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Posted July 18, 2009 (10:44PM)
Probably a silly question, but even the air we breathe can be broken down into components we can’t see. So Air is something, what is Space?
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Posted July 19, 2009 (02:09AM)
Space is just space, El D. Are you looking for some sort of particles of space? As far as I (or anyone?) knows, space doesn't break into anything other than more regions of space, which can be divided indefinitely. Space as currently understood (in physics as well as metaphysics) is continuous and dense, unlike matter.
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Posted July 19, 2009 (02:51AM)
Just trying to understand what it is, does it react to heat or cold, can it be compressed, has anyone tried to capture any of it in all these trips above the earth?
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Posted July 19, 2009 (03:19AM)
Have to go on to NM tomorrow, please don’t let this market tank while I’m gone. Wife is renting a car in the morning, if it’s from you know who, I will do my best. Nite Owl, and have a good week! |
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Posted July 19, 2009 (08:20AM)
El D, space is like the vessel that contains things, but where this analogy breaks down is that space is not in turn made of glass, metal or clay, it is the container not a material.
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Posted July 19, 2009 (07:43PM)
Here's another way to put it:-
If you sat down to list all the things in the universe, on that list you would have trees, clouds, stars, atoms, but not space. Even if you gave the list to someone to check, they wouldn't hand it back and say "Opps, you forgot 'space'." 'Space' is not another thing in the universe; more like a condition under which we comprehend the universe. (Am I becoming a Kantian in my dotage?) Please don't write back that the list is impossible to compose, this is known as a thought experiment. |
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Posted July 19, 2009 (10:13PM)
There have been several metaphysical views about space:
1. The substantival, absolute conception of space (Newton's conception): Space is a (really big) entity. By calling it an entity, I mean that it is something that can exist on its own, independent of other things. It is infinitely large and infinitely divisible. It exists necessarily (it could not conceivably have failed to exist). It is homogeneous and isotropic (no part of space is different from any other, and no direction in space is different from any other). It is unchangeable, you can't do anything to it or with it, except to occupy it. Material objects exist in space. Space has no mass or energy, and it doesn't do anything. (So no, you can't put it in a jar.) On this view, both "absolute" and "relative" motions exist: objects move absolutely when they change the part of space that they occupy. Objects are in "relative motion" when their absolute motions are different. As Newton said, absolute motion is unobservable; we only perceive relative motions with our senses. 2. The relational conception of space (Leibniz' conception): Space per se has no independent existence. There are only objects, and the spatial *relations* among them. "Space" refers, if anything, to this system of relationships among objects. So a completely empty space-time continuum is a conceptual impossibility. On this view, then, only relative motion can exist--objects "move" in the sense that they change their spatial relations to other objects. If everything were to move simultaneously, then actually nothing would be moving. (In other words, the idea of "everything moving" is an impossibility.) Leibniz and Samuel Clarke had a philosophically fascinating debate about the substantival vs. relational conceptions of space back in the 1700's (the Leibniz-Clarke correspondence). As Newton wasn't into debating, Clarke carried the Newtonian flag. (Clarke also won the debate, I might add.) 3. The Kantian conception of space: Roughly speaking, space isn't out there; it is entirely dependent on the mind. It is an artefact of the way in which we perceive things. Objects in themselves are entirely non-spatial and atemporal, but when they interact with our minds, the way in which our minds represent objects is by arranging them in this medium of "space" that the mind has created. In itself, space is nothing. This is from Immanuel Kant. 4. What does the General Theory of Relativity tell us about space? Most people think the GTR is closest to the relational conception. However, an interesting academic article by Tim Maudlin argues (persuasively) that GTR is closest to the substantival conception of Newton, out of all the alternatives above. This is because GTR treats space like an independently existing entity, with its own properties independent of the properties of the material objects in it. Space is, in a sense, even more substantial in Einstein's view, because it actually *interacts with* material objects; the 'curvature' of space-time has observable effects on the physical objects around us. In GTR, space and time are joined into a single entity, spacetime. This thing has a degree of curvature at every point. The curvature is caused by the concentration of mass/energy, and it produces observable effects (like the bending of light around gravitational masses). No, it does not react to heat or cold (heat and cold are just different degrees of kinetic energy in the molecules making up a material object). You can't capture it or move it. You might say that you can "compress" it, because one way of representing spacetime curvature is as a change in normal distance relations among spacetime points. I hope that helped somewhat. |
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Posted July 23, 2009 (10:52AM)
I've thought about this, and I agree to a point. Certainly the universe doesn't revolve around our perceptions, but neither does it revolve around our imaginations. If something cannot be physically measured, then it can not be physically perceived. I take issue with the assumption of the existence of undistinguished squares in empty space, or the existence of mental states for this reason. It seems to me that you're concluding that the concept of existence cannot be defined or delineated, since there may be things in existence beyond any human perception of comprehension. I agree with this, but doesn't it also make the concept of existence meaningless to us? |
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Posted July 24, 2009 (10:01PM)
Right, but things don't have to be physically perceived to exist. Abstract objects exist even though they can't be perceived by the senses, and similarly for space and time (um, and mental states). We might understand something intellectually without perceiving it with the five senses (which I assume is what you meant by 'physically perceive'). Wait a minute, you don't believe mental states exist? Does that mean that you believe you yourself don't have any beliefs, thoughts, feelings, or perceptions? I would distinguish two things: a) Knowing what is F, and b) Knowing what "F" means. For example, suppose someone asks me what stocks are going to do well in the coming weeks. I might say, I don't know. I don't know which stocks will do well, but I do perfectly well understand the question. I could even define it: to do well means to have a higher price than they have today. As I understand it, to "define" something is to explain the meaning of an expression. It is not to tell someone what things the expression applies to. So to define "do well in the stock market", I don't have to give you an exhaustive list of all the stocks that are going to do well; I just have to explain that to do well means to rise in price. Similarly, then, I haven't said anything that implies that existence cannot be defined, even though I have implied that we may not have a complete list of everything that exists. And our lacking this complete list does not mean that the concept of existence becomes meaningless or useless. Compare this case: Suppose I don't have perfect knowledge of which stocks will do well in the market. That doesn't mean that it is pointless or meaningless to talk about stocks doing well. (For one thing, I think I have *better reasons for thinking* certain stocks will do well than for others.) |
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Posted July 25, 2009 (01:04AM)
I’m back, a thanks for keeping the market up while I was gone! As for Space, if I understand correctly, there is no limit because it occupies everything that is not occupied? It can’t be nothing because any thing needs space to exist in, so the limit of space is really the amount of matter to occupy it? If we were capable of looking beyond any matter in space, would we perceive anything? |
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Posted July 25, 2009 (10:44AM)
Space doesn't occupy anything; things occupy space. As I think of it, space isn't nothing; it is an infinitely large thing, which all material objects occupy. If you went to "the edge of the universe" and looked out, you would see the blackness of empty space. Some people would say that there is no such thing as empty space, and there can only be space where there is matter. But I think these people are wrong. If you went to the edge and looked out, there would be empty space in front of you. There would not be an edge of space in front of you. |
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Posted July 25, 2009 (10:54AM)
Space has no beginning and no end.
God created space and the universe and God resides outside of space. Things God created occupys space. |
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Posted July 25, 2009 (11:55AM)
Right, but things don't have to be physically perceived to exist. Abstract objects exist even though they can't be perceived by the senses, and similarly for space and time (um, and mental states). We might understand something intellectually without perceiving it with the five senses (which I assume is what you meant by 'physically perceive'). Wait a minute, you don't believe mental states exist? Does that mean that you believe you yourself don't have any beliefs, thoughts, feelings, or perceptions? Yes, but don't things have to have the possibility of being physically perceived or sensed to physically exist? What laws of physics govern mental states? Otherwise, couldn't we follow a St. Anselm type proof for the existence of God? ( 1. I have an idea in my head of God as on omnipotent being. 2. God could not be an omnipotent being if he did not exist. 3. Therefore, God exists.) I would distinguish two things: a) Knowing what is F, and b) Knowing what "F" means. This is what I've been getting at. What "F" is, is. What "F" means is what we say about what is, the meaning is not what is. Defining is not just stating the meaning of an expression, it is also distinguishing the expression so that it is clear what falls outside of the meaning of that expression. This is especially true for mathematical and scientific definitions. For example, the definition of a sock is: a short stocking usually reaching to the calf or just above the ankle. Now, if I were to say that a tree could be classified as a sock, I would be obviously wrong because there is a fairly clear demarcation of what constitutes a sock, and there is an exclusive group of items that fit into that category. If the definition does not provide such a delineation that causes exclusion, then the definition is not really a definition, because everything imaginary and real falls within it's bounds. You can not conclusively state that fairies don't have a physical existence, because they may be so tiny that we just can't observe them. So while you don't need a complete list of everything that exists to state that something does or does not exist, you do need limiting criteria. |
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Posted July 26, 2009 (02:48AM)
By your definition the universe is all the matter within space? Everything within space reacts in a measurable way (I think), which would suggest space has properties, if so, how can it not be a thing? Your phrase “things occupy space” brings another thought. Like pure uncontaminated water would contain only two elements. So along the same assumption, space within the known universe is contaminated with anything that that ever existed but with no elements of its own that we know. Wouldn’t it make an interesting study looking for unknown elements? Think we could forget about a Pepsi bottle, how thick would the glass have to be to contain an absolute vacuum? |
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Posted July 26, 2009 (06:04AM)
I think what we have here is what is known as a category mistake, which is when you take two or more things of different categories and treat them as if they were of the same category. The problem is that it leads to absurdity/contradiction, where this would not happen if didn’t conflate the two things. That is what I was trying to point out with the thought experiment. Space is not another thing in the universe that you would count if you were counting things, What this has as an implication is that I dispute Owl’s notion of ever standing at the edge of the universe and looking into empty space. It would be like saying “What space does space occupy?”
Just like if we sent Plato into a room to count a dozen chairs, we would not expect him to return saying that there are 13, 12 chairs and the concept of a chair, you can’t treat ‘space’ like another thing in the universe, but rather as a condition under which we comprehend the universe. |
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Posted July 26, 2009 (11:35PM)
I don't see why that must be true. The argument as you just stated it is simply invalid. 1+2 doesn't entail 3. It would be valid if (1) said "God is an omnipotent being", but it doesn't. I don't think laws of physics govern mental states, but there might be laws of psychology (mentics?) that govern them. In any case, I don't know these laws. I can and do say that fairies don't exist. Now, if you are saying that one has to be absolutely, 100% certain of something in order to assert it, I think that's wrong. If no one had *the faintest idea* whether *anything* that anyone named existed, then I would agree that "exist" would be a useless concept. But on the other hand, if some people fail to be *absolutely certain* about whether some things exist, then that does *not* make "exist" a useless concept. Absolute certainty is required for virtually nothing in life, and is virtually never (maybe absolutely never?) an appropriate standard to impose on statements. By the way, if you impose the absolute certainty standard, then you also can't say that trees aren't socks. Maybe there are invisible giants who use hollowed-out trees as socks. And they have a magical process that makes the trees flexible so they can stick their feet into them. This is of course crazy, but so is the story about the tiny fairies. |
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Posted July 26, 2009 (11:49PM)
I am absolutely certain that the round square doesn't exist.
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Posted July 27, 2009 (12:16AM)
A pyramid comes pretty close. ? |
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Posted July 27, 2009 (12:31AM)
What I believe about space, and absolutely nothing to back it up, is what you say about standing on the edge and looking out. The reason I believe this, if there is a limit to the universe and space than I think that would imply there is more than one universe. What I mean, is there anything that has boundaries that is unique and one of a kind? To say that space has boundaries is saying that there is more of them? |
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