Surprise! Double post today! Happy? Let me introduce you to some abstract uncommon representations for spacetime. You know we usually represent spacetime as “points” in certain manifold, and we usually associate points to vectors, or directed segments, as , in … Continue reading
Hi, doctorish ladies and gentlemen! I am going to teach some bits of black hole today. For the simplest static (non-rotatory) black hole, the whole space-time is fully specified by mass , and some constants, like . The critical … Continue reading
This post contains some exercises and challenges for you. In fact, crazy me, I used some of them for my classroom usage (just a fun way to survive is to design and propose maniac ultrageek problems to your students, … Continue reading
In this year, 2015, we celebrate the Light Of Year (LOY) and one century of general relativity (GR), a misnomer for something that should be called relativistic theory of gravity. Let me celebrate the centenary of general relativity with some … Continue reading
The year 2013 is coming to its end…And I have a final gift for you. An impossible post! This year was the Bohr model 100th anniversary. I have talked about this subject already, here, here and here. The hydrogen spectrum is very important in … Continue reading