The Annotated Alice, of course, does tie in with math, because Lewis Carroll was, as you know, a professional mathematician. So it wasn’t really too far afield from recreational math, because the two books are filled with all kinds of mathematical jokes. I was lucky there in that I really didn’t have anything new to say in The Annotated Alice because I just looked over the literature and pulled together everything in the form of footnotes. But it was a lucky idea because that’s been the best seller of all my books.

As our cities and suburbs relentlessly expand, those priceless open spaces needed for recreation areas accessible to their people are swallowed up—often forever. Unless we preserve these spaces while they are still available, we will have none to preserve. Therefore, I shall propose new financing methods for purchasing open space and parklands now, before they are lost to us.

At first he who invented any art that went beyond the common perceptions of man was naturally admired by men, not only because there was something useful in the inventions, but because he was thought wise and superior to the rest. But as more arts were invented, and some were directed to the necessities of life, others to its recreation, the inventors of the latter were always regarded as wiser than the inventors of the former, because their branches of knowledge did not aim at utility.

Be very vigilent over thy Childe … If he chuse the profession of a Scholler, advise him to study the most profitable Arts: Poetry, and the Mathematichs, take up too great a latitude of the Soule, and moderately used, are good Recreations, but bad Callings, bring nothing but their owne Reward.

Büchsel in his reminiscences from the life of a country parson relates that he sought his recreation in Lacroix’s Differential Calculus and thus found intellectual refreshment for his calling. Instances like this make manifest the great advantage which occupation with mathematics affords to one who lives remote from the city and is compelled to forego the pleasures of art. The entrancing charm of mathematics, which captivates every one who devotes himself to it, and which is comparable to the fine frenzy under whose ban the poet completes his work, has ever been incomprehensible to the spectator and has often caused the enthusiastic mathematician to be held in derision. A classic illustration is the example of Archimedes….

Chess combines the beauty of mathematical structure with the recreational delights of a competitive game.

For they are not given to idleness, nor go in a proud habit, or plush and velvet garments, often showing their rings upon their fingers, or wearing swords with silver hilts by their sides, or fine and gay gloves upon their hands, but diligently follow their labours, sweating whole days and nights by their furnaces. They do not spend their time abroad for recreation, but take delight in their laboratory. They wear leather garments with a pouch, and an apron wherewith they wipe their hands. They put their fingers amongst coals, into clay, and filth, not into gold rings. They are sooty and black like smiths and colliers, and do not pride themselves upon clean and beautiful faces.

He who gives a portion of his time and talent to the investigation of mathematical truth will come to all other questions with a decided advantage over his opponents. He will be in argument what the ancient Romans were in the field: to them the day of battle was a day of comparative recreation, because they were ever accustomed to exercise with arms much heavier than they fought; and reviews differed from a real battle in two respects: they encountered more fatigue, but the victory was bloodless.

I prefer the spagyric chemical physicians, for they do not consort with loafers or go about gorgeous in satins, silks and velvets, gold rings on their fingers, silver daggers hanging at their sides and white gloves on their hands, but they tend their work at the fire patiently day and night. They do not go promenading, but seek their recreation in the laboratory, wear plain learthern dress and aprons of hide upon which to wipe their hands, thrust their fingers amongst the coals, into dirt and rubbish and not into golden rings. They are sooty and dirty like the smiths and charcoal burners, and hence make little show, make not many words and gossip with their patients, do not highly praise their own remedies, for they well know that the work must praise the master, not the master praise his work. They well know that words and chatter do not help the sick nor cure them... Therefore they let such things alone and busy themselves with working with their fires and learning the steps of alchemy. These are distillation, solution, putrefaction, extraction, calcination, reverberation, sublimination, fixation, separation, reduction, coagulation, tinction, etc.

I should like to urge some arguments for wilderness preservation that involve recreation,…. Hunting, fishing, hiking, mountain-climbing, camping, photography, and the enjoyment of natural scenery will all, surely, figure in your report. So will the wilderness as a genetic reserve, a scientific yardstick by which we may measure the world in its natural balance against the world in its man-made imbalance.

I think that each town should have a park, or rather a primitive forest, of five hundred or a thousand acres, either in one body or several, where a stick should never be cut for fuel, nor for the navy, nor to make wagons, but stand and decay for higher uses—a common possession forever, for instruction and recreation. All Walden Wood might have been reserved, with Walden in the midst of it.

If we range through the whole territory of nature, and endeavour to extract from each department the rich stores of knowledge and pleasure they respectively contain, we shall not find a more refined or purer source of amusement, or a more interesting and unfailing subject for recreation, than that which the observation and examination of the structure, affinities, and habits of plants and vegetables, afford.

In our time this search [for extraterrestrial life] will eventually change our laws, our religions, our philosophies, our arts, our recreations, as well as our sciences. Space, the mirror, waits for life to come look for itself there.

Leaving those [exercises] of the Body, I shall proceed to such Recreations as adorn the Mind; of which those of the Mathematicks are inferior to none.

Nature, who is a great economist, converts the recreation of one animal to the support of another.

One of Euler’s main recreations was music, and by cultivating it he brought with it all his geometrical spirit; … he rested his serious researches and composed his Essay of a New Theory of Music, published in 1739; a book full of new ideas presented in a new point of view, but that did not have a great success, apparently for the sole reason that it contains too much of geometry for the musician and too much music for the geometer.

Science is the labor and handicraft of the mind; poetry can only be considered its recreation.

The Europeans and the Americans are not throwing $10 billion down this gigantic tube for nothing. We're exploring the very forefront of physics and cosmology with the Large Hadron Collider because we want to have a window on creation, we want to recreate a tiny piece of Genesis to unlock some of the greatest secrets of the universe.

The maintenance of biological diversity requires special measures that extend far beyond the establishment of nature reserves. Several reasons for this stand out. Existing reserves have been selected according to a number of criteria, including the desire to protect nature, scenery, and watersheds, and to promote cultural values and recreational opportunities. The actual requirements of individual species, populations, and communities have seldom been known, nor has the available information always been employed in site selection and planning for nature reserves. The use of lands surrounding nature reserves has typically been inimical to conservation, since it has usually involved heavy use of pesticides, industrial development, and the presence of human settlements in which fire, hunting, and firewood gathering feature as elements of the local economy.

These are some of the things wilderness can do for us. That is the reason we need to put into effect, for its preservation, some other principle that the principles of exploitation or “usefulness” or even recreation. We simply need that wild country available to us, even if we never do more than drive to its edge and look in. For it can be a means of reassuring ourselves of our sanity as creatures, a part of the geography of hope.

This is a huge step toward unraveling Genesis Chapter 1, Verse 1—what happened in the beginning. This is a Genesis machine. It'll help to recreate the most glorious event in the history of the universe.
[Comment on a milestone experiment, the collision of two proton beams at higher energy than ever before, upon the restarting of the Large Hadron Collider after a major failure and shutdown for repair.]

We urgently need [the landmark National Ocean Policy] initiative, as we use our oceans heavily: Cargo ships crisscross the sea, carrying goods between continents. Commercial and recreational fishing boats chase fish just offshore. Cruise ships cruise. Oil and gas drilling continues, but hopefully we will add renewable energy projects as well. Without planning, however, these various industrial activities amount to what we call “ocean sprawl,” steamrolling the resources we rely upon for our livelihoods, food, fun, and even the air we breathe. While humankind relies on many of these industries, we also need to keep the natural riches that support them healthy and thriving. As an explorer, I know firsthand there are many places in the ocean so full of life that they should be protected.

When he had a few moments for diversion, he [Napoleon] not unfrequently employed them over a book of logarithms, in which he always found recreation.