Text: Most of the matter we see around us is made from protons and neutrons, which are each composed of 3 quarks. There are six quarks, or quark flavours, but physicists usually talk about them in terms of three pairs: up/down, charm/strange, and top/bottom. Top and bottom types are the most elementary of them all, and are the ones that make up protons and neutrons. Quarks have the unusual characteristic of having a fractional electric charge, unlike the proton and electron, which have integer charges of +1 and -1 respectively. The up, charm and top quarks have a charge of +2/3, whilst the down, strange and bottom have a charge of -1/3. Although individual quarks have fractional electrical charges, they normally combine into 'hadrons' such that these hadrons have a net integer electric charge. Protons and neutrons are good examples of quark grouping or hadrons. Researchers at the Weizmann Institute of Science have provided the first unambiguous evidence that electrons can behave in an intriguing way that seems to defy the idea of the electron being an indivisible charged elementary unit. An electron is by convention considered to be a tiny indivisible hard particle that carries the smallest negative charge in nature. Yet a daring theory of physics developed 15 years ago argues that under certain conditions, an electric current behaves as if it were made up of fractions of electronic charges. In an experiment described in September 11,1997 issue of Nature, Weizmann Institute physicists measured fractional charges one-third that of an electron. "Mind-boggling as this may seem, this phenomenon is real," says study author Rafael de-Picciotto. "Of course, electrons don't split into fragments in an electric current, but under certain conditions it is indeed possible to measure a charge smaller than that of an electron." This means, that although the electron charge is always the same well known value, it can no longer be stated that this value is the smallest possible value for electrical charge. http://blazelabs.com/f-p-frac.htm

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