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Moment of truth
The fastest man-made object that ever leave the Earth is the New Horizon spacecraft, launched in January 2006, and attained a speed of more than 36000 mph.

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necrobiosis Med.
The natural, gradual death, through a series of events involving degeneration and disintegration of cell in the living body. Cancerous cells avoid this process and results to uncontrolled cell growth. The synonyms is apoptosis.

neoprene Chem.
A trade name for synthetic rubber made by polymerization of 2-chlorobuta-1,3-diene (chloroprene). It can be copolymerized with sulfur or 2,3-dichloro-1,3-butadiene in order to achieve a desire property. It was invented by an inventor and Chemist Wallace Hume Carothers (1896-1937). Due to its superior mechanical properties and resistance to chemical attacks, neoprene has been widely used in a variety of applications. For example, as a protective material for automotives, cables, wires and chemical spillage.

nesquehonite Min.
A monoclinic mineral form of magnesium carbonate trihydrate, MgCO3.3H2O. Named after the place where it was found, at Nesquehoning Coal Mine, Pennsylvania in 1890.

Nessler's reagent Chem.
A solution of mercury(II) iodide in potassium iodide (KI) and potassium hydroxide (KOH). It is used in testing for the presence of ammonia, which forms a brown coloration or precipitate. The reagent is named after Julius Nessler (1827-1905).

neutrino Phys.
A fundamental particle that almost have zero mass and does not carry charge. It does not affect by the electromagnetic forces and interacting very weakly with matter. It can therefore passes through great distances in matter (even through the Earth). Wolfgang Pauli was the first scientist to propose the existence of the particle in 1931, when it was found that some energy was missing during a beta decay, which must have carried away by this particle. However, it was Enrico Fermi who first coined the term neutrino in 1934. The elusive particle was not detected until 1959 by Clyde Cowan and Fred Reines who subsequently won the Nobel Prize in 1995.

neutron Phys.
A hadron with zero charge (neutral) that is stable in neucleus but decays into a proton (beta decay), an electron and an antineutrino with a half-life of 12 minutes when it is outside the neucleus. The neutral particle was discovered by James Chadwick (1891-1974) in 1932. Neutron can be found in all atomic nuclei, except normal hydrogen, 1H.

neutron star Astron.
A dense ball of neutrons that remains after a supernova has destroyed the rest of the star. Typically neutron stars are about 20km across, and contain more mass than the Sun. Neutron stars are extremely dense, about 1012-1013 kg cm-3. In some cases, these stars rotate, sending out strong radio emissions. Such stars are called pulsars. Neutron stars are very dim and they are thought to consist of the dark matter in the Universe as MACHOs.

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