what is that in dog years?

Right? (looks around to see if anyone here with more experience/knowledge on the subject disagrees… if I am not clear on something, enlighten me.. ha!)

We can’t really talk about where “we” were when this happened because our region of space is only 4.6 billion years old.

Correct?
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@53
Great clarification.
But even though there’s no 3D locus of initiation, wouldn’t there still be a more condensed, general neighborhood, relative to our position today, and wouldn’t we be looking in that space-time direction ?
(i.e., reverse-engineer and picture the balloon deflating)

If the explosion occurred 13.14 billion years ago, shouldn’t the star have been significantly CLOSER to us when it actually exploded?

13.14 billion years ago, the universe was a pretty small place compared to today (albeit still pretty huge after half a billion years of ballooning).

Just my layman’s way of thinking, if we’re seeing that explosion at 13.14 billion light years away today, it should (remember, kids, layman’s thinking) have been right there when it originally popped off in the first place. So it was already 13.14 billion light years away, correct?

I believe you’re correct that the star would have been significantly closer to our point in space when the explosion occurred. But as the photons from this event traveled, the universe continued expanding. So the original distance between us would be much less than what the photon ended up traveling, which is much less than the “current” distance to the point in space where this explosion occured oh-so long ago.

If the explosion occurred 13.14 billion years ago, shouldn’t the star have been significantly CLOSER to us when it actually exploded?

13.14 billion years ago, the universe was a pretty small place compared to today (albeit still pretty huge after half a billion years of ballooning).

Just my layman’s way of thinking, if we’re seeing that explosion at 13.14 billion light years away today, it should (remember, kids, layman’s thinking) have been right there when it originally popped off in the first place. So it was already 13.14 billion light years away, correct?

I’m pretty sure someone with more experience with Expansion theory could torpedo that thought, but I’d welcome it if it made the whole picture somewhat less fuzzy.

Not necessarily. Imagine that the balloon was foggy until it reached a particular size, then the fog cleared. From the time of clearing, a ring is expanding around you that shows the extent of the visible balloon. The edges of this ring are not expanding faster than light, but you cannot see farther.

As time goes by the ring will be larger and will be encountering portions of the balloon that *are* receding faster than light relatively. Only at that point does the starting age becomes irrelevant and the expansion becomes the limiting factor.

“Using the expanding balloon analogy is misleading, I think. I rather see the surface of the balloon as the “edge” of space/time, the shell of light which was emitted by the Big Bang, and which is expanding outward at the speed of light.”

No, that’s not the right way to use the analogy. Think of the balloon as only being occupied by flatlanders. The balloon appears locally flat, and they cannot perceive the “up/down” dimension. The “center” of the balloon is not a concept to them. Instead all the dots used to be closer, and now they are farther. There is not spot on the surface that was the center. Scale everything up a dimension to us. There is no location in our 3D space that was the center.

http://www.astro.ucla.edu/~wright/cosmo_01.htm

Thanks, that makes a little more sense now…wow, my universe just expanded, although not at the speed of light

Thank you for the analogies. I do understand at least the concept of expansion of space, but still the timing of it escapes me. Light still moves at the same speed, and the expansion of space is, I presume, somewhat below that speed. As I understand it, the limits of the observable universe are those points where the apparent speed of expansion equals the speed of light.

Using the expanding balloon analogy is misleading, I think. I rather see the surface of the balloon as the “edge” of space/time, the shell of light which was emitted by the Big Bang, and which is expanding outward at the speed of light. Our galaxy is a mote of dust inside of that shell, moving (mostly) outward, away from the center, but at a much slower speed. And there my mind just boggles. I still run into the problem of light from near the beginning of the universe just managing to catch up with us now, when in fact it should be much closer to the expanding outer shell.

Wouldn’t it be more accurate to describe these things as “oldest object ever observed” or something like that?

What made GRB 090423 so different? We heard about it right away (http://www.dailygalaxy.com/my_weblog/2009/04/the-furthest-object-ever-video.html and http://www.npr.org/templates/story/story.php?storyId=103582558, etc), why did the one on the 29th take 2 years longer to hit the news?

Space isn’t expanding at the speed of light. The speed of expansion of space depends on the distance of an object. The further apart two objects are, the faster the expansion of space. This makes sense if you think about the balloon analogy.

Hubble recently nailed down the expansion rate of the universe to an uncertainty of 3.3% to be 73.8 km/s per MPc. For every additional million parsecs a galaxy is from Earth, the galaxy appears to be traveling 73.8 kilometers per second faster away from us.

My back of the envelope calculations show that the speed this event appears to be travelling away from us is, therefore, a significant fraction of c: 0.9917

Another fun fact, if my calculations are correct, this means the space between the Earth and Sun is expanding at the rate of 11.3 meters per year!

See:
http://www.nasa.gov/mission_pages/hubble/science/cosmic-expansion.html

I’ve always had a problem with the “Balloon analogy”. If space is expanding at the speed of light then something 13.4 Billion light years away (i.e. the other side of the balloon) would be expanding in the other direction with space getting bigger in between at the speed of light. So we would never see it as the light beam would never reach us.
I believe that expanding space/time is not smooth (like the surface of a balloon) but bulgy. With large bulges were space/time is expanding faster in those areas were matter (dark or light) densities are lower and deep recesses were matter densities are higher.
So we get to see some very distant objects by looking down those slower expanding valleys.