Most people have no concept of how an automatic transmission works, yet they know how to drive a car. You don’t have to study physics to understand the laws of motion to drive a car. You don’t have to understand any of this stuff to use Macintosh.

It is reasonable that forces directed toward bodies depend on the nature and the quantity of matter of such bodies, as happens in the case of magnetic bodies.

Working out another system to replace Newton’s laws took a long time because phenomena at the atomic level were quite strange. One had to lose one’s common sense in order to perceive what was happening at the atomic level.

We seem gradually to be groping toward an understanding of the world of subatomic particles, but we really do not know how far we have yet to go in this task.

I had a project for my life which involved 10 years of wandering, then some years of medical studies and, if any time was left, the great adventure of physics.

The manual for WordStar, the most popular word-processing program, is 400 pages thick. To write a novel, you have to read a novel – one that reads like a mystery to most people. They’re not going to learn slash q-z any more than they’re going to learn Morse code. That is what Macintosh is all about.

It is now quite lawful for a Catholic woman to avoid pregnancy by a resort to mathematics, though she is still forbidden to resort to physics or chemistry.

The same thing is to be understood of all bodies, revolved in any orbits. They all endeavour to recede from the centres of their orbits, and were it not for the opposition of a contrary force which restrains them to and detains them in their orbits, which I therefore call Centripetal, would fly off in right lines with a uniform motion.

Often one postulates that a priori, all states are equally probable. This is not true in the world as we see it. This world is not correctly described by the physics which assumes this postulate.

Physics is really figuring out how to discover new things that are counterintuitive, like quantum mechanics. It’s really counterintuitive.

What goes up must come down.

It is indeed a matter of great difficulty to discover, and effectually to distinguish, the true motions of particular bodies from the apparent because the parts of that immovable space, in which those motions are performed, do by no means come under the observation of our senses.

Today, all physicists know from studying Einstein and Bohr that sometimes an idea which looks completely paradoxical at first, if analyzed to completion in all detail and in experimental situations, may, in fact, not be paradoxical.

Theoretical physics is one of the few fields in which being disabled is no handicap – it is all in the mind.

To create a new standard, it takes something that’s not just a little bit different; it takes something that’s really new and really captures people’s imagination, and the Macintosh, of all the machines I’ve ever seen, is the only one that meets that standard.

I think we all change each other’s paths. I don’t know which law idea that is in physics, but I don’t think any of us can live without affecting one another.

I am not enough of a mathematician to be able to judge either the well-foundedness or the limits of relativity in physics.

Physics has a history of synthesizing many phenomena into a few theories.

All the evidence, experimental and even a little theoretical, seems to indicate that it is the energy content which is involved in gravitation, and therefore, since matter and antimatter both represent positive energies, gravitation makes no distinction.

It now appears that the way the universe began can indeed be determined, using imaginary time.

My background educationally is physics and economics, and I grew up in sort of an engineering environment – my father is an electromechanical engineer. And so there were lots of engineery things around me.

Resistance is usually ascribed to bodies at rest, and impulse to those in motion, but motion and rest, as commonly conceived, are only relatively distinguished; nor are those bodies always truly at rest, which commonly are taken to be so.

The drawing teacher has this problem of communicating how to draw by osmosis and not by instruction, while the physics teacher has the problem of always teaching techniques, rather than the spirit, of how to go about solving physical problems.

I think you should always bear in mind that entropy is not on your side.

If a projectile were deprived of the force of gravity, it would not be deflected toward the earth but would go off in a straight line into the heavens and do so with uniform motion, provided that the resistance of the air were removed.

In the past, there was active discrimination against women in science. That has now gone, and although there are residual effects, these are not enough to account for the small numbers of women, particularly in mathematics and physics.

I think the discovery of supersymmetric partners for the known particles would revolutionize our understanding of the universe.

I need physics more than friends.

The missing link in cosmology is the nature of dark matter and dark energy.

An object in motion tends to remain in motion along a straight line unless acted upon by an outside force.

The people who are doing the work are the moving force behind the Macintosh. My job is to create a space for them, to clear out the rest of the organization and keep it at bay.

If you are in a spaceship that is traveling at the speed of light, and you turn on the headlights, does anything happen?

I went to Princeton specifically to study physics.

In some sort of crude sense, which no vulgarity, no humor, no overstatement can quite extinguish, the physicists have known sin; and this is a knowledge which they cannot lose.

Gravitation is, so far, not understandable in terms of other phenomena.

Because there is a law such as gravity, the universe can and will create itself from nothing.

My father was a research scientist in tropical medicine, so I always assumed I would be a scientist, too. I felt that medicine was too vague and inexact, so I chose physics.

It was Einstein’s dream to discover the grand design of the universe, a single theory that explains everything. However, physicists in Einstein’s day hadn’t made enough progress in understanding the forces of nature for that to be a realistic goal.

No one undertakes research in physics with the intention of winning a prize. It is the joy of discovering something no one knew before.

There is no physical law precluding particles from being organised in ways that perform even more advanced computations than the arrangements of particles in human brains.

I hope I have helped to raise the profile of science and to show that physics is not a mystery but can be understood by ordinary people.

The fundamental concept in social science is Power, in the same sense in which Energy is the fundamental concept in physics.

There are children playing in the streets who could solve some of my top problems in physics, because they have modes of sensory perception that I lost long ago.

Just as the system of the sun, planets and comets is put in motion by the forces of gravity, and its parts persist in their motions, so the smaller systems of bodies also seem to be set in motion by other forces and their particles to be variously moved in relation to each other and, especially, by the electric force.

While physics and mathematics may tell us how the universe began, they are not much use in predicting human behavior because there are far too many equations to solve. I’m no better than anyone else at understanding what makes people tick, particularly women.

Everything starts somewhere, although many physicists disagree.

It is theoretically possible to warp spacetime itself, so you’re not actually moving faster than the speed of light, but it’s actually space that’s moving.

Before 1915, space and time were thought of as a fixed arena in which events took place, but which was not affected by what happened in it. Space and time are now dynamic quantities… space and time not only affect but are also affected by everything that happens in the universe.

I tell you the solemn truth, that the doctrine of the Trinity is not so difficult to accept for a working proposition as any one of the axioms of physics.

There could be no fairer destiny for any physical theory than that it should point the way to a more comprehensive theory in which it lives on as a limiting case.

It is generally recognised that women are better than men at languages, personal relations and multi-tasking, but less good at map-reading and spatial awareness. It is therefore not unreasonable to suppose that women might be less good at mathematics and physics.

The greatest progress is in the sciences that study the simplest systems. So take, say, physics – greatest progress there. But one of the reasons is that the physicists have an advantage that no other branch of sciences has. If something gets too complicated, they hand it to someone else.

When I was a young man, Dirac was my hero. He made a breakthrough, a new method of doing physics. He had the courage to simply guess at the form of an equation, the equation we now call the Dirac equation, and to try to interpret it afterwards.

In my school, the brightest boys did math and physics, the less bright did physics and chemistry, and the least bright did biology. I wanted to do math and physics, but my father made me do chemistry because he thought there would be no jobs for mathematicians.

Science predicts that many different kinds of universe will be spontaneously created out of nothing. It is a matter of chance which we are in.

It should be possible to explain the laws of physics to a barmaid.

Man can be understood only by ascending from physics, chemistry, biology, and geology. In other words, he is first of all a cosmic problem.

Chemistry, until my childhood, not that long ago, was regarded as a calculating device. Because you couldn’t reduce to physics. So it’s just some way of calculating the result of experiments. The Bohr atom was treated that way.

We get the exciting result that the total energy of the universe is zero. Why this should be so is one of the great mysteries – and therefore one of the important questions of physics. After all, what would be the use of studying physics if the mysteries were not the most important things to investigate?

We are the product of quantum fluctuations in the very early universe.

The same law takes place in a system, consisting of many bodies, as in one single body, with regard to their persevering in their state of motion or of rest. For the progressive motion, whether of one single body or of a whole system of bodies, is always to be estimated from the motion of the center of gravity.