Comments on: Hubble digs deep to see baby galaxies

By: GWamp

GWamp — Tue, 17 Jan 2012 16:36:47 +0000

@Dave72 (#47) (and any others who took to his questions)
This question always comes to mind when I see images of distant stars/galaxies. Not even in reference to are they still in that location (they’re obviously moving, so no), but do they even exist anymore?

The light emitted from these objects takes SO LONG to reach us, could it be that by the time we are seeing these objects, that if we went to them in real-time (or instantaneously, if you will), to their current location, would they still be or would they have fizzled out? Are we still seeing them simply because the light took so long to reach us, but they actually no longer exist?

At the time of this image, some of these objects were some 13 billion light years away or 475,000,000,000,000,000,000,000,000-4,750,000,000,000,000,000,000,000,000 (475 septillion-4.75 octillion) miles away (depending on if I was off a zero or not!) I don’t even know how long it would take light to travel that distance, and it may take a long time (if ever) for us to finally see them disappear, but…is this concept making any sense or is it just in my mind??? LoL I’m not a mathematician or astrophysicist by any stretch of the imagination. What math classes I passed in school, I did so with a “C”! I was even looking up the names to these numbers as I was typing this out, and it could be riddled with flaw.

Just something to envoke some thought.

By: Happy Birthday, Hubble! — Griffin Science

Happy Birthday, Hubble! — Griffin Science — Sun, 24 Apr 2011 21:45:38 +0000

[...] image above is my fav Hubble image for many reasons… post your fav on your [...]

By: Rob

Rob — Sun, 24 Apr 2011 19:27:42 +0000

Big Bang happened everywhere.

By: dhvl

dhvl — Thu, 25 Mar 2010 11:14:32 +0000

If the Big Bang occurred to create space, where did it occur?

By: DJGriz

DJGriz — Mon, 08 Mar 2010 14:32:19 +0000

Can anyone further explain the 2d balloon expansion in 3d environment? I don’t quite get how you expand it to another dimension. Or link with info?? thanks

By: Tony

Tony — Fri, 12 Feb 2010 02:14:38 +0000

To Joe Meils,

I am not sure if others have answered your questions better, but a 1-sentence explanation goes like this: your assumption that the Big Bang occurred at one point is not right (just like there are tons of other misconceptions about the Big Bang, it is not a “Bang” after all). The Big Bang occurred *everywhere*. It created all space.

By: Jeremy

Jeremy — Mon, 08 Feb 2010 06:29:58 +0000

Is there a written analysis of this image anywhere that actually explains what we see in this image? For instance, where does the info come from that leads BA to claim the little red dots come from 600 million years after the Big Bang (other than the fact that the hubblesite caption makes this claim)?

I’m especially interested to learn how this image shows those tiny red dots to be ‘baby’ galaxies, and how those galaxies differ from the galaxies we see around us. Google isn’t helping me much with this one.

Ooh, here’s a start: http://www.wired.com/wiredscience/2009/09/hubbledeepfield/

By: Basta

Basta — Wed, 03 Feb 2010 22:24:03 +0000

@79 Whoa! I didn’t even think to think of it like that, but now that I do it makes sense. To be frank, I don’t have my head wrapped totally around the special relativity thing (general relativity, more so, but still). I can get my head around this article, which makes me very happy as a quantum dilettante and somebody who never did great at math. I’m an English major. Maybe if I read up on the theory of this stuff and get to understand it better, I’ll be more inclined to try out the math again.

And OP, why the “terrible scale” of the universe?! It’s wonderful! Really, you could go to inversely comparable powers of scale with subatomic particles and even things like the Planck length. The way I see it, we’re right in the center of all this, like a famous piece of art at the Louvre. That’s the best place to be, not only from a humanistic point of view, but from a scientific one too. If a galaxy could think, do you think it would be in a good position to contemplate itself AS WELL AS an atom? That’s hard to reconcile without our unique point of view.

By: paul

paul — Thu, 28 Jan 2010 14:53:15 +0000

This may seem like a silly question, which only occured to me last night.
Given the level of detail the space telescope hubble can see, why are there no pictures of planets, moons, and other larger objects within these galaxies?
It seems like somebody has missed the point along the way, surely the detail should be on the objects making up these clusters?

By: itskurtins

itskurtins — Sun, 27 Dec 2009 08:12:12 +0000

You might also want to look for some gravitational lensing.

By: Doug

Doug — Fri, 11 Dec 2009 17:18:51 +0000

I’m proud to point out that I worked on the very first Hubble Deep Field nearly 15 years ago. I helped pick the field. My contribution was pointing out that it was far from the bright limb of the Earth and in the CVZ (Continuous Viewing Zone) so we could look at it for a LONG time and not worry as much about background light from the Earth. More have been done since with HST and others, and they just keep getting better.

By: Ken B

Ken B — Thu, 10 Dec 2009 16:49:08 +0000

Assuming you’re serious

The one time I forget to put in the smiley…

But, you have to admit that tomorrow’s APOD is often today’s BAblog entry.

By: Phil Plait

Phil Plait — Thu, 10 Dec 2009 15:56:11 +0000

Ken B (87): Assuming you’re serious, that’s not really fair. Astronomers send out press releases with images like this, and so bloggers, newspapers, etc. get them and write them up. APOD gets a zillion submissions, and only posts one image per day, so is usually a day or so behind other bloggers – and I can’t react as quickly as say Universe Today, which has multiple writers! So it’s not stealing, it’s just different sites post them after the pictures are released.

PLus, the guys at APOD are friends of mine, and we like each other’s work.

By: Ken B

Ken B — Thu, 10 Dec 2009 15:13:53 +0000

You know, you’re going to have to start suing APOD for stealing “your” images.

Once again, the day after you post an image like this, it appears on APOD.

http://apod.nasa.gov/apod/ap091209.html

By: Revolution9

Revolution9 — Thu, 10 Dec 2009 13:34:31 +0000

If we don’t legislate Dark Sky practices – the Hubble will be the only proxy we have to see anything at night. Awesome image.

By: Star Counter

Star Counter — Thu, 10 Dec 2009 06:57:31 +0000

Does this change the estimates of how many stars there are in the visible Universe? It looks like a 2003 survey made an estimate of 70 sextillion (7 * 10^22), but allowing that it could be much higher.

By: nakomaru

nakomaru — Thu, 10 Dec 2009 06:31:37 +0000

@OP “What you are seeing here is actually more energetic light emitted by galaxies that’s lost energy traveling across the expanding Universe, so by the time it gets here it’s infrared.”

This should read “is actually higher frequency light.. that’s has been reduced in frequency”. The energy isn’t lost.

@67 “The energy of the photon doesn’t change.

Yes it does. Photon energy is *only* a function wavelength. Photon energy = h*c/λ

@63 “Where does the energy previously possessed by the photons go?”

This one I’m not as authoritative on. You are right that the wave energy (radiant energy) is not lost. It is not converted to matter. I don’t think the photons split into less energetic photons (as seen with scattering), but I may be wrong and I don’t think it matters. Here’s my take on it.

If you have a single 1mm, high photon energy (& thus radiant flux) wave and you redshift it out to 1m, the photon energy has diminished 1000 fold as per E=h*c/λ, but now you also have 1000 times the wavelength.

In this way, the radiant flux has been reduced, but the duration it takes the wave to pass the observer is increased 1000 fold (3.3 ps vs 3.3 ns). The total radiant energy of the wave is the integration of the radiant flux with time. I presume that the integration is the same for both of these waves.

By: tacitus

tacitus — Thu, 10 Dec 2009 06:22:00 +0000

Michael, I may have misled you a little in my last comment. Astronomers don’t think that black holes formed before the galaxies formed. They are pretty sure that the pre-galactic era universe was clumpy (somehow) — some regions had more gas (and perhaps dark matter) then others — and, over time, gravity caused enough of the gas to accrete to form stars and then, eventually, galaxies. Once the galactic disks began to form then, at some point, there was enough mass at the center of the young galaxies for the super massive black holes to begin forming.

What I should have said is that we’re not sure yet how involved the super massive black holes were in the evolution of newborn galaxies once they had formed at the center of those galaxies. Astronomers are still trying to figure out how much influence they had, once formed, on their host galaxy.

Your picture of swiss cheese in the early universe isn’t actually that far off, but the holes would not black holes but just voids in space where there is little or no matter, and the cheese itself would be the dust and stars that slowly clumped together into galaxies and clusters of galaxies strung out over millions of light years.

I hope that clarifies things a little

By: Seamyst

Seamyst — Thu, 10 Dec 2009 01:24:35 +0000

Tacitus and gibson042, thanks! Of course, now I remember that Phil covered that scenario in Death from the Skies!…

By: Michael T.

Michael T. — Thu, 10 Dec 2009 00:57:43 +0000

@tacitus, thanks for the post. So is it too far afield to visualize the early universe as similar to a volumetric swiss cheese, where the cheese holes are black holes? I understand there is a chicken/egg issue with galaxy formation but if a black hole initiates a galaxy then at some point there was a perforation so to speak of space-time. Sorry if I am getting carried away with the cheese metaphor

By: Hubble Sets an Eye on the Dawn of Time | Disinformation

Hubble Sets an Eye on the Dawn of Time | Disinformation — Wed, 09 Dec 2009 22:47:05 +0000

[...] Plait writes on Bad Astronomy: Holy Haleakala! This picture is incredible. They pointed Hubble at a fairly empty region of space, [...]

By: Photon man

Photon man — Wed, 09 Dec 2009 22:44:47 +0000

I believe that those photons haven’t been traveling for even a second! Traveling at the speed of light, like they do, time stands still. From the photon’s point of view, no time went by at all. It’s Pop! you are created and Pop! you hit that detector. Mr. Einstein told me so.

By: tacitus

tacitus — Wed, 09 Dec 2009 22:26:07 +0000

Michael, astronomers are reasonably certain that those galaxies that are host to quasars have super-massive black holes at their center, and they have been seen as far as 13 billion light years away, so we know that some galaxies have black holes. I doubt there is any way to tell how many of those very distant galaxies that don’t have quasars have black holes, not directly anyway. The best bet is to study the evolution of galaxies and come up with better and better models for their formation from observations of closer galaxies.

I believe most astronomers think that black holes are somehow either instrumental in the formation of galaxies or are the inevitable result, but they don’t know for sure which it is yet.

By: Michael T.

Michael T. — Wed, 09 Dec 2009 21:54:48 +0000

Do all of those galaxies have a black hole at its center A few? most? Do we know or have any idea?

By: gibson042

gibson042 — Wed, 09 Dec 2009 19:59:43 +0000

@Seamyst (#71):

The answer to your question depends on the global expansion of space. Let’s model that as a function of time r_i(t) (in units of (length/time)/length), and examine a light beam traveling at constant instantaneous velocity c towards a “stationary” target whose distance at time t is d(t) and receding velocity (from expansion) is r_i(t) * d(t). If we further assume that r_i(t) is monotonically increasing, we know that the target will never be reached if r_i(t) * d(t) > c, establishing a cutoff horizon of c/r_i(t). So if the global expansion rate never falls below its present value of 74.2 km/s/Mp (http://blogs.discovermagazine.com/badastronomy/2009/05/07/the-universe-is-expanding-at-742-kmsecmpc/), we will never see anything that’s happening now more than 13.2 billion light years (http://www.google.com/search?q=%28speed+of+light%29%2F%2874.2+kilometers%2Fsecond%2Fmegaparsec%29%2F%2810^9+light+years%29) away. But things are more complex for time-varying r_i(t), in which the cutoff horizon is also time-varying. And we appear to live in precisely that universe, with r_i(t) not only increasing in the current universal epoch but also *decreasing* in the distant past!

Making a long story short, your question is answerable only after defining r_i(t), and I don’t know enough about current models to even guess. But we *can* say that the cutoff horizon only exceeds 20 billion light years while the universe is expanding at less than about 66% (http://www.google.com/search?q=%28speed+of+light%29%2F%2820+*+10^9+light+years%29+%2F+%2874.2+kilometers%2Fsecond%2Fmegaparsec%29) of its current rate. Hooray for envelope backs!