Brian Greene Quotes

In my own research when I'm working with equations, I never feel like I really understand what I'm doing if I'm solely relying on the mathematics for my understanding. I need to have a visual picture in my mind. I'm constantly translating from the math to some intuitive mind's-eye picture.

Science is a self-correcting discipline that can, in subsequent generations, show that previous ideas were not correct.

Now, from special relativity we know that energy and mass are two sides of the same coin: Greater energy means greater mass, and vice versa. Thus, according to string theory, the mass of an elementary particle is determined by the energy of the vibrational pattern of its internal string. Heavier particles have internal strings that vibrate more energetically, while lighter particles have internal strings that vibrate less energetically.

Writing for the stage is different from writing for a book. You want to write in a way that an actor has material to work with, writing in the first person not the third person, and pulling out the dramatic elements in a bigger way for a stage presentation.

Bohr advanced a heavyhanded remedy: evolve probability waves according to Schrodinger's equation whenever you're not looking or performing any kind of measurement. But when you do look, Bohr continued, you should throw Schrodinger's equation aside and declare that your observation has caused the wave to collapse.

Now, not only is this prescription ungainly, not only is it arbitrary, not only does it lack a mathematical underpinning, it's not even clear. For instance, it doesn't precisely define "looking" or "measuring." Must a human be involved? Or, as Einstein once asked, will a sidelong glance from a mouse suffice? How about a computer's probe, or even a nudge from a bacterium or virus? Do these "measurements" cause probability waves to collapse? Bohr announced that he was drawing a line in the sand separating small things, such as atoms and their constituents, to which Schrodinger's equation would apply, and big things, such as experimenters and their equipment, to which it wouldn't. But he never said where exactly that line would be. The reality is, he couldn't. With each passing year, experimenters confirm that Schrodinger's equation works, without modification, for increasingly large collections of particles, and there's every reason to believe that it works for collections as hefty as those making up you and me and everything else. Like floodwaters slowly rising from your basement, rushing into your living room, and threatening to engulf your attic, the math

The studies concluded that the graviton must be massless and chargeless, and must have the quantum mechanical property known as spin-2. (Very roughly, the graviton should spin like a top, twice as fast as the spin of a photon.)

Just as we envision all of space as really being out there, as really existing,
we should also envision all of time as really being out there, as really
existing too.

The revelation we've come to is that we can trust our memories of a past with lower, not higher, entropy only if the big bang - the process, event, or happening that brought the universe into existence - started off the universe in an extraordinarily special, highly ordered state of low entropy.

Most people don't question the practice of eating meat. Many of these people care about animals and the environment, some deeply. But for some reason-force of habit, cultural norms, resistance to change-there is a fundamental disconnect whereby these feelings don't translate into changes of behavior.

When you know the answer you want, it is often all too easy to figure out a way of getting it.

they are beyond each other's cosmic horizon.

I have long thought that anyone who does not regularly - or ever - gaze up and see the wonder and glory of a dark night sky filled with countless stars loses a sense of their fundamental connectedness to the universe

Science is the process that takes us from confusion to understanding ...

Sometimes nature guards her secrets with the unbreakable grip of physical law. Sometimes the true nature of reality beckons from just beyond the horizon.

When kids look up to great scientists the way they do to great musicians and actors, civilization will jump to the next level

Comparing infinities is a treacherous business

All you are is a bag of particles acting out the laws of physics. That to me is pretty clear.

The universe, according to quantum mechanics, participates in a game of chance.

Just as important, the energy released by the inflaton field isn't lost-instead, like a cooling vat of steam condensing into water droplets, the inflaton's energy condenses into a uniform bath of particles that fill space. This two-step process-brief but rapid expansion, followed by energy conversion to particles-results in a huge, uniform spatial expanse that's filled with the raw material of familiar structures like stars and galaxies.

The skyscraper is but a physical realization of the information contained in the architect's design.

When general relativity was first put forward in 1915, the math was very unfamiliar to most physicists. Now we teach general relativity to advanced high school students.

Sometimes attaining the deepest familiarity with a question is our best substitute for actually having the answer.

String theory is not the only theory that can accommodate extra dimensions, but it certainly is the one that really demands and requires it.

The number of e-mails and letters that I get from choreographers, from sculptors, from composers who are being inspired by science is huge.

In essence, we string theorists have been trying to work out the score of the universe, the harmonies of the universe, the mathematical vibrations that the strings would play. So musical metaphors have been with us in science since the beginning.

I can assure you that no string theorist would be interested in working on string theory if it were somehow permanently beyond testability. That would no longer be doing science.

String theorists have found special pairs of geometrical shapes for space that have completely different features when each is probed by unwrapped strings. They also have completely different features when each is probed by wrapped strings. But-and this is the punch line-when probed both ways, with wrapped and unwrapped strings, the shapes become indistinguishable. what the unwrapped strings see on one space, the wrapped strings see on the other, and vice versa, rendering identical the collective picture gleaned from the full physics of string theory.

After all, the reasoning goes, at the big bang everything emerged from one place since, we believe, all places we now think of as different were the same place way back in the beginning.

The main challenge that television presents is that I have a tendency to say things with a great deal of precision and accuracy. Often a description of that sort, which will work in a book because people can read it slowly - they can turn the pages back and so on - doesn't really work on TV because it interrupts the flow of the moving image.

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.

When we benefit from CT scanners, M.R.I. devices, pacemakers and arterial stents, we can immediately appreciate how science affects the quality of our lives.

The tantalizing discomfort of perplexity is what inspires otherwise ordinary men and women to extraordinary feats of ingenuity and creativity; nothing quite focuses the mind like dissonant details awaiting harmonious resolution.

If there is a lot of matter, gravity will cause space to curve back on itself, yielding the spherical shape. If there is little matter, space is free to flare outward in the Pringles shape. And if there is just the right amount of matter, space will have zero curvature.*

We are living through a remarkably privileged era, when certain deep truths about the cosmos are still within reach of the human spirit of exploration.

The entropy of a system is related to the number of indistinguishable rearrangements of its constituents, but properly speaking is not equal to the number itself. The relationship is expressed by a mathematical operation called a logarithm; don't be put off if this brings back bad memories of high school math class. In our coin example, it simply means that you pick out the exponent in the number of rearrangements-that is, the entropy is defined as 1,000 rather than 2^1000.

Stephen Hawking showed mathematically that the entropy of a black hole equals the number of Planck-sized cells that it takes to cover its event horizon. It's as if each cell carries one bit, one basic unit of information.

Einstein comes along and says, space and time can warp and curve, that's what gravity is. Now string theory comes along and says, yes, gravity, quantum mechanics, electromagnetism - all together in one package, but only if the universe has more dimensions than the ones that we see.

General relativity then establishes that objects move toward regions where time elapses more slowly; in a sense, all objects "want" to age as slowly as possible. From an Einsteinian perspective, that explains why an object falls when you let go of it.

So: if you buy the notion that reality consists of the things in your freeze-frame mental image right now, and if you agree that your now is no more valid than the now of someone located far away in space who can move freely, then reality encompasses all of the events in spacetime.

The universe is incredibly wondrous, incredibly beautiful, and it fills me with a sense that there is some underlying explanation that we have yet to fully understand. If someone wants to place the word 'God' on those collections of words, it's OK with me.

Free will is the sensation of making a choice. The sensation is real, but the choice seems illusory. Laws of physics determine the future.

We can certainly go further than cats, but why should it be that our brains are somehow so suited to the universe that our brains will be able to understand the deepest workings?

For me it's been very exciting to contribute to the public's understanding of how rich and wondrous science is.

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.

My view is that you don't tell the universe what to do. The universe is how it is, and it's our job to figure it out.

Oftentimes, if you're talking to a seasoned interviewer who asks you a question, they may do a follow-up if they didn't quite get it. It's rare that they'll do a third or fourth or fifth or sixth follow-up, because there's an implicit, agreed-upon decorum that they move on. Kids don't necessarily move on if they don't get it.

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.

Physicists have come to realize that mathematics, when used with sufficient care, is a proven pathway to truth.

Quantum mechanics broke the mold of the previous framework, classical mechanics, by establishing that the predictions of science are necessarily probabilistic.

I may be a Jewish scientist, but I would be tickled silly if one day I were reincarnated as a Baptist preacher.

So many galaxies, so many planets out there in the universe circling so many stars ... it just feels like there's a very good chance that there is another Earth-like planet out there that is able to support some kind of life similar to what we're familiar with.

My view is that science only has something to say about a very particular notion of God, which goes by the name of 'god of the gaps'.

We begin life as uninhibited explorers with a boundless fascination for the ever growing world to which we have access. And what I find amazing is that if that fascination is fed, and if it's challenged, and if it's nurtured, it can grow to an intellect capable of grappling with such marvels as the quantum nature of reality, the energy locked inside the atom, the curved spacetime of the cosmos, the elementary constituents of matter, the genetic code underlying life, the neural circuitry responsible for consciousness, and perhaps even the very origin of the universe.
- Brian Greene

In quantum mechanics there is A causing B. The equations do not stand outside that usual paradigm of physics. The real issue is that the kinds of things you predict in quantum mechanics are different from the kinds of things you predict using general relativity. Quantum mechanics, that big, new, spectacular remarkable idea is that you only predict probabilities, the likelihood of one outcome or another. That's the new idea.

The beauty of string theory is the metaphor kind of really comes very close to the reality. The strings of string theory are vibrating the particles, vibrating the forces of nature into existence, those vibrations are sort of like musical notes. So string theory, if it's correct, would be playing out the score of the universe.

Quantum mechanics - the physics of our world - requires that you hold such pedestrian complaints in abeyance.

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.

I can't stand clutter. I can't stand piles of stuff. And whenever I see it, I basically just throw the stuff away.

And so, whereas Bohr and the Copenhagen gang would argue that only one of these universes would exist (because the act of measurement, which they claim lies outside of Schrodinger's purview, would collapse away all the others), and whereas a first-pass attempt to go beyond Bohr and extend Schrodinger's math to all particles, including those constituting equipment and brains, yielded dizzying confusion (because a given machine or mind seemed to internalize all possible outcomes simultaneously), Everett found that a more careful reading of Schrodinger's math leads somewhere else: to a plentiful reality populated by an ever-growing collection of universes.

Physicists traced the failure to the jitters of quantum uncertainty. Mathematical techniques had been developed for analyzing the jitters of the strong, weak, and electromagnetic fields, but when the same methods were applied to the gravitational field-a field that governs the curvature of spacetime itself-they proved ineffective. This left the mathematics saturated with inconsistencies such as infinite probabilities.

Cosmology is among the oldest subjects to captivate our species. And it's no wonder. We're storytellers, and what could be more grand than the story of creation?

My mom says: 'Why aren't you a doctor?' and I'm like, 'I am a doctor!' and she's all, 'No, I mean a real doctor.' She reads my books, but she says they give her a headache.

According to string theory, if we could examine these particles with even greater precision - a precision many orders of magnitude beyond our present technological capacity - we would find that each is not pointlike, but instead consists of a tiny one-dimensional loop. Like an infinitely thin rubber band, each particle contains a vibrating, oscillating, dancing filament that physicists, lacking Gell-Mann's literary flair, have named a string.

Kaluza revealed that in a universe with an additional dimension of space, gravity and electromagnetism can both be described in terms of spatial ripples. Gravity ripples through the familiar three spatial dimensions, while electromagnetism ripples through the fourth. An outstanding problem with Kaluza's proposal was to explain why we don't see this fourth spatial dimension. It was here that Klein made his mark by suggesting the resolution explained above: dimensions beyond those we directly experience can elude our senses and our equipment if they're sufficiently small.

Many different planets are many different distances from their host star; we find ourselves at this distance because if we were closer or farther away, the temperature would be hotter or colder, eliminating liquid water, an essential ingredient for our survival.

All mathematics is is a language that is well tuned, finely honed, to describe patterns; be it patterns in a star, which has five points that are regularly arranged, be it patterns in numbers like 2, 4, 6, 8, 10 that follow very regular progression.

For most people, the major hurdle in grasping modern insights into the nature of the universe is that these developments are usually phrased using mathematics.

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.

Everett's approach, which he described as "objectively deterministic" with probability "reappearing at the subjective level," resonated with this strategy. And he was thrilled by the direction. As he noted in the 1956 draft of his dissertation, the framework offered to bridge the position of Einstein (who famously believed that a fundamental theory of physics should not involve probability) and the position of Bohr (who was perfectly happy with a fundamental theory that did). According to Everett, the Many Worlds approach accommodated both positions, the difference between them merely being one of perspective. Einstein's perspective is the mathematical one in which the grand probability wave of all particles relentlessly evolves by the Schrodinger equation, with chance playing absolutely no role. I like to picture Einstein soaring high above the many worlds of Many Worlds, watching as Schrodinger's equation fully dictates how the entire panorama unfolds, and happily concluding that even though quantum mechanics is correct, God doesn't play dice. Bohr's perspective is that of an inhabitant in one of the worlds, also happy, using probabilities to explain, with stupendous precision, those observations to which his limited perspective gives him access.

Of the many strange things Einstein's work revealed, the fluidity of time is the hardest to grasp. Whereas everyday experience convinces us that there is an objective concept of time's passage, relativity shows this to be an artifact of life at slow speeds and weak gravity. Move near light speed, or immerse yourself in a powerful gravitational field, and the familiar, universal conception of time will evaporate. If you're rushing past me, things I insist happened at the same moment will appear to you to have occurred at different moments. If you're hanging out near the edge of a black hole, an hour's passage on your watch will be monumentally longer on mine.

Two observations take us across the finish line. The Second Law ensures that entropy increases throughout the entire process, and so the information hidden within the hard drives, Kindles, old-fashioned paper books, and everything else you packed into the region is less than that hidden in the black hole. From the results of Bekenstein and Hawking, we know that the black hole's hidden information content is given by the area of its event horizon. Moreover, because you were careful not to overspill the original region of space, the black hole's event horizon coincides with the region's boundary, so the black hole's entropy equals the area of this surrounding surface. We thus learn an important lesson. The amount of information contained within a region of space, stored in any objects of any design, is always less than the area of the surface that surrounds the region (measured in square Planck units).

Physics grapples with the largest questions the universe presents. 'Where did the totality of reality come from?' 'Did time have a beginning?'

As every parent knows, children begin life as uninhibited, unabashed explorers of the unknown. From the time we can walk and talk, we want to know what things are and how they work - we begin life as little scientists.

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.

The boldness of asking deep questions may require unforeseen flexibility if we are to accept the answers.

The absolute worst thing that you ever can do, in my opinion, in bringing science to the general public, is be condescending or judgmental. It is so opposite to the way science needs to be brought forth.

String theory is the most developed theory with the capacity to unite general relativity and quantum mechanics in a consistent manner. I do believe the universe is consistent, and therefore I do believe that general relativity and quantum mechanics should be put together in a manner that makes sense.

Over the centuries, monumental upheavals in science have emerged time and again from following the leads set out by mathematics.

By dimension, we simply mean an independent direction in which, in principle, you can move; in which motion can take place. In an everyday world, we have left-right as one dimension; we have back-forth as a second one; and we have up-down as a third.

Even when I wasn't doing much 'science for the public' stuff, I found that four or five hours of intense work in physics was all my brain could take on a given day.

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.

The extreme disparity between the outsider's and insider's perspectives arises because they have vastly different conceptions of time. Although the point is far from obvious, we'll now see what appears as endless time to an outsider appears as endless space, at each moment of time, to an insider.

When you buy a jacket, you pick the size to ensure it fits. Similarly, we live in a universe in which the amount of dark energy fits our biological make-up. If the amount of dark energy were substantially different from what we've measured, the environmental conditions would be inhospitable to our form of life.

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.

Within the modified equations, Kaluza found the ones Einstein had already used successfully to describe gravity in the familiar three dimensions of space and one of time. But because his new formulation included an additional dimension of space, Kaluza found an additional equation. Lo and behold, when Kaluza derived this equation he recognized it as the very one Maxwell had discovered half a century earlier to describe the electromagnetic field.

Falsifiability for a theory is great, but a theory can still be respectable even if it is not falsifiable, as long as it is verifiable.

The fact that I don't have any particular need for religion doesn't mean that I have a need to cast religion aside the way some of my colleagues do.

if an atom were magnified to be as large as the observable universe, the same magnification would make the Planck length the size of an average tree.

My dad was a composer and a musician, but he never finished high school. His formal education was rather minimal from the standards of today's college graduates and Ph.D.'s, but he had a deep interest in questions of science and questions of the universe.

Science is a way of life. Science is a perspective. Science is the process that takes us from confusion to understanding in a manner that's precise, predictive and reliable - a transformation, for those lucky enough to experience it, that is empowering and emotional.

At high enough energy and temperature - such as occurred a mere fraction of a second after the big bang - electromagnetic and weak force fields dissolve into one another, take on indistinguishable characteristics, and are more accurately called electroweak fields.

If string theory is right, the microscopic fabric of our universe is a richly intertwined multidimensional labyrinth within which the strings of the universe endlessly twist and vibrate, rhythmically beating out the laws of the cosmos.

So, in one slightly technical line, here's the mathematical skinny. There's an equation in string theory that has a contribution of the form (D-10) times (Trouble), where D represents the number of spacetime dimensions and Trouble is a mathematical expression resulting in troublesome physical phenomena, such as the violation of energy conservation mentioned above. As to why the equation takes this precise form, I can't offer any intuitive, nontechnical explanation. But if you do the calculation, that's where the math leads. Now, this simple but key observation is that if the number of spacetime dimensions is ten, not the four we expect, the contribution becomes 0 times Trouble. And since 0 times anything is 0, in a universe with ten spacetime dimensions the trouble gets wiped away. That's how the math plays out. Really. And that's why string theorists argue for a universe with more than four spacetime dimensions.

But Einstein refused to be mathematics' pawn. He bucked the equations in favor of his intuition about how the cosmos should be, his deep-seated belief that the universe was eternal and, on the largest of scales, fixed and unchanging. The universe, Einstein admonished Lemaître, is not now expanding and never was.

Namely, each messenger particle is a string that's executing a particular vibrational pattern. A photon is a string vibrating in one particular pattern, a W particle is a string vibrating in a different pattern, a gluon is a string vibrating in yet another pattern. And, of prime importance, what Schwarz and Scherk showed in 1974 is that there is a parti Table

My emotional investment is in finding truth. If string theory is wrong, I'd like to have known that yesterday. But if we can show it today or tomorrow, fantastic.

Experience informs intuition. But it does more than that: Experience sets the frame within which we analyze and interpret what we perceive. You would no doubt expect, for instance, that the "wild child" raised by a pack of wolves would interpret the world from a perspective that differs substantially from your own. Even less extreme comparisons, such as those between people raised in very different cultural traditions, serve to underscore the degree to which our experiences determine our interpretive mindset.

A watch worn by a particle of light would not tick at all. Light realizes the dreams of Ponce de Leon and the cosmetics industry: it doesn't age.

One of the strangest features of string theory is that it requires more than the three spatial dimensions that we see directly in the world around us. That sounds like science fiction, but it is an indisputable outcome of the mathematics of string theory.

... The wonders of life and the universe are mere reflections of microscopic particles engaged in a pointless dance fully choreographed by the laws of physics.