but wait! part 2

One of the other most interesting problems with the big bang theory is entitled the flatness problem. Again this is one that I really don’t understand. The way I understand it is that there are these parameters that set the universe into motion. For an analogy let’s pretend the universe is a washing machine, and you are God. You put some clothes in (the energy that the big bang created) and turn the dial to some initial settings. Then you push the “go” button. (I love washing machines. They are an incredible invention! Oh and I adore dish washers. They get those dishes so clean!) But the settings on the universal pre-set dial are rather delicate. If you set the spin cycle to fast the universe would curve back on itself and if you set the spin cycle too slow it will become a circle. But if you set the spin cycle just right you get a flat universe. This setting on the spin cycle corresponds to a parameter called omega and I’m pretty sure it represents an energy density. But the value of omega has to be exactly 1, exactly. EXACTLY. No deviations. This is a bit odd. But I’m not sure why…or why this is important. I think I should read up on this a bit more.

but wait! part 1

But don’t get fooled by all this goodness and such! There are issues with the big bang theory. A good thing to do next would be perhaps to go through these issues one by one to take a closer look at what goes into the theory and what physics need to consider when trying to figure this out. The fist problem we can tackle is the horizon problem. If we look at the picture I’ve included you will see two main characters form xkcd (an extremely funny and nerdy comic). Hat guy is looking off into space in one directions and our main guy is looking off in the other. They see two different features of space. Now for the examples sake let’s say these two features are so far apart that the light from the galaxy on the right hasn’t reached the nebula on the left with the current age of the universe and vise versa. As you know from everyday experience for two things, like a very cold ice cube and a warm cup of cider, to have similar properties, like their temperature, they need to be in contact. It’s the same with these stellar objects. In order for one to have the same properties as the other they need to be in contact. Something, like light, needs to be exchanged between them in order for them to share the same properties. But here the light hasn’t had time travel that far and they still share those properties. We know that for sure because we are in between them and light has had time to make it to us. It’s like this across the universe. There are properties that the whole universe shares even thought the whole universe hasn’t had time to be “in contact” yet. At least that’s the way I understand it. But what I don’t understand is why this is a problem. Why couldn’t the universe have just been programmed with those parameters? Why does one thing have to be in contact with something else to have the same properties? For me this is the most mysterious cosmological problem and one I would like to study more in depth at some later date.

the underlying assumptions

Just a thought: does anyone else listen to Christmas music at this time of year. Perhaps I just miss the snow. I’ve been living in the United States for some time now and there aren’t any mountains in my region to go ski on and needless to say no snow right now. Bother. Anyway about the big bang, I figure we can start with the assumptions that are behind the theory. To quote Wikipedia, “The Big Bang theory depends on two major assumptions: the universality of physical laws, and the Cosmological Principle.” So let’s break this up. Basically, we assume that the universe holds to the laws of physics everywhere and that they don’t change anywhere or at any time. If this were not true then, for example, in the Andromeda galaxy, our closest galactic neighbor, Einstein’s theory of relativity wouldn’t work or Newton’s first law, F=ma, wouldn’t hold. As for the second on, the Cosmological principle states that universe as a whole is isotropic and homogonous. Homogonous means that stuff is uniformly spread throughout the universe. Obviously on our scale matter/energy isn’t uniformly distributed. But one a really really REALLY grand scale things are. The picture I’ve included shows a model of the grandest scale of the universe. It’s pretty homogonous, but I don’t know it doesn’t seem quite as homogonous as I would like it to be…you know to sleep well at night. Isotropic means basically the same thing. It just means that if you look one way you see the same thing as when you look another way. Which is fairly true as far as observations go. So it seems like a logical and sound assumption. But we know what assuming does.

The Big Bang

From there the rest is sort of history, at least rather more famous history. In 1964 the cosmic microwave background radiation was discovered by Arno Penzias and Robert Woodrow Wilson in a very old radio antae/horn thing. If you would like more details on that there is a very excellent documentary that I can’t recall the name of at the moment. Most likely it will come to me in the middle of the night in a flash of epiphany and I won’t be able to remember it when I wake up. But in the mean time I think I shall skip to the present, and give you my version of the big bang theory as I understand it. I may pick back up the more historical background later. But here is where I really want some correction. I probably don’t have a very accurate picture of the big bang. But here’s what I’ve got: So 15 or so billion years ago the universe had just exploded into existence. We don’t know what happened before the explosion or what caused it or what happened just after the explosion. But something exploded to create space, time and energy. This energy was very dense and…well, energetic. And as the energy spread out, it got less dense and…less energetic? I think. But anyway, it cooled off enough to form photons which were released, and this is what we see as the cosmic microwave background radiation. Then things cooled off more and began to clump into matter. This formed the particles we have today…aaaannnnndddd it went from there into the universe we see today. I think I will stop for here today. Perhaps I shall flesh out the details one by one at some later point.

Background 10

Let me make a correction. Hubble was not the first one to propose that the universe was expanding; he was the first one to see it. It was a few years until someone suggested the universe was actually expanding. The person who suggested that went on to suggest the big bang theory or as he described it, "the Cosmic Egg exploding at the moment of the creation." The most interesting part is who this person was. His name was Georges Lemaitre, a Belgium, and (get this) a Catholic priest! He was a priest. The man who first suggested the big bang theory was a priest! Is that not the most ironic thing you have ever heard? A priest. I’m still in a bit of shock over this. I mean, I’m sure he wasn’t aware or the time scale/heresy this involved. Was he? I haven’t been to any catholic establishment in quite some time (I’ve been thrown out of mass way too many times to risk it often), so I’m not quite up on doctrine, but I’m fairly sure they are not much for the whole “billions and billions of years” thing. How did this happen? Does anyone know? Cause I’m not seeing it.

Background 9

So anyway, back to Hubble. Yes so he discovered this wonderful new way to measure the distance of stars and things so what does he do? Of course, he applied it to the stars that he didn’t know the distance to. In particular he applied it to the Messier objects. You know what he found? He looked at their red shift and saw those blobs were moving away from us really fast, and, according to his new found discovery, this meant they were really really far away from us, much farther than any of the other stars. And they weren’t stars! So after we could see them in better detail and found that most of these objects where made up of hundreds and hundreds of stars. They were whole other neighborhoods of the universe, whole other Milky Ways. So we had found other galaxies. It was phenomenal; suddenly the universe was a much bigger place. Here is a picture of what we can see now. In the picture it looks like we are at the center of the universe, but that is not really true (as far as we know). It’s just that our visibility is limited, and we can only see so far away in any direction, that’s why it looks like a circle. There are different galaxies all over the place, ours is only one of many.

Aside

I asked a friend if there was any way I could see if people were visiting my blog. And they installed this nifty little counter thing, the one with the map of the world over there on the right. Yeah that one. It’s pretty cool. It lets me see where the people that visit the site are from. So I have some questions for you. First, who are you? The counter doesn’t tell me who you are or anything like that, but I am curious about those who would read this. Second, what do you think about God? I’ve spent a rather long time (far too long considering the average human’s life span) and I do believe I’ve come to some rather unorthodox conclusions about God and his relation to humans. But I would very much like to know what you think, in this new strange global community where I’m not sure if there is orthodoxy. Third, what do you think about physics? Do you think it is worthwhile? Have you studied it to any extent? Does the stuff I’m talking about here make sense? Or am I just some crazy old man teaching the birds? I just thought I’d ask. I am by nature a rather curious individual and I’m still not sure how this whole internet communication thing works.