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Wired keyboards emit electromagnetic waves, because they contain eletronic components. These eletromagnetic radiation could reveal sensitive information such as keystrokes
This quantity is defined in terms of the mean free path of a photon ln, or the average distance a photon travels along the beam between interactions with the matter.
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc.
site officiel : European Synchrotron Radiation Facility ou Installation Européenne de Rayonnement Synchrotron
Une expérience qui prouve que les téléphones dégagent de radiations puisqu'elles arrivent à te faire un oeuf dur en 65 minutes !!!
The Hadron collider will be smashing protons moving at 99.999999% of the speed of light into each other to recreate conditions existing a fraction of a second after the big bang. According to some theoretical models, tiny black holes could be produced in collisions at the LHC. They would then very quickly decay into what is known as Hawking radiation (the tinier the black hole, the faster it evaporates) which would be detected by experiments. But any physicist will tell you that there is no way to prove that generated black holes will decay!
Universal biosignatures for the detection of life. My goal is to identify processes of life that leave measurable effects on an organism's environment, but which are not tied to any particular biochemistry, in order to build a conceptual framework for the search for extraterrestrial life. To this end, I test a pair of phenomena that appear in both terrestrial (biochemical) life and in digital life. Because these two life forms are different and unrelated, any phenomenon measurable in both is suggested to be universal. The Monomer Abundance Distribution Biosignature (MADB) is any measurement of the relative concentrations of related chemical compounds that cannot be explained by abiotic processes. I observe that living systems synthesize specific chemical compounds at rates that maximize their fitness. As a result, life-bearing environmental samples exhibit compounds in abundance ratios that are clearly not the result of abiotic synthesis because those ratios belie the formation kinetics and thermodynamics that would constrain abiotic synthesis. Often, biotic samples contain high concentrations of specific large, complex molecules that are never seen in abiotic synthesis and cannot be explained unless highly specific catalysts (i.e., enzymes) are present, and energy is expended to drive thermodynamically unfavorable reactions. I catalog this effect as it appears in terrestrial biochemical systems, including amino acids and carboxylic acids, and demonstrate the universality of selection's action on the monomeric composition of life forms by studying analogous examples in digital life. I suggest how this phenomenon provides a route to the detection of even unusual or unforeseen biochemistries, and give examples of detection methods using pattern-recognition techniques that may allow us to empower an autonomous system with the general ability to detect life forms. The Layered Trophic Residue Biosignature (LTRB) is any observation of stratification in solute chemistry that indicates metabolic activity by a sequence of diverse communities. When multiple chemical resources are available, natural selection drives adaptive radiation and the formation of specialist phenotypes. Competition ensures that specialists consume resources in decreasing order of energetic potential when resources diffuse through a medium near a boundary. The result is strata of chemicals appearing in order of redox potential, which is best explained by the presence of life.
NEW materials that can change the way light and other forms of radiation bend around an object may provide a way to make objects invisible.
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]]>Hundreds of thousand of people could die in a nuclear attack, but hundreds of thousands of others could be saved. That』s because the Pentagon — after decades of searching — believes it has found a drug to treat radiation exposure. Why isn』t that d
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A breakthrough by a team of British, US and French scientists will help protect astronauts, spacecraft and satellites from radiation hazards experienced in space.