The Hubble Deep Field

[photon]

Here's another thing I love to think about.. we enjoy an amazing view of the stars and universe, it's possible it even contributed to our desire to explore and discover.

In the future there will come a time when the universe is expanding fast enough that the light from other galaxies will never reach us.. so something like the hubble ultra deep field would never be possible.

Imagine being in a time when you look out of the universe and all you see is this lonely little island of stars, no way of knowing there's anything beyond it, no cosmic background radiation, no other galaxies to measure anything by... how different will a society that develops in that turn out?

[metal_geek]

Originally Posted by photon

Here's another thing I love to think about.. we enjoy an amazing view of the stars and universe, it's possible it even contributed to our desire to explore and discover.

In the future there will come a time when the universe is expanding fast enough that the light from other galaxies will never reach us.. so something like the hubble ultra deep field would never be possible.

Imagine being in a time when you look out of the universe and all you see is this lonely little island of stars, no way of knowing there's anything beyond it, no cosmic background radiation, no other galaxies to measure anything by... how different will a society that develops in that turn out?

That's excatly right... Hard to think that who or what or when the next group of creatures comes along after us, they my never even have the chance to learn about the beginning... The evidence won't even exist for them...
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Xv1900

[Cheese]

Originally Posted by metal_geek

That's excatly right... Hard to think that who or what or when the next group of creatures comes along after us, they my never even have the chance to learn about the beginning... The evidence won't even exist for them...

Except what they find buried in our time capsules....a bible, a torah, a koran...LOL

I kid I kid!

[evman150]

Originally Posted by MolsonInBothHands

Ok, no edges or center to the universe. 3 dimensions expanding into 4? The fourth dimension being time?

Are there images looking towards the perceived epicenter of the big bang?

If I put a performance chip into my truck which allows me to drive 78 billion light years an hour, (Only slightly faster than Deerfoot trail.) and I drove in one direction, where would I be in relation to my starting point after 1, 1.5, and 2 hours? Is there a screen wrap like in the game asteroids?

There is no epicentre of the big bang. The closest answer would be to say it is where you are sitting, where I am sitting, anywhere and everywhere in the universe.

Time is not the fourth dimension I'm talking about. I'm talking about an actual fourth spatial dimension.

Nobody knows for sure, but like on the balloon, you just might end up where you started, over and over again. Of course it's kind of silly to think about since it's utterly impossible.

Originally Posted by photon

When they talk about the radius of the universe, really they usually mean the radius of the "observable" universe. So the 78 billion light year radius thing just means that the light from the beginning of the universe that is reaching us now in combination with the expansion of the universe since the beginning works out to 78 billion light years.

Okay, here's the deal with the 78 billion number. First, I need to introduce a thing called a co-moving coordinate - this goes back to the balloon example. Imagine points on a piece of paper that can be stretched out. They have a fixed coordinate position. Now stretch the paper out evenly, and the points are farther apart. But they are farther apart in proportion to the amount stretched, and they are still exactly evenly spaced as they were to begin. They still reside on the same coordinates of the grid, it is simply the grid that has stretched. Coordinates like this are called co-moving coordinates.

The universe is 13.7 Gyr old. Prima facie, the universe should be 27.4 Glyr (giga light year = billion light years) across. But it is not, it is 2x78=156 Glyr across. Why? Because what we are measuring are co-moving coordinates. Yes they are 78 Gyr away, but that is only cause the universe has stretched that much. 13.7 Gyr ago we were all in the same spot, but now the paper has been stretched out. The numbers on the grid have not changed. But we are not reading the numbers on the grid, we have our own biased numbers we write on the grid ourselves to measure the distance.

Here's a diagram:



Hope that's not too unclear. I realized I should have picked better numbers for the coordinates, but it was too late to change it in paint once I realized they were going to involve square roots. Oh well, the relation and the concepts are still there.

Originally Posted by troutman

There are a hundred billlll-yun stars in the milky way galaxy, and a hundred billll-yun galaxies. (Carl Sagan)

My idol.

[metal_geek]

Originally Posted by Cheese

Except what they find buried in our time capsules....a bible, a torah, a koran...LOL

I kid I kid!

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Korean Cooking

[photon]

Originally Posted by evman150

Awesome MS Paint Illustration

Lol nice!

So here's a question, things like gravity, atomic forces, etc all keep our galaxies, planets, and bodies together despite the expansion right?

We can see galaxies move away because the distances are large enough and the interaction between galaxies is small enough.. but obviously our galaxy isn't being torn apart by this expansion at this time.

But is that effect measurable? If I was writing software to model the galaxy and the orbits of all the stars, would I have to take that expansion into account?

To use your analogy, we have our sheet and galaxies are represented by balls resting on the sheet. The balls can freely move about the sheet if influenced by something, but as the sheet grows the balls move apart if there's no other force in play right?

Will eventually that expansion become so great (if the rate of increase doesn't change anyway) that galaxies, solar systems, and eventually matter itself be torn apart?

[evman150]

You would not have to take expansion into account.

Gravity is strong enough to totally blow away the effects of the expansion. An example of this is M31 and the Milky Way coming together. This is at odds with an expanding universe. It is an example of small scale anisotropies that exist in a large scale isotropic universe. Zoom far enough out, though, and the big picture shows what you'd expect. So yes, the balls can move freely on the sheet within reason.

And yes, eventually everything will be torn apart by the expansion. This theory is actually in vogue right now. Starting with galaxy clusters, then galaxies, then open clusters, then stellar systems, then planets, moons, asteroids, rocks, molecules, atoms, quarks....

It's not a pretty end

[photon]

Cool, thanks!

Not a pretty end, but a heck of a lot more fun than the heat death idea.

[metal_geek]

Originally Posted by photon

Lol nice!

So here's a question, things like gravity, atomic forces, etc all keep our galaxies, planets, and bodies together despite the expansion right?

We can see galaxies move away because the distances are large enough and the interaction between galaxies is small enough.. but obviously our galaxy isn't being torn apart by this expansion at this time.

But is that effect measurable? If I was writing software to model the galaxy and the orbits of all the stars, would I have to take that expansion into account?

To use your analogy, we have our sheet and galaxies are represented by balls resting on the sheet. The balls can freely move about the sheet if influenced by something, but as the sheet grows the balls move apart if there's no other force in play right?

Will eventually that expansion become so great (if the rate of increase doesn't change anyway) that galaxies, solar systems, and eventually matter itself be torn apart?

Dark Matter...
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Lovely Wendie99

[arsenal]

Ok, kind of on topic maybe, not really, but the largest black hole was recently discovered.
http://space.newscientist.com/articl...iscovered.html

in the article it says that there is a smaller black whole, which orbits around the larger black hole. I have not taken any astronomy courses, nor have I taken any physics courses, but how does the smaller black hole not get sucked into the larger black hole or vice versa?
What would happen if one black hole did consume another?
Where does all the matter go?
Why is all of this making my head hurt?

[The Fonz]

evman150, I'm taking engineering at university this fall. Do I have to learn anything that you're talking about?

[evman150]

Originally Posted by metal_geek

Dark Matter...

It is actually dark energy (the cosmological constant) which leads to the "accelerating expansion".

And to the fonz, you dont have to (get to? ) take any of this with an engineering degree. Ive only taken this material in third year astrophysics and fourth year cosmology, I suppose with grounding in second year astronomy. You only get to do the awful part of my degree, that is some of the physics and maths. Ugh.

[The Fonz]

Originally Posted by evman150

And to the fonz, you dont have to (get to? ) take any of this with an engineering degree. Ive only taken this material in third year astrophysics and fourth year cosmology, I suppose with grounding in second year astronomy. You only get to do the awful part of my degree, that is some of the physics and maths. Ugh.

Oh good haha. I was getting nervous. I like physics and math...

[photon]

Current Hubble news...

http://presscue.com/node/38728

[T@T]

Great thread, I use to watch Sagan's shows and he always tried to put the size of the universe in perspective. I guess the one that stuck with me was:

The next time your taking a barefoot walk on a beach and you feel all the little sand granules between your toes...remember that there are many more stars in the universe than all the sand granules on earth. - Carl Sagan

[Delthefunky]

Originally Posted by T@T

Great thread, I use to watch Sagan's shows and he always tried to put the size of the universe in perspective. I guess the one that stuck with me was:

The next time your taking a barefoot walk on a beach and you feel all the little sand granules between your toes...remember that there are many more stars in the universe than all the sand granules on earth. - Carl Sagan

Damn, I guess we don't have an exact count of either, but that's amazing to me.

[ericschand]

Here you go, 10,000 galaxies in one picture.

Taken by Hubble:

http://sse.jpl.nasa.gov/multimedia/g...Ultra_Deep.jpg

ers

[edit: warning, huge 6200x6200 picture]

[worth]

man...in that picture alone there has to be thousands, if not tens of thousands of separate planets with life on them, if not more.

[arsenal]

Well, even if you take a conservative estimate that only one planet in a galaxy is able to contain life (if our planet is in fact the only planet in our galaxy that contains life). Then you have about 10,000 other civilizations out there in that picture some where.

[metal_geek]

Originally Posted by worth

man...in that picture alone there has to be thousands, if not tens of thousands of separate planets with life on them, if not more.

Nah... we're alone...

We were created in gods image, and people who believe in my god are the only People in the universe thats worthy of existance. Of course thats only if you believe what I believe. If you don't hold the same beliefs as me our god will send you to the real hell, no offence to you, not your fault you haven't seen the reality of it yet, but just helps me justify my blind faith.

That picture only shows space as it was 4000 years ago, thats when our god created it. All thoese things in the pictures were examples god created on the first monday of existance.. Once you get to the edge of that picture, you'll find the entrance to heaven, if you took a picture in the other direction you would see the entrance to Hell, but scientis won't show you that picture cause they've seen it, and it's not pretty. The universe is centered around our sun, and everything has moved around that since god said let there be light. It's actually a very intelligent design, when you really look at it in great detail..

I have a whole bunch more example from THE bible thats go into very spicific deatils about creation, it'll really help you understand that picture better. Perhaps if you want I can give you a 1-800 number you can call and one of my assistant teachers will be happy to go over them with you. There's also a monthly subsciption to Designed Science magazine, that will keep you uptodate at the leading front of science and technology. It's full or articles from world renowned authors...
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