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.

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.

M-theory is the unified theory Einstein was hoping to find.

Science is beautiful when it makes simple explanations of phenomena or connections between different observations. Examples include the double helix in biology and the fundamental equations of physics.

Some desire is necessary to keep life in motion, and he whose real wants are supplied must admit those of fancy.

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

Atheism is so senseless. When I look at the solar system, I see the earth at the right distance from the sun to receive the proper amounts of heat and light. This did not happen by chance.

Mars is the only place in the solar system where it’s possible for life to become multi-planetarian.

I felt like I might as well have been living in another part of the solar system.

Gravity must be caused by an Agent acting constantly according to certain laws, but whether this Agent be material or immaterial I have left to the consideration of my readers.

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.

Gravity may put the planets into motion, but without the divine Power, it could never put them into such a circulating motion as they have about the Sun; and therefore, for this as well as other reasons, I am compelled to ascribe the frame of this System to an intelligent Agent.

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

We are continually shaped by the forces of coincidence.

Philosophers have not kept up with modern developments in science. Particularly physics.

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

I need physics more than friends.

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

Quarks came in a number of varieties – in fact, at first, only three were needed to explain all the hundreds of particles and the different kinds of quarks – they are called u-type, d-type, s-type.

Why there is one body in our System qualified to give light and heat to all the rest, I know no reason but because the Author of the System thought it convenient; and why there is but one body of this kind, I know no reason, but because one was sufficient to warm and enlighten all the rest.

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

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.

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

Everything starts somewhere, although many physicists disagree.

Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe?

I have explained the phenomena of the heavens and of our sea by the force of gravity, but I have not yet assigned a cause to gravity.

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

This most beautiful system of the sun, planets, and comets, could only proceed from the counsel and dominion of an intelligent and powerful Being.

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?

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

You can’t blame gravity for falling in love.

My discovery that black holes emit radiation raised serious problems of consistency with the rest of physics. I have now resolved these problems, but the answer turned out to be not what I expected.

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

There is nothing that living things do that cannot be understood from the point of view that they are made of atoms acting according to the laws of physics.

I think we have a good chance of surviving long enough to colonize the solar system.

And yet it moves.

God in the beginning formed matter in solid, massy, hard, impenetrable, movable particles, of such sizes and figures, and with such other properties, and in such proportion to space, as most conduced to the end for which he formed them.

My first popular book, ‚A Brief History of Time,‘ aroused a great deal of interest, but many found it difficult to understand.

It may be that there is no such thing as an equable motion, whereby time may be accurately measured. All motions may be accelerated or retarded, but the true, or equable, progress of absolute time is liable to no change.

Atoms are very special: they like certain particular partners, certain particular directions, and so on. It is the job of physics to analyze why each one wants what it wants.

There were several possible solutions of the difficulty of classical electrodynamics, any one of which might serve as a good starting point to the solution of the difficulties of quantum electrodynamics.

There are only two forces in the world, the sword and the spirit. In the long run the sword will always be conquered by the spirit.

To practice five things under all circumstances constitutes perfect virtue; these five are gravity, generosity of soul, sincerity, earnestness, and kindness.

There are no black holes in the sense of regimes from which light can’t escape to infinity.

OK, so what’s the speed of dark?

They say the universe is expanding. That should help with the traffic.

Time can behave like another direction in space under extreme conditions.

It’s time for the human race to enter the solar system.

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.

A tragic situation exists precisely when virtue does not triumph but when it is still felt that man is nobler than the forces which destroy him.

The first amazing fact about gravitation is that the ratio of inertial mass to gravitational mass is constant wherever we have checked it. The second amazing thing about gravitation is how weak it is.

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.

Electrical science has disclosed to us the more intimate relation existing between widely different forces and phenomena and has thus led us to a more complete comprehension of Nature and its many manifestations to our senses.

I read ‚The High Frontier‘ in high school. I read it multiple times, and I was already primed. As soon as I read it, it made sense to me. It seemed very clear that planetary surfaces were not the right place for an expanding civilization inside our solar system.

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.

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

Susceptibility to the highest forces is the highest genius.

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

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.

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