imposes structure. "
― Frank Wilczek , A Beautiful Question: Finding Nature's Deep Design
76
" If the world behaved classically and predictably, the billion euros invested in LEP would have underwritten a very boring machine: every collision would just reproduce the result of the first one, and there'd be only one photograph to look at. Instead, our quantum-mechanical theories predict that many results can emerge from the same cause. And that is what we find. We can predict the relative probabilities of different results. Through many repetitions, we can check those predictions in detail. In that way, short-term unpredictability can be tamed. Short-term unpredictability is, in the end, perfectly compatible with long-term precision. "
― Frank Wilczek , The Lightness of Being: Mass, Ether, and the Unification of Forces
77
" At Brookhaven National Laboratory, on Long Island, and at several other centers around the world, there are special rooms where people rarely tread. Nothing much seems to be happening in these rooms, there's no visible motion, and the only sound is the gently whir of fans that keep the temperature steady and the humidity low. In these rooms, roughly 10^30 protons and neutrons are at work. They have been organized into hundreds of computers, harnessed to work in parallel. The team races at teraflop rates, which means 10^12- a million million-FLoating point OPerations per second. We let them labor for months-10^7 seconds. At the end , they've done what a single proton does every 10^-24 second, which is figure out how to orchestrate quark and gluon fields in the best possible way so that they keep the Grid satisfied and make a stable equilibrium. "
― Frank Wilczek , The Lightness of Being: Mass, Ether, and the Unification of Forces
79
" Despite its overwhelming virtues, the Core Theory is imperfect. Indeed, precisely because it is such a faithful description of reality, we must, in pursuit of our Question, hold it to the highest esthetic standards. So scrutinized, the Core Theory reveals flaws. Its equations are lopsided, and they contain several loosely connected pieces. Furthermore, the Core Theory does not account for so-called dark matter and dark energy. Although those tenuous forms of mater are negligible in our immediate neighborhood, they persist in the interstellar and intergalactic voids, and thereby come to dominate the overall mass of the Universe. For those and other reasons, we cannot remain satisfied. "
― Frank Wilczek , A Beautiful Question: Finding Nature's Deep Design
