Physics

In this blog I will derive the Einstein field equations starting from the Hilbert action.  Since there are only two terms in the Hilbert action, one of which is left alone, there is not that much to do.  Well, there is always way more to do - how well is this step really understood?  Where does that factor come from?  What kinds of variations could one do?  The core of this blog is an extensive translation of the wikipedia page on the Einstein-Hilbert action written in my own personal style, doing minor variations so the steps made more sense to me.  Go there if my style confuses you for a step or two.
I like to explain stuff so that people like you and me think “aha!”, and not, “this guy knows a lot; I better agree though I have no clue what he is talking about”. In this manner, let me again briefly introduce one of those deeply complex and hugely controversial topics that supposedly require big sophisticated words, and then, like I hope you slowly come to expect from me, present the solution in a way that is obvious and that we all could have thought about a long time ago (if the conclusions were not so damn uncomfortable that people simply refuse even if it is presented on a silver platter).

 

Well, not really a "true" queen sacrifice, but it is still a nice little combination the one I played against a strong 1st category player today at the "Baracchi Memorial" in Venice, a one-day rapid chess tournament which is held every May in Venice in memory of a young and promising member of our chess club, who died in a car accident.

The position after black's 15th move (15. ...Be6) is the one shown below. I am white.

T.Dorigo - L.Pasqualetto, Memorial Baracchi 20/5/2012


Riding into a black hole is a fun mental exercise, so popular, there is a game about riding a train in a black hole and even a song by Bare Knuckles – the scientific rigor of these may be questioned.

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.
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.
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.
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.
CONTENTS
PART 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 Problem
PART D: The Derivation. Solving the Word Problem
PART E: Conclusion: Einstein's Style or How to not be a Crack Pot