Anyone who thinks science is trying to make human life easier or more pleasant is utterly mistaken.

Einstein, twenty-six years old, only three years away from crude privation, still a patent examiner, published in the Annalen der Physik in 1905 five papers on entirely different subjects. Three of them were among the greatest in the history of physics. One, very simple, gave the quantum explanation of the photoelectric effect—it was this work for which, sixteen years later, he was awarded the Nobel prize. Another dealt with the phenomenon of Brownian motion, the apparently erratic movement of tiny particles suspended in a liquid: Einstein showed that these movements satisfied a clear statistical law. This was like a conjuring trick, easy when explained: before it, decent scientists could still doubt the concrete existence of atoms and molecules: this paper was as near to a direct proof of their concreteness as a theoretician could give. The third paper was the special eory of relativity, which quietly amalgamated space, time, and matter into one fundamental unity. This last paper contains no references and quotes no authority. All of them are written in a style unlike any other theoretical physicist's. They contain very little mathematics. There is a good deal of verbal commentary. The conclusions, the bizarre conclusions, emerge as though with the greatest of ease: the reasoning is unbreakable. It looks as though he had reached the conclusions by pure thought, unaided, without listening to the opinions of others. To a surprisingly large extent, that is precisely what he had done.

Geology ... offers always some material for observation. ... [When] spring and summer come round, how easily may the hammer be buckled round the waist, and the student emerge from the dust of town into the joyous air of the country, for a few delightful hours among the rocks.

In the Mortality Bills, pneumonia is an easy second, to tuberculosis; indeed in many cities the death-rate is now higher and it has become, to use the phrase of Bunyan 'the captain of the men of death.'

It is as easy to count atomies as to resolve the propositions of a lover.

It is easy to obtain confirmations, or verifications, for nearly every theory—if we look for confirmations. Confirmations should count only if they are the result of risky predictions... A theory which is not refutable by any conceivable event is non-scientific. Irrefutability is not a virtue of a theory (as people often think) but a vice. Every genuine test of a theory is an attempt to falsify it, or refute it.

It is not easy to imagine how little interested a scientist usually is in the work of any other, with the possible exception of the teacher who backs him or the student who honors him.

It is obvious that man dwells in a splendid universe, a magnificent expanse of earth and sky and heaven, which manifestly is built on a majestic plan, maintains some mighty design, though man himself cannot grasp it. Yet for him it is not a pleasant or satisfying world. In his few moments of respite from labor or from his enemies, he dreams that this very universe might indeed be perfect, its laws operating just as now they seem to do, and yet he and it somehow be in full accord. The very ease with which he can frame this image to himself makes the reality all the more mocking. ... It is only too clear that man is not at home in this universe, and yet he is not good enough to deserve a better.

Let us now recapitulate all that has been said, and let us conclude that by hermetically sealing the vials, one is not always sure to prevent the birth of the animals in the infusions, boiled or done at room temperature, if the air inside has not felt the ravages of fire. If, on the contrary, this air has been powerfully heated, it will never allow the animals to be born, unless new air penetrates from outside into the vials. This means that it is indispensable for the production of the animals that they be provided with air which has not felt the action of fire. And as it would not be easy to prove that there were no tiny eggs disseminated and floating in the volume of air that the vials contain, it seems to me that suspicion regarding these eggs continues, and that trial by fire has not entirely done away with fears of their existence in the infusions. The partisans of the theory of ovaries will always have these fears and will not easily suffer anyone's undertaking to demolish them.

Perhaps we see equations as simple because they are easily expressed in terms of mathematical notation already invented at an earlier stage of development of the science, and thus what appears to us as elegance of description really reflects the interconnectedness of Nature's laws at different levels.

Physics is not religion. If it were, we'd have a much easier time raising money.

Propose theories which can be criticized. Think about possible decisive falsifying experiments—crucial experiments. But do not give up your theories too easily—not, at any rate, before you have critically examined your criticism.

Rules of Thumb
Thumb's First Postulate: It is better to use a crude approximation and know the truth, plus or minus 10 percent, than demand an exact solution and know nothing at all.
Thumb's Second Postulate: An easily understood, workable falsehood is more useful than a complex incomprehensible truth.

The description of some of the experiments, which are communicated here, was completely worked out at my writing-table, before I had seen anything of the phenomena in question. After making the experiments on the following day, it was found that nothing in the description required to be altered. I do not mention this from feelings of pride, but in order to make clear the extraordinary ease and security with which the relations in question can be considered on the principles of Arrhenius' theory of free ions. Such facts speak more forcibly then any polemics for the value of this theory .

The feeling of it to my lungs was not sensibly different from that of common air; but I fancied that my breast felt peculiarly light and easy for some time afterwards. Who can tell but that, in time, this pure air may become a fashionable article in luxury. Hitherto only two mice and myself have had the privilege of breathing it.

Truth more easily comes out of error than out of confusion.

When I received the Nobel Prize, the only big lump sum of money I have ever seen, I had to do something with it. The easiest way to drop this hot potato was to invest it, to buy shares. I knew that World War II was coming and I was afraid that if I had shares which rise in case of war, I would wish for war. So I asked my agent to buy shares which go down in the event of war. This he did. I lost my money and saved my soul.

When you can dump a load of bricks on a corner lot, and let me watch them arrange themselves into a house — when you can empty a handful of springs and wheels and screws on my desk, and let me see them gather themselves together into a watch — it will be easier for me to believe that all these thousands of worlds could have been created, balanced, and set to moving in their separate orbits, all without any directing intelligence at all.

[The steamboat] will answer for sea voyages as well as for inland navigation, in particular for packets, where there may be a great number of passengers. He is also of opinion, that fuel for a short voyage would not exceed the weight of water for a long one, and it would produce a constant supply of fresh water. ... [T]he boat would make head against the most violent tempests, and thereby escape the danger of a lee shore; and that the same force may be applied to a pump to free a leaky ship of her water. ... [T]he good effects of the machine, is the almost omnipotent force by which it is actuated, and the very simple, easy, and natural way by which the screws or paddles are turned to answer the purpose of oars.
[This letter was written in 1785, before the first steamboat carried a man (Fitch) on 27 Aug 1787.]