the universe, how big is it?

Rwp; see below

Originally posted by shavixmir
Obviously you are wrong.
If we were to meet up in Victoria station:
x, y and z (so say: Third floor, 10 meters from the McDonalds and 30 meters from the hot soup stand) but you appeared at 10 o'clock and I appeared the next day at 12 o'clock...

See. Time has to be an added dimension.

Not really. It just has to be time, a quantity separate from the spatial dimensions. The fact that we wouldn't see one another if we got to the station at separate times doesn't imply that time is comperable to the spatial dimensions. Note for example that travel in either direction on the x, y, or z axes is qualitatively the same, whereas we only appear to be able to travel in one direction (forward) through time. Time may actually not exist at all as a quality in the universe; it may simply be a perceptual ordering that we apply to catalogue the order in which events happen.

Originally posted by darthmix
Not really. It just has to be time, a quantity separate from the spatial dimensions. The fact that we wouldn't see one another if we got to the station at separate times doesn't imply that time is comperable to the spatial dimensions. Note for example that travel in either direction on the x, y, or z axes is qualitatively the same, whereas we only appear to ...[text shortened]... y simply be a perceptual ordering that we apply to catalogue the order in which events happen.

Absurd. So just because things are stuck in a two-dimensional world, rules out that there could possibly be a third dimension.

The time we're talking about here is I-time. We only experience time moving from A to B. Look it up, I have to go take a poo.

Originally posted by DoctorScribbles
No [doodoo].

Ok, fine, let's look into that.

Since:
1/(i*i)Infinity,
It is sufficiant to show that
1+1/(2*i)=2 for i->Infinity
to prove that
1/(i*i)infinity.

1+1/(2*i) is a converging series.

Homework:

Show that 1+1/(2*i) for i->Infinity equals 2.

Originally posted by darthmix
A few points of clarification: when astronomers and cosmologists say that the universe is expanding, what they mean is that all the pieces observable, physical stuff in the universe - stars, galaxies, nebulas etc. - are getting further and further apart. They do not mean that space itself - the physical plane on which all those pieces of cosmic matter exist - is actually getting bigger.

Actually they do mean that space is getting bigger.

There does seem to be a point in the universe where all those stars and galaxies and things just sort of stop. That doesn't mean that, if you could fly a spaceship out to that point, you'd hit a brick wall and that you wouldn't be able to go any further. You'd fly out into total emptiness - no more stars or asteroids or other scenery, no roadsigns or markers at all. And that's the real problem: truly empty space, by definition, does not exist. Or, it exists only as an absence of stuff. We can measure empty space only as the distance between two other points, and we can only know those points exist if some physical object is there to mark them. Since there's nothing we can see to mark the way beyond the point where the stars stop, we can't really say that the space out there actually exists. If we DID fly a spaceship out into that void, we'd only be able to say that the space behind us exists, and only because we could measure it as the distance between ourselves and the rest of the universe.
Thats just nonsense.

Originally posted by sonhouse
However, 'dark matter' fits precisely with definition # 1. It can't be observed in our visible universe. We only see its effects, and even that is called to question, if other hypotheses are true, like small mods to newonian gravity.
So untill that is worked out, it is very much a supernatural phenomena.

"Seeing it's effects" is observation.

The fact that its existence is doubtful also does not make it fit the definition of supernatural. Something is not "supernatural" simply because you are not sure if it is there, or haven't seen it. You haven't seen my children, nor do you know for sure if I have any, does that mean I have supernatural children?


1. It can't be observed in our visible universe.
You do not know that. You might have tried "it hasn't been observed" but as I mentioned above, it has, or we wouldn't even be hypothesizing about it in the first place.

Originally posted by shavixmir
Absurd. So just because things are stuck in a two-dimensional world, rules out that there could possibly be a third dimension.

Not at all. As I already pointed out, physics does predict many other spatial dimensions, usually 7 or 8 above the 3 that we can directly experience. But none of them is time. Time, as best we can tell, is a way of cataloging and ordering the irreversible sequence in which events take place; it may be nothing more than that. It certainly isn't "the 4th dimension" in that it doesn't operate like a physical dimension.

Originally posted by shavixmir


See. Time has to be an added dimension.[/b]

Aren't time and space the same? I think I heard Carl Sagan say that once--and the long-haired Asian guy on the Supermassive Black Holes program on the science channel.

Einstein formulated that space and time were a single quantity, "spacetime" in his equations for special relativity. Space and time appear to be fundamental, irreducible qualities of the universe - so fundamental that they can't be defined in terms of anything else. They may, in a mathematical sense, be the same quantity.

It's worth pointing out that space is not a dimension. The three dimensions we can perceive, and the 7+ we can't, exist in space, but space is not what they are.

Originally posted by EcstremeVenom
is there a point where you hit a barrier and there is no more space, or does it go on forever?

are you asking about THIS universe? It seems we're now up to 11 of them.

Originally posted by darthmix
A few points of clarification: when astronomers and cosmologists say that the universe is expanding, what they mean is that all the pieces observable, physical stuff in the universe - stars, galaxies, nebulas etc. - are getting further and further apart. They do not mean that space itself - the physical plane on which all those pieces of cosmic matter exis ...[text shortened]... ause we could measure it as the distance between ourselves and the rest of the universe.

Who told you such nonsense?
You obviously know nothing about cosmology or relativity or space/time, yet you talk with such certainty. If it's an opinion or something you believe, say it clearly, instead of making non supported claims as if they were true.