The silence of black

The discovery exploits a new hair analysis method that could help, in addition to police, even doctors, archaeologists and anthropologists in their research. In fact, one was created sort of "water mapping" that allows you to combine geographical areas with isotope values detected in the hair. Police forces are using this method to obtain the origin of some unidentified murder victims. Isotopes are forms of the same chemical element with different atomic weights, because they present a different number of neutrons in the nucleus (the stable isotopes are those that do not have radioactive decay). Three years ago two expected they founded IsoForensics, a company that uses stable isotope analysis to detect them Small variations of a chemical element. The team managed to map the concentrations of the stable isotopes of hydrogen and oxygen in the hair, discovering that they are a trace of those present in food and drinking water, but also in breathed...

Every atom in your body comes from a star that exploded. And the atoms in your left hand probably come from a different star than the one in your right hand. That's the most poetic thing I know about physics: you are stardust. (Lawrence Maxwell Krauss) The atom is the structure in which matter is organized in the physical world and on whose basis it is divided into fundamental elements. Multiple atoms form the molecules. While atoms are in turn formed by subatomic constituents such as protons (with positive charge), neutrons (without charge) and electrons (with negative charge). It was so called because it was initially considered the smallest and most indivisible unit of matter. Towards the end of the nineteenth century, with the discovery of the electron it was shown that the atom was actually divisible. In fact, it is in turn composed of smaller particles, to which we refer with the term of subatomic particles.Leucus (5th century BC) founded a theory according to...

Thermology studies the thermal exchanges between bodies and understands the transformations and transfers of energy between one system and another. • Temperature: temperature is an index of the degree of thermal agitation of the atoms or molecules that make up a body; it is therefore connected to the concept of kinetic energy. • Heat: heat is a way of transferring energy. There is therefore a substantial difference between the concept of heat and that of temperature. There are various methods of measuring how hot or cold a body is: • Thermal expansion: to measure how hot or cold a body is, it is necessary to resort to a phenomenon that always repeats itself in the same way, that is, thermal expansion; when heated, all bodies dilate, that is, increase their volume. • Thermoscope: instrument that exploits the phenomenon of thermal expansion and that allows you to check the temperature variations. • Thermometer: instrument that allows you to quantitatively measure the thermal st...

Hi, welcome back to the blog of " The silence of black ". Today we will deal with a topic that represents a pillar in the field of physics: " geometric optics ". Sometimes we associate and connect basic optics and geometric optics to each other, but in reality these electromagnetism branches have a concept that is anything but similar. Optics studies light radiation and associated phenomena, while geometric optics deals with those phenomena that can be described without the use of the wave concept. The latter began to spread in the early 1600s and for centuries we will see two different models of light contrast: the corpuscular model developed by Newton according to which light is a flow of microscopic particles and the wave model developed by Christiaan Huygens which in fact, from how we can deduce it from the model name, it defines light as a wave. With geometric optics we can explain: - the WAVES - the REFLECTION of light - the REFRACTION of light -...