The Universe

Originally posted by BigDoggProblem
You mean astral? 😕

While I admit this was my first thought for what he meant, too, I don't think he means that. He wants to see the whole actual physical universe with his own eyes, so I guess this could rightly be called "astro-projection".

"Astral projection" is necessarily something different, involving other dimensions, a type of soul-travel, not necessarily another point of view in our own dimension, our own universe.

Originally posted by twhitehead
I have neither said it is infinite or that it has always existed. Nobody knows whether or not it is finite in space or time.
What I am saying, is that it does not have edges. Think about the surface of the earth. Uneducated people might think that if you keep walking in one direction, you will fall off the edge of the earth. But you and I know that there ...[text shortened]... be able to explain it.

But do you realize that although it has no shape, it is not infinite?

I do not agree that not having an edge is the same thing as not having a shape, one can distinguish between negative, positive and no curvature - that is the shape saddle-like, sphere-like or flat.

Also, referring to an earlier post you made, I think that "doubling", in other words seeing the same star in opposite directions, is ruled out observationally. With certainty I can say that if inflation is true then it is ruled out theoretically as well as the inflationary expansion phase was sufficiently fast to causally disconnect regions of space - in other words the universe expanded so fast in its early history that the current universe is just too big for that to happen.

Originally posted by DeepThought
I do not agree that not having an edge is the same thing as not having a shape, one can distinguish between negative, positive and no curvature - that is the shape saddle-like, sphere-like or flat.

But those are shapes in another dimension. If we are asking what the shape of the surface of the earth is, and we are talking about 'triangle', 'square', 'hexagon' etc, then 'sphere' or 'flat' just doesn't fit in. So in two dimensions, the surface of the earth has no shape.
Similarly, in three dimensions, the universe has no shape. This is why every article Joseph was able to find talking about the shape of the universe was not actually talking about its three dimensional shape.

Also, referring to an earlier post you made, I think that "doubling", in other words seeing the same star in opposite directions, is ruled out observationally.
Can you provide any link to such observations?

With certainty I can say that if inflation is true then it is ruled out theoretically as well as the inflationary expansion phase was sufficiently fast to causally disconnect regions of space - in other words the universe expanded so fast in its early history that the current universe is just too big for that to happen.
That doesn't make sense. Please explain further.

Originally posted by josephw
Astro projection. When I can see with my own eyes the whole universe.



🙂

Here is the latest work, scales so large that galaxies are just dots in this image, it took 8 years of effort to get this far:

YouTube

Originally posted by twhitehead
But those are shapes in another dimension. If we are asking what the shape of the surface of the earth is, and we are talking about 'triangle', 'square', 'hexagon' etc, then 'sphere' or 'flat' just doesn't fit in. So in two dimensions, the surface of the earth has no shape.
Similarly, in three dimensions, the universe has no shape. This is why every arti ...[text shortened]... iverse is just too big for that to happen.
That doesn't make sense. Please explain further.[/b]

There is no reason to posit an embedding space, although various speculative theories like M-theory and Brane-Worlds have a bulk which would fulfil that role. A bug walking on the surface of a sphere could distinguish between that and a cylinder because the interior angles of a triangle do not sum to 180°. Possibly we have differing ideas about what is meant by "shape".

Apparently they've had a look at the WMAP data and find no statistically significant evidence of features on one side of the CMB mirrored on the other [1], although some people are arguing [2].

The theory of cosmological inflation has the universe increase in size by around 26 orders of magnitude in a small fraction of a second. During this time regions which were causally connected became disconnected. A cosmological horizon formed and all that we can see now was within it. Since the expansion of the universe is accelerating the cosmological horizon is lagging the expansion and regions of the universe that were not observable at the end of inflation continue to be unobservable.

[1] http://arxiv.org/abs/1303.4004
[2] http://arxiv.org/abs/1007.3466

Originally posted by DeepThought
There is no reason to posit an embedding space, although various speculative theories like M-theory and Brane-Worlds have a bulk which would fulfil that role. A bug walking on the surface of a sphere could distinguish between that and a cylinder because the interior angles of a triangle do not sum to 180°. Possibly we have differing ideas about what is ...[text shortened]... e to be unobservable.

[1] http://arxiv.org/abs/1303.4004
[2] http://arxiv.org/abs/1007.3466

I think if we could wait around long enough, new galaxies would appear due to that light finally reaching us, it's on it's way as we speak but since it is not here yet a telescope a thousand light years across wouldn't be able to detect it because there are no photons hitting us from that source yet.

Originally posted by DeepThought
There is no reason to posit an embedding space,

I agree, but nevertheless, the surface of a sphere has no defined edges and the concept of a two dimensional shape simply doesn't apply to the surface of a sphere. Similarly the concept of a 3 dimensional shape simply doesn't apply the universe. The universe does not have edges in 3 dimensional space. It is either infinite or loops around on itself.

The theory of cosmological inflation has the universe increase in size by around 26 orders of magnitude in a small fraction of a second. During this time regions which were causally connected became disconnected. A cosmological horizon formed and all that we can see now was within it.
That doesn't make sense. What does it mean to be causally disconnected, and how do you know this? What is this 'horizon' you talk of?

[1] http://arxiv.org/abs/1303.4004
[2] http://arxiv.org/abs/1007.3466
Interesting that you give observational evidence for something you claim is known for other reasons. Why did they bother looking for circles if it was already ruled out by inflation? Would the discovery of circles have proved inflation wrong?

Originally posted by twhitehead
I agree, but nevertheless, the surface of a sphere has no defined edges and the concept of a two dimensional shape simply doesn't apply to the surface of a sphere. Similarly the concept of a 3 dimensional shape simply doesn't apply the universe. The universe does not have edges in 3 dimensional space. It is either infinite or loops around on itself.

[b ...[text shortened]... was already ruled out by inflation? Would the discovery of circles have proved inflation wrong?

We disagree about the meaning of the word shape.

Light from beyond the cosmological horizon cannot reach us because that region of space is moving away from us faster than light. This means no physical agency there can cause an effect here.

My main claim was theoretical based on an inflation argument. I also claimed that observation ruled it out (but wasn't sure so said "I think" ). You seemed to ask for a reference concerning observational evidence so I found one, happily the Wikipedia page had a reference I could quote which saved me some searching.

Originally posted by sonhouse
I think if we could wait around long enough, new galaxies would appear due to that light finally reaching us, it's on it's way as we speak but since it is not here yet a telescope a thousand light years across wouldn't be able to detect it because there are no photons hitting us from that source yet.

No, that would require the universes expansion to be decelerating, in which case previously causally disconnected regions will come into view. The evidence is that the expansion of the universe is accelerating by a very small amount so that can't happen. In fact, paradoxically, the observable universe is shrinking due to the expansion. Wikipedia has a good page about this [1].

[1] http://en.wikipedia.org/wiki/Cosmological_horizon#Future_horizon

Originally posted by DeepThought
We disagree about the meaning of the word shape.

I rather doubt that. It is more likely I am just being more precise. I am happy calling a triangle or a sphere 'shapes' but when I say 2D shape, I am not talking about spheres. And when I talk about 3D shapes, I am talking about things like spheres, or pyramids, I am not talking about a shape in some higher dimension, or even whether or not the 3D space is 'flat'.

Light from beyond the cosmological horizon cannot reach us because that region of space is moving away from us faster than light. This means no physical agency there can cause an effect here.
I didn't see where in your argument you knew that this cosmological horizon existed. Surely whether or not it exists depends solely on the size of the universe (not on whether or not inflation took place).

My main claim was theoretical based on an inflation argument. I also claimed that observation ruled it out (but wasn't sure so said "I think" ). You seemed to ask for a reference concerning observational evidence so I found one, happily the Wikipedia page had a reference I could quote which saved me some searching.
OK, I understand now. But I still say your inflation argument presupposes the size of the universe for no apparent reason.

Originally posted by twhitehead
I rather doubt that. It is more likely I am just being more precise. I am happy calling a triangle or a sphere 'shapes' but when I say 2D shape, I am not talking about spheres. And when I talk about 3D shapes, I am talking about things like spheres, or pyramids, I am not talking about a shape in some higher dimension, or even whether or not the 3D space i ...[text shortened]... I still say your inflation argument presupposes the size of the universe for no apparent reason.

Well, the reason for introducing the inflation theory was to explain the large scale isotropy and homogeneity of the universe. If we could see the whole of the universe we'd be able to see such anisotropies and inhomogeneities. We have never observed a magnetic monopole, which are predicted by Grand Unified Theories, if we could observe the entire universe we should be able to observe magnetic monopoles.

Originally posted by DeepThought
Well, the reason for introducing the inflation theory was to explain the large scale isotropy and homogeneity of the universe. If we could see the whole of the universe we'd be able to see such anisotropies and inhomogeneities. We have never observed a magnetic monopole, which are predicted by Grand Unified Theories, if we could observe the entire universe we should be able to observe magnetic monopoles.

You are shifting your position. At first you said inflation directly rules out a small universe, now you are simply saying the observational evidence rules it out.
Do you agree that if we observed magnetic mono-poles, then it might be possible that inflation took place, yet the universe is smaller than the observable universe?

Originally posted by sonhouse
I think if we could wait around long enough, new galaxies would appear due to that light finally reaching us, it's on it's way as we speak but since it is not here yet a telescope a thousand light years across wouldn't be able to detect it because there are no photons hitting us from that source yet.

But we don't have that much time to wait. 😏

Originally posted by RJHinds
But we don't have that much time to wait. 😏

We are talking about millions of years before anything new would show up, most likely. You of course are talking about the 10 years we have till judgement day. Wishful thinking of course but be my guest.