Best 538 quotes in «physics quotes» category

What we are proposing,' Alicia said, 'is that the laws of physics are such that causality violation is subject to a form of version control, one that prevents a forking of history. That instead of causality violation creating an alternate universe, one version of history is outright overwritten by another. One past is replaced with another future. Which means that the memories of the past of the people in that future are replaced with memories of a different past.' Carson interrupted. 'Including the memories of any—' 'Purely hypothetical—' '—time travelers.' 'So take our time traveler from the traditional story,' Carson continued. 'He leaves his utopian future for the past. He kills the butterfly. The Magna Carta is never written. He returns to the dystopian future that his misstep created. But he doesn't see it as a dystopia: he sees it as home, the world he grew up in, the world he left to go back in time. Because he doesn't remember that first future, and has no other world to which he can compare this one. Maybe he even sees it as a utopia. Maybe everyone does. Maybe everyone in this dark place believes that they live in the best of all possible worlds.

When {Born and Heisenberg and the Göttingen theoretical physicists} first discovered matrix mechanics they were having, of course, the same kind of trouble that everybody else had in trying to solve problems and to manipulate and to really do things with matrices. So they had gone to Hilbert for help and Hilbert said the only time he had ever had anything to do with matrices was when they came up as a sort of by-product of the eigenvalues of the boundary-value problem of a differential equation. So if you look for the differential equation which has these matrices you can probably do more with that. They had thought it was a goofy idea and that Hilbert didn't know what he was talking about. So he was having a lot of fun pointing out to them that they could have discovered Schrödinger’s wave mechanics six month earlier if they had paid a little more attention to him.

When Einstein died, his greatest rival, Bohr, found for him words of moving admiration. When a few years later Bohr in turn died, someone took a photograph of the blackboard in his study. There’s a drawing on it. A drawing of the ‘light-filled box’ in Einstein’s thought experiment. To the very last, the desire to challenge oneself and understand more. And to the very last: doubt

When I was lecturing recently to a group of cardiologists at the Mayo Clinic I said... Why is it that from the moment you enter medical school to the moment you retire, the only disorder that you will ever diagnose with a physics textbook is obesity? This is biology folks, it's endocrinology, it's physiology - physics has nothing to do with it. The laws of thermodynamics are always true, the energy balance equation is irrelevant. If someone's getting fatter I guarantee you they're taking more energy than they expend (as long as they're getting heavier). And if they're getting leaner I guarantee they're expending more than they're taking in. [It's] given, let's never discuss it again. And if you say it to your patients you're telling them nothing (University Of Colorado Medical School, May 9th 2013 - via YouTube)

When I was young, I thought it is thunder that kills people. But when I learnt physics in the high school, I discovered that it is rather the lightning that does the killing. The voice of the thunder itself is just a noise. The lightning is the poise!

When I was young, I thought it was thunder that kills people. But when I learnt physics in St. Paul's High School, I discovered that it is rather the lightning that does the killing. The voice of the thunder itself is just a noise. The lightning is the poise. I learnt to take the course of my life, not by violence but rather with intelligence.

When left alone, quantum particles behave as multiple images of themselves (as waves, really), simultaneously moving through all possible paths in space and time. Now, again, why do we not experience this multitude around ourselves? Is it because we are probing things around us all the time? Why do all experiments that involve, say, the position of a particle make the particle suddenly be somewhere rather than everywhere? No one knows. Before you probe it, a particle is a wave of possibilities. After you've probed it, it is somewhere, and subsequently it is somewhere for ever, rather than everywhere again. Strange, that. Nothing, within the laws of quantum physics, allows for such a collapse to happen. It is an experimental mystery and a theoretical one. Quantum physics stipulates that whenever something is there, it can transform into something else, of course, but it cannot disappear. And since quantum physics allows for multiple possibilities simultaneously, these possibilities should then keep existing, even after a measurement is made. But they don't. Every possibility but one vanishes. We do not see any of the others around us. We live in a classical world, where everything is based on quantum laws but nothing resembles the quantum world.

[..] when we get down to the subatomic level, the solid world we live in also consists, again rather worryingly, of almost nothing and that wherever we do find something it turns out not to actually something, but only the probability that there may something there.

Why is it so difficult for us to think in relative terms? Well, for the good reason that human nature loves absoluteness, and erroneously considers it as a state of higher knowledge.

When you look deeply into yourself you may be able to see that there is, in this moment, a quality of aliveness that is animating you that is not philosophical and is not abstract. It's independent of what you think about it, what you believe about it and what you feel about it. It's always there! it is animating your breath, It is coursing the spirit, it is what makes it possible for you to think and speak and see and hear. This is the Invisible Touch.

Whether we like it or not, modern ways are going to alter and in part destroy traditional customs and values.

Why are black holes so different from all other objects in the macroscopic Universe? Why are they, and they alone, so elegantly simple? If I knew the answer, it would probably tell me something very deep about the nature of physical laws. But I don’t know.

...Why is it, that from the moment you enter medical school to the moment you retire, that the only disorder you will ever diagnosis with a physics book - is obesity? This is biology folks, it's endocrinology, it's physiology - physics has nothing to do with it. The law of thermodynamics is always true, [but] the energy balance equation is irrelevant...

...Why is it that from the moment you enter medical school to the moment you retire, the only disorder that you will ever diagnose with a physics textbook is obesity? This is biology folks, it's endocrinology, it's physiology - physics has nothing to do with it. The laws of thermodynamics are always true, the energy balance equation is irrelevant...

Which do you think is more valuable to humanity? a. Finding ways to tell humans that they have free will despite the incontrovertible fact that their actions are completely dictated by the laws of physics as instantiated in our bodies, brains and environments? That is, engaging in the honored philosophical practice of showing that our notion of "free will" can be compatible with determinism? or b. Telling people, based on our scientific knowledge of physics, neurology, and behavior, that our actions are predetermined rather than dictated by some ghost in our brains, and then sussing out the consequences of that conclusion and applying them to society? Of course my answer is b).

With only one proton in its nucleus, hydrogen is the lightest and simplest element, made entirely during the big bang. Out of the ninety-four naturally occurring elements, hydrogen lays claim to more than two-thirds of all the atoms in the human body, and more than ninety percent of all atoms in the cosmos, on all scales, right on down to the solar system. Hydrogen in the core of the massive planet Jupiter is under so much pressure that it behaves more like a conductive metal than a gas, creating the strongest magnetic field among the planets.

Within the immense ocean of galaxies and stars we are in a remote corner; amidst the infinite arabesques of forms which constitute reality we are merely a flourish among innumerably many such flourishes.

As an undergraduate, I did maths and physics. That doesn't make me a scientist. So I try to read and understand and talk to scientists.

A careful analysis of the process of observation in atomic physics has shown that the subatomic particles have no meaning as isolated entities, but can only be understood as interconnections between the preparation of an experiment and the subsequent measurement.

A consistent pursuit of classical physics forces a transformation in the very heart of that physics.

All of science can be divided into physics and stamp-collecting.

All the standard equations of mathematical physics can be separated and solved in Kerr geometry.

Wolfgang Pauli, in the months before Heisenberg's paper on matrix mechanics pointed the way to a new quantum theory, wrote to a friend, "At the moment physics is again terribly confused. In any case, it is too difficult for me, and I wish I had been a movie comedian or something of the sort and had never heard of physics." That testimony is particularly impressive if contrasted with Pauli's words less than five months later: "Heisenberg's type of mechanics has again given me hope and joy in life. To be sure it does not supply the solution to the riddle, but I believe it is again possible to march forward.

You want a physicist to speak at your funeral. You want the physicist to talk to your grieving family about the conservation of energy, so they will understand that your energy has not died. You want the physicist to remind your sobbing mother about the first law of thermodynamics; that no energy gets created in the universe, and none is destroyed. You want your mother to know that all your energy, every vibration, every Btu of heat, every wave of every particle that was her beloved child remains with her in this world. You want the physicist to tell your weeping father that amid energies of the cosmos, you gave as good as you got. And at one point you'd hope that the physicist would step down from the pulpit and walk to your brokenhearted spouse there in the pew and tell him that all the photons that ever bounced off your face, all the particles whose paths were interrupted by your smile, by the touch of your hair, hundreds of trillions of particles, have raced off like children, their ways forever changed by you. And as your widow rocks in the arms of a loving family, may the physicist let her know that all the photons that bounced from you were gathered in the particle detectors that are her eyes, that those photons created within her constellations of electromagnetically charged neurons whose energy will go on forever. And the physicist will remind the congregation of how much of all our energy is given off as heat. There may be a few fanning themselves with their programs as he says it. And he will tell them that the warmth that flowed through you in life is still here, still part of all that we are, even as we who mourn continue the heat of our own lives. And you'll want the physicist to explain to those who loved you that they need not have faith; indeed, they should not have faith. Let them know that they can measure, that scientists have measured precisely the conservation of energy and found it accurate, verifiable and consistent across space and time. You can hope your family will examine the evidence and satisfy themselves that the science is sound and that they'll be comforted to know your energy's still around. According to the law of the conservation of energy, not a bit of you is gone; you're just less orderly. Amen.

After Montesquieu, the next great addition to Sociology (which is the term I may be allowed to invent to designate Social Physics) was made by Condorcet, proceeding on the views suggested by his illustrious friend Turgot.

A lot of my theories were not applicable as a closer

A scenario is suggested by which the universe and its laws could have arisen naturally from nothing. Current cosmology suggests that no laws of physics were violated in bringing the universe into existence. The laws of physics themselves are shown to correspond to what one would expect if the universe appeared from nothing. There is something rather than nothing because something is more stable.

But even physics cannot be defined from an atomic topography.

As physics is a mental reconstruction of material processes, perhaps a physical reconstruction of psychic processes is possible in nature itself.

Classical physics has been superseded by quantum theory: quantum theory is verified by experiments. Experiments must be described in terms of classical physics.

Cambridge was the place for someone from the Colonies or the Dominions to go on to, and it was to the Cavendish Laboratory that one went to do physics.

Don't be surprised if in the 21st century lectures on meditation appear in university catalogues for physics.

[Computer science] is not really about computers and it's not about computers in the same sense that physics is not really about particle accelerators, and biology is not about microscopes and Petri dishes... and geometry isn't really about using surveying instruments.

Digital mechanics predicts that for every continuous symmetry of physics there will be some microscopic process that violates that symmetry.

Engineering is merely the slow younger brother of physics.

Don't waste your time on beaming people up or down. Instead, consider gravity waves as advanced physics of the universe that could be used to travel interstellar distances.

I am now convinced that theoretical physics is actually philosophy.

Even before string theory, especially as physics developed in the 20th century, it turned out that the equations that really work in describing nature with the most generality and the greatest simplicity are very elegant and subtle.

Ever since I was a kid, I've had an enormous interest in the sciences - everything from quantum physics to anthropology.

Everything is energy. It's physics. So I find the science of it all interesting; how 90% of stuff that's in our universe is made of stuff that we can't even measure. I find that fascinating.

For me, [John Wheeler] was the last Titan, the only physics superhero still standing.

[Heisenberg's seminal 1925 paper initiating quantum mechanics marked] one of the great jumps—perhaps the greatest—in the development of twentieth century physics.

How can you be a physics major and be shocked when you get pregnant from having sex?

I am fascinated by quantum physics.

Everything we call real is made of things that cannot be regarded as real.

Going to the moon is not a matter of physics but of economics.

Hard to be a physics major at Rice University if you have flunked calculus.

I began peering into the corners of the room, making sure all the shadows were cast by objects and obeying known laws of physics.

I do find that Western medicine is more and more open to proving energetic concepts. Why not, because modern physics is 100 percent based on it.

I don't. We've had three technological revolutions that have changed the course of human history, all driven by physics. In the first, the industrial revolution, physicists developed Newtonian mechanics and thermodynamics, which gave us the steam engine and machine power. The second technological revolution was the electricity revolution. That gave us radio, television, and telecommunications. Then, physicists developed the laser and the transistor.