A cosmic mystery of immense proportions, once seemingly on the verge of solution, has deepened and left astronomers and astrophysicists more baffled than ever. The crux ... is that the vast majority of the mass of the universe seems to be missing.
[Reporting a Nature article discrediting explanation of invisible mass being due to neutrinos]

A man can do his best only by confidently seeking (and perpetually missing) an unattainable perfection.

A theoretical physicist can spend his entire lifetime missing the intellectual challenge of experimental work, experiencing none of the thrills and dangers — the overhead crane with its ten-ton load, the flashing skull and crossbones and danger, radioactivity signs. A theorist’s only real hazard is stabbing himself with a pencil while attacking a bug that crawls out of his calculations.

Across the road from my cabin was a huge clear-cut—hundreds of acres of massive spruce stumps interspersed with tiny Douglas firs—products of what they call “Reforestation,” which I guess makes the spindly firs en masse a “Reforest,” which makes an individual spindly fir a “Refir,” which means you could say that Weyerhauser, who owns the joint, has Refir Madness, since they think that sawing down 200-foot-tall spruces and replacing them with puling 2-foot Refirs is no different from farming beans or corn or alfalfa. They even call the towering spires they wipe from the Earth’s face forever a “crop”--as if they’d planted the virgin forest! But I'm just a fisherman and may be missing some deeper significance in their nomenclature and stranger treatment of primordial trees.

Adam is fading out. It is on account of Darwin and that crowd. I can see that he is not going to last much longer. There's a plenty of signs. He is getting belittled to a germ—a little bit of a speck that you can't see without a microscope powerful enough to raise a gnat to the size of a church. They take that speck and breed from it: first a flea; then a fly, then a bug, then cross these and get a fish, then a raft of fishes, all kinds, then cross the whole lot and get a reptile, then work up the reptiles till you've got a supply of lizards and spiders and toads and alligators and Congressmen and so on, then cross the entire lot again and get a plant of amphibiums, which are half-breeds and do business both wet and dry, such as turtles and frogs and ornithorhyncuses and so on, and cross-up again and get a mongrel bird, sired by a snake and dam'd by a bat, resulting in a pterodactyl, then they develop him, and water his stock till they've got the air filled with a million things that wear feathers, then they cross-up all the accumulated animal life to date and fetch out a mammal, and start-in diluting again till there's cows and tigers and rats and elephants and monkeys and everything you want down to the Missing Link, and out of him and a mermaid they propagate Man, and there you are! Everything ship-shape and finished-up, and nothing to do but lay low and wait and see if it was worth the time and expense.

And don’t forget one in the command module.... And thanks for putting me on relay, Houston. I was missing all the action.

He that could teach mathematics well, would not be a bad teacher in any of [physics, chemistry, biology or psychology] unless by the accident of total inaptitude for experimental illustration; while the mere experimentalist is likely to fall into the error of missing the essential condition of science as reasoned truth; not to speak of the danger of making the instruction an affair of sensation, glitter, or pyrotechnic show.

I feel a desperation to make people see what we are doing to the environment, what a mess we are making of our world. At this point, the more people I reach, the more I accomplish. … I miss Gombe and my wonderful years in the forest But if I were to go back to that, I wouldn’t feel I was doing what I should be doing.

I find myself now preaching about the golden age of manned spaceflight, because something went on there, within us, that we’re missing. When we went to the Moon, it was not only just standing on a new plateau for all mankind. We changed the way everybody in the world thought of themselves, you know. It was a change that went on inside of us. And we’re losing that.

I was depressed at that time. I was in analysis. I was suicidal as a matter of fact and would have killed myself, but I was in analysis with a strict Freudian, and, if you kill yourself, they make you pay for the sessions you miss.

In an age of specialization people are proud to be able to do one thing well, but if that is all they know about, they are missing out on much else life has to offer.

Man appears to be the missing link between anthropoid apes and human beings.

My first view - a panorama of brilliant deep blue ocean, shot with shades of green and gray and white - was of atolls and clouds. Close to the window I could see that this Pacific scene in motion was rimmed by the great curved limb of the Earth. It had a thin halo of blue held close, and beyond, black space. I held my breath, but something was missing - I felt strangely unfulfilled. Here was a tremendous visual spectacle, but viewed in silence. There was no grand musical accompaniment; no triumphant, inspired sonata or symphony. Each one of us must write the music of this sphere for ourselves.

My observations of the young physicists who seem to be most like me and the friends I describe in this book tell me that they feel as we would if we had been chained to those same oars. Our young counterparts aren’t going into nuclear or particle physics (they tell me it’s too unattractive); they are going into condensed-matter physics, low-temperature physics, or astrophysics, where important work can still be done in teams smaller than ten and where everyone can feel that he has made an important contribution to the success of the experiment that every other member of the collaboration is aware of. Most of us do physics because it’s fun and because we gain a certain respect in the eyes of those who know what we’ve done. Both of those rewards seem to me to be missing in the huge collaborations that now infest the world of particle physics.

The bell ringing for church, we went thither immediately, and with hearts full of gratitude, returned sincere thanks to God for the mercies we had received: were I a Roman Catholic, perhaps I should on this occasion vow to build a chapel to some saint, but as I am not, if I were to vow at all, it should be to build a light-house. [Upon narrowly missing a shipwreck on the Scilly rocks.]
[Frequently seen summarized as, though not Franklin's own wording: Lighthouses are more helpful than churches.

The discrepancy between what was expected and what has been observed has grown over the years, and we're straining harder and harder to fill the gap.
[Commenting on the 1984 article in Nature discrediting neutrinos as the explanation for the missing mass of the universe, leaving astrophysicists more baffled for a solution.]

The laws of science are the permanent contributions to knowledge—the individual pieces that are fitted together in an attempt to form a picture of the physical universe in action. As the pieces fall into place, we often catch glimpses of emerging patterns, called theories; they set us searching for the missing pieces that will fill in the gaps and complete the patterns. These theories, these provisional interpretations of the data in hand, are mere working hypotheses, and they are treated with scant respect until they can be tested by new pieces of the puzzle.

This missing science of heredity, this unworked mine of knowledge on the borderland of biology and anthropology, which for all practical purposes is as unworked now as it was in the days of Plato, is, in simple truth, ten times more important to humanity than all the chemistry and physics, all the technical and indsutrial science that ever has been or ever will be discovered.

We don't know what we are talking about. Many of us believed that string theory was a very dramatic break with our previous notions of quantum theory. But now we learn that string theory, well, is not that much of a break. The state of physics today is like it was when we were mystified by radioactivity. They were missing something absolutely fundamental. We are missing perhaps something as profound as they were back then.

We often think, naïvely, that missing data are the primary impediments to intellectual progress–just find the right facts and all problems will dissipate. But barriers are often deeper and more abstract in thought. We must have access to the right metaphor, not only to the requisite information. Revolutionary thinkers are not, primarily, gatherers of fact s, but weavers of new intellectual structures.

Why, these men would destroy the Bible on evidence that would not convict a habitual criminal of a misdemeanor. They found a tooth in a sand pit in Nebraska with no other bones about it, and from that one tooth decided that it was the remains of the missing link. They have queer ideas about age too. They find a fossil and when they are asked how old it is they say they can't tell without knowing what rock it was in, and when they are asked how old the rock is they say they can't tell unless they know how old the fossil is.