What is space?

Light travels through it as waves. It is possibly even the reason why nothing can travel faster than light. It is said to be sufficiently "dense" so as to be able to drag whole galaxies along with it as it "expands", in a theory that seems to require ever more of it. Possibly everything matter and energy that is, is laid over it, with what we call "space" as the foundation stone. Does space have mass?

 

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Space, by definition, can't be dense or have mass.
Space is just space..

 

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[edit] In Physics
Space is one of the few fundamental quantities in physics, meaning that it cannot be defined via other quantities because there is nothing more fundamental known at present. Thus, similar to the definition of other fundamental quantities (like time and mass), space is defined via measurement. Currently, the standard space interval, called a standard meter or simply meter, is defined as the distance traveled by light in a vacuum during a time interval of exactly 1/299792458 of a second. This definition coupled with present definition of time makes our space-time to be Minkowski space and makes special relativity absolutely correct simply by definition.

Before Einstein's work on relativistic physics, time and space were viewed as independent dimensions. Einstein's discoveries have shown that due to relativity of motion our space and time can be mathematically combined into one symmetric object — space-time. (Distances in space or in time separately are not invariant versus Lorentz coordinate transformations, but distances in Minkowski space-time are — which justifies the name).

However, time and space dimensions should not be viewed as exactly equivalent in Minkowski space-time. One can freely move in space but not in time. Thus, time and space coordinates are treated differently both in special relativity (where time is sometimes considered an imaginary coordinate) and in general relativity (where different signs are assigned to time and space components of spacetime metric).


[edit] In Astronomy
Main article: Outer space
Space refers collectively to the relatively empty parts of the universe. Any area outside the atmospheres of any celestial body can be considered "space". Although space is certainly spacious, it is not always empty, and can be filled with matter. In particular, the boundary between space and Earth's atmosphere is conventionally set at the Karman line.


[edit] Spatial Measurement
Main article: Measurement
The measurement of physical space has long been important. Geometry, the name given to the branch of mathematics which measures spatial relations, was popularised by the ancient Greeks, although earlier societies had developed measuring systems. The International System of Units, (SI), is now the most common system of units used in the measuring of space, and is almost universally used within science.

Geography is the branch of science concerned with identifying and describing the Earth, utilising spatial awareness to try and understand why things exist in specific locations. Cartography is the mapping of spaces to allow better navigation, for visualisation purposes and to act as a locational device. Geostatistics apply statistical concepts to collected spatial data in order to create an estimate for unobserved phenomena. Astronomy is the science involved with the observation, explanation and measuring of objects in outer space.

From Wikipedia, the free encyclopedia

 

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space is something my closet lacks alot of.

 

Particles.

Space is the reason that light... Oh never mind.

By who? Where? Whoever it was, was dense.

Ummm.... no.

 

Enmos. How does it do what it does if it is just "nothing"?

 

Firstly, I never said that is was nothing..
Secondly, could you kindly point out what it is exactly that space does ?

 

Cosmictraveler. Interesting quotes but they explain nothing. I'm trying to go beyond the casual acceptance of space without giving it a thought of what it actually is.

 

Enmos. I got the impression that you thought it was nothing. My OP says some of what it does.

 

Well, in the strict sense of the word space actually is nothing. It's space..
They only thing in the OP I agree with that space does is that it's expanding.

 

superluminal. Particles are matter. Matter does not travel at light speed. So photons are not particles. OK?

Why should there be an ultimate speed? Because waves going through a water has an ultimate speed as do waves going through glass or any other medium, even space.

How does expanding space drag along whole galaxies if the gravity is insufficient in clusters? Space hooks?

Waves travel through space. It bends light. It can even move whole galaxies. Just because it is all pervasive, that does not mean it can be ignored. It is not waves but what waves travels through so why not a material and why not a mass.

I would like to have thought you had given a single second's thought to any of the answers you gave but no, you just did the sci-bot thing. Not in my text book so it must be wrong.

 

Enmos. How does nothing expand? Even if nothing expanded, why should it affect anything else and so cause "expansion"?

How does gravity bend light in a vacuum?

 

Look, we are using two different concepts of nothing. Space exist, but at the same time it is not a physical thing.

As an aside:
Nothing, or better non-existence, can expand if the existence around it retreats

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Enmos. If just a vacuum, space would affect nothing, so it must be something if it can affect physical things.

Can the existence retreat from everywhere at the same time?

 

Well, here's my two cents in that direction. Space is the boundaries of the universe, which is ever expanding at the speed of light by objects creating light at a sufficient magnitude to reach its end boundary. Beyond space: absolute darkness. THE black hole, so to speak. Works for Big Bang theorists as well as Creationists. The universe (space) will not expand any further than the magnitude of light generated by objects presently in space.

 

Learned Hand. Why does space only expand at light speed, like EMR, gravity, etc? If it is nothing, why does it not go on forever?

I think there would be literally nothing beyond the end of the universe. That is a 3D universe. BB only works in four physical dimension expansion so would not have an end as it would not have a starting place. Shine a torch at the end of the universe, and where space ends, so would the beam of the torch end. Throw a rock and it would just vanish where space ended. There is nothing to support either the waves of photons or atomic structure beyond where space ends, so neither matter nor energy can exist.

 

You cannot mean space is a physical thing, do you ?
And how says space itself affects anything physical ?

I was kind of joking with that one. But sure why not.. lol

 

Well, space only expands @ the speed of light because nothing travels faster. Although theories have been developed as to what may happen if one travels faster than its constant, nothing can be shown as having that propensity or capability.

 

Just a minor correction here: space is actually expanding at a speed faster than c. Since it's not matter it's not limited by the speed of light. And that's the reason that distant galaxies have been measured traveling at speeds in excess of c.

 

space is (time) * ( speed of light)