These are discussion questions for a discussion board l. This is initial post it must be 250 words… thanks for taking on this assignment in advance! Also below is two post of the other students that is in need of a response… please list all references that you may use …below I also have where u can write the initial post and the responses to the 2 students!
Discussion 1 – Astronomy
As successful as Big Bang inflationary cosmology is today, it is not necessarily the “only game in town” any longer. Nor is the Big Bang theory without its own complications and controversies. As mentioned in the class notes, it was the somewhat radical and, some would say, unsupported addition of “inflation” that saved the Big Bang theory. In this activity you will do some research into alternate scientific cosmologies or into some of the problems with inflation.
Before participating in the discussion:
- Read 29.6
- View the video Inflationary Cosmology On Trial [Video file][1 hr 23 min 57 sec]
- (View the first 37 minutes at least)
The video describes one of the current, “respectable” alternate scientific cosmologies being studied today. it is also a great summary of some of the problems with (inflationary) Big Bang theory.
Now let’s begin the discussion:
Search the Internet for information on one of these two topics: 1) Inflation or 2) alternate scientific cosmological theories. You may search for articles, blogs, or websites. It is not always easy to do, but be careful and try to discriminate between more mainstream websites and the many other, less informed, ones that exist discussing such BIG questions.
If you choose to investigate alternative, scientific cosmologies, please remember to restrict yourself to scientific theories. Your posting must answer the following questions:
- What is the name of the theory?
- Who is the author(s)?
- What are the main aspects of the theory?
- How does it differ from the conventional Big Bang theory as discussed in your readings in the textbook?
- Is any evidence given to support the theories
First response to:
The name of the theory I am exploring is the theory of inflation. A major player in the driving force behind this theory is a MIT professor of physics, cosmologist Alan Guth. Professor Guth’s research has centered on the application of theoretical particle physics to the early universe. The main aspects of the theory of inflation is it is essentially the prequel, or “bang” of the “big bang.” Inflation explains the expansion by means of gravitational repulsion. Since the advent of general relativity, it is known that gravity can act repulsively. Repulsive meaning the opposite of classic attractive gravitational force. The inflation theory describes the universe as, “unbelievably uniform on a large scale,” which cannot be understood via the conventional big bang theory. Inflation can be described very naturally. You start with a very small universe which becomes uniform- before inflation, and then inflation simply takes over and magnifies the small universe into a very large one, thus becoming everything we observe about our universe today. There is no real evidence that exists that leads to what caused the “big bang,” only what happened after the “big bang,” or the aftermath so to speak. Evidence for inflation comes from the science of particle physics, which tell at very high energy, there exist forms of matter that turn gravity to behave repulsively, leading the way for the universe on a massive path of exponential expansion
In the article, POP goes the universe, the authors argue that the theory of inflation is too flexible. They say it is flexible to the point that any outcome is possible, therefore it can’t be used to predict fundamental properties of our universe such as the warp of space and time, the amount and forms of energy, or the dispersal of matter. Their question is, if it doesn’t actually explain how the universe got started, then why are researchers still pursuing the theory.
Their alternative theory is that the universe “bounces” from contraction to expansion. The original idea of inflation is that the initial expansion would smooth out the transition from a state of matter dominated by quantum properties to matter and energy that dominates the universe today. The problem is, with current models of inflation, it would already take a flat space with smooth distribution of energy for inflationary energy to grow and dominate other forms of energy. If the conditions for inflation were already present, then the theory of inflation is not needed to create the smooth universe we see.
The bounce theory however, does not need to use inflationary energy to smooth out space time, as a span of contraction that lasts billions of years would smooth and flatten the universe. Scientists can construct models in which the rate of contraction gives rise to temperature variations after the bounce that are consistent with the pattern of hot and cold spots observed today. Recent work has produced the first detailed proposals for describing how the universe could have transitioned from contraction to expansion, enabling the construction of complete bouncing cosmologies.