Recent content by LydiaAC

Hello everyone, I want to have a simple example of an inductance calculation. The magnetic field normal to a filamentary circular current loop is not constant over the circle but if we approximate the value as that for the center, multiply by the area of the circle and divide by the current...

I would like to have P-V-T data for water in order to enter them in an Excel spreadsheet and design some exercises for the students to plot different kind of diagrams using the same data. I can generate the data using some suitable model, but I think that having real experimental data would be...

I think I was not able to write a good sentence in English in 2008. You have four vectors, "a", "b", "reciprocal a" and "reciprocal b". "Reciprocal a" is orthogonal to "b", "reciprocal b" is orthogonal to "a". The shadow that makes "reciprocal a" on "a" (or vice versa) must be 1. The...

Hello divB: I am interested in the derivation. LydiaAC

I had a friend who had set out to disprove Einstein's dilation of mass. He wanted to put a circuit on a scale, turn the circuit on, and check if the mass changed. He said that since electrons travel at light velocity, if the mass change were not there, Relativity would be proved false. I...

Interesting all the comments in this thread. I remember some people I know that have never published in international journals. The first time they tried, they received the referees comments and as they were not "oh, it is the more wonderful paper that I read in my life!", they started crying...

I majored in electrical engineering because I could not leave my city to major in physics. I later got degrees in materials physics because that was what I could study in my state of Baja California. My thesis was theoretical. I did not like to work as an "engineer" because in Mexico, you never...

This emphatic assertion made by me last year is WRONG The ratio between electrons injected from emitter to base and holes injected from base to emitter is called "injection efficiency". The fraction of electrons injected into the base which reach the colector without recombining is called...

Fluidistic is correct, I don´t know how to put accent marks with the keybord of my Laptop so I didn´t do. The word "ésta" does exist, and is exactly like fluidistic says: when "this" is an adjective you write "esta" and when it is a pronoun, you must add a special accent mark know as...

I use to call big cockroaches Periplaneta Americana and all my family know what I am talking about and even think it is funny. Of course, I am cautious of saying such a thing to people who is not in the joke. However, ten years ago, one of such bugs jumped on me and I shouted to my then new...

The correct form in Spanish is "¿Esta el gato de Schrödinger vivo o muerto? !El gato esta vivo y muerto! The general rule is "estar" for something temporary and "ser" for something permanent, but it is not a perfect rule. In the entire Spanish speaking world we say "estar vivo" and...

Engineering materials http://insting.mxl.uabc.mx/~lydia/Materiales_ingenieriles.pdf Properties of light http://insting.mxl.uabc.mx/~lydia/La_luz.pdf Theories about light http://insting.mxl.uabc.mx/~lydia/Historia_luz.pdf History of Chemistry...

Hello Cthugha: Do you think you can give a "for dummies" explanation of excitons? I do not know anything about them but their definition. It would be nice to know a little more. Lydia Alvarez

Hello Zanghe: My mistake. I am sorry for this. I thought that Phrak was your signature and this was in conflict with my knowledge that your nickname was Zhanghe. Now I can see it, but it was a sort of "cognitive dissonance" or something. I am sorry again. I am also a non-native English...

Hello DaTario: The key is in the "barrier" caused by the electric field. This electric field pushes electrons from P side to N side and holes from N side to P side. So, electrons in the N side and holes in the P side (majority carriers) need to have more energy than this barrier in order to...