Monday, November 30, 2009

By the Book 4

Interesting fact: Gorge Gamow and colleges predicted the CMB in 1948 and they predicted it would have a temperature of somewhere between 5 and 50 degrees Kelvin (it has a temperature of 2.7 K but hey they were pretty damn close).

Cosmology rule of thumb: The density of mass in the universe (one of our lines in the density graph) is inversely proportional to the square of the age of the universe. In math terms this is Density of mass =1/((age of the universe)^2).

In his book Harrison then takes the reader on a journey back in time much as we did in the backtracking series (of course he did it much more eloquently) and we will fall into step with him to when the universe is only 500,000 years old and pick up there.

Ok so first he talks about the hydrogen plasma we talked about earlier and, get this, it took about 10,000 years for the nuclei to capture their electrons. I had no idea it happened that fast. This is called the decoupling epoch…but I’m not much for complicated names…so i’ll just keep talking about the plasma like I have been. Oh, something else I should mention, when telescopes like the Hubble satellite look at space they look back in time (but I’m sure you already knew that) and they can see very far…but even with the most advanced telescope we could ever build we wouldn’t be able to see (at least with light) during or before the plasma period. Remember how I said we the light was trapped in the plasma? Well it created this fog stuff that is impossible to see into or through this fog. So our telescopes could never look past this period.

Sunday, November 29, 2009

By the Book 3

Ok…everyone have a good thanksgiving…and for those not in America…have a good week? Good. Now to get back to the physics. I have another graph for you. This one is a bit more technical but I think we are gonna try to tackle it anyway. Ok, so if you look at the graph you will see two solid lines, one labeled matter and the other labeled cosmic radiation. We have spent quite a bit of time talking about cosmic radiation, we’ve just been calling…light or photons. Anyway, the lines measure the density of the stuff in grams per cubic centimeter (How can light be measured in grams?? Well just use Einstein’s E=mc^2 to convert the amount of energy you have into a mass and there you have it.) with respect to time (here both axis are on logarithmic scales). The graph is a very nice compacted version of all the things we’ve been talking about recently especially the order that things happened in and the dominance areas. I’ll probably refer back to this graph later…I’ll just call it the density graph.

Sunday, November 22, 2009

A Little Break for the US of A

Sorry I didn't post yesterday. I've been traveling and I've decided that i won't be posting this week. We've gone to a friends house for the thanksgiving holiday. I need some time off. Hopefully I'll be more gung ho for this new round of learning after some turkey and pie!

Friday, November 20, 2009

GOD! ?




Ok here are some more images...you might have to click the pictures to see all of them. Let me know what you think..

Thursday, November 19, 2009

By the Book 2

I forgot about the gluons! We musn't forget them! They are a bit more complicated. For these puppies you can't just picture them as the billiard balls we see electrons and quarks as. Gluons are more like photons, while they are a particle, they also carry stuff...that is, photons carry enegry and deposit it and stuff...but gluons are the 'force carrier' for the strong interaction. They don't have any mass or charge, and there are 8 types.

Ok...now for the hadrons. Hadrons are just stuff made of quarks. there are a few different types of hadrons. We have measons, made of a quark and an anitquark, and baryons, made of three quarks (protons and neutrons are baryons). And that's it for the figure from yesterday.

Other particles you may or may not have heard of include the neutraino, and the muon and the ever popular higgs boson. The muon is just another kind of lepton, like the electon, exept heavier. The neutrino is just one 'flavor' of the leptons. We have an electron nuetrino a muon nuetrino and a tauon (the 3rd lepton) nuetrino and thier antiparticles. The higgs boson is another type of 'force carrier' partile that is suppose to give mass to things. It has yet to be observed (this is the job of most of the large hadron collider), but it is needed theoretically for our whole model to work.

Here is a link to the particle zoo, a very humorous look at the standard model and I've included a picture (you'll have to click on it) with a plethora of information on the stranded model and a great picture of how atoms are really composed.

Wednesday, November 18, 2009

By the Book 1



I would like to continue our discussion of the CMB, but I’m afraid things have picked up around there and I won’t be able to gather the necessary information to go any more in-depth, but I would like to continue our discussion of a time line. Up to this point I’ve been pulling in things I’ve know and going backwards. But now I would like to go a bit more out there and use a book (oh how scandalous). I’ll basically be going through Edward Harrison’s Cosmology: The Science of the Universe chapter 20. We’ll see what we find.

Note: So you remember when I talked about the “what’s dominate” eras? Well it appears that matter wasn’t dominate in our universe until about 100,000 years after the big bang. I don’t remember if I said that or not.

I found a cool graph. It’s a timeline set on a logarithmic scale. (If you don’t know what a logarithmic scale is you can look here, it’s actually really hard to describe and took me like 4 years for someone to actually explain it to me a way I could understand it.)

Ok now I will take a coupe of moments to explain what all of the things on this graph on graph. They don’t all relate directly to what we want to know but it’s a very very good thing to know what these things mean. Ok first we have monopoles and inflation, and we already talked about those. Next comes quarks. I have a picture of those. They are a fundamental particle (they aren’t made of anything). There are different kinds of them, 6 in total (and their antiparticles of course).When you put them together they make all kinds of things. When you put a certain combination of 3 quarks together you get a proton. And a different combo of 3 gives you a neutron and if you mix them up or put just 2 together you get a whole host of exotic particles. Next comes leptons. These are a little less…uniform. There are also six types of these but they are not all as common. The only one we see often is the electron, but there is also the muon and the tauon, and different ‘flavors’ of those. And tomorrow I will continue with the hadrons.

Tuesday, November 17, 2009

in the interim

ok...so i'm working on this super awesome but really long post. so i will not be posting today so i can work on that. have a good day and here have an lolcat!

Monday, November 16, 2009

GOD! ?



I had a thought. I'm personally a visual person (I have so many pictures on this blog) so I thought I'd do something with God and pictures. But if I do I really really want to guys to respond. Pleeeeeaaaaassssssseeeee! So here's what I'll do. I'll post some pictures of "God" and you respond to them telling me which ones you like best, which are most accurate for you're views on God, etc. This is suppose to be funny and informative. I'll post more pictures later as I find them.

Sunday, November 15, 2009

Backtracking 14 CMB

So now to discuss the anisotropies (different colors)in the CMB. According to Wikipedia, there are two different types of anisotropies, primary and secondary. Primary anisotropies come from collisions of the light right before it was released to wander the universe. Secondary anisotropies come from interactions the light had with the gas since the formation of the hydrogen atoms that released them. But…then things get complicated…and my computer is broken. The screen went on the fritz and now it won’t show anything. I’ll have to figure this out tomorrow. I think I might have to ask my professor friend. So I’ll get back with you on that tomorrow. Sorry about the crappy entry.

Saturday, November 14, 2009

Backtracking 13 CMB

Anyway, back to the CMB. So that picture that I posted of it last time, if you look at it you will notice there are some different colors in it. Different colors correspond to different temperatures. (I’m pretty sure this is how it works) There is an average temperature of 2.725 K (the K is for Kelvin which is just a shifted version of Celsius. 0 degrees Celsius is 273.15 kelvin). The scale on the side of the picture is the fluctuation away from this average temperature. The orange and red is slightly warmer than 2.725 K and dark blue and purple is slightly colder. But these are very tiny temperature changes. You can see that the scale on the side is in micro-kelvin, that is, in increments of .000001 K. But these changes are significant. They show us where matter started forming. The colder places are places where the matter first condensed and formed into the hydrogen atoms we talked about before.

Friday, November 13, 2009

Random aside

I have a question. This is posed at the young people. Do you still have deep intellectual discussions, in your colleges and things I mean? Like where you talk for hours about the nature of the universe and philosophy and society and you share your ideas. Do you still do that? I visited a college campus recently and talked with some of the students. They seemed very concerned with their grades and where they were going to go after school. Maybe I just don't know them very well and perhaps you just talk more in private. But does that still happen? The modern society seems to be obsessed with progress and achievement. When did that happen? And why? Is there a way to fix it?

Thursday, November 12, 2009

Backtracking 12 Nucleosynthesis

To take a quick break from the CMB, I was recently posed a very good question about where elements came from. We haven’t quite gotten there yet…but I think I can give a quick overview. The first elements were formed just after protons and neutrons were formed (ya know after inflation when things cooled down enough to form real particles). There first elements where mostly hydrogen and some helium but according to what I’ve read everything up to lithium and beryllium where formed before stars where created. From there stars and galaxies were created from the hydrogen and helium and proceeded with fusion. This made a lot of the elements (including a decent amount of carbon near the cores of ‘normal’ stars…that eventually became the earth!), but normal star fusion stops after iron. Once you reach iron it’s not energetically favorable to fuse nuclei anymore (I forget why right now…but I might be able to find out if you really want to know). Then a star dies and it blows up…or does a number of other random violent things. (I’ve included a picture of some of these random things) And when heavy elements like iron fly into other smaller elements like helium they fuse and form the heaviest elements, including the radioactive ones. And this is how the elements we know and love today were formed. There are other elements and exotic particles that are formed in the atmosphere when cosmic rays hit it (I’ve done some experiments involving these they’re fun)…but that’s a topic for another day.

Tuesday, November 10, 2009

Backtracking 11 CMB

So, as I explained yesterday, we’ve got this hydrogen plasma that traps light. This creates an opaque fog that covers the universe. But then when the temperature of the universe dropped, the electrons bonded to the protons to form hydrogen atoms and the light was freed up to move around. The picture from yesterday of this phenomenon is not really accurate in that things would be a lot more expanded and the light would move around much more without hitting anything. So what you have is basically a bunch of photons flying around in free space without anything to bounce off of. They have the same properties and distributions as they did when they were first set free. So now we can take a look at them. We sent out some satellites and they measured photon intensities at different locations and the picture up top is the kind of thing we got.

Sunday, November 8, 2009

Backtracking 9 CMB


Does anyone else think it’s highly ironic that I view Wikipedia as the most up to date and reliable source of information available? Well I do…but it’s true. I trust Wikipedia the most. Anyway, the CMB. First I should give you a little background on atoms and things. Most know that atoms are made of a nucleus and some electrons that orbit them, like in the first picture. But in the early universe matter hadn’t formed into atoms yet. Things were still too hot to do that. Instead what matter there was took the form of hydrogen plasma. Ohhhh…plasma. This is what the second picture is of. In the modern age hydrogen plasma is found in stars, nuclear accelerators, lightning, neon signs and rocket exhaust. Plasma is actually considered a different state of matter…like solid, liquid and gas. A plasma is a sort of fluid where the most of the electrons has been stripped away from their atoms, or in our case they electrons were never attracted to the atoms. So what we are really left with a bunch of hydrogen nuclei. But the nucleus of a hydrogen atom is just a proton…so we just have a bunch of protons in a strange fluidly state.

Saturday, November 7, 2009

Backtracking 8 CMB

Ok back to the timeline. Now that we’ve explored the possibilities for how our current universe (the matter or possibly dark matter dominated universe) came to be, we can move on to what came before that, the light dominated universe. By ‘light’ I actually mean radiation, so that includes all forms of light from gamma to radio waves. Basically the universe had more photons than anything. Well how do we know there was a light dominated era? Because of the CMB! The cosmic microwave background, the precious baby of modern cosmology. All the cosmologist are so so so proud of the CMB, cause it validates a lot of their ideas. And brought down some of them as well. But anyway the cosmic microwave background is a layer of microwaves that are left over from the radiation dominate era of the universe. And as to how it works…I’ll talk about that later.

Friday, November 6, 2009

Thursday, November 5, 2009

Backtracking 7 The way science is...

As I continue reading Gamow’s article things I learned are once again brought to mind and I do think they are worth sharing. So ya know how I was talking about how the larger elements where formed in star fusion? Well they didn’t know that until rather recently. In fact in this article I’m reading Gamow mentions that the heavier elements were created before the stars were formed. This, of course is not the prevailing theory today but they that’s what they thought back then. They also thought the universe was about 5 billion years old. So since we measure the radioactive elements (ya know like carbon 14 from carbon dating for the dino’s) to be about 5 billion years old they thought they had to be formed very early on in the universe…which lead to all kinds of wrong assumptions. But, today we know heavy elements are formed in stars and the universe is about 14 billion years old. Just goes to show you how if we have one or two pieces of the puzzle wrong we can get a lot wrong.

Wednesday, November 4, 2009

Backtracking 6 Super massive black holes

I think this is how it goes: in those big dust clouds that formed when the dominance switched from radiation to matter, there formed a black hole and it sucked in a bunch of dust and grew really big and spewed out radiation which heated up the surrounding dust and triggered millions of stars to form. And the same radiation that formed them pushed them away from the black hole so they didn’t get eaten (of course I’m sure some of them got eaten first. Then when the black hole had eaten everything that it hadn’t pushed away it when to sleep and stopped sucking in matter and emitting radiation and nothing would go near it and it would lay there, dormant waiting for the day when it can feast again! Who knew astrophysics had scary stories. This explanation might be a bit exaggerated, but you get the general idea. It was actually the black hole that created the galaxy, or triggered galaxy formation.

Tuesday, November 3, 2009

Backtracking 5 Black holes

Recently, as in the last 20 years or so, people have been taking a good look at black holes (pun intended…ya get it…cause you can’t see them…cause they’re black…anyway). We look at them by observing the motion of the things around them. Then we can find where they are and how big they are. And we’ve found some big ones. There are 4 general classes of black holes, tiny ones like the one the Large Hardon Collider is suppose to make, small ones created when stars violently blow up (the ones in sci-fi movies), big ones that theorists have predicted are them, but we don’t know that much about them, and super massive, the monsters that we have observed at the center of every galaxy we’ve looked for them in. I once saw this wonderful documentary on super massive black holes but I couldn’t really find it so here’s one that seems to be just as good. These giant objects sleep, literately, at the center of most galaxies, including our own and are thought to play a major role in galaxy formation.

Monday, November 2, 2009

Backtracking 4 Star formation

Today I read part of an essay by George Gamow entitled ‘Modern Cosmology’. It was written in 1954. I didn’t realize this until I was several pages into the essay…so I kept on reading…but I don’t know how much of what he says is still held up as truth today. So take these next couple of entries with a grain of salt or two. Yesterday I said we would talk about radiation dominance, but I have found more information about the switch in dominance from radiation to matter so I think I shall expound upon that. According to Gamow when this switch took place, giant clouds of matter started forming they took the shape of giant dust clouds clumping together. (I’ve included a picture of a modern dust cloud. Of course at this point in the universe there weren’t any stars…but just pretend.) Then when you get enough dust and just the right amount of radiation mixed up (like so many good cocktails I know) you get magic. In a complicated and very violent moment the cloud condenses and forms a star. And if you get lots of clouds you get lots of stars…and lots of stars form a galaxy. And there you have it, galaxy formation…of course that’s not quite that simple.

Sunday, November 1, 2009

Backtracking 3 Domination

Next we can talk about the ‘what’s dominate?’ eras. Right now we are in the ‘dark energy’ dominate era. But what does this really mean? Dominate means that that is what there is the most of. In the ‘dark energy’ dominate era, now, there is more dark energy than anything else. So… it is the driving force of the universe. That is why we are expanding at an accelerated rate. The dominance of an energy term make us accelerate. Before that was a matter dominance. I’m not sure, and I don’t think cosmologists know either, but somehow and at some point the dark energy overpowered the matter, including dark matter. Before this point matter was dominate and the expansion of the universe was decelerating. Before that, 70,000 years after the big bang, the dominance switched to matter from radiation. So… light was the dominating force in the universe. And that is what we will talk about tomorrow.