Hubble goes deep

[Lunatic Goofballs]

I guess my question is: isn't there some limit to how far we can see back. I mean, for how long does an explosion continue to emit light, and why hasn't that light blown past us..

It confunds me a little as to how we can see back quite so far, is it because we're racing out at the speed of light ourselves in some way?

This light has always been heading our way. Most of these galaxies are already quite old. We just have an instrument powerful enough to detect the light. Most of those galaxies will continue to emit light and we'll continue to see them for a very long time as long as we have an appropriate instrument. These aren't pulses. They're constant sources of light.

As far as a limit, yes. There's a limit how far back we can see. That limit is up for some conjecture, but it's pretty firmly held that seeing back beyond 380,000 years after the Big Bang or so because quantum energy as we understand it probably formed somewhere in the first 380,000 years. http://www.knowledgetreeproject.org/beginningweb.htm

[Avenio]

I guess my question is: isn't there some limit to how far we can see back. I mean, for how long does an explosion continue to emit light, and why hasn't that light blown past us..

It confunds me a little as to how we can see back quite so far, is it because we're racing out at the speed of light ourselves in some way?

It isn't necessarily the length of the shine, its the extreme distance. The light from those galaxies took billions of years to reach the telescope, and they can travel for billions more. There are very few things that can stop light in the universe, but the light naturally loses its energy and redshifts, making it more and more difficult for our telescopes to detect. The farthest known away objects are quasars (Currently held by GRB 090423), created by extremely massive explosions deep in the universe's history, only sticking out because of their extreme brilliance.

EDIT: Basically what Lunatic Goofballs said.

[Nadkor]

[I've always felt astronomy was one of the least useful fields, although its somewhat interesting. I guess thats why I'm not giving this the reverence some seem to think it deserves.

It's useful in that it helps satisfy the basic human desire to know more.

I always think that if knowledge as an entity in itself isn't valued we live in a very sad society indeed.

I'm a very results oriented person, obviously many people enjoy it a lot, and its one of the few scientific things to get wide mention in the media, so don't worry- society isn't lacking curiosity.

Well, in respect of the second paragraph in my previous post I was talking in generalities; but, you know, whatever.

[Lackadaisical2]

A lack of answer leads me to believe space physicists are just making this shit up,

I don't quite get it either- I suppose the parts that are moving away from us could have emitted light form as much as 12 Billion years ago, and for that to just now be hitting us (since we're moving in opposite directions, as you pointed at, at quite a large speed).[/quote]

In fact, modifying my webcam a little, I've managed to see back to just before the big bang, the results are surprising..

http://www.youtube.com/watch?v=oHg5SJYR ... playnext=1

Nicely done.

[Lackadaisical2]

[I've always felt astronomy was one of the least useful fields, although its somewhat interesting. I guess thats why I'm not giving this the reverence some seem to think it deserves.

It's useful in that it helps satisfy the basic human desire to know more.

I always think that if knowledge as an entity in itself isn't valued we live in a very sad society indeed.

I'm a very results oriented person, obviously many people enjoy it a lot, and its one of the few scientific things to get wide mention in the media, so don't worry- society isn't lacking curiosity.

Well, in respect of the second paragraph in my previous post I was talking in generalities; but, you know, whatever.

And? Thats just one example of an nearly useless field that we manage to spend billions every year on in this country alone...

I really don't think curiosity will ever be quelled in humanity- when it is, we'll cease to be human.

[Rothbardiaz]

http://www.sciencenews.org/view/generic/id/52740/title/Hubble_goes_deep_and_wide_for_new_view_of_galaxies

Hubble looks further back in time than ever before, seeing galaxies as they were 13.7 billion years ago.

http://www.sciencenews.org/pictures/hub ... y_zoom.jpg

It's really something, isn't it? With rare exception, every single object, right down to the tiniest specks are all galaxies. More than 7500 of them in an area of space the size of a piece of paper 2mm on a side held up at arm's length. And to think they almost scrapped Hubble.

I find it really awesome and wondrous. How about you?

and just think, thats only a small fraction of the observable universe. that is what it looks like as far as we can see in every single direction, and for all we know it keeps on going just like that past the point we can see...

[KiloMikeAlpha]

Look at it this way. Take a golf ball. That is the center of the universe right before the big bang. Glue one end of a string to each "dimple" on the gold ball and straighten each string. Each string represents the light energy coming from the big bang. You can add MANY MANY MANY more strings, but eventually, as you get further and further away, you will be in a area devoid of "strings". If you are in that area, which is devoid of strings, you would not see the original golfball.


What does all this mean? I am not sure, but I see it as a pretty weird concept explaining why we can even see any VERY distant stars in the first place.

[New Manvir]

As much as Tacos?

Somewhere out there is a taco galaxy and I shall find it!

Just be careful you don't end up on that terrible Planet of the Tacos. Wait a minute...Statue of Liberty...that was *our* planet!

[Dakini]

I guess my question is: isn't there some limit to how far we can see back. I mean, for how long does an explosion continue to emit light, and why hasn't that light blown past us..

We can't see anything before the first ~379,000 years (except possibly gravitational effects, I'm not too clear on this). I think the farthest thing we're able to see is the cosmic microwave background radiation (CMBR). Basically, at the beginning of the universe it was too hot for electrons and atomic nuclei to form atoms (well, at the very beginning there weren't nuclei) which meant that the universe was ionized and light scattered easily and frequently so light couldn't really go anywhere. When the universe cooled enough for electrons to pair up with nuclei (379,000 years after the big bang) only light of specific energies would interact with the resulting atoms so light could move about more freely.
Although the light from these galaxies is younger than that and due to the stars in the galaxies creating light.

It confunds me a little as to how we can see back quite so far, is it because we're racing out at the speed of light ourselves in some way?

We can basically see that far because there isn't anything in the way (at least where we see that far) and we're looking for a very long time at very faint objects. We're probably moving away from some galaxies at the speed of light, but I'm not sure if we can see those galaxies anymore (though maybe at some point we would have been able to).

[KiloMikeAlpha]

[I've always felt astronomy was one of the least useful fields, although its somewhat interesting. I guess thats why I'm not giving this the reverence some seem to think it deserves.

It's useful in that it helps satisfy the basic human desire to know more.

I always think that if knowledge as an entity in itself isn't valued we live in a very sad society indeed.

I'm a very results oriented person, obviously many people enjoy it a lot, and its one of the few scientific things to get wide mention in the media, so don't worry- society isn't lacking curiosity.

Well, in respect of the second paragraph in my previous post I was talking in generalities; but, you know, whatever.

And? Thats just one example of an nearly useless field that we manage to spend billions every year on in this country alone...

I really don't think curiosity will ever be quelled in humanity- when it is, we'll cease to be human.

Right. What is this money giving us? Nothing. Lets go back to the moon, or commit to landing a man on Mars and bringing him home in 10 years. Imagine the technology that would come from that endeavor. Intergalactic peeping Toms? Not so much.

[Getbrett]

[I've always felt astronomy was one of the least useful fields, although its somewhat interesting. I guess thats why I'm not giving this the reverence some seem to think it deserves.

It's useful in that it helps satisfy the basic human desire to know more.

I always think that if knowledge as an entity in itself isn't valued we live in a very sad society indeed.

I'm a very results oriented person, obviously many people enjoy it a lot, and its one of the few scientific things to get wide mention in the media, so don't worry- society isn't lacking curiosity.

Well, in respect of the second paragraph in my previous post I was talking in generalities; but, you know, whatever.

And? Thats just one example of an nearly useless field that we manage to spend billions every year on in this country alone...

I really don't think curiosity will ever be quelled in humanity- when it is, we'll cease to be human.

You're either ignoring or ignorant of the following: the universal law of gravitation, general relativity, quantum field theory, particle physics, nuclear physics and huge quantities of other knowledge gleaned from observations of space that apply directly to life on Earth and the technologies we take for granted.

[Nadkor]

[I've always felt astronomy was one of the least useful fields, although its somewhat interesting. I guess thats why I'm not giving this the reverence some seem to think it deserves.

It's useful in that it helps satisfy the basic human desire to know more.

I always think that if knowledge as an entity in itself isn't valued we live in a very sad society indeed.

I'm a very results oriented person, obviously many people enjoy it a lot, and its one of the few scientific things to get wide mention in the media, so don't worry- society isn't lacking curiosity.

Well, in respect of the second paragraph in my previous post I was talking in generalities; but, you know, whatever.

And? Thats just one example of an nearly useless field that we manage to spend billions every year on in this country alone...

And, like I said, if we have a society where knowledge isn't valued then we live in a sad society. I believe knowledge is valuable.

The use of Hubble? It adds to the general pool of knowledge. Ergo; valuable.

I really don't think curiosity will ever be quelled in humanity- when it is, we'll cease to be human.

No, of course curiosity will never be quelled. That's a large part of my point. Hubble exists largely because our curiosity will never be quelled. Those who dismiss Hubble, and space exploration, dismiss curiosity as nothing meaningful.

[UnhealthyTruthseeker]

Ignoring infinite energy issues, can we put some faster-than-light rockets, or some quantum tunneling outboard motor onto earth a little further towards the edge of the universe so we can see even further back...

...or some mirror we can throw out there to get a better view..

..whatever you space physicists do.

Well no matter what we do, we can't see outside of the Hubble radius.

[Weylara]

A lack of answer leads me to believe space physicists are just making this shit up,

In fact, modifying my webcam a little, I've managed to see back to just before the big bang, the results are surprising..

http://www.youtube.com/watch?v=oHg5SJYR ... playnext=1

I'm now in severe shock.

[Barringtonia]

I get what people are saying but I'm just imagining a, ammm, well just a big explosion really. Now I can understand that we're at the outer edges of that explosion looking back but I'd somewhat imagine the initial part...

..well, now I think about it I guess the centre emits the light...

I guess it's just the scale of it all that confunds me, 13+ billion years...

I wonder if the Universe sometimes thinks 'boy, time flies by as you get older'.

[Dakini]

[I've always felt astronomy was one of the least useful fields, although its somewhat interesting. I guess thats why I'm not giving this the reverence some seem to think it deserves.

It's useful in that it helps satisfy the basic human desire to know more.

I always think that if knowledge as an entity in itself isn't valued we live in a very sad society indeed.

I'm a very results oriented person, obviously many people enjoy it a lot, and its one of the few scientific things to get wide mention in the media, so don't worry- society isn't lacking curiosity.

Well, in respect of the second paragraph in my previous post I was talking in generalities; but, you know, whatever.

And? Thats just one example of an nearly useless field that we manage to spend billions every year on in this country alone...

I really don't think curiosity will ever be quelled in humanity- when it is, we'll cease to be human.

Right. What is this money giving us? Nothing. Lets go back to the moon, or commit to landing a man on Mars and bringing him home in 10 years. Imagine the technology that would come from that endeavor. Intergalactic peeping Toms? Not so much.

Dude, manned space missions are nowhere near as useful as unmanned missions in terms of getting the most science for one's buck.

[UnhealthyTruthseeker]

You're either ignoring or ignorant of the following: the universal law of gravitation, general relativity, quantum field theory, particle physics, nuclear physics and huge quantities of other knowledge gleaned from observations of space that apply directly to life on Earth and the technologies we take for granted.

For fuck's sake, interest in celestial mechanics essentially started all of real physics.

[UnhealthyTruthseeker]

Just to correct some people, the big bang doesn't have a center.

[Barringtonia]

Just to correct some people, the big bang doesn't have a center.

Oh go on, is this something related to the idea that the universe is like the outside of a ballon, that if you walk in one direction you'll end up back where you started?

[Dakini]

I get what people are saying but I'm just imagining a, ammm, well just a big explosion really.

The big bang isn't an explosion. It's an expansion of spacetime. Think of it as blowing up a balloon or baking a loaf of raisin bread instead of like a grenade.

Now I can understand that we're at the outer edges of that explosion looking back but I'd somewhat imagine the initial part...

We're nowhere near the edge of the universe. We aren't actually clear on whether it has edges, but if it does, we certainly can't see them.

..well, now I think about it I guess the centre emits the light...

No, generally stars emit light. There's some glowing gas and CMBR and this business, but the light in those galaxies is mostly stars.

[Dakini]

Just to correct some people, the big bang doesn't have a center.

Oh go on, is this something related to the idea that the universe is like the outside of a ballon, that if you walk in one direction you'll end up back where you started?

That depends on the geometry of the universe. It's thought that the universe is flat so this wouldn't happen.

The universe is like a balloon in that if you think of how galaxies move away from each other, it's sort of like putting stickers on a balloon and inflating it (instead of like an explosion). The space between the galaxies is expanding and the galaxies themselves aren't going anywhere (except relative to one another).

[UnhealthyTruthseeker]

Oh go on, is this something related to the idea that the universe is like the outside of a ballon, that if you walk in one direction you'll end up back where you started?

Even if the universe doesn't have that shape, the big bang does not have a center. It is an expansion of space over time, not an explosion. Every point is uniformly moving away from every other point.

[KiloMikeAlpha]

[I've always felt astronomy was one of the least useful fields, although its somewhat interesting. I guess thats why I'm not giving this the reverence some seem to think it deserves.

It's useful in that it helps satisfy the basic human desire to know more.

I always think that if knowledge as an entity in itself isn't valued we live in a very sad society indeed.

I'm a very results oriented person, obviously many people enjoy it a lot, and its one of the few scientific things to get wide mention in the media, so don't worry- society isn't lacking curiosity.

Well, in respect of the second paragraph in my previous post I was talking in generalities; but, you know, whatever.

And? Thats just one example of an nearly useless field that we manage to spend billions every year on in this country alone...

I really don't think curiosity will ever be quelled in humanity- when it is, we'll cease to be human.

Right. What is this money giving us? Nothing. Lets go back to the moon, or commit to landing a man on Mars and bringing him home in 10 years. Imagine the technology that would come from that endeavor. Intergalactic peeping Toms? Not so much.

Dude, manned space missions are nowhere near as useful as unmanned missions in terms of getting the most science for one's buck.

Science =/= Technology. Scratch-resistant Lenses? Freeze-Dried Food? Athletic Shoes? CAT & MRI Technologies? Dipping Dots? All kinds of things we use today came from the space race. We need a manned mission to Mars to kick start innovation again.

http://www.thespaceplace.com/nasa/spinoffs.html

DISCLAIMER: Being part of the manned mission to Mars is on my bucket list, so I may be biased here.

[Lackadaisical2]

[I've always felt astronomy was one of the least useful fields, although its somewhat interesting. I guess thats why I'm not giving this the reverence some seem to think it deserves.

It's useful in that it helps satisfy the basic human desire to know more.

I always think that if knowledge as an entity in itself isn't valued we live in a very sad society indeed.

I'm a very results oriented person, obviously many people enjoy it a lot, and its one of the few scientific things to get wide mention in the media, so don't worry- society isn't lacking curiosity.

Well, in respect of the second paragraph in my previous post I was talking in generalities; but, you know, whatever.

And? Thats just one example of an nearly useless field that we manage to spend billions every year on in this country alone...

And, like I said, if we have a society where knowledge isn't valued then we live in a sad society. I believe knowledge is valuable.

The use of Hubble? It adds to the general pool of knowledge. Ergo; valuable.

I really don't think curiosity will ever be quelled in humanity- when it is, we'll cease to be human.

No, of course curiosity will never be quelled. That's a large part of my point. Hubble exists largely because our curiosity will never be quelled. Those who dismiss Hubble, and space exploration, dismiss curiosity as nothing meaningful.

Don't worry, its meaningful, just useless (in a dispassionate sort of sense, although I wouldn't rule out it being possibly useful in the future, I'm just not seeing it- and no one seems to be suggesting otherwise).

You're either ignoring or ignorant of the following: the universal law of gravitation, general relativity, quantum field theory, particle physics, nuclear physics and huge quantities of other knowledge gleaned from observations of space that apply directly to life on Earth and the technologies we take for granted.

I was actually wondering when someone would bring those up

I honestly would question how applicable a lot of the stuff NASA does is although, I think that, as per the above, a lot of useful sciency stuff is sort of discovered accidentally, or tangentially to what we actually are trying to achieve/observe.

[UnhealthyTruthseeker]

We're nowhere near the edge of the universe. We aren't actually clear on whether it has edges, but if it does, we certainly can't see them.

The universe having actual boundaries (rather than being open or compact) would be problematic, wouldn't it? Wouldn't the edges of the universe end up having infinite curvature?