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toothdust
2008-Dec-01, 04:54 PM
From ScienceDaily (http://www.sciencedaily.com/releases/2008/11/081124102701.htm):

"Something vital is missing in the far distant reaches of the universe: hydrogen -- the raw material for stars, planets and possible life.

The discovery of its apparent absence from distant galaxies by a team of Australian astronomers is puzzling because hydrogen gas is the most common constituent of normal matter in the universe.

If anything, hydrogen was expected to be more abundant so early in the life of the universe because it had not yet been consumed by the formation of all the stars and galaxies we know today."


Very odd indeed, and frankly, I am surprised I had to post this topic here. I thought someone would have spotted this last week already. Talk about a monkey wrench in the standard model, eh?

PraedSt
2008-Dec-01, 06:39 PM
There is a bit that says:
His group analysed the data from optical telescopes and found that, although apparently dim due to their immense distances, the distant galaxies actually emit vast amounts of energy.

This energy is generally believed to result from the friction of the material spiralling at close to the speed of light into the black hole lurking within the heart of each galaxy. These "quasars" are found all over the sky but occur predominantly in the early universe.

"At such distances, only the most optically bright objects are known," Dr Curran says. "The intense radiation from the matter accreting into the black hole in these quasars is extreme and we believe that this radiation is ripping the electrons from the atoms, destroying the hydrogen gas."

This would leave the gas as a soup of free subatomic particles known as a "plasma", which cannot be detected at the radio frequencies searched.
Doesn't this mean that hydrogen is there? It's just that it's getting ionised...(?)

toothdust
2008-Dec-02, 06:32 AM
So if hydrogen is being destroyed in the earlier universe, why do we see more in the older universe? Funny how the standard model thumpers are ignoring this one...

Jens
2008-Dec-02, 07:05 AM
So if hydrogen is being destroyed in the earlier universe, why do we see more in the older universe? Funny how the standard model thumpers are ignoring this one...

I guess the implication is probably that later on, the gas became un-ionized, if that is the right term. That it re-formed, if you want.

slang
2008-Dec-02, 08:12 AM
Funny how the standard model thumpers are ignoring this one...

Yeah man, I totally agree. The "standard model thumpers" should immediately throw away years and years of study after such a devastating news article. Especially such a well written article with such excellent choice of words.

So let's see what the article says: they found less hydrogen than expected (in the sources they looked at), they did find ionized hydrogen, this is happening in early quasars, and they're working at the very edge of what current radiotelescopes can do.

Should we then assume that the total amount of hydrogen in the universe was much less than there is today and all of current cosmology is wrong? Or is this a study that might tell us something interesting about how the brightest quasars work or appear in early galaxies? Or maybe more than expected hydrogen was already clumped to galaxy structures?

It's an interesting article for sure, but I think it's a little premature for sweeping conclusions and ad-homs.

PraedSt
2008-Dec-02, 04:45 PM
So if hydrogen is being destroyed in the earlier universe, why do we see more in the older universe? Funny how the standard model thumpers are ignoring this one...
As far as I know, ionised hydrogen is still classified as hydrogen. It's not another element. So I'm not sure how these astronomers can say it's 'missing'. I'd welcome any corrections to my understanding.

toothdust
2008-Dec-04, 01:59 AM
Yeah man, I totally agree. The "standard model thumpers" should immediately throw away years and years of study after such a devastating news article. Especially such a well written article with such excellent choice of words.

...

It's an interesting article for sure, but I think it's a little premature for sweeping conclusions and ad-homs.

Yeah, I threw that in there hoping to get some more responses.

I agree that a news article isn't any reason to jump to conclusions, but those astronomers thought it was somewhat of a big deal, hence the published title of the article.

Whatever the outcome of this puzzle, something new and intriguing has been discovered that on the surface seems to require a slight revision to current models.

Neverfly
2008-Dec-04, 11:52 AM
yes, much more needs to be known before jumping to any conclusions.

But it is very interesting.

Hopefully, further study will be able to enlighten us. If a revision of the Standard Model is in order, so much the better.
It only increases our understanding.

But we can't assume that's going to happen just yet. First, we need to understand the why of it. Then we can adjust the theory.

geonuc
2008-Dec-04, 12:02 PM
Yeah, I threw that in there hoping to get some more responses.
That sort of posting may not win you many friends.

Cougar
2008-Dec-04, 03:03 PM
So if hydrogen is being destroyed in the earlier universe, why do we see more in the older universe? Funny how the standard model thumpers are ignoring this one...

Funny how you seem to base your beliefs on a complete lack of understanding.

Hydrogen being "destroyed"? One who apparently knows so little about physics should really avoid jumping to rash and typically untenable conclusions.

It is not normally a relevant question, but in this case, with the history of your participation here, one is led to wonder about the motivation behind your attempted sniping and disrespectful attitude. :confused:

toothdust
2008-Dec-11, 04:41 AM
Funny how you seem to base your beliefs on a complete lack of understanding.

My beliefs? Sorry, I don't "believe" in anything. Do you?

My "complete lack of understanding"? Are you implying that I know literally nothing about physics and astronomy? Sounds dangerously close to an ad hominen to me.


Hydrogen being "destroyed"? One who apparently knows so little about physics should really avoid jumping to rash and typically untenable conclusions.

Bad word choice. At least now I am upgraded to "knows so little" in your mind.


It is not normally a relevant question, but in this case, with the history of your participation here, one is led to wonder about the motivation behind your attempted sniping and disrespectful attitude. :confused:

Oh, can't take a little joke?:rolleyes: What do you care about my motivation? Does it make you feel better if I say straight out that I don't like the BBT? For that matter I don't like ANY of the theories out there. You know as well as I do (or, "as little" as I do) that there are many more alternative model thumpers than there are BBT thumpers. I try and learn about all theories.

And as for disrespectful, I would say your belittling me trumps my 'meant to be humorous' comment.


That sort of posting may not win you many friends.

Aww, I think you guys can handle a bit of jostling now and then. If you think that I think the majority of astronomers are somehow emotionally attached to BBT, your sorely mistaken.

I think I have a rather splendid relationship with very many members on BAUT. I mean, jeez, I'm even getting along with Neverfly these days.:eek:

Ara Pacis
2008-Dec-11, 09:05 AM
My interpretation of the article is that the quasars are so bright that quasar is all they can see that far away. Kinda like how you can see the high-beams of a car coming down the road at night but can't see the car. It doesn't mean the car isn't there.

toothdust
2008-Dec-11, 02:38 PM
What is the relevance of them saying that the distant quasar galaxies they are looking at are consuming more hydrogen than expected, and/or "destroying" hydrogen atoms by stripping them of their electrons turning them to a plasma, which they say they are unable to detect by means they are using.

To me it sounds like they are saying that some of the oldest quasar galaxies they are looking at are processing/consuming hydrogen much faster than is to be expected to leave us with the current amount of hydrogen we see in the most recent universe.

Then again, they are only looking at quasar galaxies. Do we know if any nearby galaxies were quasars in their younger days?

Spaceman Spiff
2008-Dec-11, 04:34 PM
The astronomers were looking for the spectral signature of neutral hydrogen gas. It emits at 21 cm (http://en.wikipedia.org/wiki/Hydrogen_line) (due to the interaction between the "spins" of the electron and proton and their magnetic moments), and the wavelength that arrives here is stretched by a factor of 1+ z, where z is the object's redshift. These are meter wave radio telescopes, and so appropriate instruments to observe this form of light emitted in the high redshift (early) universe.

What they're saying is that the spectral signatures of neutral hydrogen in the host galaxies of these quasars indicate a lower neutral hydrogen content than "expected", although I don't know what was to be "expected" given that we KNEW already that luminous quasars are capable of ionizing the entire host galaxy and vast volumes of low density gas around them.

As happens so often in these "press releases" to science news outlets, there is information loss in translation from the precise languages of science and the maths that underlie its models to something that everyone else can understand (call it "lost in translation"). Hydrogen itself is NOT missing -- just its neutral component, that is, the form of hydrogen that consists of 1 electron bound to its proton. Hydrogen is NOT destroyed (or consumed) in these environments -- it is ionized, that is, the single protons and electrons are free from one another due to the high energy radiation from the quasar that floods the environment.

The quote from one of the astronomers, Dr. Curran:

Since hydrogen gas is consumed by star formation, we may expect more hydrogen gas in the distant, and therefore earlier, universe as all of the stars we see today have yet to form.is just bizarre (and confusing). Yes, slowly over time, some of the hydrogen content of galaxies is converted into helium and the heavy elements by stars. But that has nothing to do with the neutral/ionized ratio of the state of hydrogen. I can only guess it was garbled by the interviewer or I don't know what.

Spaceman Spiff
2008-Dec-11, 04:50 PM
Then again, they are only looking at quasar galaxies. Do we know if any nearby galaxies were quasars in their younger days?

Yes, as a matter of fact, we do. The joint/co-evolution of galaxies and supermassive black holes (http://adsabs.harvard.edu/abs/2008arXiv0808.1254S) is a recent, large and expanding field of astrophysics. This (http://arxiv.org/abs/astro-ph/0504097) and this (http://adsabs.harvard.edu/abs/2006ApJ...650...42L) are just two sample papers among ~ a hundred. In a nutshell, observations have led us to the conclusion that ~all massive galaxies have supermassive black holes lying at the centers, and the mass of the central black hole and that of the stellar spheroid are correlated. Quasars are what result from the dumping gas into them. Shut off the gas supply, the black hole sits quiescently. There is a 4 million solar mass black hole at the center of the Milky Way (http://antwrp.gsfc.nasa.gov/apod/ap081211.html), a wimp by comparison to the 10^8-10^10 solar mass black holes involved in quasars. It is presently quiescent.