Surprise! Second post today. It is a nice post, I believe. Usually, we see the world using photons in certain wavelengths. Our eyes can see only a very limited width of the electromagnetic spectrum. The quantum revolution taught us that … Continue reading

# Category Archives: Mathematics

Today or not today. That is the point. Today. How to know if a given particle or sytem is (special) relativistic? That is a tricky question, since the reality is…Everythin is (special) relativistic. The question would be when you can … Continue reading

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

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

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

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

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

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

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

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