Physics

Riding into a black hole is a fun mental exercise.  General relativity predicts* that an observer who falls freely into a large black hole will have no means with which she can establish whether she is at the event horizon, which is the radius below which there is no escape possible.  I explained this more detailed in Black Hole Duality: Not noticing crashing with light speed.  Nevertheless, many popular descriptions leave the feeling as if the event horizon is also locally, to the one who falls freely through it and his close surroundings that fall with her, a recognizable…

This blog required programming.  The basic idea is to have four degrees of freedom for the four parameters living inside a four dimensional quaternion.  Four for loops did the trick. The BIG problem with adding more parameters to an animation is the number of events grows exponentially.  My forte with one parameter animations often uses a thousand quaternion events.  A million quaternions would be needed for two parameters, yikes.  My computer often gags on that many quaternions (other people have a much lower tolerance, an integer less than one).  Go up to a 4-…

In this sorry age for Supersymmetry (SUSY) phenomenologists, it is quite easy to step on an aching toe while discussing the results of the Large Hadron Collider experiments, whose results have let these physicists down by excluding the presence of SUSY where most of them used to put their moneys until yesterday. The knee-jerk reaction I frequently observe (e.g. see the thread of my recent post on the cMSSM) in the most stubborn SUSY enthusiasts is to seek refuge in a concept which could be summarized as follows: "There is only one true realization of SUSY in Nature, and one point of the…

In the previous blog post we discussed entropy. I provided you with a less well-known perspective on entropy and demonstrated that this generic perspective is fully compatible with the more traditional (and more narrow) thermodynamics view on entropy. I promised you a toy model to elucidate the information-theoretical entropy that was introduced. You have been waiting patiently, and you get your new toy today. But before we start playing, let's test your patience for a few more minutes, and first expand upon the results obtained in the previous blog post. Trivializing The Second law…

A few hundred thousand billion free-floating, Earth-sized planets may exist in the space between stars in the Milky Way, argues an international team of scientists in Astrophysics and Space Science. Because it's required for astronomy claims this decade, they make note that those planets could have alien life. The scientists have proposed that these life-bearing planets originated in the early Universe within a few million years of the Big Bang, and that they make up most of the so-called 'missing mass' of galaxies. They calculate that such a planetary body would cross the inner solar system…

A little group theory a la QFT Demystified. David Tong's Procedure.  The Norm of the quaternion is --------------. The Norm of a biquaternion is --------------. Can I solve a problem is relativity with Biquaterions?

Derive SR from 1.Preservation of Causality and 2.The Constancy of the speed of light. with a focus on the spacetime interval. (like Brian Cox)

Since "spacetime" is simply a term for a space that has a component we call "time", we need only concentrate on spaces in a somewhat general sense.  Now, as Derek Potter, on this site, pointed out to me, a little while ago, "To us, a space is somewhere to put a box :)"  So, let's take a short "detour" to address what we will mean by a space, in this series. Spaces Manifolds and Tangent Spaces Einstein did something very different with his General Theory of Relativity.  Something that had not been done in science anytime before that.  He actually separated the space "…

I recently found a physics book I've enjoyed so much I'd like to share it with others interested in physics. Because physics is a hobby for me and something I've studied in the past, I enjoy books that cover a lot of ground with sufficient mathematical precision while being with concise. I don't need to relearn everything. I still know what a vector is.I've recently found the perfect book:  6 Theories of Modern Physics by  Charles Seiffe.  Other Concise Books Dirac. The General Theory of Relativity Einstein. The Meaning of Relativity If I only could keep a few books here are…

CONTENTSPART A: Introduction: does the inertia of a body depend upon its energy content?PART B: The Toolkit: mathematical and physical assumptions PART C: The Thought Experiment and the Word ProblemPART D: The Derivation. Solving the Word ProblemPART E: Conclusion: Einstein's Style or How to not be a Crack Pot PART A:  Does the inertia of a body depend upon its energy content? Students of physics know the answer to the question Einstein asked in the title of his celebrated paper, "Does the inertia of an object body depend upon its energy content?" because in it Einstein derived the…