This book was written in a way that helped explain complex concepts in a more digestible way. Even so, some of the ideas went right over my head and twisted my brain around. But I guess that's quantum physics for you in general. I enjoyed the little anecdotes about various people which appeared as footnotes. From these anecdotes, I gathered that physicists who specialize in quantum physics seem like quirky and colorful, fun people with unique personalities. Non-conformists. But again, maybe it comes with the territory.
Thinking about quantum physics and the subatomic world keeps amazing me with the fact that oxygen is made of these particles and that we are breathing them in all the time and expelling other particles. We can't see them but they are "things" that keep us alive. And just using oxygen as a reminder of the subatomic world around me keeps me in awe of the fact of our existence here and the components that create us and allow us this human experience.
"In all this discussion, I should not neglect to mention the practical value of what we might reasonably call 'our friend, the electron.' Whether on the surface of the Sun or within a compact fluorescent lamp, it is the motion of electrons that causes light to be emitted. In the retina of your eye, it is electrons within molecules that absorb light and let you see. In high-tension lines and motors and generators and computers and household gadgets, it is electrons that do the work of the industrial age. And within every living cell, it is the trading of electrons back and forth that powers life." pg. 17
"Fermi offered a theory in which electrons are created at the moment they are ejected from nuclei. This groundbreaking theory underlies everything that we have learned about particles since. All interactions of all particles involve creation and annihilation of particles. Our seemingly stable world is built on a near-infinitude of catastrophic events in the subatomic world." pg. 20
"If you could expand a proton to the size of a pea, the atom in which it resides would be about a mile across. There is indeed a lot of space within an atom." pg. 34
"According to quantum theory, if you don't measure it, there is no way of saying what the component might be--it is unpredictable and unknowable. This is a consequence of one of the most mind-stretching of all the ideas in quantum physics, the idea of superposition, that a system can exist in two or more states of motion at the same time. Applied to angular momentum, it's as if a satellite circling Earth could be following a number of different orbits at the same time, with various tilts relative to the Equator." pg. 58
"What Born proposed, and what we now accept, is that no matter how much you know about a quantum system, its behavior is still subject to laws of probability. It is a daunting idea that even if you know everything that can be known about a particular system, you cannot predict what it will do, and that if two systems are completely identical, they may behave in different ways. It's as if at a bridge tournament, identically prepared decks were provided to two tables and then the hands that were dealt were not the same." pg. 67
"How can it be that a nucleus can seem to be a liquid droplet and at the same time act like a gas of free nucleons? The answer lies in the nature of the nuclear force (which, ultimately, arises from the exchange of gluons among quarks). This force allows a proton or neutron to glide more or less unimpeded from one side of a nucleus to the other. But if a nucleon tends to stray away from its mass of fellow nucleons, it is pulled back sharply into the fold. The strong force at the edges of the nucleus produces something much like the surface tension of a liquid. So the nucleus as a whole can vibrate and oscillate like a liquid droplet even while the particles within it move more like the molecules in a gas. The theory of this dual nature of a nucleus goes by the name unified model or collective model." pg. 82
"Think of the marvels of the world that follow from a few simple principles and facts. Without the neutron there would be no element other than hydrogen. Without the exclusion principle and the rules for combining angular momenta, there would be a drab, largely inert set of atoms, no periodic table, and a world without life and color. Without the proton's charge, there would be no assembling of electrons into atoms, and nuclei would exist in endless number with nothing useful to do." pg. 87
"Without the stabilization of the neutron, it would be a dull universe indeed, consisting only of hydrogen--and cold hydrogen at that, as there would be no nuclear fusion to release energy and light the stars. It's a sobering thought that if the neutron were a little more massive than it actually is or the nuclear force a little weaker, there would be no stabilization of the neutron and no us." pg. 94
"It's a good thing, in a way, that the weak interaction is a participant in the Sun's fusion reactions. That helps explain why the Sun has been shining already for about 5 billion years and will shine for 5 billion more. Each second, the Sun converts 4.6 million tons of mass into energy." pg. 99
"The idea that a positron moving forward in time and an electron moving backward in time are really the same was first advanced by John Wheeler, Feynman's advisor at Princeton. Here is how Wheeler describes this epiphany in his autobiography: 'Sitting at home in Princeton one evening [in 1940 or 1941] it occurred to me that a positron could be interpreted as an electron moving backward in time. I was excited enough about that idea to phone my graduate student Richard Feynman at the Graduate College, the on-campus residence where he lived. "Dick," I said, "I know why all electrons and all positrons have the same mass and the same charge. They are the same particle!"'" pg. 143-144
"Val Fitch likes to say that the failure of PC (and T) invariance is the reason that we are here. Physicists now reckon that because of the lack of perfect symmetry between matter and antimatter, the early universe, shortly after the Big Bang, contained a not quite equal number of quarks and antiquarks. For every 1 billion quarks, according to calculations, there were 999 million antiquarks. When the dust cleared, one quark out of each billion survived, to make protons, neutrons, galaxies, stars, planets, and us." pg. 167
"But when you shrink the mass enough to enter the particle world, wavelength becomes very significant indeed. Because of its wave nature, an electron within an atom spreads out to encompass the whole atom. Similarly, neutrons and protons within the nucleus spread themselves over the nuclear volume. Only when a particle is accelerated to great energy does its wavelength shrink to less than the size of a nucleus or even the size of a single neutron or proton. Then the high-energy particle, with its shrunken wavelength, becomes a good probe of the smallest distances." pg. 177
"When a wave passes through an opening or by an edge, it bends. That is called diffraction. It can be seen in water waves that pass a ship at anchor, or it can be experienced indirectly by the fact that your wireless phone usually works even if there is a building between you and the cellular antenna. The diffraction effect is more pronounced for larger wavelength, which explains why longer-wavelength AM radio signals bend around obstacles more readily than shorter-wavelength FM signals do. Driving in the canyons of a big city, you are likely to find AM stations to be a bit more reliable than FM stations." pg. 182
"What the two-slit experiment teaches us--and what myriad other experiments confirm--is that a particle acts as a particle when it is created and annihilated (emitted and absorbed) and acts as a wave in between. To get our heads around it, we just have to give up the idea that a photon is a particle at any moment other than the moments of its birth and death." pg. 186
"The wave-particle duality is too often assigned a fairy-book character, as if a particle can magically morph into a wave and back again, or be both things at once. What is that streaking by? Is it a particle? Is it a wave? Is it both? What quantum physics actually tells us is that a particle behaves as a particle when it is created or annihilated (emitted or absorbed) and as a wave in between. Measurements reveal particles. Predictions of what the results of a measurement might be use waves. The wave therefore represents a kind of possibility, or potentiality. The particle represents reality." pg. 205
"Tunneling, an odd little feature of quantum physics, has turned out to be the reason stars shine." pg. 233
"It seems likely that superconductors will also find use in magnetically levitated vehicles of the future." pg. 235
"This is where Einstein's 'spooky action at a distance' comes in. You could measure the spin of that left-going photon a meter or a mile or a light-year from where it was created. At the moment you make the measurement, you can conclude what the spin direction of the other photon must be--two meters or two miles or two light-years away. Establishing with certainty the spin direction of one photon determines the spin direction of the other photon at that instant, even though, up until the measurement is made, the spin directions of both photons are uncertain and unknown. All of this because the two photons, until the moment of measurement, constitute a single quantum system, not two separate quantum systems." pg. 248
"A dozen years later [after quantum jumps] quantum theorists offered the concept of the 'collapse of the wave function.' Their idea was that an electron (or any quantum system) spreads through space as a wave, and when a measurement is performed, revealing a specific location or other property for the particle, the wave function 'collapses.' This is a way to think about the transition from probability to actuality." pg. 260
Book: borrowed from SSF Main Library.