LOG#237. GW music.

The spectrum of gravitational waves!!!!! Purely gravitational wave music! The blog post today will cover two topics from elementary viewpoints: falling into a non-rotating black hole and gravitational wave “music”, i.e., gravitational wave formulae! It is a hard equilibrium just … Continue reading

LOG#235. Hyperballs.

Hi, everyone. The saddest thing about job (working with teenagers and other people) is that it delays other stuff, like blogging! So, you should be patient about getting more of “my stuff”. What is going on today? Hyperballs. Or hyperspheres … Continue reading

LOG#230. Spacetime as Matrix.

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

LOG#221. Kepler+Cosmic speeds.

Hi, there! Today some Kepler third law stuff plus cosmic speed calculations and formulae. Cosmic speed sounds cool…But first… From High School, you surely calculated how fast is  A PLANET moving around the sun (or any star, indeed). To simplify … Continue reading

LOG#217. The 2 pillars.

Time of Cosmic Voyages https://www.youtube.com/watch?v=xEdpSgz8KU4 This is a long post, despite not being a special post (remember I make one of those every 50 posts). What are we going to see here? A five part post! Part(I). A descriptive prelude. … Continue reading

LOG#215. Entanglement is the key?

Hi everyone! Is entanglement the key? A tribute to Ant-Man and Hawking today as the preamble, Quantum Chess playing for heroes like you: Entanglement is the subject we have today. Entanglement is that spooky weird feature of the quantum realm … Continue reading

LOG#214. Supertranslations.

Surprise! Twice in a day! Yes, I have much to tell yet, alive…Beyond the holographic principle, and things like gravity is Yang-Mills squared or that open strings squared are closed strings, we have had other important development in the theory … Continue reading

LOG#213. No boundary.

Hello, again! Yes, three consecutive days posting. A change! I missed blogging these months of nightmares. I hope these posts terminate your wait. The wait is over. And I can not wait too. Tempus fugit. Today, we will be discussing … Continue reading

LOG#212. Understanding gravity(II).

Hi, there! In the previous blog post and log, we introduced the high energy stringy part of the 4-point (particle!) tree approximation amplitude for the graviton scattering in type (II) superstrings (1)   This “simple” formula gives no negative probability … Continue reading

LOG#211. Understanding gravity (I).

Hi, everywhere! Have you missed me? A little short thread begins. This thread is based on some Nima’s talk on the understanding on gravity. Do we understand gravity? Classically, yes. Quantumly, it is not so easy. String theory is the … Continue reading