(Assembled from disclosures made by space people in various communications.)
Having conceived of completely empty space and satisfied ourselves regarding the geometry of it and the limitations of measurement which are inherent in it, we may quite properly ask ourselves, how real it is it? Does our space, the space which surrounds us, actually have these characteristics? We know that our space contains lots of things we consider as quit real, and we may ask of what are they made, and what is their basic reality?
To conceive of an abstract quality and assign to it concrete properties and then call it a real substance is most unsatisfactory in the face of our notions regarding everyday matter. We would much prefer to have something more tangible as a starting point. Consequently, even though reality actually is a concept just as intangible as our rectilinear concept, it might assist understanding if some primordial quantity could be introduced as a medium of expression. The early postulation of ether and the still earlier Greek Ylm might fulfill this requirement. Both were considered to be all-pervading strictly continuous substances out of which matter was fabricated, and to have whatever properties were necessary for the formation of matter, without regard to how conflicting these properties might be. There is no fundamental objection to the use of such a medium of expression, since we will find that all references to it actually cancel out anyway. However, if it will serve as a crutch to help us in our first faltering steps, by all mean let's use it.
In our considerations of Ylm or ether we have something that is structureless, imponderable, and without boundaries, and in every sense intangible. Our concept of space provides a place in which we can conceive of the ether as being located, but by what manipulation can we convert this imponderable substance into ponderable matter?
Instinctively we know that we must make use of space as we have it, and that which we find therein, if we are to designate reality as distinct from the continuous background of ether. If we cannot designate some portion of the ether as being unique and distinguishable from all the rest, then we cannot say that we have established any degree of reality.
What is required then is for us to conceive of something which may be done, some manipulation which when completed will designate without uncertainty a certain region as being unique above all others, and therefore real. Ordinary spatial measurement we know to be inadequate since they are all relative to the arbitrary standard with which they were measured. Obviously what is needed is something which in itself is absolute: something that will display the same value no matter where or how it is inspected, something against which a measurement may be made with assurance that when made it will not change. Furthermore, to assume the arbitrary injection of such a standard merely begs the question, since we transfer the question of reality from the substance to the yardstick that measured it, without yet establishing the reality of the yardstick. No, we must find that for which we seek in our concept of space itself.