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glen chapman
2004-May-10, 10:03 PM
Anyone know a good 'primer' describing the period from the big bang to the first round of star generation.

So far all I can find is super basic....school student level....Or high level scientific papers.

Things I am looking for are - when did matter begin to get charge. When did hydrogen actually form. My understanding is the early universe, matter and energy were interchangable....having trouble grasping this concept.

Finally has any one ever considered what the universe may have ended up like with only hydrogen as the ingreident.

Any help would be good

Brady Yoon
2004-May-11, 03:14 AM
Hydrogen atoms formed briefly after the Big Bang, probably in about 1 second. Sorry, my knowledge of the early universe is very limited.
:x

Finally has any one ever considered what the universe may have ended up like with only hydrogen as the ingreident.


That's exactly what happened. The early universe only contained hydrogen, helium, and trace amounts of lithium. The rest of the elements were created in the cores of massive first-generation stars and scattered throughout interstellar space by supernovae. All of the elements that humans are made out of were formed in these stars. If this process never happened, carbon based life wouldn't be possible, and life would be nonexistent or based on hydrogen.

Tobin Dax
2004-May-11, 05:46 AM
Let's see how I can help here. I did a project involving the creation of elements by the big bang, and I'm about to finish a class on that and similar topics.

I don't think that particles "began to get charge." Electric charge is a fundamental property of particles, as far as we know. When particles are created, they must have the appropriate charge. If it doesn't have that charge, it's not that particle.

The current accepted theory is that the universe began at a very hot temperature. It did cool quickly--as Brady Yoon said, most of the hydrogen and helium were formed within about a second (*maybe* two). But the time before it cooled was what you are asking about. When the universe was hot, it was a sea of highly energetic photons. However, when these photons collided with each other (and they easily did), they havd more than enough energy to make fundamental particles--quarks, electrons, and others. This is just like the zero-point energy/"quantum foam" in quantum mechanics, except that it was possible to make things much more massive than electrons. Because these particles could be (and were) made, the universe wasn't just a sea of photons, it was a sea of photons, quarks, electrons, gluons, etc. (Gluons are the particles that transmit the strong force.) This is commonly referred to as the quark-gluon plasma. Once the universe cooled enough so that the quarks could not remain free, they had to combine into particles, such as protons and neutrons. Most other particles that the quarks can form would eventually decay into the particles we see around us.

At about one second, the universe was coll enough that heavy particles weren't forming, but the conditions were more intense than in the center of the sun, and the protons were converted into helium until the universe cooled past the temperature necessary to do that. It was also able to make some lithium (a tiny amount), but couldn't make notable amounts of anything heavier. This is how the elemental composition of the universe remained until the first stars formed.

Since this post is long enough already, I'll let someone else answer the mass-energy question. However, I can answer your last queation in some manner. In order for the universe to be made of only hydrogen (protons), it would have to be expanding very fast so that it cooled way too quickly to give helium any time to form. This would require a whole lot of dark energy around early in the universe to make it expand that fast. What about the neutrons? They decay into protons, and so eventually the universe would be only protons (ignoring electrons and other particles).

I'll be around again at this time tomorrow night to answer any other questions you have about this.

Dax

TravisM
2004-May-11, 11:09 AM
Tobin Dax, I'd like to interject, but I can't! Every statement, superb.
glen chapman - Try to think of this high temperature and it cooling rapidly, allowing the radiation (photons) to 'condense' into little 'droplets' of matter. It's easiest to picture for me mentally, even though it isn't 100% correct. Lemme know Tobin, if this next part is close...
At exreemly high temperatures all forces converge. They are the same. That's what we do in 'super colliders.' We are making huge GeVs worth of energy. Gigga electron Volts (I think that's what it stands for). These high energies translate into high temperatures allowing the formation of extreemly wierd types of particels, all folded neatly into the 'standard model.'
Okay, you didn't ask, but some one bring up why there isn't much anti-matter around... and why we think it's 'missing'.

glen chapman
2004-May-11, 12:40 PM
Thanks guys for the outstanding responses...From here I can attack some of those research papers I bumped into

Once again...heaps and heaps off thanks

Glen Chapman

ngc3314
2004-May-11, 01:52 PM
Thanks guys for the outstanding responses...From here I can attack some of those research papers I bumped into

Once again...heaps and heaps off thanks

Glen Chapman


On top of the above, I might modestly suggest the final few links from
http://www.astr.ua.edu/keel/galaxies/
which cover some snippets of cosmology and galaxy formation. Last revised about a year ago, some some updates are already inevitable.

Crimson
2004-May-11, 01:58 PM
Chapter 7 ("Ashes of Creation") of Ken Croswell's cosmology book The Universe at Midnight (http://KenCroswell.com/universeatmidnight.html) describes in detail the creation of the light elements during the first few minutes of the universe's life and how astronomers 14 billion years later established the primordial abundances of these elements.

Hamlet
2004-May-11, 02:27 PM
Tobin Dax did a great job summerizing the early Big Bang. =D>

I'll just add in a some links that I have found useful.

There is some good material here (http://www.astronomynotes.com/cosmolgy/s1.htm).

I found this (http://map.gsfc.nasa.gov/m_uni.html) link to be very informative.

My first real exposure to the early BB was the book The First Three Minutes: A Modern View of the Origin of the Universe (http://www.amazon.com/exec/obidos/tg/detail/-/0465024378/104-4638764-4607165?v=glance) by Steven Weinberg. It may be a bit out of date now, but a lot of the fundamental concepts should still be relevant.

George
2004-May-11, 02:32 PM
Anyone know a good 'primer' describing the period from the big bang to the first round of star generation.

Do you have a learning preference (e.g. books, websites, this BB, etc.)?

Inflation theory goes with Big Bang theory as well. String theory and M-Theory also strive to explain a great deal more.

Tobin Dax
2004-May-12, 12:33 AM
Thanks, Travis and Hamlet. Now tell that to my professor. ;) I'm really fascinated by this topic--it's a shame that the prof isn't taking new students right now.

Travis, you're spot-on with that description. Supercolliders are great for people interested in particles in the big bang because they can recreate those GeV (or even TeV) energies.

Glen, ooc, what are the papers you're looking at? Also, feel free to pm me if you have other questions about this. I'll answer them to the best of my ability.