Astronomers Detect the Earliest Galaxies

FiReaNGeL writes "Astronomers, using NASA's Hubble Space Telescope, have uncovered a primordial population of compact and ultra-blue galaxies that have never been seen before. They are from 13 billion years ago, just 600 to 800 million years after the Big Bang. These newly found objects are crucial to understanding the evolutionary link between the birth of the first stars, the formation of the first galaxies, and the sequence of evolutionary events that resulted in the assembly of our Milky Way and the other 'mature' elliptical and majestic spiral galaxies in today's universe."

Comments

13 Billion years ago?

[Chapter80]

Old news!

Re:13 Billion years ago?

[ari_j]

Plus, it's a dupe. I read this on the mirror universe Slashdot yesterday.

Re:13 Billion years ago?

[kiehlster]

I heard the people from these galaxies read it 13 billion years ago through the art of time viewing.

Wow, that's astounding

[JustNilt]

I wonder when we'll find the earliest possible ones now. I always thought it took longer for them to form stars, etc.

Re:Wow, that's astounding

[mdsolar]

How soon they form depend on your cosmological simulation. Something had to be forming to reionize the universe, but it did not have to be galaxies of a sufficient size that you would notice them. But, the further the existence of quasars was pushed back, the more you needed somewhat organized bodied in which they could form even earlier so there were indications that some massive galaxies form early.

Re:Wow, that's astounding

[Anonymous Coward]

Except that it's not nonsense :)

They've already found the closest thing to the big bang that's visible: the hot dense opaque plasma that's visible as the cosmic microwave background radiation, the characteristics of which coincide perfectly with the big bag theory.

Re:Wow, that's astounding

[Red Flayer]

the characteristics of which coincide perfectly with the big bag theory.

You leave my wife out of this!

Re:Wow, that's astounding

[Chris Burke]

the characteristics of which coincide perfectly with the big bag theory.

Blah blah blah. Look, I don't want to hear about how observations matched predictions. That's not science.

It's like this: I don't understand Big Bang Theory, therefore I don't like it, therefore it's nonsense, therefore your "evidence" is really just your prejudice, therefore we're obviously going to find galaxies that are ten billion years older than these ones, and therefore my theory of the Giant Cosmic Bunny Orgy Theory, which is obvious if you even think about it rationally, will be proven correct once and for all and I'll be elected the President of Physics.

Re:Wow, that's astounding

[Chris Burke]

Except, um, that is science.

No it isn't.

Re:Wow, that's astounding

[Chris Burke]

This isn't an argument!

*ding* Good Morning!

Re:Wow, that's astounding

[Anonymous Coward]

I believe the comment you were looking for was "woosh!"

Re:Wow, that's astounding

[tyrione]

the characteristics of which coincide perfectly with the big bag theory.

You leave my wife out of this!

From the looks of it I'd hate to break it to you but she's been working hard and heavy behind your back.

"Mature" galaxies?

[Anonymous Coward]

Can anyone confirm the applicability of Rule 34 to "mature" galaxies? Inquiring minds have noticed that it applies for almost anything else called mature!

Re:"Mature" galaxies?

[sexconker]

http://media.aftenposten.no/archive/01011/SPACE-CHANDRA-NEBU_1011148x.jpg

Re:"Mature" galaxies?

[Chris Burke]

DUDE! How about a NSFW warning next time?!

Very cool

[mdsolar]

I suspect I have identified such objects from submillimeter observations http://arxiv.org/abs/0802.1666 but it is very good to see a more robust population identified here.

Really?

[SnarfQuest]

Is 600 million years long enough to develop a complete galaxy? I'd think that might be too short for even a solor system to develop.

Re:Really?

[Monkeedude1212]

I am not an astrophysicist, but why not? What WOULD be a a "normal" length of time for a galaxy to develop? And on what grounds do you base that reference point?

If the big bang is anything like -I- imagine it, it might only take a single year to form a galaxy

Re:Really?

[mdsolar]

It may be. That is about a dynamical timescale for a galaxy merger. Star formation takes much less time than 600 million years. You would not be forming a lot of earth-like planets at that time because there was very little in the way of dust early on. Most solid phase material may have been ice rather than dust owing to the early relatively high abundance of oxygen produced in pair-instability supernovae.

Re:Really?

[mdsolar]

Google can be your friend: http://en.wikipedia.org/wiki/Dynamical_time_scale

Here is a classic paper on galaxy formation: http://articles.adsabs.harvard.edu/full/1977MNRAS.179..541R you can get rough timescales from there. More modern treatments include early clustering of dark matter to speed the process along. Dark matter obviates the need to worry about cooling times to some extent though consideration of lithium hydride cooling may be important before the first prompt supernovae provide some metals (most likely pair-instability SNe). You can find out more in my paper linked above.

Re:Really?

[mister_playboy]

Since the average temperate of the Universe would have been much greater back then, all that heat could have sped up the process quite a bit compared to the current day.

Re:Really?

[mdsolar]

Actually, the warm background can interfere with gas clouds cooling enough to collapse to become stars since the gas needs to cool radiatively. So, the warmth of the universe is a hindrance to some extent.

Re:Really?

[antic]

I am not an astrophysicist, but why not?

Not smart enough? Parental pressure to follow your father into plumbing? A death in the family during a critical part of your schooling? Lived too far from suitable tertiary institutions? Can I have a hint? :P

Re:Really?

[dunng808]

Took the words right out of my mouth.

Re:Really?

[countertrolling]

Time was so much faster then
It's slower then that now

Re:Really?

[mdsolar]

If the gas can't cool, then internal pressure can hold it up against collapse.

Re:Really?

[nschubach]

Maybe too smart? ;)

Oh God

[cromar]

So now the "scientists" are even saying that the galaxies come from from monkeys?! Blasphemers!

Big Deal. I can draw this crap in Photoshop...

[Jackie_Chan_Fan]

Big Deal. I can draw this crap in Photoshop for a lot less than the millions these jokers spend... Write me a check NASA!

The Cake is a Lie!

Re:Big Deal. I can draw this crap in Photoshop...

[Anonymous Coward]

This is amazing they can still get data like this, I thought Hubble was stuck in the sand on Mars...

Re:Big Deal. I can draw this crap in Photoshop...

[Jackie_Chan_Fan]

it really is amazing what NASA has done. I'm in awe of everything they do. They're wonderful people.

Ultra-Blue?

[e2d2]

My understanding of cosmology is at best limited, but shouldn't these galaxies appear red-shifted to the extreme? They are furthest and hence should be moving the away from us at an extremely fast pace. Is the name Ultra-blue restricted to element analysis based on spectrum? I'm just confused about the blue light.

Re:Ultra-Blue?

[MichaelSmith]

My understanding of cosmology is at best limited, but shouldn't these galaxies appear red-shifted to the extreme? They are furthest and hence should be moving the away from us at an extremely fast pace. Is the name Ultra-blue restricted to element analysis based on spectrum? I'm just confused about the blue light.

Looking at this bit:

They are so blue that they must be extremely deficient in heavy elements, thus representing a population that has nearly primordial characteristics."

I assume this means that light, hydrogen-heavy objects will get hotter for a given amount of heat energy because of their lower density. Maybe these galaxies are red shifted, but they are relatively blue in relation to their red shift.

Re:Ultra-Blue?

[x2A]

The light we're seeing comes from a long long time ago, from when the galaxies were actually getting closer. Either that or it's because it's from such a long time ago that stars had only managed to produce the smaller elements and so were bluer because of the lack of oxygen. At least, that's the colour I go when I'm lacking oxygen, I assume galaxies are the same.

I think I need my bed...

Re:Ultra-Blue?

[mdsolar]

These galaxies are intrinsically blue at their rest wavelength. They have young stars and little dust.

Re:Ultra-Blue?

[Bigjeff5]

I believe the only reason they can see these galaxies is because they were blue to begin with.

They are using Hubble's infra-red telescope to see them, so that should tell you how far they have shifted. Obviously the pretty picture has been adjusted back to the original color. If you'll notice, the older galaxies (from 600 mil years post Big Bang) are a darker blue than the younger (700 mil years post BB).

The next ones they find will probably have to be pushing violet.

Re:Ultra-Blue?

[Chris Burke]

mdsolar said why they're called blue -- cus that's the color of light they're emitting.

They are extremely red-shifted (in fact astronomers typically talk about such distances/timescales in terms of degree of red-shift). It's not like if you were to peer at these galaxies in a telescope they'd look blue. In fact you probably wouldn't see anything at all; Hubble is almost certainly (huh? rtfa?) using it's near-infrared cameras for this.

Re:Ultra-Blue?

[kclittle]

I *think* TFA is implying that they can determine the intrinsic color, even when highly red-shifted, and that this intrinsic color is extremely blue due to the lack of any elements other than hydrogen and helium. This would be expected, because no elements heavier than helium had yet been synthesized.

Re:Ultra-Blue?

[Volante3192]

The next ones they find will probably have to be pushing violet.

There's an Ultraviolet joke in here somewhere...

Re:Ultra-Blue?

[Shotgun]

I'm confused.

You have a telescope that receives light from a distant object. At first:

-you don't know what it is made of

-you don't know how far away it is

-and you don't know how fast its relative motion is

How can you use red shift to predict relative motion? A shift implies a motion, and you don't know where it is moving from.

How can you make any prediction about composition if you can't be sure of the shift?

How can you make and prediction about distance if you are making up numbers about the previous two?

I've got to read a book or two on cosmology sometime. I suspect there is a lot of 'splaining left out.

And I would expect the oldest galaxies to have the least amount of hydrogen left, having had stars burning it the longest.

Re:Ultra-Blue?

[e2d2]

The article didn't explain the "rest wavelength" that was noted above in a comment. That's what I was looking for. The light has been "shifted back" to how it would appear if there was no relative movement between observer and the target galaxy.

Re:Ultra-Blue?

[Anonymous Coward]

-you don't know what it is made of

All you have to do is run a spec analysis on the light rays. Each element produces a specific light band pattern. This can be blue/red shift calibrated

-and you don't know how fast its relative motion is

Actually you can. That's EXACTLY what red/blue shift is.

How can you use red shift to predict relative motion? A shift implies a motion, and you don't know where it is moving from.

Doesn't matter where it is moving from. It matters how it is moving RELATIVE to you the observer.

How can you make any prediction about composition if you can't be sure of the shift?

Because the element based bands, while they can shift frequency, DO NOT CHANGE RELATIVE TO EACHOTHER!

How can you make and prediction about distance if you are making up numbers about the previous two?

They are not making them up.

I've got to read a book or two on cosmology sometime. I suspect there is a lot of 'splaining left out.

Or a few dozen...

And I would expect the oldest galaxies to have the least amount of hydrogen left, having had stars burning it the longest.

Yes but considering most of the observable universe appears to be hydrogen that's a SHIT LOAD of mass to burn through.

Re:Ultra-Blue?

[brainboyz]

Yes but considering most of the observable universe appears to be hydrogen that's a SHIT LOAD of mass to burn through.

I'll add to this that if the light is 13 billion years old, the galaxies might have burned through everything by now but we wouldn't know because the light carrying the information to witness the change hasn't physically reached us yet.

Re:Ultra-Blue?

[Arancaytar]

having had stars burning it the longest.

Except that we're seeing these galaxies as they were when they were young.

Re:Ultra-Blue?

[itlurksbeneath]

And I would expect the oldest galaxies to have the least amount of hydrogen left, having had stars burning it the longest.

True, but you're seeing the galaxy as it was 13 billion (emphasis homage to Carl Sagan) years ago when it was relatively new, yes?

Re:Ultra-Blue?

[Daniel Dvorkin]

This is just a guess, but I'm thinking you can look for spectral lines characteristic of certain elements and simple compounds, and see how far down the spectrum they're shifted, to determine the overall degree of redshift. Once you have that information, you have a pretty good idea how far away the galaxy is. Any astronomers want to jump in and tell me if this is right, wrong, or "not even wrong?"

Re:Ultra-Blue?

[camperdave]

A few basic Astronomy tidbits for you:

Elements emit light at characteristic colors - frequencies of light. Eg, copper emits a bluish green color. By looking at the spectrum of the object, you can tell what the object is made of. If an object is moving, the spectrum will be shifted relative to normal due to the doppler effect. If it is shifted to higher frequencies the object is approaching you. If the spectrum is red shifted, it is moving away. The greater the shift, the greater the velocity.

Certain stars are close enough to Earth that we can triangulate their distance, using the orbit of the earth as the base of the triange. There is a certain class of star called a cepheid variable, some of which are in triangulateable range. Cepheids give off regular bursts of light, and due to the process by which they do that, the amount of light they give off is proportional to the frequency of the bursts. By using the inverse square law you can tell how far away a cepheid is by its brightness.

Thus, you can tell how far away a galaxy is by looking at its cepheid stars. So, by careful observation, you can detect the composition, speed, direction, distance, and age of a star. By looking at many stars, you can detect patterns like: the farther away a star is, the faster it is moving away from us.

Re:Ultra-Blue?

[Bigjeff5]

Elements emit light at characteristic colors - frequencies of light.

To clarify so the GP doesn't think copper emits some blurred haze of green, elements emit very specific wavelenths of light that can be easily differentiated when the light is separated via a prism.

You'll see bands of light of various strenghts, and very conspicuous black lines at frequencies where it does not emit any light. Because the light was emmitted at the exact same moment (by definition), the redshift is exactly the same for all frequencies. The pattern never changes even though the the light all shifts red.

From these patterns, we know exactly what distant stars are made of. Because we have all of these elements on Earth, we know exactly what color they start out as, and exactly what their pattern is.

So, to sum up, splitting the light with a prism gives us the pattern. The pattern is compared to known elements to give us the element(s) the star is made of. The element(s) gives us the original color, which we can use to compare against the observed light. The observed red-shift from the original color gives us the distance.

Re:Ultra-Blue?

[Bigjeff5]

Actually it's because the galaxy is almost entirely hydrogen, which emits blue light.

What they picked up was infra-red light. By shining that through a prism, you get the elements the galaxy is composed of. From the elements you can get the original color (all elements radiate a very specific set of frequencies that act like a fingerprint). Compare the original color to the observed color, which has shifted so far it has gone from up near violet down into the infra-red, and you get distance and therefore age.

If we are able to find anything older than these we'll probably have to start looking at sub-infrared radiation. I don't know how you get a prism to split radio waves, though.

Re:Ultra-Blue?

[Bigjeff5]

They certainly can, it's called spectrography.

Different elements have a very distinct pattern of frequencies of light they emit when they are radiating. Since we can cause these elements to radiate on Earth to see what the base frequencies are, all we have to do is compare the pattern to the known patterns of the elements to figure out the primary elements in the galaxy. From there we can compare the base frequencies to the red-shifted frequencies and get distance/time. Hydrogen is mostly various blue wavelengths, with a very small amount of red, and absolutely nothing else.

These galaxies are almost exclusively Hydrogen, which radiates primarily blue. That means if you were sitting right in the middle of one of these galaxies at the time this light was emitted (600-700 million years after the big bang), everything would be blue. All the stars, all the gassy clouds (which were probably everywhere), all of it would be blue, because all of it would be hydrogen.

For the pictures, they just shifted the colors back to their original blue, that's not actually what was recorded. We can't see what was actually recorded, because it was recorded with the infra-red equipment on the Hubble.

Re:Ultra-Blue?

[mdsolar]

There is a lot of recycling that goes on so most stars now are made of material that was in a previous generation of stars. But, there are stars in our galaxy from those early times. They are low enough mass (less than 0.7 times the mass of the Sun) so that they have lifetimes longer than the age of the universe. Certain globular clusters in the Milky Way appear to be from about that time.

Re:Ultra-Blue?

[camperdave]

I'm not an astronomer, but I did take a course once. You're right and wrong. By itself, the red shift will only tell you how fast it is moving relative to you. It won't directly tell you how far. Astronomers have pieced together a bunch of distance determining methods into what they call the Cosmic Distance Ladder. In general, the larger the red shift, the farther away the object, but not always. Certain regions of the sky have smaller or larger red shifts than they are "supposed" to have. These differences are being explained by postulating the existence of "dark matter" or "dark energy".

Re:Ultra-Blue?

[camperdave]

Dang! Should have previewed. There was supposed to be a link for distance determining methods, but I fouled it up. Sorry.

Re:Ultra-Blue?

[fremsley471]

This would be expected, because no elements heavier than helium had yet been synthesized.

Poor lithium, you were at the ball but no-one remembers you.

Re:Ultra-Blue?

[anarchyboy]

I'm confused.

You have a telescope that receives light from a distant object. At first:

-you don't know what it is made of

-you don't know how far away it is

-and you don't know how fast its relative motion is

How can you use red shift to predict relative motion? A shift implies a motion, and you don't know where it is moving from.

How can you make any prediction about composition if you can't be sure of the shift?

How can you make and prediction about distance if you are making up numbers about the previous two?

I've got to read a book or two on cosmology sometime. I suspect there is a lot of 'splaining left out.

And I would expect the oldest galaxies to have the least amount of hydrogen left, having had stars burning it the longest.

It goes like this:
You use epctral analysis to determine what its made of by looking for known patterns in the spectrum of the light

You measure the redshift, to estimate the distance you either guess the absolute magnitude (which can often be done with gallaxies to at least give an upper limit) or you use hubbles law and assuming you have a good value of hubbles parameter you can convert red shift to distance. This is a bit circular and relies on you allready having found the distance of lots of objects without having to resort to this.

The redshift gives the relative motion and can be measured very acuratly and very easily.

You can tell the composition beofer you know the shift in fact you use the composition you get the shift.

While your not making up the numbers of the previous two it is worth pointing out that the distance measurement is not independent in some cases so you have to be very carefull the measurement of distance may be relying on your cosmological assumptions. Not all distance measurements are like this but the further back you go the harder it is to get a an independent measurement.

If you read a couple of books on cosmology most will cover these very basic principles any explaining left out will be in the larger more advanced books on cosmology.

Remember telescopes look back in time, these gallaxies are the ones that formed earliest.

Re:Ultra-Blue?

[niktemadur]

13 billion (emphasis homage to Carl Sagan)

Offtopic, but WTHell: Watch Cosmos again and be on the lookout for "billions and billions", and it's not there, anywhere at all. This was uttered by Johnny Carson, in a Tonight Show bit where he parodied Carl. But the phrase turned out to be too good to not be true, so it became a classic case of "print the legend".

Re:Ultra-Blue?

[nschubach]

I was thinking more about plaid.

Re:Ultra-Blue?

[itlurksbeneath]

He never said "billions and billions", but there was a particular way that he said words with "illions" on the end (billions, trillions, etc). See this video as an example.

Re:Ultra-Blue?

[kclittle]

Ok, ok! There were incredibly small amounts of lithium and beryllium produced in the big bang, as in 10e-8 percent or something... :)

Re:Ultra-Blue?

[Volante3192]

If they go plaid, the universe will have to pull its emergency break.

Re:Ultra-Blue?

[Slur]

Also worth mentioning that the Big Bang wasn't an event where a bunch of stuff existed as a dot within a big infinite space. Prior to the Big Bang there was no space and no time. Space itself inflated as a shared property of all energy. Space continues to inflate in the same manner. And given that the expansion is accelerating it looks as though space begets space.

Re:Ultra-Blue?

[x2A]

would they actually be using a physical prism anyway? Seems like a great way to lose a bunch of those precious photons, I'd think it'd be better done mathmatically with rather large computers with lots of bits... if ya think, spectrum analysis on audio has been well within the reach of computers for quite some time, fundamentally I can't imagine it being too different. In which case, infra red, microwave, radiowave, you just need a larger window to analyse to fit enough of the wavelength in.

just a thought

[houbou]

In theory, at the very edge of universe, is it possible that the primordial light has yet made itself visible? if someone could .. in theory.. travel there, would they be able to see the very creation itself?

Re:just a thought

[Monkeedude1212]

Yes. Which is why Faster Than Light travel is also considered (in some respects) Time Travel.

Re:just a thought

[Shotgun]

Yes. They'd just need to travel faster than the speed of light, and then have a very strong telescope.

Re:just a thought

[hrimhari]

Are you asking about the edge as it was when the light we might detect now was emitted billions of years ago or the edge as it is now? I find it kind of difficult to speculate about the later since we're always billions of years behind of any sight we may get from it...

Re:just a thought

[Bigjeff5]

According to TFA, hydrogen re-ionization when most of the universe was still opaque, gassy hydrogen and was not burning in the form of stars, blocks almost all of the light from 400 million to 900 million years after the BB. The only reason these galaxies were visible is because they believe they had extremely efficient hydrogen ionization, which is also why they were so blue. Before 400 million years post BB you have stars and galaxies only just forming, so I don't think there would be much in the way of light at all to be seen.

Also remember that the Big Bang is not an explosion in space, it's an explosion of space, so there might not be any visible light emmitted at all from the very beginning.

Re:just a thought

[John Hasler]

> ...at the very edge of universe...

The universe has no edge.

Re:just a thought

[sznupi]

But we ARE seeing the "beginning" - that's the microwave background radiation, oldest emitted light that we can see (just after the universe stopped being was opaque)

Star Wars

[jag7720]

A long time ago in a galaxy far far away...

I wonder if Luke saw them.

What is evolutionary about this?

[Thoguth]

I know a lot of people use the term "evolutionary" as a synonym for "gradual" or "slow" but when I think of evolution, I think of the specific process of mutations and reproduction by which a population changes over time. Unless there's something new about galaxies I've never heard of, I don't understand why the term "evolutionary" is the best word to describe the development of the early universe. (Or anything at astronomical scales that I can think of.)

Re:What is evolutionary about this?

[Arancaytar]

Evolutio is Latin for "unfolding", and evolvere Italian for "to develop".

Mutation and reproduction has nothing to do with it. What it means is a "gradual, unfolding development".

Re:What is evolutionary about this?

[Toonol]

Darwinian selection is the process by which animal species change over time. That is one example of evolution, a specific example which happens to rely on hereditary characteristics, reproduction, and so forth.

But 'evolution' is a word that simply means change over time. Evolution was used as a term long before Darwin; indeed, it was known that animals evolved before there was any good explanation for how they evolved. The term 'evolution' isn't limited to living creatures any more than the term 'drive' is limited only to cars. It's simply the most common usage of the word. It's probably better to use the term 'natural selection' when you're referring to the evolution of species. Natural selection requires reproduction, for instance, while evolution doesn't.

Hubble NewsCenter link

[Suddenly_Dead]

The corresponding Hubble NewsCenter article includes more details and more, larger images.

Stupid question

[codepigeon]

Ok, I admit I don't know a lot about this subject, but if they are seeing this far into the "past", they have to be looking in one direction right? I assume that the Big Bang started at one point. So therefore, there must be one spot in the sky that they are looking at, and thus the "spot" that the universe came into existence.

Is this spot in the sky widely known? Where is it? And assuming the explosion would be spherical, would we ever be able to see galaxies that shot off in the other directions?

Re:Stupid question

[Petrushka]

if they are seeing this far into the "past", they have to be looking in one direction right? I assume that the Big Bang started at one point.

The sibling post gives a perfectly good analogy to explain this, but you probably already knew it. Another way of putting it that I sometimes find helpful: the Big Bang didn't happen at such-and-such a location, which can be plotted as X, Y, Z coordinates. The Big Bang happened everywhere. It's just that Everywhere was really really really tiny back then.

Re:Stupid question

[Bigjeff5]

Another way to look at it, is that at the instant before the big bang there was no universe, or you could say the universe was infinitely small. After the BB the universe was expanding, but there was still no space outside the universe. Everything we consider "space" is all packed inside the universe, and the universe was a lot smaller then than it is.

The classic analogy is the balloon analogy. Imagine three dimensional space is the two dimensional surface of a balloon with tiny points all over it representing matter. As the balloon expands, all points on the surface move away from each other, and the balloon has gotten larger. However, the center of the balloon is not on the 2d surface, the center of the balloon is in the 3rd dimension. Therefore, relative to the surface there is no center.

Now, bump everything up one dimension and you have our universe. The "surface" is three dimensional space, and it is expanding along the fourth dimension. We have no way of seeing the fourth dimension, just like a 2d creature on the surface of the balloon could do nothing but look forward, backward, left and right we can only do that plus up and down. We would need to add another dimension to our repertoir to view the fourth dimension, but we can't conceptualise beyond the abstract about what that might be. However, we can definitely see that everything in the third dimension is moving away from everything else. Therefore space is expanding, and no matter which way we look everything is moving away. In fact, no matter what vantage point you take in the universe it will always look the same, because the "surface" of the universe is what is expanding.

It's a bit mind numbing to think about, but there is no direction you can look at and figure out "where" the big bang was. There is no "where" in the third dimension, the where is in a dimension that we are not equipped to experience. All we can do is measure its effects in our own dimension.

I like Carl Sagan's explanation of the fourth dimension best, but wikipedia does a good job, if a bit on the technical side.

Re:Stupid question

[JSBiff]

I have a followup question to this: Is the universe now, or did it ever, expand at or faster than the speed of light, as space itself expanded? The whole notion of looking 'back in time' to see a galaxy that close to the big bang has me a little bit puzzled. What I mean is, my understanding of this whole idea of 'looking back in time' with a telescope is that light travels at the speed of light, and if we know a galaxy is X billion light-years away from Earth, then we say that the images we see *now* originally left that galaxy X billion years ago (well, ok, there's probably some sort of calculus needed to adjust for the fact that the universe is expanding, and the points in space are getting farther away from each other *even as the light travels between galaxies*).

But, it still seems to me strange that we could 'see' back in time to .6 or .8 Billion years after the big bang, when there has subsequently been 13.2 to 13.4 Billion years. The only way I can conceptually make that work out is if the Universe is expanding at nearly the speed of light. My reasoning is this: at .6 to .8 Billion years after the big bang, the 'diameter' of the Universe would have to have been less-than-or-equal .6 or .8 Billion light years, wouldn't it? That is based upon the presumption that no two bits of matter in the Universe can ever move away from each other at or faster than the speed of light (so, the radius of the Universe would be constrained to expanding at 1/2 C, wouldn't it?). I would think that the *diametric* expansion of the universe would have been something less than the speed of light - maybe like 1/2-2/3 C (so, the radius would have only expanded at something like 1/4 - 1/3 C)? (The only real basis I have for that is simply that I've never heard of anything other than light, and sub-atomic particles, moving at any significant fraction of the speed of light, but I really have no idea here - help me out).

Anyhow, getting back to my point - if the Universe was less than 1 Billion light-years between the farthest points of space *at that time*, how is it possible that it took 13+ Billion years for the light to reach Earth from that time? The mathematics of the situation makes no sense to me. I mean, I *do* get that even as the light travels, the distance it needs to travel to reach us is constantly increasing, but it would seem like the light travels so much faster than anything else, that it wouldn't take that long.

I mean, let's say, for example, that we start at the year 1 Billion ABB (After the Big Bang). Let's say, for example, the Universe was .5 Billion light-years in diameter, and the diameter was increasing at a rate of .5 Bn light years every 1 Bn years (in other words, the diameter is expanding at 1/2 C). Ok, so a bunch of photons leave Galaxy A to travel to Galaxy B which is at the furthest possible point in the Universe. After travelling for .5 Bn years the photons reach the point where Galaxy B *used to be*, but Galaxy B has kept moving, and is now .25 Bn light years farther away than it started. So the photons travel on for another .25 Bn years, but once again Galaxy B has moved on, and is now .125 Bn light years away. As we can see, this progression keeps halving the distance and halving the time travelled by the light. I haven't calculated out the exact time it would take for the light to finally reach Galaxy B, but because of this progression of halving, I think it's going to be somewhere around the year 2 Bn?

So, getting back to my original question, how is it possible that we could ever 'look back' *that far* in time. I could buy that we could look back 5, or maybe even 7 Billion years, but I don't see how it's possible to see back farther than that?

Re:Stupid question

[TapeCutter]

The BB is still happening, the "expansion" of the observable universe (small 'u') is just another way of saying space is still exploding into existance, in otherwords the universe IS the big bang. The cosmic microwave background (CMB) is a shell of expanding "light" that came from very early in the long bang. The CMB encloses our universe.

It's claimed that the CMB shell is a universal frame of reference until recently it had been assumed no such universal frame of reference existed, however it's existance does not violate general releativity as some might claim. It's also claimed the geometry of the observable universe is very close to flat (ie: euclidian). Iff those two claims are true then the BB's blue touch paper (geometric center of the universe) is located at the geometric centere of the CMB light shell. However given general relativity you probably need a "god's eye" view of the universe to find it.

Re:Stupid question

[cntThnkofAname]

I have wondered this for SO long, and it would be really interesting to hear a qualified answer. That being said I will take a crack at how I think this may be possible. I think I, and most people, are thinking about the universe wrong. The universe is not some object, everything inside it is, and everything inside the universe abides by the laws of physics. So the universe can expand at what ever rate it wants. I know this brings up the problem of things much be traveling away from each other faster than C, but I had an idea after reading through your question. The overall matter in the universe is finite (we believe) so, because the universe is expanding like BigJeff says (in the 4th dimension), and we think of the 4th dimension as a plane observable by the 5th dimension, and a point observable by the 6th dimension, I would think because the universe is expanding in a higher dimension that it is not actually the "edge of the universe" that is growing and matter filling in the space, but it's the actual space between particles that is expanding. If every particle in the universe moved away from the next by a millimeter in a year, I'm guessing that the universe would seam to expand faster than light without actually breaking any laws. And I would assume from this that gravity is a bit of a limiting factor in keeping particles from moving apart. It's just a thought I had reading your question, and it's nap time now.

Re:Stupid question

[mdsolar]

This probably does not help much but the cosmological redshift is not from velocity but rather from space stretching along the path of the photon, which stretches the photon, increasing its wavelength.

Re:Stupid question

[Chapter80]

I like Carl Sagan's explanation of the fourth dimension best, but wikipedia [wikipedia.org] does a good job, if a bit on the technical side.

But the wikipedia article on the fifth dimension can help clarify the issue much more. Your balloon analogy doesn't hold up, when it goes up, up and away. It's almost as if you are claiming that in three dimensions, we have a sweet blindness of the fourth. When in fact, using the fifth dimension, you can go where you want to go.

Once you observe using the fifth dimension, everything's changed. We're observing these distance galaxies in the constellation Aquarius, while trying to let the sun shine in. But all this nonsense about wavelengths, without the fifth dimension, we fail to see that light sings.

Re:If they are so old, why do they look so distant

[mdsolar]

In fact, they are spread out somewhat in appearance because there is no "vanishing point" as you might have in a drawing with a road or rail tracks. The smaller universe of that time has to be spread over the same amount of sky so there is some magnification to make this happen. Try putting different redshifts in here http://www.astro.ucla.edu/~wright/CosmoCalc.html and look at how the scale changes (kpc/" is kiloparsecs per arcsecond). You can plot it on some paper and see how it changes.

Re:If they are so old, why do they look so distant

[pclminion]

It has to do with the expanding universe, period. Take a balloon and draw a bunch of regularly spaced dots on it with a marker. Now inflate the balloon. The dots all get farther away from each other. Moreover, there is no "center" to the expansion that lies on the surface of the balloon -- no one point can be said to be the center from which all other points move away. In this analogy, the speed of light would be the maximum speed at which the dots could move about on the surface of the balloon -- this is totally unrelated to the expansion of the balloon itself.

Re:If they are so old, why do they look so distant

[TapeCutter]

We're not spots on a balloon, we're currants in an expanding pudding.

Basic question

[vivek7006]

- We know that the universe started expanding from a single point.
- We also know that there are galaxies which are billions of light-years away from us.
- This implies that the universe must have
expanded faster than the speed of light after the big-bang explosion.

I cant wrap my head around that. How is faster than light expansion possible?

Re:Basic question

[ceoyoyo]

Why shouldn't it be? Relativity only puts constraints on how fast you can move through space, not how fast space itself can stretch.

Re:Basic question

[nschubach]

- We know that the universe started expanding from a single point.

Know is such a strong word...

Re:Basic question

[John Hasler]

> We know that the universe started expanding from a single point.

Not "from". That implies a center. There is no center.

Re:How is this possible?

[dido]

For more information on these I suggest reading this article. The metric expansion of space is much more complicated.

Why do astronomers...

[pongo000]

...speak of these galaxies as if they currently exist? If these galaxies are 11-13 billion light years away, haven't they since morphed into mature galaxies (or even moved even further away from us)?

In any event, all of this is rather fascinating to a non-astronomer. It's truly mind-boggling to be looking at images of an event that happened many billions of years ago...

Re:Open the archive

[mdsolar]

6000 is probably about right. I expect you can get the data from here: http://archive.stsci.edu/ Now there are 6001.

So who lives there?

[Lorens]

Those galaxies have had a lot of time to develop life. Maybe prioritize that direction for SETI...

Re:So who lives there?

[Chapter80]

Those galaxies have had a lot of time to develop life. Maybe prioritize that direction for SETI...

I can't make sense of this.

If we can observe these galaxies as they appeared 13 Billion years ago, then any SETI observation would be an observation of how they looked 13 Billion years ago. And so the "lot of time to develop life" is irrelevant (unless I let my SETI@Home program run for 13 Billion years...)

Or were you going for +5 Funny?

Young Universe Physicists

[hallux.sinister]

When they manage to spot a body in space that, by the very best methods they can use to attain the age of very distant objects, which seems to be, oh... say, about 22 billion years old, they're going to scratch their heads and mutter, "well... that's odd".

As we observe objects at greater and greater distances, they have to keep revising their age-estimate of the universe. In the end, I think that they will eventually conclude the universe is infinitely vast, and infinitely old. This of course implies that either the all mass in the universe has infinitesimal density, or there is infinite mass, distributed more or less evenly in infinite space, of which we can only observe a small portion.

Difficult as this may be to contemplate, I believe that since, mathematically, n*INFINITY=INFINITY, for all positive real 'n', it is possible for x to equal infinity, y to equal infinity, and because infinity is an EXCLUDED endpoint of the real number system, and therefore NOT a real number, x can be UNEQUAL to y. So we can have infinite mass, distributed in an infinite volume, in a universe with neither beginning nor end.

What amazes me is how physicists, looking down their noses at the literal interpretation of the various creation myths, (such as the Young Earth crowd,) while embracing a theory (which is no more than a belief, really, with a different authority appealed to) that the universe was manufactured by a supreme particle. They've changed the details of the story, but for some reason, it seems people just cannot manage to wrap their heads around the idea of there being something without a "before there was".

So if they are allowed and able, in the end to do their experiments, I think they're going to get some truly baffling results.

~Hal

Don't confuse the VISIBLE universe and the ENTIRE universe.
They're not necessarily the same thing.

Re:Young Universe Physicists

[Chris Burke]

As we observe objects at greater and greater distances, they have to keep revising their age-estimate of the universe.

And here we have spotted the farthest-away objects ever, and it required no revision of the age of the universe. There has been some adjustment towards 'older', but most of the time these days when the age of the universe is adjusted, it's towards more precision, not increasing age.

x can be UNEQUAL to y. So we can have infinite mass, distributed in an infinite volume, in a universe with neither beginning nor end.

Of course two infinite quantities can be unequal. Integers and real numbers are an obvious example. Unrelated, but the proof is more complicated, since multiplication is undefined for infinity. It's not a number.

while embracing a theory (which is no more than a belief, really, with a different authority appealed to)

Yeah, the authority of experimental evidence and verified predictions. If you think that there's nothing more to cosmological theory than some authority saying so from on high, then you're just not aware of how it came about.

They've changed the details of the story, but for some reason, it seems people just cannot manage to wrap their heads around the idea of there being something without a "before there was".

Actually physicists are quite readily able to wrap their head around something without a "before there was", and in fact a beginning-less universe was one of the leading theories when the Big Bang was first being proposed. It was only after the evidence came out strongly in favor of the Big Bang that the other theories began to fall out of favor. If theory is nothing more than belief from authority, then why was the "belief" du jour (which happens to be closer to your belief) abandoned? It wasn't overnight, either... A lot of scientists didn't like the idea at first.

However this doesn't mean astrophysicists have abandoned the idea of a universe with no beginning. The Big Bang Theory specifically does not make any predictions about what happened at or before the Bang. Some hypothesis are that the Big Bang is just one of many Bangs and the universe is repeatedly created/destroyed. Another is that the Big Bang was really just a collision between higher-order dimensions, and that many universes such as ours could have been created, even infinitely many. Still another is that space-time itself came into existence in the Big Bang, and therefore the concept of "before there was" is meaningless. Try wrapping your head around that!

The problem is there is no evidence for any of these hypothesis. So it is still very much up in the air. No authority is going to come down from the mount with a stone tablet and declare the answer. Whatever experiments you imagine they aren't "allowed" to conduct are being conducted, and the evidence will decide.

Wow!

[hoover]

Wow, just wow. Hubble is going stronger than ever, it's hard to believe there was talk of retiring it because the refurbishing costs would be "too high". Yay Hubble!

Re:If they are so old, why do they look so distant

[pclminion]

If that were true, then there would be a central point that everything else was expanding away from. It would also imply an edge to the universe. The balloon analogy reduces space to two dimensions, but in reality there are three, so you need to imagine a "hyperballoon." It's still only an analogy, but it helps understand the geometry of what we think is happening.

Young Universe Cosmologists (correction)

[hallux.sinister]

Sure, if it makes you feel better.

(Sigh.)

The point was and is, just as when the Catholic Church was considered the guardian of all knowledge, (at least in Europe,) and an observation was made which pointed out that one of their stances was incorrect, (by being in direct contravention to what was observed,) they resisted, tormented those who disagreed, but ultimately had to revise their position when it became obvious they were wrong; so it is today.

Someone like me points out a theory has a problem, but that theory is so entrenched in the minds of its adherents that people try to shout him down, rather than listen, or instead make patronizing remarks. Like yours. The nice thing about science though, is that eventually, observation TRUMPS hypothesis, no matter how dearly cherished, so I don't really need to argue this point, I can simply wait.

The tip-off to the rip-off, as they once said, about the Big Bang Theory is that it requires the suspension of the laws of physics at the beginning to work. There are several other important problems, but that's the most glaring, IMAHO.

So I'll put it to you. What is the Schwarzschild radius of an object with the mass of... oh, say... the entire observable universe? (According to Wikipedia, the Schwarzschild Radius of an object with as small a mass as our sun is 3km. The SR of an entire galaxy, to say nothing of... everything, would be substantially larger.)

How exactly is it that what we observe today got from being smaller than the head of a pin to LARGER than that? Oh, and then there's the CMB. Interestingly enough, if that's radiant energy from the supposed "Bang", how exactly did the Earth get IN FRONT OF IT, for our radio-telescopes to be in position to intercept it? If you can't understand what I mean, try this experiment: fire a gun AWAY from you, and try to run in front of and CATCH the bullet. Since the bullet travels hundreds (if not thousands) of miles per hour faster than you can, unless you started out in front of it, catching it would be, well, a tricky proposition.

Young Universe Cosmologists (I used the wrong word before, sorry,) contend the CMB is energy thrown out at the moment of the "Bang" right? (Perhaps I misunderstood.) We'd have to be IN FRONT of the expanding sphere, or on the surface of the light-cone, as it were, to see it. This would require the matter which would one day become the Earth, to have travelled FASTER than light, wouldn't it?

Clearly you misunderstood the last part of my post, which might explain your patronizing tone. I meant, (by "allowed") whatever experiments it is PHYSICALLY POSSIBLE to conduct, not what some PERSON SAYS they may or mayn't. My fault I guess for trying to be subtle.

I guess I'm the fool though, expecting rational discourse on /. Honestly, I usually don't read the comments, I come here to read interesting and/or funny tech stories, and when I post, usually I'm just venting. Perhaps you think I am a Creationist, and that's where your attitude comes from. Honestly, I don't really care, but I'm not a Creationist. The point I was trying to make, though failing, in your case, apparently, was that Bangists are really just Creationists, but they've replaced the characters in the story. It's still the same story, if you can see it objectively.

I believe the universe had no beginning, will have no end, and either way it doesn't matter because the entire span of my life is so short I'll never know either way. Our entire species has lived, and shall die in less than the blink of a cosmological eye. We can argue all we like, but I'd rather just go out for ice-cream.

Re:Young Universe Cosmologists (correction)

[Chris Burke]

The point was and is, just as when the Catholic Church was considered the guardian of all knowledge, (at least in Europe,) and an observation was made which pointed out that one of their stances was incorrect, (by being in direct contravention to what was observed,) they resisted, tormented those who disagreed, but ultimately had to revise their position when it became obvious they were wrong; so it is today.

And my counter point is that if the Church was Science, Copernicus and Galileo would have been heralded as heroes and revolutionaries because they had extensive and convincing evidence to support the heliocentric theory. Did you not read my post? The Big Bang Theory was such a revolution. It was not the favored theory, and only became so because of it's ridiculous success at making predictions that were later shown to be true! The reason physicists resist contention to such a theory is because there is so much evidence behind it, that it would take a great deal of truly surprising evidence to overturn it. But if you have a theory which produces such evidence, then your name will go down in history along with similar revolutionaries like Einstein, Heisenberg, Faraday, Young, etc.

Someone like me points out a theory has a problem, but that theory is so entrenched in the minds of its adherents that people try to shout him down, rather than listen, or instead make patronizing remarks.

Oh, and "those silly scientists, they don't understand infinity, or things without a beginning!" or "Big Bang Theory is just an appeal to authority", both of which are demonstrably untrue, isn't patronizing? Please! I'm patronizing you because you think that not understanding physics is a solid basis for insulting the intelligence and integrity of physicists everywhere. That deserves a patronizing tone.

The nice thing about science though, is that eventually, observation TRUMPS hypothesis, no matter how dearly cherished, so I don't really need to argue this point, I can simply wait.

And exactly WHAT observation leads you to believe that you're right? Oh, right, you're just sitting on your ass and waiting. You're not making any observations. You have no evidence for your theory. All the actual observational evidence points towards the Big Bang Theory being correct. You're just imagining and wishing that future observations will prove you right. Now who exactly is operating based on belief and dogma here?

Science is willing to accept that Big Bang Theory is wrong as long as compelling evidence comes along. Is your Church of the Ego willing to similarly accept this possibility? Or are you going to be sitting around your hole life, assuming you'll eventually be proven right?

You keep saying "observation triumphs", so you seem to be blissfully unaware of how observation has verified the current theory. If you really believed what you say, wouldn't that interest you?

Oh, and then there's the CMB. Interestingly enough, if that's radiant energy from the supposed "Bang", how exactly did the Earth get IN FRONT OF IT, for our radio-telescopes to be in position to intercept it? We'd have to be IN FRONT of the expanding sphere, or on the surface of the light-cone, as it were, to see it. This would require the matter which would one day become the Earth, to have travelled FASTER than light, wouldn't it?

Hehe. See, you don't even understand the CMB well enough to realize what's truly mind-boggling about it. It's not just that we can see this remnant of the Big Bang, it's that we see it roughly uniformly in all directions. So we aren't "in front of the expanding sphere", because then we'd see the CMB from only one direction and at once instant. Instead we're INSIDE the sphere in which the Big Bang took place, and the CMB emanated from all points in space and we're seeing the far reaches of it.

See, the Big Bang was not an explosion in space, it was an explosion of space.

Re:Young Universe Cosmologists (correction)

[Slur]

You ask a lot of important questions, but most of them come from a misunderstanding of the situation - what you might call the prejudice of being *inside* the system. But keep pursuing those questions! And be careful about your attitude towards the word "theory." By placing the word in bold, you're emphasizing its informal usage, which stresses uncertainty. But in science the word has a formal meaning. In the parlance of science the most *certain* models that exist are theories. For what you're trying to express, you should say "the Big Bang Hypothesis."

Oh, and belief is okay.

[Chris Burke]

I believe the universe had no beginning, will have no end, and either way it doesn't matter because the entire span of my life is so short I'll never know either way.

And you know what? If all you had said is that you have this belief, then I wouldn't have taken issue with your post at all. I have beliefs too. You can have a good, rational discussion about beliefs as long as you acknowledge them as such. Beliefs aren't evidence, though, which is where philosophy diverges from science even though the latter is based in the former.