LOG#199. M-sigma.

Black holes are coming! No, winter is coming! NOOOO! Winter is here, and black holes, as shown by LIGO, are not coming. They are already here, as they were already supposed to exist due to X-ray astronomy. Moreover, LIGO-VIRGO, LISA, … Continue reading

LOG#193. Bits on black holes (II).

The second and last blog post in this thread is about the analogies between black holes and condensed matter theory, in particular with phases of matter like fluids or superconductors. That is what explains my previous picture…And this post! Are … Continue reading

LOG#192. Bits on black holes (I).

  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

LOG#191. The hooke and the dyson.

Hello, metriplectic followers and friends! I have often written about Stoney units or Planck units in this blog. Indeed, I have a complete thread about systems of units. For Stoney and Planck units, you get some basic units of S.I. … Continue reading

LOG#183. Bohrlogy: some pocket formulae.

This post continues the Bohrlogy thread I did some time ago. It aims to parallel electric Bohr (atom), the gravitational Bohr atom and the black hole atom (as new!). Note that , and , . First of all, the common … Continue reading

LOG#174. Basic black hole physics.

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

LOG#155. Maximal tension, Λ and quantum gravity.

Hi, folks! Before the upcoming series of thematic blog posts (they are on their way, eager readers), I found a very interesting paper to discuss. The paper is this http://arxiv.org/abs/1408.1820 and the pdf file can be found here http://arxiv.org/pdf/1408.1820v1.pdf . The author of the … Continue reading

LOG#154. Moonshine and 42: THE PAPER.

“(…) The answer to the Great Question…is…Forty-two(…)” said Deep Thought with infinity majesty and calm (frequently found quote from The Hitchhiker’s Guide to the Galaxy, Douglas Adams, London 1979) Dear readers, yesterday, while I was editing, re-editing and writing my … Continue reading

LOG#150. Bohr and Doctor Who: A=mc³.

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 Astronomy, … Continue reading