Our universe is not stable according to the currently measured values of the top quark and Higgs particle masses. There is a non-null probability that at any instant in the next billions of years the present “false vacuum” will change to a “true vacuum” by quantum tunneling, destroying all matter, energy and spacetime without any […]
Superconductors are a particularly strange kind of metal. What makes them different is their behavior at very low temperatures – extremely low, that is, close to absolute zero. Basic thermodynamics dictates that in this regime we should expect all motion to cease, the constituents of the material being frozen at fixed positions. And with no […]
Sad as it may be, every star must die. At some point during its life it stops burning nuclear elements to sustain itself via radiation pressure, and collapses. Its ultimate fate depends on its mass; most of them are not massive enough to produce a supernova by themselves, but they die in an equally spectacular […]
Let’s start with a thought experiment. We are looking up to a starry night sky. What if we turn off every star in our Galaxy? The heavens would become much darker, but some light sources would still be working. The Moon and planets? Great, let’s turn them off too. Yet another Solar System phenomenon would […]
A couple of weeks ago I had the chance of having a fulfilling chat with Riccardo Cerulli, one of DAMA main researchers. They are at the very center of a skepticism tornado about their results on Dark Matter direct detection, and I asked as many questions as he let me to try to solve this […]
Black holes are not only gravitationally attractive: they also capture people’s attention. Just mention these two words in a course of elementary astronomy or in a public conference and you will find most eyes wide open. Even though they are common in observational astronomy, their singular physics and their fantastic dimensions makes them earn a […]
Supernovae are one of the most fascinating events in stellar astrophysics. Most stars suffer explosions at some point of their last days but the most massive ones explode releasing incredible amounts of energy and rivaling in brightness with the rest of the galaxy they live in. What they leave behind is hydrogen enriched with materials […]
Last month, a lot of newspapers and websites have been promoting this article on Nature referring to a recent preprint uploaded by Stephen W. Hawking to the internet repository ArXiv. In this work, summarizing what he talked about in a conference given last August, the English physicist argue that, since event horizons, the definitory property […]
Time scales for astrophysical phenomena are sometimes thought to be overwhelmingly large and to exceed by far human life. While this is true for many cases, there are others which take the blink of an eye. Halfway between them, some interesting facts seem to happen in historical time scales and therefore have been analyzed by […]
Much attention has been payed lately to the novice comet C/2012 S1, more widely known as comet ISON. At the crest of the wave, it was even said that the integrated brightness of the comet after the perihelion could exceed that of the full moon. It was nicknamed “the comet of the century” and everybody […]