all our knowledge, both of time and space, is essentially relative....Position we must evidently acknowledge to be relative, for we cannot describe the position of a body in any terms which do not express relation....There are no landmarks in space; one portion of space is exactly like every other portion....We are, as it were, on an unruffled sea.

A feature of the relativity theory which seems to have aroused special interest among philosophers is the absoluteness of the velocity of light. In general velocity is relative. If I speak of a velocity of 40 km/s, I must add “relative to the earth”, “relative to Arcturus”, or whatever reference body I have in mind. No one will understand anything from my statement unless this is added or implied. But it is a curious fact that if I speak of a velocity of 299.796 km/s, it is unnecessary to add the explanatory phrase. Relative to what? Relative to any and every star or particle of matter in the universe.

I have said more than once, that I hold space to be something purely relative, as time; an order of coexistences, as time is an order of successions.

So in the physics of the heart, distance is relative; it’s time that’s absolute.

[Y]ou've probably heard of the theory of relativity. ...Most of us have heard the assertion that you can't transmit information faster than the speed of light. Most of us... hear it on authority only. We don't really understand why not. ...The reason is ...there's no absolute notion of time. Time depends on which coordinate system you're using... on your frame of reference... As seen from one frame of reference, event A can be before event B and as seen from another frame of reference, event B came first. The world [universe] hasn't got a standard definition of time.

The rhythm of relations of color and size makes the absolute appear in the relativity of time and space.

Time and space are interrelated. To overlook either of them is to be partially blind. What we plead against is man’s unconditional surrender to space, his enslavement to things. We must not forget that it is not a thing that lends significance to a moment; it is the moment that lends significance to things.

Time is relative; its only worth depends upon what we do as it is passing.

To our natural and human reason, I say that these terms ‘large,’ ‘small,’ ‘immense,’ ‘minute,’ etc. are not absolute but relative; the same thing in comparison with various others may be called at one time ‘immense’ and at another ‘imperceptible.

The Theory of Relativity confers an absolute meaning on a magnitude which in classical theory has only a relative significance: the velocity of light. The velocity of light is to the Theory of Relativity as the elementary quantum of action is to the Quantum Theory: it is its absolute core.

Although the peculiarly fundamental nature of time in relation to ourselves is evident as soon as we reflect that our judgments concerning time and events in time appear themselves to be 'in' time, whereas our judgments concerning space do not appear themselves in any obvious sense to be in space, physicists have been influenced far more profoundly by the fact that space seems to be presented to us all of a piece, whereas time comes to us only bit by bit. The past must be recalled by the dubious aid of memory, the future is hidden from us, and only the present is directly experienced. This striking dissimilarity between space and time has nowhere had a greater influence than in physical science based on the concept of measurement. Free mobility in space leads to the idea of the transportable unit length and the rigid measuring rod. The absence of free mobility in time makes it much more difficult for us to be sure that a process takes the same time whenever it is repeated.

This fact... proves that space measurements are reducible to time measurements. Time is therefore logically prior to space.

I do not define time, space, place, and motion, as being well known to all. Only I must observe, that the common people 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.

Time and Space are Adverbs.