Since I expect the concept of gravitational waves to once become very popular in the next few days, I wrote some quick notes on them, I.e., where they come from. They are handwritten, as I didn’t have time to LaTeX them, but, hopefully, they’ll be useful to interested readers! Also note that, gravitational waves are […]
Tag: cosmology
One of my earliest works was deriving equations which themselves were forms of Einstein’s field equations that described the state of the early universe, which may have had dominant viscous effects. I was delighted to learn that these equations were published in Springer’s Handbook of Spacetime Cosmology textbook. Here is a snapshot of the textbook […]
Our new paper was accepted for publication in Physical Review D. The goal of the paper was to calculate the probability that a multiverse could emerge from a more general background spacetime, in this case, Bianchi Type I coupled to a chaotic inflaton potential. Basically, we found that a multiverse being generated from such a […]
In many physics and chemistry courses, one is typically taught that heat propagates according to the heat equation, which is a parabolic partial differential equation: , where is the thermal diffusivity and is material dependent. Note also, we are considering the one-dimensional case for simplicity. Now, let be a solution to this problem, which represents […]
The purpose of this post is to demonstrate some very beautiful (I think!) mathematics that arises form Darwinian evolutionary theory. It is a real shame that most courses and discussions dealing with evolution never introduce any type of mathematical formalism which is very strange, since at the most fundamental levels, evolution must also be governed by […]
Nowadays, one cannot watch a popular science tv show, read a popular science book, take an astrophysics class without hearing about black holes. The problem is that very few people discuss this topic appropriately. This is further evidenced that these same people also claim that the universe’s expansion is governed by the Friedmann equation as […]
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Some of Lemaitre’s Contributions
Many have no doubt heard of Lemaitre’s important contributions to cosmology theory. In this brief post, I provide links to Lemaitre’s original papers: 1. Lemaitre proposing that the universe is expanding: Full paper available here for free 2. Lemaitre proposing that the universe had a beginning, the original Big Bang model: Full paper requires subscription […]
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Cosmology Lectures on the Web
Here are some links to some excellent cosmology lectures on YouTube. The videos actually teach you cosmology, as you would see it in a university/college setting. They do require some knowledge of General Relativity, but one in principle, can get away by knowing what a metric tensor is, Christoffel symbols are, and the various Riemann […]
Many people have obviously been reading Lawrence Krauss’ infamous book: “A Universe from Nothing: Why There is something Rather Than Nothing” Krauss and many other physicists continuously engage in this type of low-level philosophy with the ironic goal of diminishing the value of philosophy using “science”. This paper dissects all the arguments in Krauss’ book […]
I greatly debated with myself on whether to write this posting. I have seen Interstellar twice now including the special 70 mm IMAX screening, and am seeing it a third time later today. Simply put, the movie is fascinating. It combines, (yes) accurate science and real depictions of general relativistic effects with a great story […]
Relativity Digest 