The electric catfish of the Nile was well known to the ancient Egyptians.[9] The Egyptians used the electric shock from them when treating arthritis pain.[10] They would use only smaller fish.
Large fish may generate an electric shock from 300 to 400 volts.
The Egyptians depicted the fish in their mural paintings and elsewhere;[9] the first known depiction of an electric catfish is on a slate palette of the predynastic Egyptian ruler Narmer about 3100 BC.[7][8]
An account of its electric properties was given by an Arab physician Abd al-Latif al-Baghdadi of the 12th century; then as now, the fish was known by the suggestive name of الرعد el raad, which means "thunder".[9]
The shock of these catfish is used to stun prey and in defense. It is not known to be fatal to humans,[2] but large electric catfish can stun an adult person.[10] In small electric catfish, the generated current is far less and only feels like a tingle to humans.[10]
"The Golden Number is not the product of mathematical imagination but the natural principle of the laws of equilibrium." From averages established from measurements of the human body, it has been proved that the navel divides the total height of the body in the proportion of Φ to 1. This formula is applied to classical Greek sculpture, and in Egypt as well, except that in Egypt the crown of the head is excluded. Let us recall, in this regard, the significance of the value Φ and the geometric structure that defines Φ. The value , or the Golden Number Φ , corresponds to the proportion C / B = B / A when C = A + B There i...
Heisenberg's uncertainty principle can be explained thus: 1.if it is possible to locate precisely a moving object at a given moment, 2. it is no longer possible to know its exact speed at this moment. Inversely, If one can specify the speed of a moving object at a given moment, then it will be impossible to know its exact location. 3. Certainly it is a matter of intra-atomic phenomena. The fact of observing the location of the electron—or at least the probability of its position—signifies an action in regard to it, which modifies it or changes its course. Thus, the fact of observing the phenomenon modifies its nature, so that, at a given moment, only one of the two elements can be known exactly: either its location or its speed We can later "group" these data, separately observed, in order to ignore acknowledge the simultaneous phenomenon without really knowing it at all ...
Theory [ edit ] The underlying premise of spectroscopy is that light is made of different wavelengths and that each wavelength corresponds to a different frequency. The importance of spectroscopy is centered around the fact that every element in the periodic table has a unique light spectrum described by the frequencies of light it emits or absorbs consistently appearing in the same part of the electromagnetic spectrum when that light is diffracted. This opened up an entire field of study with anything that contains atoms. Spectroscopy is the key to understanding the atomic properties of all matter. As such spectroscopy opened up many new sub-fields of science yet undiscovered. The idea that each atomic element has its unique spectral signature enabled spectroscopy to be used in a broad number of fields each with a specific goal achieved by different spectroscopic procedures. The National Institute of Standards and Technology maintains a public Atomic Spec...
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