Albert Einstein was a philosopher and physicist who revolutionized physics in the early 1900s once with quantum theory and twice more with relativity.

Quotes by Albert Einstein in Time One

Compared with this problem, the original theory of relativity is child’s play.

Does Oxford stop at this train?

From this it follows that one can reach a satisfactory theory only if one is able to dispense with the ether hypothesis.

I do not believe that it will lead to the goal if one sets up a classical theory and then ‘quantizes’ it.

[I]f anyone can do it, then it will be Bohm.

For us believing physicists, the distinction between past, present and future is only an illusion, however persistent.

Concepts that have proven useful in ordering things easily achieve such authority over us that we forget their earthly origins and accept them as unalterable givens. … The path of scientific progress is often made impassable for a long time by such errors.

No logical path leads to construction of a theory, only a groping design with meticulous consideration of objective facts.

[I]n the minds of physicists space remained until the most recent time simply the passive container of all events, playing no part in physical happenings itself.

To deny the ether is ultimately to assume that empty space has no physical qualities whatever. The fundamental facts of mechanics do not harmonize with this view.

[T]he universe according to Newton is finite, although it may possess an infinitely great total mass.

...continuum ...should be banned from the theory as a supplementary construction not justified by the essence of the problem, which corresponds to nothing “real”.

The theoretical framework of quantum mechanics would then be exploded.

[I]t will be seen that I have not succeeded in formulating boundary conditions for spatial infinity. Nevertheless, there is still a possible way out …. For if it were possible to regard the universe as a continuum which is finite (closed) with respect to its spatial dimensions, we should have no need at all of any such boundary conditions.

The existence of the gravitational field is inseparably bound up with the existence of space.

According to the general theory of relativity space without ether is unthinkable ….

I admit that the general theory of relativity is closer to the ether hypothesis than the special theory. This new ether theory, however, would not violate the principle of relativity, because the state of this … ether would not be that of a rigid body in an independent state of motion. . . .

How does it come about that alongside of the idea of ponderable matter, which is derived by abstraction from everyday life, the physicists set the idea of the existence of another kind of matter, the ether?… according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. Thus we may also say, I think, that the ether of the general theory of relativity is the outcome of the Lorentzian ether. . . . But this ether may not be thought of as endowed with the quality characteristic of ponderable media, as consisting of parts which may be tracked through time. The idea of motion may not be applied to it.

working strenuously on the further development of a theory on the connection between gravitation and electricity.”

Quantum mechanics is very impressive. But an inner voice tells me that it is not yet the real thing. The theory produces a good deal but hardly brings us closer to the secret of the Old One. I am at all events convinced that He does not play dice.

I tend more and more to the opinion that one cannot come further with a continuum theory.

If one asks what, irrespective of quantum mechanics, is characteristic of the world of ideas of physics, one is first of all struck by the following: the concepts of physics relate to the outside world….

Even the great initial success of the quantum theory does not make me believe in the fundamental dice game, although I am well aware that our younger colleagues interpret this as a consequence of senility.

[I]n the theory of [special] relativity the velocity c plays the part of a limiting velocity, which can neither be reached nor exceeded by any real body.

It is indeed an exacting requirement to have to ascribe physical reality to space in general, and especially to empty space.

“now” loses for the extended world its objective meaning … .

According to the theory of relativity, action at a distance with the velocity of light always takes the place of instantaneous action at a distance or of action at a distance with an infinite velocity of transmission.

(G)eometry however is not concerned with the relation of the ideas involved in it to objects of experience, but only with the logical connection of these ideas among themselves.

Who would imagine that this simple law has plunged the conscientiously thoughtful physicist into the greatest intellectual difficulties.

How can it be that mathematics, being after all a product of human thought which is independent of experience, is so admirably appropriate to the objects of reality?

All natural laws are therefore claimed to be, ‘in principle,’ of the statistical variety and our imperfect observation practices alone have cheated us into a belief in strict causality.

Human beings, vegetables, or cosmic dust, we all dance to a mysterious tune, intoned in the distance by an invisible piper.

… [the continuum] should be banned from the theory as a supplementary construction not justified by the essence of the problem, which corresponds to nothing “real”. But we still lack the mathematical structure unfortunately. How much I have already plagued myself in this way!

I still believe in the possibility of a model of reality―that is to say, of a theory which represents things themselves ….

[T]he creative principle resides in mathematics.

Through no skill of interpretation can this psi-function be turned into a passable description of a real state of affairs; in reality there is just no intermediary between exploded and unexploded.

I must confess that I was not able to find a way to explain the atomistic character of nature. My opinion is that … one has to find a possibility to avoid the continuum (together with space and time) altogether. But I have not the slightest idea what kind of elementary concepts could be used in such a theory.

The problem seems to me how one can formulate statements about a discontinuum without calling upon a continuum (space-time) as an aid; the latter should be banned from the theory ….

Today faith in unbroken causality is threatened … by the representatives of physics.

… a spacious chest resembling a room with an observer inside [to which] is fixed externally a hook with rope attached …

[T]he theoretical physicist’s picture of the world … demands the highest possible standard of rigorous precision in the description of relations, such as only the use of mathematical language can give.

[T]he physicist cannot simply surrender to the philosopher the critical contemplation of theoretical foundations; for he himself knows best and feels more surely where the shoe pinches.

The eternal mystery of the world is its comprehensibility.

The … justification for a physical concept lies exclusively in its clear and unambiguous relation to facts that can be experienced.

[W]e cannot attach any absolute signification to the concept of simultaneity, but that two events which, viewed from a system of coordinates, are simultaneous, can no longer be looked upon as simultaneous events when envisaged from a system which is in motion relatively to that system.

A knowledge of the existence of something we cannot penetrate, of the manifestations of the profoundest reason and the most radiant beauty, which are only accessible to our reason in their most elementary forms—it is this knowledge and this emotion that constitute the truly religious attitude; in this sense, and in this alone, I am a deeply religious man.

I’m convinced more and more that the electrodynamics of moving bodies as it is presented today doesn’t correspond to reality. . .

The whole fifty years of continuous brooding have not brought me nearer to the answer to the question ‘What are light quanta?’ Nowadays every Tom, Dick and Harry thinks he knows it, but he is mistaken.

… a big castle in the air that I’ve built you.

In a consistent theory of relativity there can be no inertia relatively to “space,” but only an inertia of masses relatively to one another.

It’s the theory that determines what one can observe.

even if they cannot both be ascertained by measurement in the same individual case. According to this point of view, the [wave] function represents an incomplete description of the real state of affairs.

I see the most essential thing in the overcoming of the inertial system, a thing that acts upon all processes, but undergoes no reaction. This concept is in principle no better than that of the center of the universe in Aristotelian physics.

I consider it entirely possible that physics cannot be based upon … continuous structures. Then nothing will remain of my whole castle in the air including the theory of gravitation, but also nothing of the rest of contemporary physics.

Try and penetrate with our limited means the secrets of nature and you will find that, behind all the discernible concatenations, there remains something subtle, intangible and inexplicable

If my theory of relativity is proven correct, Germany will claim me as a German and France will declare that I am a citizen of the world. Should my theory prove untrue, France will say that I am a German and Germany will declare that I am a Jew.

Since the mathematicians have invaded the theory of relativity, I do not understand it myself anymore.