LOG#246. GR attacks, GR effects!

Newtonian gravity is not coherent with special relativity. Einstein was well aware about it and he had to invent General Relativity (GR). Armed with the equivalence principle, a mystery since ancient times of Galileo, the equivalence between inertial and gravitational … Continue reading

LOG#245. What is fundamental?

  Some fundamental mottos: Fundamental spacetime: no more? Fundamental spacetime falls: no more? Fundamentalness vs emergence(ness) is an old fight in Physics. Another typical mantra is not Shamballa but the old endless debate between what theory is fundamental (or basic) … Continue reading

LOG#244. Cartan calculus.

I am going to review the powerful Cartan calculus of differential forms applied to differential geometry. In particular, I will derive the structure equations and the Bianchi identities. Yes! Firstly, in a 2-dim manifold, we and introduce the Cartan 1-forms … Continue reading

LOG#243. Elliptic trigonometry.

Jacobi elliptic functions allow to solve many physical problems. Today I will review briefly some features. Let me first highlight that the simple pendulum, Euler asymmetric top, the heavy top, the Duffing oscillator, the Seiffert spiral motion, and the Ginzburg-Landau … Continue reading

LOG#242. Hyperbolic magic.

Beta-gamma fusion! Live dimension! Do you like magic? Mathemagic and hyperbolic magic today. Master of magic creates an “illusion”. In special relativity, you can simplify calculations using hyperbolic trigonometry!   (1)   (2)   are common relativistc equation. Introduce now: … Continue reading

LOG#241. Flatland & Fracland.

Flatland is a known popular story and book. I am going to review the Bohr model in Flatland and, then, I am going to strange fractional (or fractal) dimensions, i.e., we are going to travel to Fracland via Bohrlogy today … Continue reading

LOG#240. (Super)Dimensions.

  Hi, everyone! Sorry for the delay! I have returned. Even in this weird pandemic world…I have to survive. Before the blog post today, some news: Changes are coming in this blog. Whenever I post the special 250th post, the … Continue reading