Space may be considered as an n-dimensional extent in which points, variables, objects or events have relationships, such as relative position and direction. A mathematical space is a set or universe with some defined structure. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum known as spacetime. Space may also refer to outer space, the relatively empty space between celestial bodies such as galaxies, stars, planets and moons. This article may include references to any or all of the above.
- Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.
- SWA Magazine: Talking about spacecraft, what do you think about the shuttle program?
- Asimov: Well, I hope it does get off the ground. And I hope they expand it, because the shuttle program is the gateway to everything else. By means of the shuttle, we will be able to build space stations and power stations, laboratory facilities and habitations, and everything else in space.
- SWA Magazine: How about orbital space colonies? Do you see these facilities being built or is the government going to cut back on projects like this?
- Asimov: Well, now you've put your finger right on it. In order to have all of these wonderful things in space, we don't have to wait for technology - we've got the technology, and we don't have to wait for the know-how - we've got that too. All we need is the political go-ahead and the economic willingness to spend the money that is necessary. It is a little frustrating to think that if people concentrate on how much it is going to cost they will realize the great amount of profit they will get for their investment. Although they are reluctant to spend a few billions of dollars to get back an infinite quantity of money, the world doesn't mind spending $400 billion every years on arms and armaments, never getting anything back from it except a chance to commit suicide.
- God, the supreme being, is neither circumscribed by space, nor touched by time; he cannot be found in a particular direction, and his essence cannot change. The secret conversation is thus entirely spiritual; it is a direct encounter between God and the soul, abstracted from all material constraints.
- Avicenna, as quoted in 366 Readings From Islam (2000), ed., Robert Van der Weyer.
- As a solitary planetary system we may be inconspicuous, but so is the individual human. He does not thereby lose his dignity.
- N. J. Berrill, You and the Universe (1958), p. 198
- Space is as infinite as we can imagine, and expanding this perspective is what adjusts humankind’s focus on conquering our true enemies, the formidable foes: ignorance and limitation.
- Vanna Bonta, The Impact of Space Activities Upon Society (ESA Br) European Space Agency (2005)
- The impact of space activities is nothing less than the galvanizing of hope and imagination for human life continuum into a future of infinite possibility.
- Vanna Bonta, The Impact of Space Activities Upon Society (ESA Br) European Space Agency (2005)
- Manned space flight . . . has opened for us thus far only a tiny door for viewing the awesome reaches of space. Our outlook through this peephole at the vast mysteries of the universe only confirms our belief in its creator.
- [T]he program which Immanuel Kant proposed back in the 1760s... was this: our knowledge of the outside world depends on our modes of perception... Unfortunately, a great revolution took place in or about the year 1768, when he read a paper by Euler which intended to show that space was indeed absolute as Newton had suggested and not relative as Leibnitz suggested. (...in the eighteenth century the question of whether Newton's... or Leibnitz's view of the world was right profoundly affected all philosophy.) After reading Euler's argument... Kant... for the first time proposed that... we must be conscious of [absolute space] a priori. ...Kant died in 1804, long before new ideas about space... had been published... And since one of the things that happened in [our] lifetime has been the substitution of... a Leibnitz universe, the universe of relativity, for Newton's universe... we should think that out again.
- Jacob Bronowski, The Origins of Knowledge and Imagination (1978) Ref: Kant, "Concerning the Ultimate Foundations of the Differentiation of Regions in Space" (1768) in Kant: Selected Precritical Writings and Correspondence with Beck Tr. and Intro., G. B. Kerford and D. E. Walford (1968)
- Space can be mapped and crossed and occupied without definable limit; but it can never be conquered. When our race has reached its ultimate achievements, and the stars themselves are scattered no more widely than the seed of Adam, even then we shall still be like ants crawling on the face of the Earth. The ants have covered the world, but have they conquered it — for what do their countless colonies know of it, or of each other?
- Arthur C. Clarke, We'll Never Conquer Space (1960)
- We cannot predict the new forces, powers, and discoveries that will be disclosed to us when we reach the other planets and set up new laboratories in space. They are as much beyond our vision today as fire or electricity would be beyond the imagination of a fish.
- Arthur C. Clarke, Space and the Spirit of Man (1965)
- Kant's attitude toward Newton's absolute space is somewhat confused. At times he defends the absoluteness... At other times he presents his own arguments in favor of the relativity of space and motion. ...At any rate the problem of the absoluteness of space and time in classical science refers not to the essence of space and time (a problem which would degenerate into one of metaphysics, hence would be meaningless to the scientists), but solely to a discussion of those conceptions which are demanded of the world of experience. Hence we may realise that a man ignorant of mechanics is in no position to pass an opinion one way or the other. And Kant's knowledge of Newtonian mechanics was extremely poor, to say the least.
- A. D'Abro, The Evolution of Scientific Thought from Newton to Einstein (1927) footnote, p. 417-418
- We now come to our concepts and judgments of space. It is essential here also to pay strict attention to the relation of experience to our concepts. It seems to me that Poincaré clearly recognized the truth in the account he gave in his book, "La Science et l'Hypothese." Among all the changes which we can perceive in a rigid body those are marked by their simplicity which can be made reversibly by an arbitrary motion of the body; Poincaré calls these, changes in position. By means of simple changes in position we can bring two bodies into contact. The theorems of congruence, fundamental in geometry, have to do with the laws that govern such changes in position.
- Geometry is grasping space. And since it is about the education of children, it is grasping that space in which the child lives, breathes and moves. The space that the child must learn to know, explore, conquer....
- Hans Freudenthal, Mathematics as an Educational Task (1973) p. 403
- Space. It seems to go on and on forever. Then you get to the end, and a monkey starts throwing barrels at you.
- Why are the heavens not filled with light? Why is the universe plunged into darkness?
- Edward Robert Harrison, Darkness at Night: a Riddle of the Universe (1987), p. 1
- Beyond a critical point within a finite space, freedom diminishes as numbers increase. ...The human question is not how many can possibly survive within the system, but what kind of existence is possible for those who do survive.
- 1. Space is not an empirical concept which has been derived from external experience. For in order that certain sensations should be referred to something outside myself... the representation of space must already be there. ...this external experience becomes possible only by means of the representation of space.
2. Space is a necessary representation a priori, forming the very foundation of all external intuitions. It is impossible to imagine that there should be no space... Space is therefore regarded as a condition of the possibility of phenomena, not as a determination produced by them; it is a representation a priori which necessarily precedes all external phenomena.
3. On this necessity of an a priori representation of space rests on the apodictic certainty of all geometric principles, and the possibility of their construction a priori. For if the intuition of space were a concept gained a posteriori, borrowed from general external experience, the first principles of mathematical definition would be nothing but perceptions. They would be exposed to all the accidents of perception, and there being but one straight line between two points would not be a necessity, but only something taught in each case by experience. Whatever is derived from experience possesses a relative generality only, based on induction. We should therefore not be able to say more than that, so far as hitherto observed, no space has yet been found having more than three dimensions.
4. Space is not a discursive or so-called general concept of the relations of things, but a pure intuition. ...
5. Space is represented as an infinite quantity. ...If there were not infinity in the progression of intuition, no concept of relations of space could ever contain a concept of infinity.
- Einstein's space is no closer to reality than Van Gogh's sky. The glory of science is not in a truth more absolute than the truth of Bach or Tolstoy, but in the act of creation itself. The scientist's discoveries impose his own order on chaos, as the composer or painter imposes his; an order that always refers to limited aspects of reality, and is based on the observer's frame of reference, which differs from period to period as a Rembrandt nude differs from a nude by Manet.
- Arthur Koestler, The Act of Creation , London, (1970) p. 253.
- Thirty spokes converge upon a single hub
It is the hole in the centre that the purpose of the axle depends.
We make a vessel from a lump of clay
It is the empty space within the vessel that makes it useful.
We make doors and windows for a room.
But it is the those empty spaces that make the room habitable.
Thus while the tangible has advantages
It is the intangible that makes it useful.
- Space, like time, engenders forgetfulness; but it does so by setting us bodily free from our surroundings and giving us back our primitive, unattached state.
- No creature loves an empty space;
Their bodies measure out their place.
- Andrew Marvell, Upon Appleton House, to My Lord Fairfax
- When we contemplate the whole globe as one great dewdrop, striped and dotted with continents and islands, flying through space with other stars all singing and shining together as one, the whole universe appears as an infinite storm of beauty.
- John Muir, Travels in Alaska (1915)
- Hitherto I have laid down the definitions of such words as are less known, and explained the sense in which I would have them to be understood in the following discourse. I do not define time, space, place and motion, as being well known at all. Only I must observe, that the vulgar conceive those quantities under no other notions but from the relation they bear to sensible objects. And thence arise certain prejudices, for the removing of which, it will be convenient to distinguish them into absolute and relative, true and apparent, mathematical and common.
...II. Absolute space, in its own nature, without regard to any thing external, remains always similar and immovable. Relative space is some moveable dimension or measure of the absolute spaces; which our senses determine by its position to bodies; and which is vulgarly taken for immovable space; such is the dimension of a subterraneous, an æreal, or celestial space, determined by its position in respect of the earth. Absolute and relative space, are the same in figure and magnitude; but they do not remain always numerically the same. For if the earth, for instance, moves, a space of our air, which relatively and in respect of the earth remains always the same, will at one time be one part of the absolute space into which the air passes, at another time it will be another part of the same, and so, absolutely understood, it will be perpetually mutable.
III. Place is a part of space which a body takes up, and is according to the space, either absolute or relative. I say, a part of space; not the situation, nor the external surface of the body. For the places of equal solids, are always equal; but their superficies, by reason of their dissimilar figures, are often unequal. Positions properly have no quantity, nor are they so much the places themselves, as the properties of places. The motion of the whole is the same thing with the sum of the motions of the parts; that is, the translation of the whole, out of its place, is the same thing with the sum of the translations of the parts out of their places; and therefore the place of the whole, is the same thing with the sum of the places of the parts; and for that reason, it is internal, and in the whole body.
- There is something missing in our understanding of space.
- Once the threshold is crossed when there is a self-sustaining level of life in space, then life's long-range future will be secure irrespective of any of the risks on Earth (with the single exception of the catastrophic destruction of space itself). Will this happen before our technical civilisation disintegrates, leaving this as a might-have-been? Will the self-sustaining space communities be established before a catastrophe sets back the prospect of any such enterprise, perhaps foreclosing it for ever? We live at what could be a defining moment for the cosmos, not just for our Earth.
- Space, the final frontier. These are the voyages of the Starship Enterprise. Its five-year mission: to explore strange new worlds, to seek out new life and new civilizations, to boldly go where no man has gone before.
- Since, in the long run, every planetary society will be endangered by impacts from space, every surviving civilization is obliged to become spacefaring--not because of exploratory or romantic zeal, but for the most practical reason imaginable: staying alive.
- I have sat by night beside a cold lake
And touched things smoother than moonlight on still water,
But the moon on this cloud sea is not human,
And here is no shore, no intimacy,
Only the start of space, the road to suns.
- F. R. Scott, Trans Canada
- Without space, there is no time.
- Dejan Stojanovic in “A Star Deep in the Mind”
- Entering a cell, penetrating deep as a flying saucer to find a new galaxy would be an honorable task for a new scientist interested more in the inner state of the soul than in outer space.
- Dejan Stojanovic in “Inner Space”
- For instance, letting the people who came up with the foolish idea of a space elevator know the extent of their foolishness by making them go ”What the...?!” Or using my feelings toward certain things such as “What’s with the present political system and international situation?!” as motivation and launch a counterattack against them.
- Yoshiyuki Tomino 
- At any rate, whether we expect another invasion or not, our views of the human future must be greatly modified by these events. We have learned now that we cannot regard this planet as being fenced in and a secure abiding place for Man; we can never anticipate the unseen good or evil that may come upon us suddenly out of space. It may be that in the larger design of the universe this invasion from Mars is not without its ultimate benefit for men; it has robbed us of that serene confidence in the future which is the most fruitful source of decadence, the gifts to human science it has brought are enormous, and it has done much to promote the conception of the commonweal of mankind. It may be that across the immensity of space the Martians have watched the fate of these pioneers of theirs and learned their lesson, and that on the planet Venus they have found a securer settlement. Be that as it may, for many years yet there will certainly be no relaxation of the eager scrutiny of the Martian disk, and those fiery darts of the sky, the shooting stars, will bring with them as they fall an unavoidable apprehension to all the sons of men.
- H.G. Wells The War of the Worlds, Book II, Ch. 10 (Ch. 27 in editions without Book divisions): The Epilogue
- I experience the same sense of absurdity when I listen to a cosmologist like Stephen Hawking telling us that the universe began with a big bang fifteen billion years ago, and that physics will shortly create a 'theory of everything' that will answer every possible question about our universe; this entails the corollary that God is an unnecessary hypothesis. Then I think of the day when I suddenly realized that I did not know where space ended, and it becomes obvious that Hawking is also burying his head in the sand. God may be an unnecessary hypothesis for all I know, and I do not have the least objection to Hawking dispensing with him, but until we can understand why there is existence rather than nonexistence, then we simply have no right to make such statements. It is unscientific. The same applies to the biologist Richard Dawkins, with his belief that strict Darwinism can explain everything, and that life is an accidental product of matter. I feel that he is trying to answer the ultimate question by pretending it does not exist.
- Colin Wilson in Alien Dawn, pp. 301-302