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Electricity is the set of physical phenomena associated with the presence and motion of matter possessing an electric charge. Electricity is related to magnetism , both being part of the phenomenon of electromagnetism , as described by Maxwell's equations .
These can be divided broadly into prehistorical periods and historical periods (when written records began to be kept). In archaeology and anthropology , prehistory is subdivided into the three-age system , this list includes the use of the three-age system as well as a number of various designation used in reference to sub-ages within the ...
In 1733 Du Fay discovered what he believed to be two kinds of frictional electricity; one generated from rubbing glass, the other from rubbing resin. [40] From this, Du Fay theorized that electricity consists of two electrical fluids, "vitreous" and "resinous", that are separated by friction and that neutralize each other when combined. [41]
Isaac Newton suggests the existence of an aether in the Third Book of Opticks (1st ed. 1704; 2nd ed. 1718): "Doth not this aethereal medium in passing out of water, glass, crystal, and other compact and dense bodies in empty spaces, grow denser and denser by degrees, and by that means refract the rays of light not in a point, but by bending them gradually in curve lines? ...
Condensed matter physics is the largest field of contemporary physics. Historically, condensed matter physics grew out of solid-state physics, which is now considered one of its main subfields. [80] The term condensed matter physics was apparently coined by Philip Anderson when he renamed his research group—previously solid-state theory—in ...
Classical mechanics was initially understood through the study of motion and force by thinkers like Galileo Galilei and Isaac Newton, the importance of the concept of energy was made clear in the 19th century with the principles of thermodynamics, particularly the conservation of energy which established that energy cannot be created or ...
Research concerning the relationship between the thermodynamic quantity entropy and both the origin and evolution of life began around the turn of the 20th century. In 1910 American historian Henry Adams printed and distributed to university libraries and history professors the small volume A Letter to American Teachers of History proposing a theory of history based on the second law of ...
Whereas gravity acts on all things that have mass, electromagnetism acts on all things that have electric charge. Furthermore, as there is the conservation of mass according to which mass cannot be created or destroyed, there is also the conservation of charge which means that the charge in a closed system (where no charges are leaving or ...