Electrostatics is the branch of science that eals with the phenomena arising from what seems to be stationary electric charges. Since ancient history it is known that some materials attract light particles after rubbing. The greek word for amber, ήλεκτρον (electron), gave name for many areas of natural science. Electrostatic phenomena arise from the forces that electric charges carry out on each other. Such forces are described by Coulomb's law. Electrostatic phenomena include such as simple as the attraction of plastic wrap to your hand after you remove it from a package to apparently spontaneous explosion of grain silos, to damage of electronic components during manufacturing, to the operation of photocopiers. Electrostatics involves the buildup of charge on the surface of objects due to contact with other surfaces. Although charge exchange happens whenever any two surfaces contact and separate, the effects of charge exchange are usually only noticed when at least one of the surfaces has a high resistance to electrical flow. This is because the charges that transfer to or from the highly resistive surface are more or less trapped there for a long enough time for their effects to be observed. These charges then remain on the object until they either bleed off to ground or are quickly neutralized by a discharge: e.g., the familiar phenomenon of a static 'shock' is caused by the neutralization of charge built up in the body from contact with nonconductive surfaces.