An electron is a subatomic particle that carries a negative electric
charge. It has no known substructure and is believed to be a point
particle. An electron has a mass that is approximately 1/1836 that of
the proton. The intrinsic angular momentum (spin) of the electron is a
half integer value of
<sup>1</sup><big>⁄</big><sub>2</sub>, which means
that it is a fermion. Electrons, which belong to the first generation
of the lepton particle family, participate in gravitational,
electromagnetic and weak interactions. Electrons have quantum
mechanical properties of both a particle and a wave, so they can
collide with other particles and be diffracted like light. Since an
electron is a fermion, no two electrons can occupy the same quantum
state, a property known as the Pauli exclusion principle. The electron
was identified as a particle in 1897 by J. J. Thomson and his team of
British physicists. In many physical phenomena, such as electricity,
magnetism, and thermal conductivity, electrons play an essential role.
An electron generates a magnetic field while moving, and it is
deflected by external magnetic fields. The exchange or sharing of the
electrons between two or more atoms is the main cause of chemical
bonding.
Read the rest of this article:
<http://en.wikipedia.org/wiki/Electron>
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Today's selected anniversaries:
1783:
The first successful untethered flight by humans in a hot air balloon
was made by Jean-François Pilâtre de Rozier and François Laurent
d'Arlandes in Paris.
<http://en.wikipedia.org/wiki/History_of_ballooning%23First_manned_flight>
1920:
Irish War of Independence: On Bloody Sunday in Dublin, the Irish
Republican Army killed more than a dozen British intelligence officers
known as the Cairo Gang, and the Auxiliaries of the Royal Irish
Constabulary opened fire on players and spectators at a Gaelic football
match in Croke Park.
<http://en.wikipedia.org/wiki/Bloody_Sunday_%281920%29>
1964:
The Verrazano-Narrows Bridge , a suspension bridge connecting Staten
Island and Brooklyn in New York City at the Narrows, opened to traffic,
becoming the largest suspension bridge in the world at the time.
<http://en.wikipedia.org/wiki/Verrazano-Narrows_Bridge>
1974:
Explosives placed in two central pubs in Birmingham, England, killed 21
people and injured 182 others, and eventually led to the arrest and
imprisonment of six people that became known as the Birmingham Six.
<http://en.wikipedia.org/wiki/Birmingham_pub_bombings>
1977:
"God Defend New Zealand" became New Zealand's second national anthem,
on equal standing with "God Save the Queen", which had been the
traditional one since 1840.
<http://en.wikipedia.org/wiki/God_Defend_New_Zealand>
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Wiktionary's word of the day:
plicate (adj):
Folded lengthwise, especially in multiple in parallel sections;
corrugated
<http://en.wiktionary.org/wiki/plicate>
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Wikiquote quote of the day:
If your object is to secure liberty, you must learn to do without
authority and compulsion. If you intend to live in peace and harmony
with your fellow-men, you and they should cultivate brotherhood and
respect for each other. If you want to work together with them for your
mutual benefit, you must practice cooperation. The social revolution
means much more than the reorganization of conditions only: it means
the establishment of new human values and social relationships, a
changed attitude of man to man, as of one free and independent to his
equal; it means a different spirit in individual and collective life,
and that spirit cannot be born overnight. It is a spirit to be
cultivated, to be nurtured and reared, as the most delicate flower it
is, for indeed it is the flower of a new and beautiful existence.
--Alexander Berkman
<http://en.wikiquote.org/wiki/Alexander_Berkman>