The Power of Ten (a.k.a. It's a BIG universe!)

[_truth dancer]

Here is one of my favorites!

http://micro.magnet.fsu.edu/primer/java ... owersof10/

~dancer~

[_Tarski]

Heh... really cool. It would be cool if that was redone with modern ideas, like the idea that you couldn't "zoom out" and see all the galaxies. As far as we know, there is no end.

Wow, looks like you need to look at Microwave Background Radiation and call me in the morning.

Well, he is right. The most popular model is an open universe with the spacelike sections being infinite (topologically a copy of R^3).

MBR is compatible with many geometries; closed and positively curved, open and flat or negatively curved.
Fine details of MBR suggest an essential flat space on the large scale. It is still expanding though and picturing this is subtle.

[_Nephi]

Okay, Mercury, if you're contradicting Nephi's "there is no end" assertion, then it appears that you believe there is an end. Which makes sense, since if it's expanding, then it had to have been smaller before, and therefore not be entirely infinite even now.

So, will you please explain, for my benefit at least, the reason you dispute Nephi's "there is no end" assertion?

(I'm not challenging you here. I really, truly don't know.)

I really want to know too! This is something that has always interested me.

The concept that there is no central point of an expanding 3D structure is very hard to grasp because we cannot really comprehend what a 4-dimensional thing looks like (which is what the universe is), so to help make this concept understandable, we can step it down by one dimension and apply the same question....

Imagine if you will a 2 dimensional universe (like a sheet of paper). Now, we are going to curve this sheet of paper, but to those in that universe, they cannot really see the curve. This curve shall be in the shape of a sphere; specifically a balloon. Now, on the surface of this balloon we will put "dots", and these dots represent objects in this 2D universe. If I blow up the balloon, notice that each dot is now expanding AWAY from every other dot. The further two dots are away from each other, the faster they are expanding away from each other. Now, this concept is easily to visualize. So ask the same question...

At what point are all these dots expanding from? The answer is that there is not point. If you could suck out the balloon so that it starts from a single point, but blows up like a balloon from there (expands), there is not central point on the 2d surface area of the balloon that they are expanding from.

I think what the previous man who told me that I don't have a concept of the universe was trying to imply was that since there is a cosmic background radiation that we can see in all directions, and that we cannot see past that, then that must be the edge of the universe, but just as there is not edge to the surface of the earth, there is no edge to an expanding universe. The universe is not just the matter you see expanding into space. The universe is the matter and the space that you see, and the space is expanding. Its like the space around you is increasing.

There is a concept that something in the universe can be so far away from us that its causality does not effect us (ie, we cannot see it, and it does not effect us), so it is not part of our universe, however, that does not mean that the universe ends at the edge of our "causality sphere". There is matter within our causality sphere which is effect by matter that is NOT a part of our causality sphere, therefore we are indirectly connected to that which is outside our causality sphere.

Hard concepts. Hope I made it easier to understand.

[_Gazelam]

From the scriptures and other writings I have read, the Universe simply is, and as Gods are organized and grow, they go forth and organize the material that is out there. The way I understand it is that they create suns, and then melt down the dust of the universe to form new worlds. New worlds to be populated with the intelligences that are organized as the work goes forth as well.

So it seems that the universe is disorganized, and the supreme intelligences go forth and organize the material. And there is no empty space, just disorganized space.

[_Nephi]

So it seems that the universe is disorganized, and the supreme intelligences go forth and organize the material. And there is no empty space, just disorganized space.

This uses very undefined terms so you may be right, depending upon the definition of the terms. If by disorganized material you imply that there is space w/material that is not organized into stars, galaxies, etc etc etc, that there is just a cloud of gas, then yes, there are places like this out there, but all that we can see leads to there being some organization within the clouds of gas that there are (such as our galaxy we are in). However, I do want to make sure that we understand, there universe is expanding, and it is not expanding in to empty space (which is a common mistake that individuals make).

[_Mercury]

Heh... really cool. It would be cool if that was redone with modern ideas, like the idea that you couldn't "zoom out" and see all the galaxies. As far as we know, there is no end.

[SNIP!]

. . . I am implying that hanging out in the physics common area does not "osmotically" bestow upon you an understanding of cosmology. Get some core concepts down and then maybe I can take your analysis of science seriously.

Okay, Mercury, if you're contradicting Nephi's "there is no end" assertion, then it appears that you believe there is an end. Which makes sense, since if it's expanding, then it had to have been smaller before, and therefore not be entirely infinite even now.

So, will you please explain, for my benefit at least, the reason you dispute Nephi's "there is no end" assertion?

(I'm not challenging you here. I really, truly don't know.)

Honestly, the Universe might have no end. But the Microwave Background radiation tells us that the universe was once at a point, a singularity in which all observable matter was collected which then began expanding into the known universe.

At the "core" of the matter all there is no center of the universe. What we have at our disposal is a point in space time in which all light available to us has converged to give us a picture of the universe. this radiation tells us certain things. The MBR data shows us that at the "edge" of the universe there was once an expansion of matter, but not a central point of emanation. im not trying to further myself as the local cosmology expert so some of that might be incorrect.

Several tools are at our disposal:

WMAP:
http://map.gsfc.nasa.gov/aboutmap.html

CMBR:
http://zebu.uoregon.edu/~imamura/123/lecture-1/cmbr.html

[_Mercury]

From the scriptures and other writings I have read, the Universe simply is, and as Gods are organized and grow, they go forth and organize the material that is out there. The way I understand it is that they create suns, and then melt down the dust of the universe to form new worlds. New worlds to be populated with the intelligences that are organized as the work goes forth as well.

So it seems that the universe is disorganized, and the supreme intelligences go forth and organize the material. And there is no empty space, just disorganized space.

With such simplistic, nonscientific information I don't see how yo could possibly be wrong.

All sarcasm aside, by defaulting to a fictitious cosmology you discount directly observable evidence that is POWERS OF TEN more credible than your "scriptures". This alone should be a crime.

Once again Gaz, your world view is in direct contradiction to reality, and you present it in a fashion that says you rely on the writings of madmen in order to interpret your surroundings.

[_Nephi]

Honestly, the Universe might have no end. But the Microwave Background radiation tells us that the universe was once at a point, a singularity in which all observable matter was collected which then began expanding into the known universe.

At the "core" of the matter all there is no center of the universe. What we have at our disposal is a point in space time in which all light available to us has converged to give us a picture of the universe. this radiation tells us certain things. The MBR data shows us that at the "edge" of the universe there was once an expansion of matter, but not a central point of emanation. I'm not trying to further myself as the local cosmology expert so some of that might be incorrect.

Several tools are at our disposal:

The way this is phrased can lead to the belief that there was all this space around this point and that point expanded into it. If this is what you mean, then it is incorrect. It is better to say that the universe began expanding. The word "into" can imply something that is not happening (and I know you know this, just wanted to point this out to others).

The MBR can imply a finite universe, but this is negated by the inflation model (which is the current supported idea about the early universe). If inflation is correct, then much of the universe was pushed beyond our sphere of causality and beyond our limits of seeing due to limits upon the speed of light. The MBR is only a measure of the temperature of the early universe for our causality sphere. We can assume it is the same for all the universe, but we cannot see how much of the universe is outside our sphere.

As for "how much" there is in the total universe its only a guess, and incalculable (with current astro-physical models). It could be infinite (and we have nothing that disproves this), or it could be that its much smaller than what we see, and we are just looking around back at our selves over several billion years where the universe doesn't look anything like it does to us now (like looking so far west that you see the back of your head).

by the way, I was a physics major for quite a while, but decided not to do as such, mercury. I continued to hang out and was a member of SPS and the astrophysics groups on campus because I have more friends there who are more intellectual than in the CS department.

[_ozemc]

http://www.youtube.com/watch?v=yCfDRvDWid0

COOL

HA! That was good!

Kind of reminds me of the old talk about how we're really just in a really big dustball that fell off someone's coffee table, and when it hits the floor, the universe is done.

Weird!

[_Gazelam]

Once again Gaz, your world view is in direct contradiction to reality, and you present it in a fashion that says you rely on the writings of madmen in order to interpret your surroundings.

So what are you saying? I should change authors?