As we have discussed in our previous post, there is an important debate in the scientific community regarding the existence of negative absolute temperatures. The debate is not over, and both sides have valuable arguments, but in any case, one thing has already been proved. If negative absolute temperatures are real, the requirement to achieve […]
Condensed matter • Materials • Physics • Quantum physics • Theoretical physics
At low temperatures, the resistivity of a metal (the inverse of its conductivity) is nearly constant. As the temperature of a material is lowered and as we approach absolute zero the resistivity should approach a constant value. Many metals, known as normal metals, behave in this way. The behaviour of another class of metals and […]
Sunlight is the most important energy source of Earth. All earthlings live thanks to the ability of plants and bacteria to transform solar energy into chemical one. As sunlight is a free, and practically unlimited, energy source it is easy to understand the general interest in finding efficient ways of transforming it into electrical power […]
Almost everyone with basic knowledge of physics have one clear concept, there is a minimum temperature and it is called ‘absolute zero’. This temperature corresponds to -273.15 degrees in the Celsius scale. In the Kelvin or absolute scale it is zero, by definition. Furthermore, there is another idea that is also widespread: absolute zero is […]
Of all the advances made in theoretical physics in the last twenty years, I still have no doubt that the most impressive one is the so called Maldacena’s conjecture, the guess that the physics involved in some models of quantum gravity living in a very concrete 5-dimensional spacetime has a one-to-one correspondence with the physics […]
The second law of thermodynamics is one of the oldest and most tested physical laws. Unfortunately, it prevents us from doing very useful things, like creating a perpetual motion machine of the second kind. This law is extremely important for both theoretical and practical purposes and, because of that, it has been broadly studied since […]
Both thermodynamics and quantum mechanics are very important theories, but they are applicable to very different kinds of systems. Thermodynamics describes macroscopic systems where the number of particles is huge (around Avogadro’s number: 6.022×1023). On the other hand, quantum mechanics describes the behavior of microscopic particles. The regimes where these two theories can be applied […]
A lot of ink has been wasted in the last decades discussing whether string theory is a good description of nature or merely a mathematica construct with no connection at all with reality. However, the answer to this question actually lays at least in the middle of both options and for sure not any close […]
Quantum mechanics and relativity constitute the two main revolutions in physics on the twentieth century. Furthermore, the counterintuitive character of quantum mechanics yields to a rich branch of different possible interpretations, and there are still many open questions. Not solving, but just defining these questions, was the main purpose of a conference entitled “Quantum physics […]
The gecko, a climber´s hero, a lizard able to get a grip even face down on the smoothest ceiling or on the most vertical slippery surfaces. That, the adherence is one of the most striking features in most of the species in the family Gekkonidae. In Spain they are also known as “lagartijas” or “salamanquesas” […]