… the rules of clockwork might apply to familiar objects such as snookerballs, but when it comes to atoms, the rules are those of roulette.

…where the electron behaves and misbehaves as it will,
where the forces tie themselves up into knots of atoms
and come united…

“By convention there is color, by convention sweetness, by convention bitterness, but in reality there are atoms and the void,” announced Democritus. The universe consists only of atoms and the void; all else is opinion and illusion. If the soul exists, it also consists of atoms.

[After science lost] its mystical inspiration … man’s destiny was no longer determined from “above” by a super-human wisdom and will, but from “below” by the sub-human agencies of glands, genes, atoms, or waves of probability. … A puppet of the Gods is a tragic figure, a puppet suspended on his chromosomes is merely grotesque.

[Certain students] suppose that because science has penetrated the structure of the atom it can solve all the problems of the universe. ... They are known in every ... college as the most insufferable, cocksure know-it-alls. If you want to talk to them about poetry, they are likely to reply that the "emotive response" to poetry is only a conditioned reflex .... If they go on to be professional scientists, their sharp corners are rubbed down, but they undergo no fundamental change. They most decidedly are not set apart from the others by their intellectual integrity and faith, and their patient humility in front of the facts of nature.... They are uneducated, in the fullest sense of the word, and they certainly are no advertisement for the claims of science teachers.

[Decoding the human genome sequence] is the most significant undertaking that we have mounted so far in an organized way in all of science. I believe that reading our blueprints, cataloguing our own instruction book, will be judged by history as more significant than even splitting the atom or going to the moon.

[Man] … his origin, his growth, his hopes and fears, his loves and his beliefs are but the outcome of accidental collocations of atoms; that no fire, no heroism, no intensity of thought and feeling can preserve an individual life beyond the grave; that all the labour of the ages, all the devotion, all the inspiration, all the noonday brightness of human genius are destined to extinction in the vast death of the solar system, and that the whole temple of Man's achievement must inevitably be buried beneath the debris of a universe in ruins…

[Misquotation; not by Einstein.] If only I had known, I should have become a watchmaker. [Apparently remorseful for his role in the development of the atom bomb.]

[Mitscherlich Law of Isomerism] An equal number of atoms, combined in the same way produce the same crystal forms, and the same crystal form does not depend on the nature of the atoms, but only on their number and mode of combination.

[On the practical applications of particle physics research with the Large Hadron Collider.] Sometimes the public says, “What's in it for Numero Uno? Am I going to get better television reception? Am I going to get better Internet reception?” Well, in some sense, yeah. … All the wonders of quantum physics were learned basically from looking at atom-smasher technology. … But let me let you in on a secret: We physicists are not driven to do this because of better color television. … That's a spin-off. We do this because we want to understand our role and our place in the universe.

[Professor W.L. Bragg asserts that] In sodium chloride there appear to be no molecules represented by NaCl. The equality in number of sodium and chlorine atoms is arrived at by a chess-board pattern of these atoms; it is a result of geometry and not of a pairing-off of the atoms.

[The] structural theory is of extreme simplicity. It assumes that the molecule is held together by links between one atom and the next: that every kind of atom can form a definite small number of such links: that these can be single, double or triple: that the groups may take up any position possible by rotation round the line of a single but not round that of a double link: finally that with all the elements of the first short period [of the periodic table], and with many others as well, the angles between the valencies are approximately those formed by joining the centre of a regular tetrahedron to its angular points. No assumption whatever is made as to the mechanism of the linkage. Through the whole development of organic chemistry this theory has always proved capable of providing a different structure for every different compound that can be isolated. Among the hundreds of thousands of known substances, there are never more isomeric forms than the theory permits.

[To elucidate using models] the different combining powers in elementary atoms, I … select my illustrations from that most delightful of games, croquet. Let the croquet balls represent our atoms, and let us distinguish the atoms of different elements by different colours. The white balls are hydrogen, the green ones chlorine atoms; the atoms of fiery oxygen are red, those of nitrogen, blue; the carbon atoms, lastly, are naturally represented by black balls. But we have, in addition, exhibit the different combining powers of these atoms … by screwing into the balls a number of metallic arms (tubes and pins), which correspond respectively to the combining powers of the atoms represented … to join the balls … in imitation of the atomic edifices represented.

[We should] abandon all attempts to construct perceptual models of atomic processes.

[About describing atomic models in the language of classical physics:] We must be clear that when it comes to atoms, language can be used only as in poetry. The poet, too, is not nearly so concerned with describing facts as with creating images and establishing mental connections.

[When asked “Dr. Einstein, why is it that when the mind of man has stretched so far as to discover the structure of the atom we have been unable to devise the political means to keep the atom from destroying us?”] That is simple, my friend. It is because politics is more difficult than physics.

A stands for atom; it is so small No one has ever seen it at all.
B stands for bomb; the bombs are much bigger,
So, brother, do not be too fast on the trigger.
H has become a most ominous letter.
It means something bigger if not something better.

Dass die bis jetzt unzerlegten chemischen Elemente absolut unzerlegbare Stoffe seien, ist gegenwärtig mindestens sehr unwahrscheinlich. Vielmehr scheint es, dass die Atome der Elemente nicht die letzten, sondern nur die näheren Bestandtheile der Molekeln sowohl der Elemente wie der Verbindungen bilden, die Molekeln oder Molecule als Massentheile erster, die Atome als solche zweiter Ordnung anzusehen sind, die ihrerseits wiederum aus Massentheilchen einer dritten höheren Ordnung bestehen werden.
That the as yet undivided chemical elements are absolutely irreducible substances, is currently at least very unlikely. Rather it seems, that the atoms of elements are not the final, but only the immediate constituents of the molecules of both the elements and the compounds—the Molekeln or molecule as foremost division of matter, the atoms being considered as second order, in turn consisting of matter particles of a third higher order.
[Speculating in 1870, on the existence of subatomic particles, in opening remark of the paper by which he became established as co-discoverer of the Periodic Law.]

Den förslags-mening: att olika element förenade med ett lika antal atomer af ett eller flere andra gemensamma element … och att likheten i krystallformen bestämmes helt och hållet af antalet af atomer, och icke af elementens.
[Mitscherlich Law of Isomerism] The same number of atoms combined in the same way produces the same crystalline form, and the same crystalline form is independent of the chemical nature of the atoms, and is determined only by their number and relative position.

Nature is curious, and such worke may make,
That our dull sense can never finde, but scape.
For Creatures, small as Atomes, may be there,
If every Atome a Creatures Figure beare.
If foure Atomes a World can make, then see
What severall Worlds might in an Eare--ring bee:
For Millions of these Atomes may bee in
The Head of one Small, little, Single Pin.
And if thus Small, then Ladies may well weare
A World of Worlds, as Pendents in each Eare.

~~[Attributed without source]~~ I have broken the machine (the atom) and touched the ghost of matter.

A cell is regarded as the true biological atom.

A Dr van’t Hoff of the veterinary college at Utrecht, appears to have no taste for exact chemical investigation. He finds it a less arduous task to mount Pegasus (evidently borrowed from the veterinary school) and to proclaim in his La Chemie dans l’espace how, during his bold fight to the top of the chemical Parnassus, the atoms appeared to him to have grouped themselves together throughout universal space. … I should have taken no notice of this matter had not Wislicenus oddly enough written a preface to the pamphlet, and not by way of a joke but in all seriousness recommended it a worthwhile performance.

A star is drawing on some vast reservoir of energy by means unknown to us. This reservoir can scarcely be other than the subatomic energy which, it is known exists abundantly in all matter; we sometimes dream that man will one day learn how to release it and use it for his service. The store is well nigh inexhaustible, if only it could be tapped. There is sufficient in the Sun to maintain its output of heat for 15 billion years.

A wonder then it must needs be,—that there should be any Man found so stupid and forsaken of reason as to persuade himself, that this most beautiful and adorned world was or could be produced by the fortuitous concourse of atoms.

According to Democritus, atoms had lost the qualities like colour, taste, etc., they only occupied space, but geometrical assertions about atoms were admissible and required no further analysis. In modern physics, atoms lose this last property, they possess geometrical qualities in no higher degree than colour, taste, etc. The atom of modern physics can only be symbolized by a partial differential equation in an abstract multidimensional space. Only the experiment of an observer forces the atom to indicate a position, a colour and a quantity of heat. All the qualities of the atom of modern physics are derived, it has no immediate and direct physical properties at all, i.e. every type of visual conception we might wish to design is, eo ipso, faulty. An understanding of 'the first order' is, I would almost say by definition, impossible for the world of atoms.

After that cancellation [of the Superconducting Super Collider in Texas, after $2 billion had been spent on it], we physicists learned that we have to sing for our supper. ... The Cold War is over. You can't simply say “Russia!” to Congress, and they whip out their checkbook and say, “How much?” We have to tell the people why this atom-smasher is going to benefit their lives.

After the discovery of spectral analysis no one trained in physics could doubt the problem of the atom would be solved when physicists had learned to understand the language of spectra. So manifold was the enormous amount of material that has been accumulated in sixty years of spectroscopic research that it seemed at first beyond the possibility of disentanglement. An almost greater enlightenment has resulted from the seven years of Röntgen spectroscopy, inasmuch as it has attacked the problem of the atom at its very root, and illuminates the interior. What we are nowadays hearing of the language of spectra is a true 'music of the spheres' in order and harmony that becomes ever more perfect in spite of the manifold variety. The theory of spectral lines will bear the name of Bohr for all time. But yet another name will be permanently associated with it, that of Planck. All integral laws of spectral lines and of atomic theory spring originally from the quantum theory. It is the mysterious organon on which Nature plays her music of the spectra, and according to the rhythm of which she regulates the structure of the atoms and nuclei.

All change is relative. The universe is expanding relatively to our common material standards; our material standards are shrinking relatively to the size of the universe. The theory of the “expanding universe” might also be called the theory of the “shrinking atom”. …
:Let us then take the whole universe as our standard of constancy, and adopt the view of a cosmic being whose body is composed of intergalactic spaces and swells as they swell. Or rather we must now say it keeps the same size, for he will not admit that it is he who has changed. Watching us for a few thousand million years, he sees us shrinking; atoms, animals, planets, even the galaxies, all shrink alike; only the intergalactic spaces remain the same. The earth spirals round the sun in an ever-decreasing orbit. It would be absurd to treat its changing revolution as a constant unit of time. The cosmic being will naturally relate his units of length and time so that the velocity of light remains constant. Our years will then decrease in geometrical progression in the cosmic scale of time. On that scale man’s life is becoming briefer; his threescore years and ten are an ever-decreasing allowance. Owing to the property of geometrical progressions an infinite number of our years will add up to a finite cosmic time; so that what we should call the end of eternity is an ordinary finite date in the cosmic calendar. But on that date the universe has expanded to infinity in our reckoning, and we have shrunk to nothing in the reckoning of the cosmic being.
We walk the stage of life, performers of a drama for the benefit of the cosmic spectator. As the scenes proceed he notices that the actors are growing smaller and the action quicker. When the last act opens the curtain rises on midget actors rushing through their parts at frantic speed. Smaller and smaller. Faster and faster. One last microscopic blurr of intense agitation. And then nothing.

All that can be said upon the number and nature of elements is, in my opinion, confined to discussions entirely of a metaphysical nature. The subject only furnishes us with indefinite problems, which may be solved in a thousand different ways, not one of which, in all probability, is consistent with nature. I shall therefore only add upon this subject, that if, by the term elements, we mean to express those simple and indivisible atoms of which matter is composed, it is extremely probable we know nothing at all about them; but, if we apply the term elements, or principles of bodies, to express our idea of the last point which analysis is capable of reaching, we must admit, as elements, all the substances into which we are capable, by any means, to reduce bodies by decomposition.

All the events which occur upon the earth result from Law: even those actions which are entirely dependent on the caprices of the memory, or the impulse of the passions, are shown by statistics to be, when taken in the gross, entirely independent of the human will. As a single atom, man is an enigma; as a whole, he is a mathematical problem. As an individual, he is a free agent; as a species, the offspring of necessity.

All things are made of atoms—little particles that move around in perpetual motion, attracting each other when they are a little distance apart, but repelling upon being squeezed into one another. In that one sentence ... there is an enormous amount of information about the world.
His suggestion that the most valuable information on scientific knowledge in a single sentence using the fewest words is to state the atomic hypothesis.

All things on the earth are the result of chemical combination. The operation by which the commingling of molecules and the interchange of atoms take place we can imitate in our laboratories; but in nature they proceed by slow degrees, and, in general, in our hands they are distinguished by suddenness of action. In nature chemical power is distributed over a long period of time, and the process of change is scarcely to be observed. By acts we concentrate chemical force, and expend it in producing a change which occupies but a few hours at most.

Although we know nothing of what an atom is, yet we cannot resist forming some idea of a small particle, which represents it to the mind ... there is an immensity of facts which justify us in believing that the atoms of matter are in some way endowed or associated with electrical powers, to which they owe their most striking qualities, and amongst them their mutual chemical affinity.
[Summarizing his investigations in electrolysis.]

An aromatic compound may be defined as a cyclic compound with a large resonance energy where all the annular atoms take part in a single conjugated system.

An atom must be at least as complex as a grand piano.

An atom-blaster is a good weapon, but it can point both ways.

An unelectrified atom is so elusive that unless more than a million million are present we have no means sufficiently sensitive to detect them, or, to put it another way, unless we had a better test for a man than for an unelectrified molecule, we should be unable to find out that the earth was inhabited. … A billion unelectrified atoms may escape our observation, whereas a dozen or so electrified ones are detected without difficulty.

Ancient stars in their death throes spat out atoms like iron which this universe had never known. ... Now the iron of old nova coughings vivifies the redness of our blood.

And even your atom, my dear mechanists and physicists—how much error, how much rudimentary psychology is still residual in your atom!

And for rejecting such a Medium, we have the Authority of those the oldest and most celebrated Philosophers of Greece and Phoenicia, who made a Vacuum, and Atoms, and the Gravity of Atoms, the first Principles of their Philosophy; tacitly attributing Gravity to some other Cause than dense Matter. Later Philosophers banish the Consideration of such a Cause out of natural Philosophy, feigning Hypotheses for explaining all things mechanically, and referring other Causes to Metaphysicks: Whereas the main Business of natural Philosophy is to argue from Phaenomena without feigning Hypotheses, and to deduce Causes from Effects, till we come to the very first Cause, which certainly is not mechanical; and not only to unfold the Mechanism of the World, but chiefly to resolve these and such like Questions. What is there in places almost empty of Matter, and whence is it that the Sun and Planets gravitate towards one another, without dense Matter between them? Whence is it that Nature doth nothing in vain; and whence arises all that Order and Beauty which we see in the World? ... does it not appear from phaenomena that there is a Being incorporeal, living, intelligent, omnipresent, who in infinite space, as it were in his Sensory, sees the things themselves intimately, and thoroughly perceives them, and comprehends them wholly by their immediate presence to himself.

And new philosophy calls all in doubt,
The Element of fire is quite put out;
The Sun is lost, and th’earth, and no mans wit
Can well direct him where to look for it.
And freely men confesse that this world’s spent,
When in the Planets, and the Firmament
They seeke so many new; and then see that this
Is crumbled out againe to his Atomies.
’Tis all in pieces, all cohaerence gone;
All just supply, and all Relation;
Prince, Subject, Father, Sonne, are things forgot,
For every man alone thinkes he hath got
To be a phoenix, and that then can bee
None of that kinde, of which he is, but hee.

And shall an atom of this atom world
Mutter the theme of heaven?

Anything made out of destructible matter
Infinite time would have devoured before.
But if the atoms that make and replenish the world
Have endured through the immense span of the past
Their natures are immortal—that is clear.
Never can things revert to nothingness!

Are the atoms of the dextroacid (tartaric) grouped in the spirals of a right-hand helix or situated at the angles of an irregular tetrahedron, or arranged in such or such particular unsymmetrical fashion? We are unable to reply to these questions. But there can be no reason for doubting that the grouping of the atoms has an unsymmetrical arrangement with a non-superimposable image. It is not less certain that the atoms of the laevo-acid realize precisely an unsymmetrical arrangement of the inverse of the above.

As a man who has devoted his whole life to the most clear headed science, to the study of matter, I can tell you as a result of my research about atoms this much: There is no matter as such. All matter originates and exists only by virtue of a force which brings the particle of an atom to vibration and holds this most minute solar system of the atom together. … We must assume behind this force the existence of a conscious and intelligent mind. This mind is the matrix of all matter.

As a physicist who devoted his entire life to sober science, to the study of matter, I am sure that I am free from the suspicion of being considered a zealot. And so, according to my research of the atom, I say this: There is no matter in itself. All matter arises and exists only through a force that vibrates the atomic particles and holds them together to form the tiniest solar system of the universe. However, since there is no intelligent force or eternal power in the entire universe—mankind has not been able to invent the much-anticipated perpetuum mobile—we must accept a conscious intelligent mind behind this force. This spirit is the cause of all matter.

As far as I see, such a theory [of the primeval atom] remains entirely outside any metaphysical or religious question. It leaves the materialist free to deny any transcendental Being. He may keep, for the bottom of space-time, the same attitude of mind he has been able to adopt for events occurring in non-singular places in space-time. For the believer, it removes any attempt to familiarity with God, as were Laplace’s chiquenaude or Jeans’ finger. It is consonant with the wording of Isaiah speaking of the “Hidden God” hidden even in the beginning of the universe … Science has not to surrender in face of the Universe and when Pascal tries to infer the existence of God from the supposed infinitude of Nature, we may think that he is looking in the wrong direction.

As regards the co-ordination of all ordinary properties of matter, Rutherford’s model of the atom puts before us a task reminiscent of the old dream of philosophers: to reduce the interpretation of the laws of nature to the consideration of pure numbers.

As soon as we touch the complex processes that go on in a living thing, be it plant or animal, we are at once forced to use the methods of this science [chemistry]. No longer will the microscope, the kymograph, the scalpel avail for the complete solution of the problem. For the further analysis of these phenomena which are in flux and flow, the investigator must associate himself with those who have labored in fields where molecules and atoms, rather than multicellular tissues or even unicellular organisms, are the units of study.

Astronomy affords the most extensive example of the connection of physical sciences. In it are combined the sciences of number and quantity, or rest and motion. In it we perceive the operation of a force which is mixed up with everything that exists in the heavens or on earth; which pervades every atom, rules the motion of animate and inanimate beings, and is a sensible in the descent of the rain-drop as in the falls of Niagara; in the weight of the air, as in the periods of the moon.

Astronomy is older than physics. In fact, it got physics started by showing the beautiful simplicity of the motion of the stars and planets, the understanding of which was the beginning of physics. But the most remarkable discovery in all of astronomy is that the stars are made of atoms of the same kind as those on the earth.

At first, the sea, the earth, and the heaven, which covers all things, were the only face of nature throughout the whole universe, which men have named Chaos; a rude and undigested mass, and nothing more than an inert weight, and the discordant atoms of things not harmonizing, heaped together in the same spot.

At quite uncertain times and places,
The atoms left their heavenly path,
And by fortuitous embraces,
Engendered all that being hath.
And though they seem to cling together,
And form 'associations' here,
Yet, soon or late, they burst their tether,
And through the depths of space career.

At this stage you must admit that whatever is seen to be sentient is nevertheless composed of atoms that are insentient. The phenomena open to our observation so not contradict this conclusion or conflict with it. Rather they lead us by the hand and compel us to believe that the animate is born, as I maintain, of the insentient.

Atoms and molecules … from their very nature can never be made the objects of sensuous contemplation.

Atoms are not indivisible, for negatively electrified particles can be torn from them by the action of electrical forces.

Atoms are not things.

Atoms are round balls of wood invented by Dr. Dalton.
Answer given by a pupil to a question on atomic theory, as reported by Sir Henry Enfield Roscoe.

Atoms for peace. Man is still the greatest miracle and the greatest problem on earth. [Message tapped out by Sarnoff using a telegraph key in a tabletop circuit demonstrating an RCA atomic battery as a power source.]

Atoms have a nucleus, made of protons and neutrons bound together. Around this nucleus shells of electrons spin, and each shell is either full or trying to get full, to balance with the number of protons—to balance the number of positive and negative charges. An atom is like a human heart, you see.

Atoms or systems into ruin hurl’d,
And now a bubble burst, and now a world.

Bohr’s standpoint, that a space-time description is impossible, I reject a limine. Physics does not consist only of atomic research, science does not consist only of physics, and life does not consist only of science. The aim of atomic research is to fit our empirical knowledge concerning it into our other thinking. All of this other thinking, so far as it concerns the outer world, is active in space and time. If it cannot be fitted into space and time, then it fails in its whole aim and one does not know what purpose it really serves.

Borel makes the amusing supposition of a million monkeys allowed to play upon the keys of a million typewriters. What is the chance that this wanton activity should reproduce exactly all of the volumes which are contained in the library of the British Museum? It certainly is not a large chance, but it may be roughly calculated, and proves in fact to be considerably larger than the chance that a mixture of oxygen and nitrogen will separate into the two pure constituents. After we have learned to estimate such minute chances, and after we have overcome our fear of numbers which are very much larger or very much smaller than those ordinarily employed, we might proceed to calculate the chance of still more extraordinary occurrences, and even have the boldness to regard the living cell as a result of random arrangement and rearrangement of its atoms. However, we cannot but feel that this would be carrying extrapolation too far. This feeling is due not merely to a recognition of the enormous complexity of living tissue but to the conviction that the whole trend of life, the whole process of building up more and more diverse and complex structures, which we call evolution, is the very opposite of that which we might expect from the laws of chance.

But I must confess I am jealous of the term atom; for though it is very easy to talk of atoms, it is very difficult to form a clear idea of their nature, especially when compounded bodies are under consideration.

But it is necessary to insist more strongly than usual that what I am putting before you is a model—the Bohr model atom—because later I shall take you to a profounder level of representation in which the electron instead of being confined to a particular locality is distributed in a sort of probability haze all over the atom.

By blending water and minerals from below with sunlight and CO₂ from above, green plants link the earth to the sky. We tend to believe that plants grow out of the soil, but in fact most of their substance comes from the air. The bulk of the cellulose and the other organic compounds produced through photosynthesis consists of heavy carbon and oxygen atoms, which plants take directly from the air in the form of CO₂. Thus the weight of a wooden log comes almost entirely from the air. When we burn a log in a fireplace, oxygen and carbon combine once more into CO₂, and in the light and heat of the fire we recover part of the solar energy that went into making the wood.

By convention sweet is sweet, by convention bitter is bitter, by convention hot is hot, by convention cold is cold, by convention colour is colour. But in reality there are atoms and the void. That is, the objects of sense are supposed to be real and it is customary to regard them as such, but in truth they are not. Only the atoms and the void are real.

By Emerson scientific conceptions are continually transmuted into the finer forms and warmer hues of an ideal world. Our present theme is touched upon in the lines—
“The journeying atoms, primordial wholes
Firmly draw, firmly drive by their animate poles.”

By the 18th century science had been so successful in laying bare the laws of nature that many thought there was nothing left to discover. Immutable laws prescribed the motion of every particle in the universe, exactly and forever: the task of the scientist was to elucidate the implications of those laws for any particular phenomenon of interest. Chaos gave way to a clockwork world. But the world moved on ...Today even our clocks are not made of clockwork. ... With the advent of quantum mechanics, the clockwork world has become a lottery. Fundamental events, such as the decay of a radioactive atom, are held to be determined by chance, not law.

Carbon has this genius of making a chemically stable two-dimensional, one-atom-thick membrane in a three-dimensional world. And that, I believe, is going to be very important in the future of chemistry and technology in general.

Carbon is, as may easily be shown and as I shall explain in greater detail later, tetrabasic or tetratomic, that is 1 atom of carbon = C = 12 is equivalent to 4 At.H. The simplest connection of C with an element of the first Group, with H or Cl for example, is therefore: CH₄ and CCl₄.

Certain elements have the property of producing the same crystal form when in combination with an equal number of atoms of one or more common elements, and the elements, from his point of view, can be arranged in certain groups. For convenience I have called the elements belonging to the same group … isomorphous.

Circumstantial evidence can be overwhelming. We have never seen an atom, but we nevertheless know that it must exist.

Compare ... the various quantities of the same element contained in the molecule of the free substance and in those of all its different compounds and you will not be able to escape the following law: The different quantities of the same element contained in different molecules are all whole multiples of one and the same quantity, which always being entire, has the right to be called an atom.

Consider now the Milky Way. Here also we see an innumerable dust, only the grains of this dust are no longer atoms but stars; these grains also move with great velocities, they act at a distance one upon another, but this action is so slight at great distances that their trajectories are rectilineal; nevertheless, from time to time, two of them may come near enough together to be deviated from their course, like a comet that passed too close to Jupiter. In a word, in the eyes of a giant, to whom our Suns were what our atoms are to us, the Milky Way would only look like a bubble of gas.

Da Vinci was as great a mechanic and inventor as were Newton and his friends. Yet a glance at his notebooks shows us that what fascinated him about nature was its variety, its infinite adaptability, the fitness and the individuality of all its parts. By contrast what made astronomy a pleasure to Newton was its unity, its singleness, its model of a nature in which the diversified parts were mere disguises for the same blank atoms.

Dear Professor Rutherford, We students of our university physics club elect you our honorary president because you proved that atoms have balls.

Decades spent in contact with science and its vehicles have directed my mind and senses to areas beyond their reach. I now see scientific accomplishments as a path, not an end; a path leading to and disappearing in mystery. Science, in fact, forms many paths branching from the trunk of human progress; and on every periphery they end in the miraculous. Following these paths far enough, one must eventually conclude that science itself is a miracle—like the awareness of man arising from and then disappearing in the apparent nothingness of space. Rather than nullifying religion and proving that “God is dead,” science enhances spiritual values by revealing the magnitudes and minitudes—from cosmos to atom—through which man extends and of which he is composed.

Democritus sometimes does away with what appears to the senses, and says that none of these appears according to truth but only according to opinion: the truth in real things is that there are atoms and void. “By convention sweet”, he says, “by convention bitter, by convention hot, by convention cold, by convention colour: but in reality atoms and void.”

Diamond, for all its great beauty, is not nearly as interesting as the hexagonal plane of graphite. It is not nearly as interesting because we live in a three-dimensional space, and in diamond each atom is surrounded in all three directions in space by a full coordination. Consequently, it is very difficult for an atom inside the diamond lattice to be confronted with anything else in this 3D world because all directions are already taken up.

Do not trust atoms. They make up everything.

During my stay in London I resided for a considerable time in Clapham Road in the neighbourhood of Clapham Common... One fine summer evening I was returning by the last bus 'outside' as usual, through the deserted streets of the city, which are at other times so full of life. I fell into a reverie (Träumerei), and 10, the atoms were gambolling before my eyes! Whenever, hitherto, these diminutive beings had appeared to me, they had always been in motion: but up to that time I had never been able to discern the nature of their motion. Now, however, I saw how, frequently, two smaller atoms united to form a pair: how the larger one embraced the two smaller ones: how still larger ones kept hold of three or even four of the smaller: whilst the whole kept whirling in a giddy dance. I saw how the larger ones formed a chain, dragging the smaller ones after them but only at the ends of the chain. I saw what our past master, Kopp, my highly honoured teacher and friend has depicted with such charm in his Molekular-Welt: but I saw it long before him. The cry of the conductor 'Clapham Road', awakened me from my dreaming: but I spent part of the night in putting on paper at least sketches of these dream forms. This was the origin of the 'Structural Theory'.

Each new atom brings something of the personality of its element to the molecule, and this conspiracy of atoms results in a molecule with properties that are richer than those of each atom alone.

Earlier this week … scientists announced the completion of a task that once seemed unimaginable; and that is, the deciphering of the entire DNA sequence of the human genetic code. This amazing accomplishment is likely to affect the 21st century as profoundly as the invention of the computer or the splitting of the atom affected the 20th century. I believe that the 21st century will be the century of life sciences, and nothing makes that point more clearly than this momentous discovery. It will revolutionize medicine as we know it today.

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 theory 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.

Energy is the measure of that which passes from one atom to another in the course of their transformations. A unifying power, then, but also, because the atom appears to become enriched or exhausted in the course of the exchange, the expression of structure.

Engineers apply the theories and principles of science and mathematics to research and develop economical solutions to practical technical problems. Their work is the link between scientific discoveries and commercial applications. Engineers design products, the machinery to build those products, the factories in which those products are made, and the systems that ensure the quality of the product and efficiency of the workforce and manufacturing process. They design, plan, and supervise the construction of buildings, highways, and transit systems. They develop and implement improved ways to extract, process, and use raw materials, such as petroleum and natural gas. They develop new materials that both improve the performance of products, and make implementing advances in technology possible. They harness the power of the sun, the earth, atoms, and electricity for use in supplying the Nation’s power needs, and create millions of products using power. Their knowledge is applied to improving many things, including the quality of health care, the safety of food products, and the efficient operation of financial systems.

Everybody now wants to discover universal laws which will explain the structure and behavior of the nucleus of the atom. But actually our knowledge of the elementary particles that make up the nucleus is tiny. The situation calls for more modesty. We should first try to discover more about these elementary particles and about their laws. Then it will be the time for the major synthesis of what we really know, and the formulation of the universal law.

Everything is made of atoms ... Everything that animals do, atoms do. ... 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.

Finally I got to carbon, and as you all know, in the case of carbon the reaction works out beautifully. One goes through six reactions, and at the end one comes back to carbon. In the process one has made four hydrogen atoms into one of helium. The theory, of course, was not made on the railway train from Washington to Ithaca … It didn’t take very long, it took about six weeks, but not even the Trans-Siberian railroad [has] taken that long for its journey.

Firm support has been found for the assertion that electricity occurs at thousands of points where we at most conjectured that it was present. Innumerable electrical particles oscillate in every flame and light source. We can in fact assume that every heat source is filled with electrons which will continue to oscillate ceaselessly and indefinitely. All these electrons leave their impression on the emitted rays. We can hope that experimental study of the radiation phenomena, which are exposed to various influences, but in particular to the effect of magnetism, will provide us with useful data concerning a new field, that of atomistic astronomy, as Lodge called it, populated with atoms and electrons instead of planets and worlds.

For the better part of my last semester at Garden City High, I constructed a physical pendulum and used it to make a “precision” measurement of gravity. The years of experience building things taught me skills that were directly applicable to the construction of the pendulum. Twenty-five years later, I was to develop a refined version of this measurement using laser-cooled atoms in an atomic fountain interferometer.
[Outcome of high school physics teacher, Thomas Miner, encouraging Chu's ambitious laboratory project.]

For the world was built in order,
And the atoms march in tune.

For us, an atom shall be a small, spherical, homogeneous body or an essentially indivisible, material point, whereas a molecule shall be a separate group of atoms in any number and of any nature.

From all we have learnt about the structure of living matter, we must be prepared to find it working in a manner that cannot be reduced to the ordinary laws of physics. And that not on the ground that there is any “new force” or what not, directing the behavior of the single atoms within a living organism, but because the construction is different from anything we have yet tested in the physical laboratory.

From the infinitely great down to the infinitely small, all things are subject to [the laws of nature]. The sun and the planets follow the laws discovered by Newton and Laplace, just as the atoms in their combinations follow the laws of chemistry, as living creatures follow the laws of biology. It is only the imperfections of the human mind which multiply the divisions of the sciences, separating astronomy from physics or chemistry, the natural sciences from the social sciences. In essence, science is one. It is none other than the truth.

From the intensity of the spots near the centre, we can infer that the protein molecules are relatively dense globular bodies, perhaps joined together by valency bridges, but in any event separated by relatively large spaces which contain water. From the intensity of the more distant spots, it can be inferred that the arrangement of atoms inside the protein molecule is also of a perfectly definite kind, although without the periodicities characterising the fibrous proteins. The observations are compatible with oblate spheroidal molecules of diameters about 25 A. and 35 A., arranged in hexagonal screw-axis. ... At this stage, such ideas are merely speculative, but now that a crystalline protein has been made to give X-ray photographs, it is clear that we have the means of checking them and, by examining the structure of all crystalline proteins, arriving at a far more detailed conclusion about protein structure than previous physical or chemical methods have been able to give.

Given for one instant an intelligence which could comprehend all the forces by which nature is animated and the respective situation of the beings which compose it—an intelligence sufficiently vast to submit these data to analysis, it would embrace in the same formula the movements of the greatest bodies in the universe and those of the lightest atom; to it nothing would be uncertain, and the future as the past would be present to its eyes.

Gods are born and die, but the atom endures.

Haemoglobin is a very large molecule by ordinary standards, containing about ten thousand atoms, but the chances are that your haemoglobin and mine are identical, and significantly different from that of a pig or horse. You may be impressed by how much human beings differ from one another, but if you were to look into the fine details of the molecules of which they are constructed, you would be astonished by their similarity.

Has Matter innate Motion? Then each Atom,
Asserting its indisputable Right
To dance, would form an Universe of Dust.

Has Matter more than Motion? Has it Thought,
Judgment, and Genius? Is it deeply learn’d
In Mathematics? Has it fram’d such Laws,
Which, but to guess, a Newton made immortal?—
If so, how each sage Atom laughs at me,
Who think a Clod inferior to a Man!

Have you ever seen one?

I am afraid all we can do is to accept the paradox and try to accommodate ourselves to it, as we have done to so many paradoxes lately in modern physical theories. We shall have to get accustomed to the idea that the change of the quantity R, commonly called the 'radius of the universe', and the evolutionary changes of stars and stellar systems are two different processes, going on side by side without any apparent connection between them. After all the 'universe' is an hypothesis, like the atom, and must be allowed the freedom to have properties and to do things which would be contradictory and impossible for a finite material structure.

I am further inclined to think, that when our views are sufficiently extended, to enable us to reason with precision concerning the proportions of elementary atoms, we shall find the arithmetical relation alone will not be sufficient to explain their mutual action, and that we shall be obliged to acquire a geometric conception of their relative arrangement in all three dimensions of solid extension.

I am now convinced that we have recently become possessed of experimental evidence of the discrete or grained nature of matter, which the atomic hypothesis sought in vain for hundreds and thousands of years. The isolation and counting of gaseous ions, on the one hand, which have crowned with success the long and brilliant researches of J.J. Thomson, and, on the other, agreement of the Brownian movement with the requirements of the kinetic hypothesis, established by many investigators and most conclusively by J. Perrin, justify the most cautious scientist in now speaking of the experimental proof of the atomic nature of matter, The atomic hypothesis is thus raised to the position of a scientifically well-founded theory, and can claim a place in a text-book intended for use as an introduction to the present state of our knowledge of General Chemistry.

I can accept the theory of relativity as little as I can accept the existence of atoms and other such dogmas.

I celebrate myself, and sing myself,
And what I assume you shall assume,
For every atom belonging to me as good belongs to you.

I do not understand modern physics at all, but my colleagues who know a lot about the physics of very small things, like the particles in atoms, or very large things, like the universe, seem to be running into one queerness after another, from puzzle to puzzle.

I do not want chemistry to degenerate into a religion; I do not want the chemist to believe in the existence of atoms as the Christian believes in the existence of Christ in the communion wafer.

I don’t know if I would call it a miracle. I would call it a spectacular example of what people can do. To me, it’s like putting the first man on the moon or splitting the atom. We’ve shown that if the right treatment is given to people who have a catastrophic injury that they could walk away from it.
Expressing optimism for further recovery for Kevin Everett, a Buffalo Bills football player who suffered a paralyzing spinal injury during a game (9 Sep 2007), but after two days of hospital treatment had begun voluntarily moving his arms and legs. Green credits as significant to the recovery was that within minutes of his injury, the patient was quickly treated with intravenous ice-cold saline solution to induce hypothermia.

I have a peculiar theory about radium, and I believe it is the correct one. I believe that there is some mysterious ray pervading the universe that is fluorescing to it. In other words, that all its energy is not self-constructed but that there is a mysterious something in the atmosphere that scientists have not found that is drawing out those infinitesimal atoms and distributing them forcefully and indestructibly.

I have paid special attention to those Properties of the Positive Rays which seem to throw light on the problems of the structure of molecules and atoms and the question of chemical combination … I am convinced that as yet we are only at the beginning of the harvest of results which will elucidate the process of chemical combination, and thus bridge over the most serious gap which now exists between Physics and Chemistry.

I hope that in 50 years we will know the answer to this challenging question: are the laws of physics unique and was our big bang the only one? … According to some speculations the number of distinct varieties of space—each the arena for a universe with its own laws—could exceed the total number of atoms in all the galaxies we see. … So do we live in the aftermath of one big bang among many, just as our solar system is merely one of many planetary systems in our galaxy? (2006)

I like relativity and quantum theories
because I don't understand them
and they make me feel as if space shifted about
like a swan that
can't settle,
refusing to sit still and be measured;
and as if the atom were an impulsive thing
always changing its mind.

I remember discussions with Bohr which went through many hours till very late at night and ended almost in despair; and when at the end of the discussion I went alone for a walk in the neighboring park I repeated to myself again and again the question: Can nature possibly be as absurd as it seemed to us in these atomic experiments?

I remember, I remember,
When an atom was so small
It really hardly paid you
To think of one at all.
It was so small that anywhere
An atom safe could be
And pass his time in molecules
In elemental glee.

I should like to call the number of atom groups, with which an elementary atom coordinates … to form a complex radical, the coordination number of the atom in question … We must differentiate between valence number and coordination number. The valence number indicates the maximum number of monovalent atoms which can be bound directly to the atom in question without the participation of other elementary atoms … Perhaps this concept [of coordination number] is destined to serve as a basis for the theory of the constitution of inorganic compounds, just as valence theory formed the basis for the constitutional theory of carbon compounds.

I think the facts leave no doubt that the very mightiest among the chemical forces are of electric origin. The atoms cling to their electric charges, and opposite electric charges cling to each other.

I think the name atomic theory was an unfortunate one. We talk fluently about atoms as the smallest particles that exist, and chemists regard them as indivisible … To my mind the infinitely small is as incomprehensible as the infinitely great. … we cannot comprehend it, we cannot take it in. And so with the atom. Therefore I think that it would have been better to have taken a different word—say minim—which would have been a safer term than atom.

I try to identify myself with the atoms ... I ask what I would do If I were a carbon atom or a sodium atom.

I was an impostor, the worthy associate of a brigand, &c., &c., and all this for an atom of chlorine put in the place of an atom of hydrogen, for the simple correction of a chemical formula!

I was sitting writing at my textbook but the work did not progress; my thoughts were elsewhere. I turned my chair to the fire and dozed. Again the atoms were gambolling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by the repeated visions of the kind, could now distinguish larger structures of manifold confirmation: long rows, sometimes more closely fitted together all twining and twisting in snake like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke; and this time also I spent the rest of the night in working out the rest of the hypothesis. Let us learn to dream, gentlemen, then perhaps we shall find the truth... But let us beware of publishing our dreams till they have been tested by waking understanding.

I will paint for [man] not only the visible universe, but all that he can conceive of nature’s immensity in the womb of an atom.

I would efface the word atoms from science, persuaded that it goes further than experience... In chemistry we should never go further than experience. Could there be any hope of ever identifying the minuscule entities?

I would rather be ashes than dust!
I would rather that my spark should burn out in a brilliant blaze than it should be stifled by dry-rot.
I would rather be a superb meteor, every atom of me in magnificent glow, than a sleepy and permanent planet.
The proper function of man is to live, not to exist.
I shall not waste my days in trying to prolong them.
I shall use my time.

If a mixture of different kinds of electrified atoms is moving along in one stream, then when electric and magnetic forces are applied to the stream simultaneously, the different kinds of atoms are sorted out, and the original stream is divided up into a number of smaller streams separated from each other. The particles in any one of the smaller streams are all of the same kind.

If atoms do, by chance, happen to combine themselves into so many shapes, why have they never combined together to form a house or a slipper? By the same token, why do we not believe that if innumerable letters of the Greek alphabet were poured all over the market-place they would eventually happen to form the text of the Iliad?

If molecules can be structurally identical and yet possess dissimilar properties, this can be explained only on the ground that the difference is due to a different arrangement of the atoms in space.

If one has left this entire system to itself for an hour, one would say that the cat still lives if meanwhile no atom has decayed. The psi-function of the entire system would express this by having in it the living and dead cat (pardon the expression) mixed or smeared out in equal parts.

If the 'Principle of Relativity' in an extreme sense establishes itself, it seems as if even Time would become discontinuous and be supplied in atoms, as money is doled out in pence or centimes instead of continuously;—in which case our customary existence will turn out to be no more really continuous than the events on a kinematograph screen;—while that great agent of continuity, the Ether of Space, will be relegated to the museum of historical curiosities.

If the atoms in [a] decimetre cube of lead were all put into a chain side by side the same distance apart as they are in the normal lead, the strings of atoms so formed would reach over six million million miles.