Physics quotes

I would like nuclear fusion to become a practical power source. It would provide an inexhaustible supply of energy, without pollution or global warming. Time travel used to be thought of as just science fiction, but Einstein's general theory of relativity allows for the possibility that we could warp space-time so much that you could go off in a rocket and return before you set out. The radiation left over from the Big Bang is the same as that in your microwave oven but very much less powerful. It would heat your pizza only to minus 271.3*C - not much good for defrosting the pizza, let alone cooking it. Most sets of values would give rise to universes that, although they might be very beautiful, would contain no one able to wonder at that beauty. According to 'M' theory, ours is not the only universe. Instead, 'M' theory predicts that a great many universes were created out of nothing.
String theory has the potential to show that all of the wondrous happenings in the universe - from the frantic dance of subatomic quarks to the stately waltz of orbiting binary stars; from the primordial fireball of the big bang to the majestic swirl of heavenly galaxies - are reflections of one, grand physical principle, one master equation. Black holes, we all know, are these regions where if an object falls in, it can't get out, but the puzzle that many struggled with over the decades is, what happens to the information that an object contains when it falls into a black hole. Is it simply lost? Einstein's theory of relativity does a fantastic job for explaining big things.
Quantum mechanics is fantastic for the other end of the spectrum - for small things.
Relativity challenges your basic intuitions that you've built up from everyday experience. It says your experience of time is not what you think it is, that time is malleable. Your experience of space is not what you think it is; it can stretch and shrink. Before the discovery of quantum mechanics, the framework of physics was this: If you tell me how things are now, I can then use the laws of physics to calculate, and hence predict, how things will be later.
Nature's patterns sometimes reflect two intertwined features: fundamental physical laws and environmental influences. It's nature's version of nature versus nurture. Physicists are more like avant-garde composers, willing to bend traditional rules... Mathematicians are more like classical composers. In the far, far future, essentially all matter will have returned to energy. But because of the enormous expansion of space, this energy will be spread so thinly that it will hardly ever convert back to even the lightest particles of matter. Instead, a faint mist of light will fall for eternity through an ever colder and quieter cosmos. The math of quantum mechanics and the math of general relativity, when they confront one another, they are ferocious antagonists and the equations don't work. I've seen children's eyes light up when I tell them about black holes and the Big Bang. Physics grapples with the largest questions the universe presents.
"Where did the totality of reality come from?"
"Did time have a beginning?"
The pinpoints of starlight we see with the naked eye are photons that have been streaming toward us for a few years or a few thousand. We're on this planet for the briefest of moments in cosmic terms, and I want to spend that time thinking about what I consider the deepest questions. In any finite region of space, matter can only arrange itself in a finite number of configurations, just as a deck of cards can be arranged in only finitely many different orders. If you shuffle the deck infinitely many times, the card orderings must necessarily repeat. As scientists, we track down all promising leads, and there's reason to suspect that our universe may be one of many - a single bubble in a huge bubble bath of other universes. I would say in one sentence my goal is to at least be part of the journey to find the unified theory that Einstein himself was really the first to look for. When you drive your car, E = mc2 is at work. As the engine burns gasoline to produce energy in the form of motion, it does so by converting some of the gasoline's mass into energy, in accord with Einstein's formula. A unified theory would put us at the doorstep of a vast universe of things that we could finally explore with precision. How can a speck of a universe be physically identical to the great expanse we view in the heavens above? The real reason why general relativity is widely accepted is because it made predictions that were borne out by experimental observations. Every moment is as real as every other. Every "now," when you say, "This is the real moment," is as real as every other "now" - and therefore all the moments are just out there. Just as every location in space is out there, I think every moment in time is out there, too. Sometimes nature guards her secrets with the unbreakable grip of physical law. Sometimes the true nature of reality beckons from just beyond the horizon. Supersymmetry is a theory which stipulates that for every known particle there should be a partner particle. For instance, the electron should be paired with a supersymmetric "selectron," quarks ought to have "squark" partners, and so on. String theory envisions a multiverse in which our universe is one slice of bread in a big cosmic loaf. The other slices would be displaced from ours in some extra dimension of space. There was a time when 'universe' meant 'all there is.' Everything. The whole shebang. The notion of more than one universe, more than one everything, would seemingly be a contradiction in terms. I think the appropriate response for a physicist is: "I do not find the concept of God very interesting, because I cannot test it." There may be many Big Bangs that happened at various and far-flung locations, each creating its own swelling, spatial expanse, each creating a universe - our universe being the result of only one of those Big Bangs. Free will is the sensation of making a choice. The sensation is real, but the choice seems illusory. Laws of physics determine the future. They imply that a region of space the size of a pea would be stretched larger than the observable universe in a time interval so short that the blink of an eye would overestimate it by a factor larger than a million billion billion billion. For instance, a black hole as light as a small asteroid would emit about as much radiation as a million-megaton hydrogen bomb, with radiation concentrated in the gamma-ray part of the electromagnetic spectrum.