LOG#231. Statistical tools.

Subject today: errors. And we will review formulae to handle them with experimental data. Errors can be generally speaking: 1st. Random. Due to imperfections of measurements or intrinsically random sources. 2st. Systematic. Due to the procedures used to measure or … 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#228. The scientific method.

What is the scientific method? There are many definitions out there, but I am providing mine, the one I explain to my students, in this short post. SCIENTIFIC METHOD (Definition, not unique) A (cyclic) method/procedure to gather/organize, check (verify or … Continue reading

LOG#227. Cosmic energy.

Short post number two! Surprise! Have you ever wondered what is the cosmic energy of the Universe? Well, giving up certain General Relativity issues related to the notion of energy in local sense, there is indeed a global notion of … Continue reading

LOG#223. Pi-logy.

Hi, there. Today some retarded Pi-day celebration equations (there is a longer version of this, that I wish I could publish next year). Some numbers and estimates for pi-related equations: 1st. Hawking radiation temperature (Schwarzschild’s 4d black hole case). (1) … 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#220. Higgs&Symmetries.

    Why the leaves are green? Why the sky is blue? Why diamonds are hard? The Quantum Mechanics can indeed answer those questions, and even more subtle questions. The Standard Model (SM) is the frontier in our knowledge of … 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

LOG#209. A cosmic link with a non-trivial zeta zero?

Some weeks ago, the Riemann zeta function and the Riemann hypothesis were again in the news. Sir Michael Atiyah proposed a (wrong) failed proof of the Riemann hypothesis. My blog has an history of being controversial from time to time. … Continue reading