April 26th, 2013
The Borde-Vilenkin-Guth Theorem states that any universe, which has, on average, a rate of expansion greater 0 that system had to have a finite beginning. This would apply in any multiverse scenario as well. There are four exceptions to the theorem.*
1. First Exception: Initial Contraction (Havg<0) … (The average rate of the Hubble expansion is less than zero)
- Main Problem: Another problem this raises is that this requires acausal fine-tuning. Any attempt to explain the fine-tuning apart from a fine-tuner is left bereft of any explanation.
2. Second Exception: Asymptotically static (Havg=O)
- Main Problem: The exception is that it does not allow for an expanding or evolutionary universe. This model cannot be true. The best evidence and empirical observations indicate that the universe is not static; rather, it is expanding and evolving. This might have been a great model under Newton but not since Einstein’s field equation concerning the energy-momentum of the universe.
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March 22nd, 2013
I’ve been waiting for new Planck data to come in for a while now and I’ve been very excited about this. First we had COBE (Cosmic Background Explorer) that gave us the first images of the cosmic microwave background radiation approximately 380,000 years after the big bang when light became visible. This discovery led George Smoot and John Mather to receive the Nobel Prize in Physics (2006).
Then we had the Wilkinson Microwave Anisotropy Prove (WMAP) satellite, which provided a much clearer and more defined resolution revealing a much more precise picture of the early universe.
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February 14th, 2013
The bulk of my graduate research is focused on the work and thought of Max Tegmark, an MIT astrophysicist/cosmologist, who’s responsible for a tremendous contribution to multiverse models. In honor of Charles Darwin’s 204th birthday he did an article for the Huffington Post, “Celebrating Darwin: Religion and Science are Closer Than You Think.” There are some very interesting survey results regarding faith and conflict between evolution and big bang cosmology.
So is there a conflict between science and religion? The religious organizations representing most Americans clearly don’t think so. Interestingly, the science organizations representing most American scientists don’t think so either: For example, the American Association for the Advancement of Science states that science and religion “live together quite comfortably, including in the minds of many scientists.” This shows that the main divide in the U.S. origins debate isn’t between science and religion, but between a small fundamentalist minority and mainstream religious communities who embrace science.
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January 14th, 2013
The properties of our universe appear to be finely-tuned for the existence of life. Cosmologists would like to explain the numbers and values that describe these properties we observe. Their attempt is to show that these constants and values in nature are completely determined as a product of inflation, which entails multiverse scenarios. Inflationary cosmology seems to not only solve fine-tuning implications but it also solves the horizon problem. That is, the early universe’s expansion rate was exponentially fast—faster than the speed of light and if it expanded at such a rate information (light) could not propagate beyond the cosmic horizon. Due to these problems much theoretical focus and work has been implemented in to the field of cosmology and physics developing an inflationary cosmology and string theory.
The eternally inflating multiverse is often used to provide a consistent framework to understand coincidences and fine-tuning in the universe we inhabit. This theory primarily appears in several forms, which attempt to explain the mechanism that drives the rapid expansion of the universe. Before developing these models there are a few basic premises that must be agreed upon: the size of the universe, the Hubble expansion, homogeny and isotropy, and the flatness problem.
It is unanimously agreed upon that the Hubble volume we inhabit is incredibly large. According to standard Friedmann-Lemaître-Robertson-Walker (FRW) cosmology, without inflation, one simply postulates 1090 elementary particles.
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July 12th, 2012
We know the universe began 13.7 billion years ago in an immensely hot dense state much smaller than a single atom. It began to expand about a million billion billion billion billionth of a second after the big bang. Gravity separated away from the other forces. The universe then underwent an exponential expansion called inflation. In about the first billionth of a second or so, the Higgs field kicked in, and the quarks, the gluons, the electrons that make us up got mass. The universe continued to expand and cool. After about a few minutes there was hydrogen and helium in the universe. That’s all. The universe was about 75% hydrogen, 25% helium. It still is today. It continued to expand about 300 million years. Then light was big enough to travel through the universe. It was big enough to be transparent to light, and that’s what we see in the cosmic microwave background. After about 400 million years, the first stars formed and that hydrogen, that helium, then began to cook into heavier elements… Stars were cooked up, exploded, and then re-collapsed into another generation of stars and planets. And on some of those planets in that first generation of stars could fuse with hydrogen to form water, liquid water on the surface… The laws of physics, the right laws of physics, they’re beautifully balanced. They couldn’t have been different. If the weak force were different then carbon and oxygen wouldn’t be stable in the hearts of stars and there would be none of that in the universe. And I think that’s a wonderful and significant story. (Brian Cox, TED2008, March 2008)
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June 29th, 2012
If the big bang was so dense then how come it wasn’t a black hole?
Think of it as a black hole backwards. At the moment of the big bang there was, what we now know as, the cosmological constant–dark energy which drives the expansion or inflation of the universe. Without this force there would be no expansion. Understanding this question will help us understand how the universe will end. We have three options for a physical eschatological scenario to occur. 1) Gravity will overcome the expanding force and the universe will collapse back in on itself creating an intense heat death. 3) If the force keeps expanding forever then there will be a thermodynamic equilibrium and there will be a maximal stretching and a cold death. 3) Or, there will be a big rip in which the force expands so fast that it continually rips the whole universe apart.