what scientist believe happened to form the universe, and it is called the Big Bang Theory.

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1 Schjelderup 1 Ari Schjelderup David Schaffer PHYS /30/11 The Big Bang Theory When I was a little girl I asked my mom how long god had been around. She told me he had been around forever. When I didn t understand, she told me it was something you can only understand after you die. I asked her about if it was the same with the universe, and she told me she didn t know. So, did it just appear at some point? Did it form over a long time? But if it formed, there would have to have been something there in the first place, and that would have been the universe. And stuff can t just appear out of nowhere! I used to get into deep thought about it, it would go in circles, and I would have to stop thinking about it out of irritation. At this time I was still very young, around seven years old. I didn t look it up or anything, I just thought about it. So, what s the answer? Did it just appear out of nowhere? How long ago did it happen? And how in the world would we know? Let s say there was a nothing. No gases, atoms, no space, and not even time. Then, maybe instantaneously, a little dense thing smaller than an atom, filled with light, appeared. This was the very small universe. Space expanded during the first trillionth of a trillionth of a trillionth second the universe grew more than a trillionth of a trillionth of a trillionth time bigger. It is hard to believe, very hard to believe, that the stars and galaxies we see today began in a very condensed piece of energy that was very small. But this is all hypothetical right? No one could have proof about something that happened 13.7 billion years ago! or could they. What I just explained is what scientist believe happened to form the universe, and it is called the Big Bang Theory.

2 Schjelderup 2 Well, first, it s true that it can t be proven, almost everything in science isn t proven, that s why it s why thy are called theories. However, it is a level of evidence that can answer our question. The first piece of evidence is that the universe is expanding. Edwin Hubble, from whom the Hubble Telescope was named, used the redshift to find out that galaxies are flying apart due to the expansion of space itself. So, if galaxies are moving apart, they were probably once closer. The next piece of evidence was the realization that the Big Bang would make intense radiation. Twenty years after this idea came to be Arno Penzias and Robert Wilson detected a faint crackling with their radio receiver while they were scanning the sky. At first it was thought to be static, but it turned out to be a the radiation left over from the Big Bang. If it had cooled steadily since the Big Bang, the amount there, was right. The third piece of strong evidence has to do with helium. All the baryonic matter in the universe is 24% helium. The helium couldn t have come form the nuclear reactions inside stars because it hans t been going on long enough to have made this much. But it is the right amount that would have been made in the Big Bang. Lastly, if the universe were did change, if it was infinite, and everyplace the same, there would be stars all over the sky, and it would be light, even at night. Even dust would not change that because et dust would be heated so much over a long period of time that it would become just as hot as the stars. Either the universe has a limited amount of stars, or the universe changes. Yet, some don t believe that the Big Bang happened. Eric Lerner, for instance, believes that there are several things wrong evidence for the big bang. Lerner points out that if the Big Bang really did happen, there shouldn t be anything older than it. But there is a large-scale void

3 Schjelderup 3 that couldn t have been formed in the ti since the big bang happened because it must have taken at least 70 billion years to be formed, and the Big Bang was supposed to have happened 13.7 billion years ago. This means that either the Big Bang Theory is wrong, the prediction on how long ago it happened is wrong, or the prediction that the void had to form in 70 billion years, is wrong. For the Big Bang Theory to be true, there must be much more dark matter than plain matter. But white dwarfs and warm plasma clouds that discovered show that there is enough ordinary matter to report for gravitational effects observed, which means that there is no room for more dark matter. So maybe the Big Bang Theory has some flaws, or maybe it s even more complicated than it already seems (if that s possible).the idea began a couple of decades ago, and there is still research going on, and the Big Bang Theory will never be proved to be correct. Also, this is the most successful explanation for how the universe began, and it explains so many things. Einstein found out that the general law of relativity predicted that the universe could not be sitting still because if it were, everything would collapse due to gravity. At the time, Einstein thought the universe was static, so he came up with the cosmological constant. The cosmological constant acted like a balance, a counteraction with the force of gravity. The reason he did this was because he insisted that the universe stood still. If he hadn t been so sure of himself, maybe he would have come up with the right answer; that the universe is still expanding. After Hubble discovered this, Einstein called his idea the greatest blunder of his career.

4 Schjelderup 4 Resonantly however, after some stars appeared to be older than the universe was supposed to be. The way this could happen was if the universe is expanding faster than it did before, and the way this could happen is by the cosmological constant. If it [Einstein s equations of general relativity] is not zero, then it represents a repulsive force or a type of energy (sometimes called dark energy or quintessence that might cause the expansion of the universe to accelerate with time. In other words when the equations of general relativity is not zero, then it might represents a type of energy that might cause the expansion of the universe to accelerate with time. My satisfaction for knowing the answer to the universe has never faded from when I was a little girl, but when I first heard about the big bang I got a little more interested. I m still just human, and I can t comprehend something so amazing, but it is fun to hear about how the universe might have been created. It still doesn t make sense to me how many of these things occur, and where the smaller-than-atom universe came from (the one before the big bang happened), but there is still time. Being able to learn about a reasonable theory on how the universe was created is good enough for me right now. After all, the universe is a big place, and learning about how it might have been created, is amazing.

5 Schjelderup 5 Work Cited: Lerner, Eric. The big bang never happened. New York: Vintage Books, Maran, Stephen. Astronomy for dummies. Hoboken, NJ: Wiley, 2005 Weinberg, Steven. Einstein s Mistakes Physics Today (2005_: Academic Search Premier. Web. 17 Nov. 2011