Electrical energy is now the dominant form of energy consumption in industrialized countries and is an essential element in the operation of many of the devices we use every day. For decades, one of the most poorly understood yet most practical properties of a piece of solid matter was its ability, or lack of ability […]
Recently, a new experiment has attracted a lot of attention. It was published in Nature and entitled as “Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres ” . Many scientific and non-scientific media took account of the results of the experiment and published short news with fancy titles as Quantum ‘spookiness’ passes […]
One of the first recognized successes of the early quantum theory arose, not from the study of radiation, but from the theory of solids. Once again in the physics of the first half of the 20th century Albert Einstein was at the forefront; but this time the story is seldom told. After presenting the hypothesis […]
We finished our last article saying that it is one thing to accept this newly stated connection between electric and magnetic fields; but it is a little bit harder, and more interesting, to understand the physical necessity for such a connection. We will try to explain this necessity now avoiding the use of mathematics, step […]
We recently explored the concepts that Faraday introduced regarding the relationship between electricity and magnetism. In this article we focus on their treatment by Maxwell. The work of Oersted, Ampere, Henry, and finally Faraday had established two basic principles of electromagnetism: 1. An electric current in a conductor produces magnetic lines of force that circle […]
Newton suggested that the apparent colours of natural objects depend on which colour is most strongly reflected or scattered to the viewer by the object. In general, there is no simple way of predicting from the surface structure, chemical composition, etc., what colours a substance will reflect or scatter. However, the blue colour of the […]
We now refer to light as the form electromagnetic radiation to which the human eye is sensitive and on which our visual awareness of the universe and its contents relies. If we want to go a step forward we could say that its macroscopic behaviour is best explained by a set of differential equations proposed […]
We know that incident light can provoke a strong optical response in metallic nanostructures due to the excitation of resonant plasmonic modes, i.e, the electrons in the metal become excited by the photons in the incident light and oscillate collectively. One of the most interesting properties of plasmon resonances is their associated enhancement and confinement […]
In the previous articles (I, II), we have characterized the simplest class of supersymmetric heterotic compactification backgrounds. In particular, we have finished the second article with the following result: There is a class of admissible Heterotic internal manifolds characterized as being six-dimensional, oriented, spin, Riemannian compact manifolds admitting a parallel spinor respect to the Levi-Civita […]
With “many-body problem” we usually make reference to one that is very difficult to obtain exact solutions for, because the system involves interactions between more than two bodies. This kind of problem appears both in classical and quantum systems. In order to understand the physics of many-body systems, it is necessary to make use of […]