Beginning in 1928, Felix Bloch, an assistant to Werner Heisenberg in Leipzig, began to make some realistic assumptions in an attempt to formulate a more complete quantum mechanics of electrical conductivity. First, because he wanted to assign a definite momentum and energy to each of the electrons, but not a definite position or a time […]
Biology • Health • Physiology
If you have ever tried to lose weight by exercising you probably know is not that easy. However, you might be happy to know that the problem is not only a matter of motivation. It’s been consistently reported that the effect of exercise on weight is surprisingly smaller than what theory would predict. The reasons […]
During World War II the Germans relied on their strong chemical knowledge to overcome the limited access to critical raw materials that the circumstances of the war itself imposed. One of these raw materials was Chilean saltpeter (sodium nitrate), which was the base for explosives. The solution was to use a chemical process designed to […]
Deep in the ice below the Amundsen-Scott South Pole Station, in Antartica, lies one of the great works that our modern civilization has produced. A kilometer and a half under the frozen surface there is a very special place for science and discovery. Darkness surrounds it but it’s able to see the entire cosmos. The […]
Sleep is a naturally recurring state of mind and body characterized by altered consciousness, relatively repressed sensory inputs, inhibition of nearly all voluntary muscles, and reduced interactions with surroundings. We spend around one third of our lives sleeping although why we sleep is still theme of debate. Sleep seems to assist animals with improvements in […]
Common glass, used in windows or bottles, for example, is made by heating a mixture of calcium oxide (lime), sodium carbonate (soda), and silicon (IV) oxide (sand), resulting in a calcium silicate. This silicate is not a crystal but a solid in which atoms are random and have no long-range orderd pattern. These kind of […]
When we approximate two superconducting materials at low temperature, so that they are only separated by a very thin layer (less than 10 nanometres thick) of an insulating material, some new and very interesting electrical effects can be observed. If normal conducting metals are separated by such a barrier in that conditions it is possible […]
Amputees are people that have had a limb removed by trauma, medical illness, or surgery. In this latter case, it is used to control pain or a disease process in the affected limb, such as malignancy or gangrene. Nevertheless, most new amputations occur due to complications of the vascular system, especially from diabetes. It is […]
The direct search for dark matter has been a thriving experimental field since a couple of decades, and a new and promising experimental approach has been recently developed and tested: the use of an atomic clock inner mechanics. This whole new idea seems to be relatively cheap since no huge technological development is needed, and […]
Gold is the quintessential noble metal. Its lack of chemical reactivity, particularly to acids and atmospheric corrosion, together with is rarity and malleability make it the precious metal it is since ancient times. Today, if we go for a description of gold in a chemistry textbook, we find something similar to this: A soft yellow […]