from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun The act or process of splitting into parts.
- noun A nuclear reaction in which an atomic nucleus, especially a heavy nucleus, such as an isotope of uranium, splits into fragments, usually two fragments of comparable but unequal mass, and releases a few neutrons and about 100 million electron volts of energy. Nuclear fission may occur spontaneously or may be induced by the absorption of a neutron, which can initiate a nuclear chain reaction.
- noun Biology An asexual reproductive process in which a unicellular organism divides into two or more independently maturing daughter cells.
- intransitive verb To cause (an atom) to undergo fission.
- intransitive verb To undergo fission.
from The Century Dictionary.
- noun The act of cleaving, splitting, or breaking up into parts.
- noun In biology, the automatic division of a cell or an independent organism into new cells or organisms; especially, such division as a process of multiplication or reproduction. Also
fissuration. See cut under Paramecium.
from the GNU version of the Collaborative International Dictionary of English.
- noun A cleaving, splitting, or breaking up into parts.
- noun (Biol.) A method of asexual reproduction among the lowest (unicellular) organisms by means of a process of self-division, consisting of gradual division or cleavage of the into two parts, each of which then becomes a separate and independent organisms; as when a cell in an animal or plant, or its germ, undergoes a spontaneous division, and the parts again subdivide. See
Segmentation, and Cell division, under Division.
- noun (Zoöl.) A process by which certain coral polyps, echinoderms, annelids, etc., spontaneously subdivide, each individual thus forming two or more new ones. See
- noun (Physics) The act or process of disintegration of an atomic nucleus into two or more smaller pieces; called also nuclear fission. The process may be spontaneous or induced by capture of neutrons or other smaller nuclei, and usually proceeds with evolution of energy.
from Wiktionary, Creative Commons Attribution/Share-Alike License.
- noun The
processwhereby one item splits to become two.
- noun physics The process of splitting the
nucleusof an atominto smaller particles; nuclear fission
- noun biology The process by which a
bacteriumsplits to form two daughter cells.
- verb To cause to undergo fission.
- verb intransitive To undergo fission.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- noun a nuclear reaction in which a massive nucleus splits into smaller nuclei with the simultaneous release of energy
- noun reproduction of some unicellular organisms by division of the cell into two more or less equal parts
from The American Heritage® Dictionary of the English Language, 4th Edition
from Wiktionary, Creative Commons Attribution/Share-Alike License
Help support Wordnik (and make this page ad-free) by adopting the word fission.
When an organ becomes divided it receives at the hands of descriptive botanists the appellations cleft, partite, or sect, according to the depth of the division; hence in considering the teratological instances of this nature, the term fission has suggested itself as an appropriate one to be applied to the subdivision of an habitually entire or undivided organ.
Vegetable Teratology An Account of the Principal Deviations from the Usual Construction of Plants Maxwell T. Masters
(1878-1968) interpreted the fission of uranium (the term fission is another Copenhagen contribution), in terms of the "liquid drop model."
Nuclear fission is neither clean nor safe nor unlimited.
Think Progress » Demoralizing His Supporters, Obama Calls Nukes, Coal, And Oil Drilling ‘Clean Energy Jobs’ 2010
Once we secure all that, I hope that we can figure out how to use it in fission reactors to create electricity of be batteries for deep space probes (for where solar panels won't generate enough power).
I think nuclear fission is a bad way to get energy.
The discovery of nuclear fission is very momentous and indeed dangerous, but even more, it is full of promise.
Nuclear fission is one of the major discoveries of all time, and the circumstances of its birth have inevitably done much to impress the layman with the destructive rather than the constructive powers of the science that brought it into being.
The Contribution of Creative Chemistry to the Humanities 1957
[...] Nuclear Fission: Fusion may be commercially available by 2040 if we’re lucky, but fission is here today.
Fission vs. Fusion 2009
- Nuclear power is produced by harnessing the heat produced by the splitting of atoms inside uranium - a process known as fission.
Nuclear fission occurs when heavy atoms such as uranium or plutonium split into smaller, lighter atoms, releasing neutrons and energy.
Is this the future of nuclear power??? GayandRight 2009
seanahan commented on the word fission
"He (American biologist William A. Arnold) could have gone to Berkeley to pick up radioisotope technique, but would have missed living in Copenhagen, learning from de Hevesy - would have missed contributing a coinage to the gamble that is history.... 'Later that day Frisch looked me up and said, 'You work in a microbiology lab. What do you call the process in which one bacterium divides into two?' And I answered, 'binary fission'. He wanted to know if you could call if 'fission' alone, and I said you could'"
-- From "The Making of the Atomic Bomb" by Richard Rhodes, Frisch referring to Otto Frisch, who with Lise Meitner first postulated nuclear fission.
November 9, 2007