What is Space?

[qibbish]

We often hear people talk about space expansion, space warps, folds in space, the topology of space and - of course - things existing within space. This is a very long overdue question, but can anybody explain exactly what space is?<br /><br />Does space have any meaning if one removes all the atoms and energy fields from within it (let's assume higgs fields don't exist for this)? Does the word "space" have physical meaning like "book" or "sun" or is it more an abstraction, like the concept of our alphabet (i.e. "alphabet" ceases to have meaning if all the letters are removed from it; it only exists in relation to what it contains).<br /><br /><br />Thanks!

 

[dragon04]

"Space" to me, is an oversimplified term to express an environment around us.<br /><br />"Space" implies that something occupies it. It's a definition of the container that holds something. With nothing, there would be no space. <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[siarad]

Space perhaps <i>is</i> something. <br />It has magnetic permeability & electric permittivity.<br />It has impedance, 377 Ohms I think, aircraft are painted in 377 Ohm paint to aid RADAR invisibility.<br />Used to be known as aether but as we can't measure our speed w.r.t it, aetherists became a laughing stock <img src="/images/icons/rolleyes.gif" /> & space no longer became it's container but an entity. The fact remains these properties exist <img src="/images/icons/wink.gif" />

 

[newtonian]

gibbish - there is more than one definition of space, of course. It depends on the context in which the word is used - and I would suggest checking out dictionaries.<br /><br />I will stick to astronomy as a context.<br /><br />Isaiah 40:22 states God is stretching out the heavens like a fine gauze. A gauze has threads and filaments. Our universe is stretching out and has 'threads' and 'filaments."<br /><br />In this illlustration, which describes the real universe, the distance (= space) between any two sufficiently distant (spaced apart) points increases (unless a thread breaks and rebounds - compare blue shifted galaxies).<br /><br />Note above that space = distance.<br /><br />Did you realize that this would be meaningless without dimensions?<br /><br />Space implies and requires dimensions - it does not have to be just 3 dimensions, btw.<br /><br />But I do not wish to go into String theories or in depth on multiple universes and dimensions unless you want me to.<br /><br />Staying simple, space involves 3 dimensions.<br /><br />We do not know if our universe had 3 dimensions before the big bang - I suspect it did, but I am not at all sure of that.<br /><br />Now space in our neck of the woods - or our section of the universe - is not empty - but distance (= space) would exist between objects in the universe even if the space in between was totally empty - which, again, it is not.<br /><br />In other words, the 3 dimensions of our universe are not dependent on anything, matter or energy, existing in any location or area within our universe.<br /><br />Note I said the 3 dimensions of our universe - one may include time as a 4th dimension. <br /><br />Then we might try explaining space-time - but I'll leave that for another poster - relativity is not newtonian.<br /><br />To get this into perspective - the bigger picture - 1 Kings 8:27 indicates that God cannot be contained within our heavens nor even withing the heaven of the heavens.<br /><br />That implies other universes within a much

 

[aetherius]

If the universe was created from nothing then space, as part of the unvierse, must be something. Space is simply the name we give to the portion of reality that we cannot identify as energy or any of its phases. There is a "substance" (aether) to space but we just can't measure it. We have to redefine the aether to differentiate it from the historical context.

 

[newtonian]

Aetherius - well, we try to measure space.<br /><br />And the universe was not created from nothing, in my opinion - remember the law of conservation of matter and energy!

 

[kyle_baron]

We often hear people talk about space expansion, space warps, folds in space, the topology of space and - of course - things existing within space. This is a very long overdue question, but can anybody explain exactly what space is?<br /><br />Here's what some famous people said about space (from the book The Fabric of the Cosmos by Brian Greene):<br /><br /><br />Newton: The transparent, empty arena in which all motion takes place, and exists as a real physical entity he called "Absolute Space". Absolute space remains always similar and unmovable.<br /><br />Henry More: Seventeenth century theologian/philosopher believed if space were empty it would not exist.<br /><br />Gottfried Leibniz: German philosopher, "without objects in space, space itself has no independent meaning or existance. If all objects were removed from space (completely empty) it would be as meaningless as an alphabet that's missing its letters. This is the standard Big Bang contemporary thinking. <br /><br />Einstein: Because the speed of light is constant, we conclude that space and time are in the eye of the beholder. Each of us carry our own clock. Yet, when we move relative to each other, the clocks do not agree. Each of us carry our own yardstick. When we move, relative to one another, the yardsticks do not agree. If space and time did not behave this way, the speed of light would not be constant, and would depend on the observers state of motion.<br /><br />Einstein clearly won the debate. His description of space is our post BB space. However, I believe Newton's "Absolute Space" which remains always similar and unmoveable, gives a good description of a pre BB space. <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>

 

[jatslo]

Space is an empty volume, and space is not an empty volume. For example, this is my space, that is your space, and that empty space is reserved for the unfortunate fool who triggers the trap door.

 

[doc_harra]

you may try and find some sense in these posts (Is hard subject to mention)<br />http://uplink.space.com/showflat.php?Cat=&Board=askastronomer&Number=435091&page=&view=&sb=&o=&vc=1<br /><br />http://uplink.space.com/showthreaded.php?Cat=&Board=askastronomer&Number=453135&Search=true&Forum=All_Forums&Words=doc_harra&Match=Username&Searchpage=0&Limit=25&Old=allposts&Main=447201 <br /><br />I will try add some new text <br />What is not space ?<br />Space is the difference between knife Fork and Spoon ?

 

[qso1]

I recall the days when the Universe meant all encompassing inclusive of space or so I assumed years ago. I look at it like space as the void that all physical objects occupy. In that sense, the BB could have occured in this void rather than as theorists suggest, arise out of nothing, no time, no physical existence. Some theorists that is that tend to suggest nothing existed before the BB, nothing surrounded the singularity that exploded into the Universe per the BB. I find it hard to concieve that there could be such a state of non-existence. Of course, thats just me.<br /><br />Other theorists talk of other Universes and multiverses etc. I don't know if there is that firm of an accepted definition anymore. I'm no scientist, much less a cosmologist but I have researched it enough that I suspect what has been passed down to me today will change tomorrow. <div class="Discussion_UserSignature"> <p><strong>My borrowed quote for the time being:</strong></p><p><em>There are three kinds of people in life. Those who make it happen, those who watch it happen...and those who do not know what happened.</em></p> </div>

 

[xmo1]

Hello qibbish:<br /><br />Check my homepage for an mpeg called Local Space at the center bottom of the page. The 'dust' is the accumulation of matter that exists in a galaxy. You see a lot of empty space when you leave the galaxy.<br /><br />The key word is 'see.' Much of what is in the universe is not visible to the human eye.<br /><br />I have not seen a realistic depiction of those things that are not seeable in interstellar space, except a graphic of the Cosmic Background Radiation, in a region similar to that represented in the mpeg, although it would be interesting.<br /><br />So what you have is space with mass densities ranging from empty to full, but that is only a small account of the actual consistency of the universe.<br /><br />Voyagers 1 and 2, and the Hubble Space Telescope are interesting projects that help people understand what space is. <div class="Discussion_UserSignature"> <p>DenniSys.com</p> </div>

 

[nikolaus008]

What is space? We know that space is filled with ice, gas and dust, dirt, but what is all the gas and dust within? a vacuum? So is the Vacuum the medium for matter resonating at the speed of light and slower? The Vacuum seems to be a barrier. A line between matter resonating at the speed of light slower, and matter resonating faster than the speed of light. Barriers are sometimes violent places. Like the speed of sound. Like oceans on Earth. The surf can be deadly in some places.<br /><br />Like water is the medium of life on Earth, space is the medium of matter that sustains Stars and systems of planets. Like we are within our planet, space is within???what? The other side, matter that is faster than light? What is outside? and endless Sea of Galaxies? The evolution of elements and matter? of Life? The Earth exist within a galaxy, that exist among infinitely more than billions of Galaxies that Humans refer to as the Universe, that exist within the Vacuum of Space, that exist within???????? What? What is space within? and can we get to it?

 

[weeman]

We don't know what space exists within. With that question, I believe you are asking what is at the edges, or outside of the Universe. No one knows exactly what space exists within. If it does have an end, who knows whats beyond that. If it is infinite, then it exists within itself I guess you could say.<br /><br /><font color="yellow"> We know that space is filled with ice, gas and dust, dirt, but what is all the gas and dust within? a vacuum? </font><br /><br />The term vacuum being applied to space is a common misconception. We think of it as being a vacuum because it has no pressure. If I go out in space in my space ship or space suit, I better hope to god that my ship or suit has no holes in it <img src="/images/icons/smile.gif" /> <br /><br />However, the true definition of a vacuum means a space that is devoid of all matter, also known as "void". Even in space there are tiny particles of some kind of matter floating about. I'm not sure of the exact numbers, but I know some people on this board might be able to tell you the estimated number of atoms within each cubic foot of space.<br /><br />As far as it being the barrier for matter going slower/faster than light, I think you have to look at it in two different ways. Since galaxies are moving away from us in every direction, astronomers theorize that it is the very dimensions of space that are expanding. The galaxies aren't moving on their own, the space between them is constantly expanding. <br /><br />All matter in the Universe is limited to the speed of light, or C. However, the dimensions of space are not necessarily limited to any specific speed limit. Space could very well expand at a much faster rate than the speed of light, while all matter within it cannot. <div class="Discussion_UserSignature"> <p> </p><p><strong><font color="#ff0000">Techies: We do it in the dark. </font></strong></p><p><font color="#0000ff"><strong>"Put your hand on a stove for a minute and it seems like an hour. Sit with that special girl for an hour and it seems like a minute. That's relativity.</strong><strong>" -Albert Einstein </strong></font></p> </div>

 

[rfoshaug]

<blockquote><font class="small">In reply to:</font><hr /><p>Since galaxies are moving away from us in every direction, astronomers theorize that it is the very dimensions of space that are expanding. The galaxies aren't moving on their own, the space between them is constantly expanding.<p><hr /></p></p></blockquote><br /><br />This is a concept I have always had trouble understanding.<br /><br />If space itself was expanding, then it shouldn't be just the distance between galaxies that was expanding, but also the distances between stars, planets and even atoms, shouldn't it? If space doubled its size so that a particular galaxy was twice as far away, then everything should be twice as big, even your arm so that what was an arm's length away before should be an arm's length away now (because your arm is twice the lenght it used to be). And we, being twice as big and having double-sized eyes would not notice any difference at all.<br /><br />Or am I misunderstanding the concept?<br /><br /><br />Another thing I've been pondering is this: What if far-away galaxies are not moving away from us? All this is based on the red-shifting of light which we assume is Doppler shift. But what if, in addition to Doppler shift, there is another way for light to be shifted? What if photons have a natural tendency to lose frequency if they travel over millions of years - so slowly that it can't be observed in a laboratory (unless you do an experiment that lasts for millions of years)? What would that do to the theories in cosmology? Is there other evidence that the universe is expanding except for redshift?<br /><br />I'm no scientist and I do not know very much about the nature of light. And I'm not saying that it is so - it's just a thought. <br /><br /><img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font color="#ff9900">----------------------------------</font></p><p><font color="#ff9900">My minds have many opinions</font></p> </div>

 

[alokmohan]

There is no absolute space,absolute time.Depends on the frame of reference.,There may be no question of end absolutely.General theory of relativity talks of nature of space.

 

[why06]

We don't know for sure that space is expanding but the red shift suggest it. The Problem I have is does this contistute the expanding of space-time. Maybe the galaxies are moving awat for another reason. <br /><br />And why does not the force of gravity negate this force to attract different galaxies?<br />Does this expansion of Space-time constitute Gravity. <img src="/images/icons/wink.gif" /><br /><br /><img src="/images/icons/smile.gif" /><font color="yellow">As for you Nikolaus<font color="white">...<br />There are many other threads pertainging to the question your asking.<br />My standard reply: Space-time is the only place matter exists. If you want to go beyond that you may cease to exist. No one can tell you what is outside this universe for this is all we know....<br />..Do not think of darkness outside of it because color does not exist, Do not think of there being an out side because this is a geometric concept. There will be no outside. You mayend up in another universe , but this is pure speculation... You won't even know your outside it because time will not be there. <br /><br />Im sorry but all imformation in this universe travels through particles and waves.... We can not see an outside universe because it does not exist to matter. <br />The fact is no one knows whats out there because. Its like imagining your self in another place than 4-D space-time........<font color="yellow"> Impossible... <img src="/images/icons/laugh.gif" /><br /><br /></font></font></font> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>

 

[trumptor]

"The Vacuum seems to be a barrier. A line between matter resonating at the speed of light slower, and matter resonating faster than the speed of light."<br /><br />I've actually wondered something similar to this myself before. Could it be possible for matter to travel faster than the speed of light? At the speed of light, mathematically matter would become infinitely massive and require an infinite amount of energy, but nothing forbids it from exceeding the speed of light, does it?<br /><br />Mathematically wouldn't it be possible for matter to exist at all speeds except for c? Could c be a limit in a non-continuous funtion where one type of matter travels at below c and from our own observations, begins to warp its shape, mass, time as it approaches c from the negative side never being allowed to hit c because of the energy, time and mass constraint? Could there also be another class of matter that can only exist at above c which can never slow to c because of the same constraints? How would it behave according to the theory of relativity at speeds far above c? Can it be possible that matter can exist at both sides of the limit and only not be able to exist at c, making c the limit for the speed of matter from + and - sides with no value at c? <br /><br />On a sidenote, what comes after being an atom? A molecule? I'm assuming you morph into bigger things the more you post, but is there a place on the board that explains it or do you just keep posting until you become something new? Can different people turn into different things? Its a pretty neat little tag idea <div class="Discussion_UserSignature"> <p><em><font color="#0000ff">______________</font></em></p><p><em><font color="#0000ff">Caution, I may not know what I'm talking about.</font></em></p> </div>

 

[why06]

there are thought to be particles of a very speculative nature called tachyons which are said to move faster than the speed of light, but YES you can travel faster than "c" just not at it<br /><br /><br /><br />Oh and look in FAQ for rankings: <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <div>________________________________________ <br /></div><div><ul><li><font color="#008000"><em>your move...</em></font></li></ul></div> </div>