How many stars does it take to screw in a lightbulb?

[jami cat]

3 questions:

err...a star last like 5 billion years and umm...the universe is 14 billion years old...so, are we on our 3rd generation star formations?
Considering average star formation/destruction.

Exactly, when do galaxies start forming, during the first generation stars? So, what came first, the stars or the galaxies in which they lie?
I don't recall any stars hanging out in the middle of nowhere going either poof-I'm here or boom-I'm outta here, outside of some galactic formation.
So, are stars the product of Galaxy formation?

Exactly how many stars had to blow up in the general vicinity to create the heavier elements to re-join again into a 1 pound Iron meteorite that blasted its way into the earths atmosphere and landed at my feet?
Considering the vast distances that stars are from one another. Wouldn't the explosion of a large star over a several light-year radius dissipate into rather nothingness?
Didn't it take 4 billion years to create out solar system from this dust?
But, wasn't all this stuff already here prior to that?

There seems to be; a time frame issue,"How long does it take a solar system make," or a density issue of "How much stuff is really between stars?"
or between one's ears :P

I confused :/

[Twinsun]

hmm I believe that first there were the stars and then there formed planets revolving around them and THEN, put together, they made up galaxies ;)

[jami cat]

hmm I believe that first there were the stars and then there formed planets revolving around them and THEN, put together, they made up galaxies ;)

Yea, that's it...the stars all migrated to the warmth of the Black Hole, like moths to a flame.
That's how they cook crab nebula's...mmmmm

[Twinsun]

well this is a rather general theory on how the first cosmic objects began to form and from what I know it's exactly how I said ... now about the supposed HUGE black hole at the center of some galaxies, I cannot yet conceive how a black hole could stand there devouring the galaxy minute by minute, YET not consuming it at all ... I think I have another answer for this one but I'll post a new thread regarding it cause I have some doubts about it

[dgavin]

From my understanding there are two lines of thought about the first objects in our universe. Both have about equal validity at this time, so much more research is needed to determine which way it happened.

1. The initial material collapsed and being dense enough in the early universe, it collapsed strait into the glactic core Super massive BH's that we have today.

2. The initial material collapsed into 1000 sun mass sized stars, although beyound the size limit now, the material was dense enough back then. These first generations stars only lasted about 1000 years before dieing and forming MBH's of about 750 solar masses. The Explosions of these stars pushed the dense matter around into fillaments between the bubbles, where the galaxies we now have still exhibit the clumping around these filiments.

[jami cat]

BMBH's
I heard of Stellar Mass Black Hole=SMBH. What's BMBH?

Isn't there some math involved in determining Star birth/death ratio to matter density?

Why does this seem to happen early on in the universe, versus now?

Shouldn't the laws of physics be the same for the whole of universal time?
(i.e Stars blew like pop tarts in toasters in the early universe, Why? Were there lots of Toasters then?)
If so, what happened to 'em?

[dgavin]

I heard of Stellar Mass Black Hole=SMBH. What's BMBH?

Isn't there some math involved in determining Star birth/death ratio to matter density?

Why does this seem to happen early on in the universe, versus now?

Shouldn't the laws of physics be the same for the whole of universal time?
(i.e Stars blew like pop tarts in toasters in the early universe, Why? Were there lots of Toasters then?)
If so, what happened to 'em?

Sorry had Meant SMBH for Super Massive Black Holes.

I think the reason behind both the therioes is the matter/energy desity of the universe was much greater then today. (The same matter and energy but in a much smaller area of maybe 100,000 LY, instead of the 13.8billion LY size of the universe today. This alowed either the matter to collapse strait into SMBH's or made the First generation of the short lived hyper stars.

Basicaly, from my understanding, the matter/energy was so dense, that accretion of matter didn't stop until the First Stars or BH's reached about 1000 solar masses (about 7 times more then the limit now adays).

In the case of the first stars they were fusing in a shell burning method. (they didn;t transition from Hydogen to helium, to Carbon, Oxygen, Nitrogen, Sodium, Neon, Magnesium in stages, they were hot enough to fuse all). In fact it's -remotely- possible as they were accretining enough matter(gravitational energy), to even fuse Iron for a short time at the very end of thier lives (probably the last few days to month of thier lives)

The Second Generation stars were also massive (about 200 Solar masses), but not like the first generation hyper stars. More akin to Wolf-Ryant stars that were at the size limit and tended to blow off a lot of thier material.

Third Generation stars began to form around either the remnent BH's of the first stars, (or the BH's formed strait from cloud collapes) and were the begining of Galaxy Formations.

Out sun is approximately a fifth generation star.

The First Star theroy is the slightly favored one, as it explains the filiment structrure of galaxy groupings. However this means thier BH remnents are part of the dark matter repulive zones causing the expansion of space now adays. Which leads to some obvoius issues with it.

I'm really a amature vulcanologist though, so maybe someone more learned in astropyisics will chime in. Most of this is parroting what learned from watching science channels (and thier not always reliable)

[jami cat]

So,
What were the contents of this this primordial soup, at the time the popcorn started a poppin'?

Does it take a Hydrogen atom 14 billion years to be a part of a chunk of iron, to land at my feet and then give me the opportunity to post this in a forum?

Are all atom parts (quarks) that ever existed, still in existence?

How can everything already be created, before it was created?

[dgavin]

Well recent developments in Loop Quantum Gravity theroy suggests that our universe began shotly after the collapse of another universe.

That universe collapesed not to a singularity, but to a point where it's Energy/Denisty was so compact, that gravity became repulsive, the big bang of our universe.

Here is the link to that. Confirmation of the old Recycling Universe Therory (http://www.science.psu.edu/alert/Bojowald6-2007.htm).

The Bad Astronomer also did a blog entry (http://www.badastronomy.com/bablog/2007/07/01/what-happened-before-the-big-bang/) on it.

This leaves many unaswered questions, such as why is our universe's expansion accelrating to what may be a point of no return for this cycle to continue. How did the very first Universe of this cycle come into being in the first place? Brane Collisions? Or is it an infinite cycle of Universes? No Begining and no ending, as the point where the collapse of the old universe and expansion into the new universe exists outside of time?

These are questions that may never get answered.

[dgavin]

Oh to answer you other question on Iron.

The First Stars only lasted about 1000 years then exploded in Hyper Nova's. So the first Iron (and other heavier elements) formed only after 1000 years of the first stars.

[Twinsun]

I believe that if we are to take into account the BigBang, there ahd to be a primordial object ... I mean from nothingness, the Universe came to existence and somewhere at some time, dust and other stuff had to gather in order to form the first object ever created ... now that could have been a star or just a rocky formation

[m1omg]

well this is a rather general theory on how the first cosmic objects began to form and from what I know it's exactly how I said ... now about the supposed HUGE black hole at the center of some galaxies, I cannot yet conceive how a black hole could stand there devouring the galaxy minute by minute, YET not consuming it at all ... I think I have another answer for this one but I'll post a new thread regarding it cause I have some doubts about it

It is not devouring the gallaxy.
Even when some star happens to wander too close, it takes many years for a black hole to devour it.
The BH's are pretty harmless objects.

[m1omg]

Oh to answer you other question on Iron.

The First Stars only lasted about 1000 years then exploded in Hyper Nova's. So the first Iron (and other heavier elements) formed only after 1000 years of the first stars.

wrong, completely
1000000 years

[m1omg]

So,
What were the contents of this this primordial soup, at the time the popcorn started a poppin'?

Does it take a Hydrogen atom 14 billion years to be a part of a chunk of iron, to land at my feet and then give me the opportunity to post this in a forum?

Are all atom parts (quarks) that ever existed, still in existence?

How can everything already be created, before it was created?

matter and energy cannot be created nor destroyed

[Tim Thompson]

err ... a star last like 5 billion years and umm ... the universe is 14 billion years old ... so, are we on our 3rd generation star formations? Considering average star formation/destruction.
You can't count generations of stars so easily as that, because the lifetime of a star is sensitive to the mass of the star. The first generation of red dwarf stars is still with us, and may well survive as long as the universe does. A minimal mass red dwarf star, about 0.08 solar masses, will last as a main sequence star (fusing hydrogen into helium in its core, like the sun) for about 100,000,000,000,000 (100 trillion) years. A star as massive as the sun will hang around for only about 10,000,000,000 (10 billion) years. A star 10 times the mass of the sun will last only about 30,000,000 (30 million) years. A star 100 times as massive as the sun would last only about 100,000 years as a main sequence star (assuming a star that massive could ever be a true "main sequence" star). These lifetimes come from a general formula: t = (Mstar)-2.5*1010 where "t" is the lifetime of the star in years, Mstar is the mass of the star (in solar masses), and 1010 is the main sequence lifetime of the sun in years. The first generation of stars were most likely very massive (like 100 solar masses) and so do not last long (i.e., Barkana & Loeb, 2001 (http://arxiv.org/abs/astro-ph/0010468)).


Exactly, when do galaxies start forming, during the first generation stars? So, what came first, the stars or the galaxies in which they lie? I don't recall any stars hanging out in the middle of nowhere going either poof-I'm here or boom-I'm outta here, outside of some galactic formation. So, are stars the product of Galaxy formation?
We know what the universe looked like when it was about 300,000 years old, from the cosmic microwave background. With telescopes, we can see what the universe looked like when it was about 800,000,000 years old. The time between is as yet invisible to us. We know that galaxies formed, and evolved significantly, during that time that is invisible to us (i.e., HUDF-JD2 (http://hubblesite.org/newscenter/archive/releases/cosmology/distant-galaxies/2005/28/) in the Hubble Ultra Deep Field (http://hubblesite.org/newscenter/archive/releases/cosmology/distant-galaxies/2004/07/)). So the answer is that we do not know the answers to your questions yet. Maybe supermassive stars formed first, or maybe the galaxy size structures formed first, and stars formed in them. See Madau, 2007 (http://arxiv.org/abs/0706.0123) & Loeb, 2007 (http://adsabs.harvard.edu/abs/2007astro.ph..2298L).

There are intergalactic stars, and there is no reason why stars cannot form in extragalactic einvironments. But most intergalactic stars are flung out of galaxies during close interactions or collisions of galaxies (i.e., Duc, et al., 2007 (http://arxiv.org/abs/astro-ph/0610392), Zibetti, et al.,, 2005 (http://adsabs.harvard.edu/abs/2005MNRAS.358..949Z)).


Exactly how many stars had to blow up in the general vicinity to create the heavier elements to re-join again into a 1 pound Iron meteorite that blasted its way into the earths atmosphere and landed at my feet?
I should think that one star could pull that off quite easily.


Considering the vast distances that stars are from one another. Wouldn't the explosion of a large star over a several light-year radius dissipate into rather nothingness?
No. The interstellar medium (http://en.wikipedia.org/wiki/Interstellar_medium) is a long way from "nothingness", and is quite substantial. Supernova shockwaves in the pre-existing interstellar medium can trigger new star formation. Likewise, the colliding shockwave from multiple, near simultaneous supernovae can also trigger star formation. See The Interstellar Medium Learning Pages (http://www-ssg.sr.unh.edu/ism/intro.html).


Didn't it take 4 billion years to create out solar system from this dust? But, wasn't all this stuff already here prior to that?
Of course, the stuff the solar system is made of must be ther before you can make the solar system out of it. Our solar system is only one of many, which came before, or formed later. It's a continuous process.


There seems to be; a time frame issue, "How long does it take a solar system make," or a density issue of "How much stuff is really between stars?"
Yes. It takes time to do anything, and it takes something to do it with (i.e., mass, density, energy & etc.).

Choose a more appropriate topic title and you might get more answers sooner.

[jami cat]

Choose a more appropriate topic title and you might get more answers sooner.

Thanks for the responses...

Maybe I should have titled it, "How Many stars does it take to get to the center of a Tootsie Pop?"
:P

[Doodler]

3 questions:

err...a star last like 5 billion years and umm...the universe is 14 billion years old...so, are we on our 3rd generation star formations?
Considering average star formation/destruction.

The generational age average of stars is not a linear function. Some of the first stars (so-called Population III) are estimated to have been thousands of solar masses with lifespans barely millions of years before exploding. Primarily because they were utterly non-metallic with only hydrogen and helium available as component matter. In order for the core to achieve the necessary critical mass density to trigger fusion, you needed a LOT of hydrogen.

Current stars are smaller not only because the material available is more dispersed and harder to gather up, but also because there's a measurable amount of heavier elements within them that allows the cores to reach critical mass with less hydrogen than the first stars.

The generation gaps aren't clean breaks between one another, either. In order to move from Population III to Population II stars, enough heavy elements had to be formed in the first supernovae to begin seriously altering the compositional make up of typical stars. There were likely thousands of "generations" of Pop III stars before enough heavy elements had been generated to affect the vast majority of newly formed stars, and its likely that Pop II stars were around even in the heyday of Pop III in the stars born in the remnants of the first Type II supernovae.

Even now, there's a fairly even distribution of Population II and Population I stars, so its not really fair to say we're in the "third generation" of star formation just yet.

Honestly, "generation" might not even be the best term for them. They're more like different species of star, with each succeeding type of star evolving from the first as more heavy elements enter the mix. Generations imply that one replaces the other, where speciation allows for multiple generations to exist side by side as one takes over from another.

[Sticks]

From the thread title I thought this was about all those rock stars using their own private jets and limos to appear at Live Earth :D

[Jerry]

Some of the first stars (so-called Population III)...
As astronomers so often paint things, the numbers are backwards.

Imagine how many accidents would happen if engineers labeled hot stuff cold low voltage high, and so on. These guys are freshman killers.

[Peter Wilson]

Then there was that famous McDonalds cup of hot coffee that wasn't labled at all :eek:

...must have been cosmologists!

[Hornblower]

How about color photography filter instructions that refer to a "warming" filter and the resultant lower color temperature in the same sentence?

This is an inherent conflict between the psychological "warmth" of a reddish cast and the actual temperature of an incandescent light source of that color, as compared with sunlight. That terminology predates the discovery of the relationship of color and temperature at the light source. We could say there is a rough analogy with some of the astronomical stuff. Some of the old terminology predates modern knowledge of the actual sequence of formation, but remains in use.

[Glom]

Star lifetime is determined by mass. The Sun is a dwarf star. On the H-R diagram, it sits well away from the top. I forget though. Are the blue supergiants within the main sequence band.

Does metal content have anything to do with how big a star will get? Somehow, I'm associating large stars with metal poor stars and small stars with metal rich stars like the Sun.