[flr (OP)]

What is space made of?

[flr (OP)]

If it is just a mathematical construct of no physical substance, then what keeps things apart (i.e. at a distance from each others)?
There must be a "filler" between things to keep them apart?

[yor_on]

Nice one Flr

And yeah, a smooth, relative a 'bit' universe, sort of?
What fill in the 'bits'?

In a 'smooth' universe nothing 'fills it in', but in a 'bit' universe? And nothing 'fitting the bits' together?
Why, isn't that a 'smooth' universe too?

I like paths instead, ignoring that question. Everything can be described in relations, and possibly (hopefully) you can depending on choice of  'system', and your definitions and limits, also make those 'paths' into fractals.
=

Meaning that possibly the universe can be described as being one consistent 'path', as some use a wave function to describe it. Weird stuff

[Pincho]

If you ask questions on a science site they will always give you replies based on the Standard Model. People are not allowed to reply with their own models. So your question in here is replied with the case that quantum physics means that all positions in spacetime are quantized.. fragmented.

In other models there are other ways to fill in the gaps.

[lightarrow]

What is space made of?

Space is made of x and y bind together by z.
And what x, y and z are made of? They are made of t, u and v.
And what are t, u and v made of?
They are made of....
....
....
Your question is meaningless.

[lightarrow]

If it is just a mathematical construct of no physical substance, then what keeps things apart (i.e. at a distance from each others)?

Why they shouldn't stay apart?

[flr (OP)]

what's in between to have them apart?

[yor_on]

It's not meaningless to me, although I've been wondering about it in form of 'background dependencies' or not it seems to come down to the same idea. What fill in the 'bits' if it is a 'bit' universe. That can be seen as the question if you need a 'background' on which the 'bits' dance, becoming our universe, or if the 'bits' indeed are the universe, in which case the idea becomes a smooth one to me. Smolin's universe is 'back ground independent' if I remember right, as is Einsteins. And checking: http://www.einstein-online.info/spotlights/background_independence : I do remember right

But paths don't need a background. I believe that is our relations to the universe creating both 'dimensions' and the 'space' we find, which makes me almost but not really, certifiable.

[evan_au]

As one small step towards answering your question of "What keeps things apart in space?"...

Space is filled with "Fields":

• The Gravitational Field, which has infinite range, and is always attractive (as far as we know)
• The Electromagnetic Field, which has infinite range, and can both attract and repel; since opposites attract, they quickly cancel each other out on the large scale, apart from the light/photons which can propagate forever
• The Higgs Field, which gives things the inertial aspect of mass [and if I understood correctly, may have something to do with the expansion of the universe??]
• And several others which have shorter ranges, so we can ignore them if we are looking at what fills interstellar space, rather than what fills the space inside an atomic nucleus.

How these Fields affect objects in space:

• Since Gravity attracts over long distances, objects will speed up as they approach another object, giving them the speed to move away again. This cyclic interplay between gravitational potential energy and kinetic energy means that most "normal" sized objects are kept apart by their elliptical, parabolic or hyperbolic orbits.
• Newton showed that if the equation for gravity departs even slightly from an inverse-square law, there will not be an exact exchange between gravitational & kinetic energy; energy will be lost on every orbit, and our solar system would collapse into the central object (as would our galaxy and local cluster).
• Things do change a little for extra-large objects like stars and black holes, where radiation pressure and magnetic fields can delay other material from approaching the central object (or even expel it at high velocity from near the poles of the black hole).
• Observational evidence shows that the universe is expanding, so more space is "forming" between the galaxies we can see; this also keeps things apart, even if the origin of this accelerating expansion is still somewhat mysterious...

So, what keeps things apart in space is the gravitational attraction between all things, which falls off as the distance squared.

[lightarrow]

what's in between to have them apart?

Space. Why you don't like this answer? In physics, as in every other things, included language, keeping asking "what this is made of? Where does it come from? Why is this?" you will eventually find basic, undefined terms and concepts.
You don't believe me? Which is the meaning of the word "meaning"?

[Ethos_]

It's not meaningless to me,

Nor to me either yor_on............But I do understand where Lightarrow is coming from. Because we are trying to understand a universe that may well be beyond our complete understanding, we may have to accept some limitation in our definability of expression.

[lightarrow]

Ok, I didn't mean that the question is meaningless "a priori": if physics had an answer in terms of something more fundamental than space, we would already know it.

[Pincho]

Like I said.. the standard Model isn't all models. When people say "We do not know." they mean people who believe in the standard model. I believe that I know what space is made from, but I am not allowed to post the answer in here. But at the same time, I don't like people using the word 'we' when I am in the thread.

[Ethos_]

But at the same time, I don't like people using the word 'we' when I am in the thread.

Those of us who participate in this thread are referred to as WE. If you care not to be associated with WE, then I suggest you involve yourself in another thread.

[Pincho]

But at the same time, I don't like people using the word 'we' when I am in the thread.

Those of us who participate in this thread are referred to as WE. If you care not to be associated with WE, then I suggest you involve yourself in another thread.

Sorry, but nobody has the right to say WE do not understand the universe for the people in the thread.

Because we are trying to understand a universe that may well be beyond our complete understanding

[Ethos_]

Sorry, but nobody has the right to say WE do not understand the universe for the people in the thread.

BTW, I did say: "beyond our complete understanding."

When you get your Nobel Prize, "WE" will be quite happy to listen to your expert opinions.

[Pincho]

Sorry, but nobody has the right to say WE do not understand the universe for the people in the thread.

BTW, I did say: "beyond our complete understanding."

When you get your Nobel Prize, "WE" will be quite happy to listen to your expert opinions.

It doesn't matter if my idea is right, or I am deluded, you just can't speak for everyone, it's not good etiquette. I feel insulted by the fact that you can include me, and say that I don't understand the Universe. I make guesses.. I know that, but I feel that I make good guesses. We don't live long enough to find out if we are right, or wrong, so we live with our guesses until we die. Now my guess was eventually also guessed by Stephen Hawking, he made the same guess about 4 years after me. So I feel happy that two of us came to the same conclusion. That is the closest I will get to a proof, I was backed up by Stephen Hawking. For personal reasons that is nice to know.

Here is the video, which is relevant to this thread... Go to 28min 30 seconds, and watch from there. It has a simple explanation for the substance that fills space. It sounds simple, but if you ever dig deeper into the explanation, it turns into my entire theory. However in this case with Stephen Hawking it turns into the Big Bang...

http://www.youtube.com/watch?v=vkEIpBlqazk

[Ethos_]

but I feel that I make good guesses. We don't live long enough to find out if we are right, or wrong, so we live with our guesses until we die.

This sentence from your last post supports my comment that WE are all still unsure about the complete nature of the universe.

Listen my friend; I really don't want us to be in conflict with each other. I realize that you have particular theories and ideas about the cosmos that may or may not line up with the Standard Model. And that's OK, we all have the freedom to speculate about these questions. And when I use the word WE, I was sincerely not trying to discount the views that you may have.

The Standard Model is, at least for the present, the currently accepted guide for the limited understanding we now have. Let's be honest my friend. The scientific community must have some basis for foundation, otherwise there will exist absolutely no continuity among us. The Standard Model is that foundation until a better model is proven. And history has shown us that WE, notice I now use this word with greater caution, will certainly need to change our minds when a better theory comes our way.

Peace..................

[yor_on]

Heh we can all be moody at times. We're humans, a rather peculiar species But we have one good thing going for us, and that would be the ladies

[Pmb]

What is space made of?

Space isn't "made" of anything. All science has at its root observation. We observe different objects(don't ask me what an object is). While it's not possible to define space in terms of simpler physical entities, one can think of if as follows: it is that which we use to describe objects, i.e. in terms of size and location. One can say that space is what we measure with a ruler and a property of space is that which allows objects to be different. By this I mean that by "different objects" it is meant that the objects are located at different places and has "empty" space between them, i.e. that which is the absence of an object.

There is book on this subject by Max Jammer called Concepts of Space: The History of Theories of Space in Physics by Dover Pub.

Also, a friend of mine has a web page on the subject at http://users.wfu.edu/brehme/space.htm

It should be noted that geometry is what we use to describe thing in space and is  branch of mechanics, not mathematics.