Timeline of United States discoveries

Timeline of United States discoveries

webelements.com/silicon/))

1831 Discovery of chloroform

Chloroform is a chemical compound known as trihalomethanes that does not undergo combustion in air, although it will burn when mixed with more flammable substances. Chloroform was first discovered in July 1831 by American physician Samuel Guthrie, independently a few months later by French chemist Eugne Soubeiran and then by German chemist Justus von Liebig.

1859 Discovery of petroleum jelly

Petroleum jelly, petrolatum or soft paraffin is a semi-solid mixture of hydrocarbons originally promoted as a topical ointment for its healing properties. The raw material for petroleum jelly was discovered in 1859 by Robert Chesebrough, a chemist from New York. In 1870, this product was branded as Vaseline Petroleum Jelly.

1873 Discovery of chemical potential

In thermodynamics, physics, and chemistry, chemical potential, symbolized by , is a term introduced by the American engineer, chemist, and mathematical physicist Josiah Gibbs in his 1873 paper A Method of Geometrical Representation of the Thermodynamic Properties of Substances by Means of Surfaces.
1877 Discovery of Deimos

Deimos is the smaller and outer of Mars two moons. It was discovered by Asaph Hall in 1877.

1877 Discovery of Phobos

Phobos is the larger and closer of Mars’ two small moons. It was discovered by Asaph Hall in 1877.

1891 Discovery of Amalthea

Amalthea is the third moon of Jupiter in order of distance from the planet. It was discovered on September 9, 1892, by Edward Emerson Barnard.

1899 Discovery of Phoebe

Phoebe is an irregular satellite of Saturn. It was discovered by William Henry Pickering on March 17, 1899 from photographic plates that had been taken starting on August 16, 1898 at Arequipa, Peru by DeLisle Stewart.

1908 Discovery of Seyfert galaxies

Seyfert galaxies are a class of galaxies with nuclei that produce spectral line emission from highly ionized gas, named after Carl Keenan Seyfert, the astronomer who first identified the class in 1943 although they were first discovered by Edward A. Fath in 1908 while he was at the Lick Observatory.

1910 Discovery of propane

Propane is a three-carbon alkane, normally a gas, but compressible to a transportable liquid. It is derived from other petroleum products during oil or natural gas processing. It is commonly used as a fuel for engines, barbecues, portable stoves and residential central heating. Propane was first identified as a volatile component in gasoline by Dr. Walter O. Snelling of the U.S. Bureau of Mines in 1910.

1912 Discovery of the smoking-cancer link

Dr. Isaac Adler was the first to strongly suggest that lung cancer is related to smoking in 1912.

1914 Discovery of Sinope

Sinope is a retrograde irregular satellite of Jupiter discovered by Seth Barnes Nicholson at Lick Observatory in 1914.

1915 Discovery of the Zener diode

A Zener diode is a type of diode that permits current in the forward direction like a normal diode, but also in the reverse direction if the voltage is larger than the breakdown voltage known as “Zener knee voltage” or “Zener voltage”. The device was named after Clarence Zener, who discovered this electrical property.

1916 Discovery of covalent bonding

The idea of covalent bonding can be traced several years to Gilbert N. Lewis, who in 1916 described the sharing of electron pairs between atoms. He introduced the so called Lewis notation or electron dot notation or The Lewis Dot Structure in which valence electrons are represented as dots around the atomic symbols.

1916 Discovery of heparin

Heparin, a highly-sulfated glycosaminoglycan, is widely used as an injectable anticoagulant and has the highest negative charge density of any known biological molecule. It can also be used to form an inner anticoagulant surface on various experimental and medical devices such as test tubes and renal dialysis machines. It was discovered by Jay McLean and William Henry Howell in 1916.

1917 Discovery of Vitamin A

Vitamin A, a bi-polar molecule formed with bi-polar covalent bonds between carbon and hydrogen, is linked to a family of similarly shaped molecules, the retinoids, which complete the remainder of the vitamin sequence. Its important part is the retinyl group, which can be found in several forms. In foods of animal origin, the major form of vitamin A is an ester, primarily retinyl palmitate, which is converted to an alcohol in the small intestine. Vitamin A can also exist as an aldehyde, or as an acid. The discovery of vitamin A stemmed from research dating back to 1906, indicating that factors other than carbohydrates, proteins, and fats were necessary to keep cattle healthy. By 1917 one of these substances was independently discovered by Elmer McCollum at the University of Wisconsinadison, and Lafayette Mendel and Thomas Osborne at Yale University.

1925 Discovery of cepheid variables

Extragalactic astronomy is the branch of astronomy concerned with objects outside the Milky Way Galaxy. In other words, it is the study of all astronomical objects which are not covered by galactic astronomy. It was started by Edwin Hubble when, in 1925, he discovered the existence of Cepheid variables in the Andromeda Galaxy. This discovery proved the existence of a galaxy over one million light-years away and thus extragalactic astronomy was created.

1930 Discovery of Pluto

Following the discovery of the planet Neptune in 1846, there was considerable speculation that another planet might exist beyond its orbit. The search began in the mid-19th century but culminated at the start of the 20th century with a quest for Planet X. Percival Lowell proposed the Planet X hypothesis to explain apparent discrepancies in the orbits of the gas giants, particularly Uranus and Neptune, speculating that the gravity of a large unseen planet could have perturbed Uranus enough to account for the irregularities. The discovery of Pluto by Clyde Tombaugh in 1930 initially appeared to validate Lowell’s hypothesis, and Pluto was considered the ninth planet until 2006.

1931 Discovery of heavy hydrogen

Heavy hydrogen is a stable isotope of hydrogen with a natural abundance in the oceans of Earth of approximately one atom in 6500 of hydrogen (~154 PPM). It was first predicted in 1926 by Walter Russell and later discovered in 1931 by Harold Urey.

1931 Discovery of cosmic radio waves

Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. While trying to track down a source of electrical interference on telephone transmissions, Karl Guthe Jansky of Bell Telephone Laboratories discovered radio waves emanating from stars in outer space while investigating static that interfered with short wave transatlantic voice transmissions. Thus, the field of radio astronomy was born.

1932 Discovery of the positron

The existence of positrons was first postulated in 1928 by Paul Dirac as a consequence of the Dirac equation and later discovered in 1932 by Carl D. Anderson, who gave the positron its name.

1932 Discovery of homeostasis

Homeostasis is the property of a system, either open or closed, that regulates its internal environment so as to maintain a stable, constant condition. It was first proposed and coined by Walter Bradford Cannon, a former professor and chairman of the Department of Physiology at Harvard Medical School, and popularized it in his book The Wisdom of the Body.

1933 Discovery of heavy water

Harold Urey discovered the isotope deuterium in 1931 and was later able to concentrate it in water. Urey’s mentor Gilbert Newton Lewis isolated the first sample of pure heavy water by electrolysis in 1933.

1933 Discovery of polyvinylidene chloride

Polyvinylidene chloride is a polymer derived from vinylidene chloride. Its use can be found in water-based coating, the production of household items and industrial products. Ralph Wiley, a Dow Chemical lab worker, accidentally discovered polyvinylidene chloride in 1933.

1936 Discovery of elliptical galaxies

An elliptical galaxy is a galaxy having an approximately elliptical shape and a smooth, nearly featureless brightness profile. They range in shape from nearly spherical to highly flattened and in size from hundreds of millions to over one trillion stars. It was originally described by Edwin Hubble in his 1936 work he Realm of the Nebulae
1936 Discovery of the muon

The muon is an elementary particle similar to the electron, with negative electric charge and a spin of 12. It was discovered by Carl D. Anderson and Seth Henry Neddermeyer in 1936 while they studied cosmic radiation.

1936 Discovery of Vitamin E

Tocopherol, a class of chemical compounds of which many have vitamin E activity, describes a series of organic compounds consisting of various methylated phenols. During feeding experiments with rats Herbert McLean Evans concluded in 1922 that besides vitamins B and C, an unknown vitamin existed. Although every other nutrition was present, the rats were not fertile. This condition could be changed by additional feeding with wheat germ. It took several years until 1936 when the substance was isolated from wheat germ and the formula C29H50O2 was determined by Herbert McLean Evans and K.S. Bishop. The structure was determined shortly thereafter in 1938.

1936 Discovery of sodium thiopental

Sodium thiopental, better known as Sodium Pentothal, thiopentone sodium, or trapanal, is a rapid-onset short-acting barbiturate. It was discovered in the early 1936 by Ernest H. Volwiler and Donalee L. Tabern while working for Abbott Laboratories.

1937 Discovery of Niacin

Niacin, also known as vitamin B3, is a water-soluble vitamin which prevents the deficiency disease pellagra. Niacin was extracted from livers by Conrad Elvehjem who later discovered the active ingredient, then referred to as the “pellagra-preventing factor” and the “anti-blacktongue factor.”
1937 Discovery of K-electron capture

Electron capture is a decay mode for isotopes that will occur when there are too many protons in the nucleus of an atom and insufficient energy to emit a positron. However, it continues to be a viable decay mode for radioactive isotopes that can decay by positron emission. K-electron capture was discovered by Luis Alvarez, who demonstrated it in 1937 and reported it in The Physical Review in April 1938.

1938 Discovery of fluropolymers

A fluoropolymer is a fluorocarbon based polymer with multiple strong carbonluorine bonds. It is characterized by a high resistance to solvents, acids, and bases. Fluoropolymers were discovered in 1938 by Dr. Roy Plunkett when he accidentally polymerized tetrafluoroethylene to form polytetrafluoroethylene.

1938 Discovery of animal echolocation

Echolocation, also called biosonar, is the biological sonar used by several animals such as dolphins, shrews, bats, and whales. The term was coined by Donald Griffin and Robert Galambos, who discovered its use by bats in 1938.

1938 Discovery of Carme

Carme is a retrograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson at Mount Wilson Observatory in California in July 1938.

1938 Discovery of Lysithea

Lysithea is a prograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson in 1938 at Mount Wilson Observatory.

1943 Discovery of streptomycin

Streptomycin is an antibiotic drug, the first of a class of drugs called aminoglycosides to be discovered, and was the first antibiotic remedy for tuberculosis. Streptomycin cannot be given orally as it must be administered by regular intramuscular injection. In 1943, Albert Schatz discovered Streptomycin.

1945 Discovery of promethium

Promethium is a chemical element whose existence was first predicted by Bohuslav Brauner in 1902. It was first produced and proven to exist at Oak Ridge National Laboratory (ORNL) in 1945 by Jacob A. Marinsky, Lawrence E. Glendenin and Charles D. Coryell by separation and analysis of the fission products of uranium fuel irradiated in the Graphite Reactor.

1948 Discovery of warfarin

Warfarin is an anticoagulant and pesticide. It was initially used as a pesticide but was later found to be effective and relatively safe for preventing thrombosis and embolism in many disorders and is currently the most widely used anticoagulant worldwide. It was discovered by Karl Paul Link and chemists at the University of Wisconsinadison.

1948 Discovery of Miranda

Miranda is the smallest and innermost of Uranus’ five major moons. It was discovered by Gerard Kuiper on February 2, 1948 at McDonald Observatory.

1948 Discovery of seratonin

Seratonin is a monoamine neurotransmitter synthesized in serotonergic neurons in the central nervous system (CNS) and enterochromaffin cells in the gastrointestinal tract of animals including humans. It was isolated and named in 1948 by Maurice M. Rapport, Arda Green, and Irvine Page of the Cleveland Clinic.

1948 Discovery of tetracycline

Tetracycline is a broad-spectrum polyketide antibiotic indicated for use against many bacterial infections. It is commonly used to treat acne today, and played a historical role in stamping out cholera in the developed world. It was discovered by Benjamin Minge Duggar in 1948.

1949 Discovery of Nereid

Nereid, also known as Neptune II, is a moon of Neptune. Nereid was discovered on May 1, 1949 by Gerard P. Kuiper, who proposed the name in the report of his discovery. It is named after the Nereids, sea-nymphs of Greek mythology.

1951 Discovery of barium stars

Barium stars are G to K class giants, whose spectra indicate an overabundance of s-process elements by the presence of singly ionized barium, Ba II, at 455.4 nm. Barium stars also show enhanced spectral features of carbon, the bands of the molecules CH, CN and C2. The class was originally recognized and defined by William Bidelman and Philip Keenan.

1951 Discovery of Ananke

Ananke is a retrograde irregular satellite of Jupiter. It was discovered by Seth Barnes Nicholson at Mount Wilson Observatory in 1951.

1952 Discovery of rapid eye movement

Rapid eye movement (REM) sleep is a normal stage of sleep characterized by rapid movements of the eyes. REM sleep is classified into two categories: tonic and phasic. The phenomenon of REM sleep and its association with dreaming was discovered by Eugene Aserinsky and Nathaniel Kleitman with assistance from William C. Dement, a medical student at the time, in 1952 during their tenures at the University of Chicago. Kleitmann and Aserinsky’s seminal article was published September 10, 1953.

1953 Discovery of DNA structure

In 1953, based on X-ray diffraction images and the information that the bases were paired, James D. Watson along with Francis Crick discovered what is now widely accepted as the first accurate double-helix model of DNA structure.

1955 Discovery of the antiproton

The antiproton is the antiparticle of the proton. It was discovered by University of California, Berkeley physicists Thomas Ypsilantis, Emilio Segr, Clyde Wiegand and Owen Chamberlain in 1955.

1956 Discovery of porous silicon

Porous silicon (pSi) is a form of the chemical element silicon which has an introduced nanoporous holes in its microstructure, rendering a large surface to volume ratio in the order of 500m2/cm3. It was first discovered by accident in 1956 at Bell Labs by Arthur Uhlir Jr. and Ingeborg Uhlir.

1956 Discovery of the kaon

A kaon is any one of a group of four mesons distinguished by the fact that they carry a quantum number called strangeness. It was first discovered by Leon Lederman and a group of scientists from Columbia University at Brookhaven National Laboratory.

1956 Discovery of the antineutron

The antineutron is the antiparticle of the neutron. An antineutron has the same mass as a neutron, and no net electric charge. However, it is different from a neutron by being composed of antiquarks, rather than quarks. It was discovered by Bruce Cork, William Wenzell, Glenn Lambertson and Oreste Piccioni in 1956.

1956 Discovery of the neutrino

Neutrinos are elementary particles that travel close to the speed of light, lack an electric charge, are able to pass through ordinary matter almost undisturbed and are thus extremely difficult to detect. The neutrino was first postulated in 1930 by Wolfgang Pauli and later discovered in 1956 by Clyde Cowan, Frederick Reines, F. B. Harrison, H. W. Kruse, and A. D. McGuire.

1956 Discovery of nucleic acid hybridization

Hybridization, discovered by Alexander Rich and David R. Davies in 1956, is the process of combining complementary, single-stranded nucleic acids into a single molecule.

1958 Discovery of the Van Allen radiation belt

The Van Allen radiation belt is a torus of energy charged particles around Earth, held in place by Earth’s magnetic field. On the sun side, it is compressed because of the solar wind and on the other side, it is elongated to around three earth radii. This creates a cavity called the Chapman Ferraro Cavity, in which the Van Allen radiation belts reside. The existence of the belt was confirmed by the Explorer 1 and Explorer 3 missions in early 1958, under Dr. James Van Allen at the University of Iowa.

1959 Discovery of antiprotons

The antiproton is the antiparticle of the proton. It was discovered in 1955 by University of California, Berkeley physicists Owen Chamberlain and Emilio Segr for which they earned the 1959 Nobel Prize in Physics.

1960 Discovery of seafloor spreading

Seafloor spreading occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics. It was first proposed by Harry Hammond Hess and Robert Sinclair Dietz in 1960.

1961 Discovery of the eta meson

The eta meson is a meson made of a mix of up quark, down quark, strange quark, quarks and antiquarks. It was discovered by a team at the University of California, Berkeley using the Bevatron.

1964 Discovery of the xi baryon

In particle physics, subatomic particle (Xi) is a name given to a range of baryons with one up or down quark and two heavier quarks. They are sometimes called the cascade particles because of their unstable state, they decay rapidly into lighter particles through a chain of decays. The first discovery of the Xi particle was at Brookhaven National Laboratory in 1964.

1964 Discovery of cosmic microwave background radiation

In cosmology, the cosmic microwave background radiation CMB is a form of electromagnetic radiation filling the universe. The CMB’s discovery in 1964 by astronomers Arno Penzias and Robert Wilson was the culmination of work initiated in the 1940s, earning them a Nobel Prize in 1978.

1964 Discovery of the quark

A quark is a type of elementary particle found in nucleons and other subatomic particles. They are a major constituent of matter, along with leptons. The quark model was first postulated independently by physicist Murray Gell-Mann in 1964.

1964 Discovery of the Hepatitis B virus

The Hepatitis B virus was discovered in 1965 by Baruch Blumberg, while working at the National Institutes of Health.

1965 Discovery of aspartame

Aspartame is the name for an artificial, non-saccharide sweetener, aspartyl-phenylalanine-1-methyl ester; that is, a methyl ester of the dipeptide of the amino acidsaspartic acid and phenylalanine. Aspartame was discovered in 1965 by James M. Schlatter, a chemist working for G.D. Searle & Company. Schlatter had synthesized aspartame in the course of producing an anti-ulcer drug candidate.

1965 Discovery of pulsating white dwarves

A pulsating white dwarf is a white dwarf star whose luminosity varies due to non-radial gravity wave pulsations within itself. The first pulsating white dwarf was discovered by Arlo U. Landolt when he observed in 1965 and 1966 that the luminosity of HL Tau 76 varied with a period of approximately 12.5 minutes.

1968 Discovery of the up quark

The up quark is a first-generation quark with a charge of +(2/3)e. The existence of up quarks was first postulated when Murray Gell-Mann and George Zweig developed the quark model in 1964, and the first evidence for them was found in deep inelastic scattering experiments in 1968.

1968 Discovery of the down quark

The down quark is a first-generation quark with a charge of 13. It is the second-lightest of all the six of quarks, the lightest being the up quark. Down quarks are most commonly found in nucleons. Its protons contains one down quark and two up quarks, while neutrons contain two down quarks and one up quark. Down quarks were theorized by Murray Gell-Mann and George Zweig when they discovered the quark model in 1968.

1969 Discovery of Mosher’s acid

Mosher’s acid, or -methoxytrifluorophenylacetic acid, discovered by Harry S. Mosher in 1969, is a carboxylic acid which was first used as a chiral derivitizing agent.

1969 Discovery of interstellar formaldehyde

Interstellar formaldehyde was first discovered in 1969 by Lewis Snyder, David Buhl, B. Zuckerman and Patrick Palmer using the National Radio Astronomy Observatory. Formaldehyde was detected by means of the 111 – 110 ground state rotational transition at 4830 MHz.

1970 Discovery of reverse transcriptase

In biochemistry, a reverse transcriptase, also known as RNA-dependent DNA polymerase, is a DNA polymerase enzyme that transcribes single-stranded RNA into double-stranded DNA. It was discovered by Howard Temin at the University of Wisconsinadison, and independently by David Baltimore in 1970 at Massachusetts Institute of Technology.

1974 Discovery of the J/ meson

The J/ is a subatomic particle, a flavor-neutral meson consisting of a charm quark and a charm anti-quark. Mesons formed by a bound state of a charm quark and a charm anti-quark are generally known as “charmonium”. Its discovery was made independently by two research groups, one at the Stanford Linear Accelerator Center, headed by Burton Richter, and one at the Brookhaven National Laboratory, headed by Samuel Ting at Massachusetts Institute of Technology. They accidentally discovered they had found the same particle, and both announced their discoveries on November 11, 1974.

1974 Discovery of the charm quark

The charm quark is a second-generation quark with an electric charge of +23 e. It is the third most massive of the quarks, at about 1.5 GeV/c2 and roughly one and a half times the mass of the proton. It was predicted in 1964 by Sheldon Lee Glashow and James Bjorken and first observed in November 1974, with the simultaneous discovery of the J/|J/ meson charm particle at Stanford Linear Accererator Center by a group led by Burton Richter and at Brookhaven National Laboratory by a group led by Samuel C. C. Ting.

1974 Discovery of the binary pulsar

A binary pulsar is a pulsar with a binary companion, often another pulsar, white dwarf or neutron star. The first binary pulsar, PSR 1913+16 or the “Hulse-Taylor binary pulsar” was discovered in 1974 at Arecibo by Joseph Hooton Taylor, Jr. and Russell Hulse, for which they won the 1993 Nobel Prize in Physics.

1974 Discovery of Leda

Leda is a prograde irregular satellite of Jupiter. It was discovered by Charles T. Kowal at the Mount Palomar Observatory on September 14, 1974.

1975 Discovery of Themisto

Themisto is a small prograde irregular satellite of Jupiter. It was discovered by Charles T. Kowal and Elizabeth Roemer in 1975.

1976 Discovery of D mesons

D mesons are the lightest particle containing charm quarks. They are often studied to gain knowledge on the weak interaction. Since the D meson is the lightest meson containing a charm quark, it must change the charm quark into another quark to decay. D mesons were discovered in 1976 during the Mark I experiments at the Stanford Linear Accelerator Center.

1977 Discovery of the tauon

The tauon is a negatively charged elementary particle with a lifetime of 2.91013 s and a mass of 1,777 MeV/c2. It was detected in a series of experiments between 1974 and 1977 by Martin Lewis Perl with his colleagues at the Lawrence Berkeley National Laboratory.

1977 Discovery of the rings of Uranus

The planet Uranus has a system of rings intermediate in complexity between the more extensive set around Saturn and the simpler systems around Jupiter and Neptune. The rings of Uranus were discovered on March 10, 1977, by James L. Elliot, Edward W. Dunham, and Douglas J. Mink. More than 200 years ago, William Herschel also reported observing rings, but modern astronomers are skeptical that he could actually have noticed them, as they are very dark and faint.

1977 Discovery of the upsilon meson

The upsilon meson is a flavorless meson formed from a bottom quark and its antiparticle. It was discovered by the E288 collaboration, headed by Leon Lederman , at Fermilab in 1977, and was the first particle containing a bottom quark to be discovered because it is the lightest that can be produced without additional massive particles. It has a mean lifetime of 1.211020 second and a mass about 10 GeV.

1977 Discovery of the bottom quark

The bottom quark is a third-generation quark with a charge of 13e. The bottom quark was discovered by the E288 experiment at Fermilab in 1977 when collisions produced bottomonium.

1978 Discovery of restriction endonucleases

A restriction enzyme is an enzyme that cuts double-stranded or single stranded DNA at specific recognition nucleotide sequences known as restriction sites. Such enzymes, found in bacteria and archaea, are thought to have evolved to provide a defense mechanism against invading viruses. Inside a bacterial host, the restriction enzymes selectively cut up foreign DNA in a process called restriction; host DNA is methylated by a modification enzyme to protect it from the restriction enzyme activity. The Nobel Prize in Medicine was awarded, in 1978, to Daniel Nathans, Werner Arber and Hamilton Smith for the discovery of restriction endonucleases.

1978 Discovery of Charon

Charon, discovered by James W. Christy on June 22, 1978 while working at the United States Naval Observatory, is the largest moon of the dwarf planet Pluto.

1979 Discovery of Metis

Metis is the innermost moon of Jupiter. It was discovered in 1979 by Stephen Synnott in images taken by Voyager 1.

1979 Discovery of Thebe

Thebe is the fourth of Jupiter’s moons by distance from the planet. It was discovered by Stephen Synnott in images from the Voyager 1 space probe taken on March 5, 1979 while orbiting around Jupiter.

1979 Discovery of the rings of Jupiter

The planet Jupiter has a system of rings, known as the rings of Jupiter or the Jovian ring system. It was the third ring system to be discovered in the Solar System, after those of Saturn and Uranus and was first observed in 1979 by the Voyager 1 space probe.

1980 Discovery of Pandora

Pandora is an inner satellite of Saturn. It was discovered in 1980 from photos taken by Voyager 1, and was provisionally designated S/1980 S 26.

1980 Discovery of Prometheus

Prometheus is an inner satellite of Saturn that was discovered in 1980 from photos taken by Voyager 1. It was provisionally designated S/1980 S 27.

1980 Discovery of Atlas

Atlas is a moon of Saturn that was discovered by Richard Terrile in 1980 from Voyager photos and was designated S/1980 S 28.

1981 Discovery of Larissa

Larissa, also known as Neptune VII, is the fifth closest inner satellite of Neptune. It was first discovered by Harold J. Reitsema, William B. Hubbard, Larry A. Lebofsky and David J. Tholen based on fortuitous ground-based stellar occultation observations on May 24, 1981, and given the temporary designation S/1981 N 1, being announced on May 29, 1981.

1985 Discovery of Puck

Puck is an inner satellite of Uranus. It was discovered in December 1985 by the Voyager 2 spacecraft.

1986 Discovery of Portia

Portia is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 3, 1986 and was given the temporary designation S/1986 U 1.

1986 Discovery of Juliet

Juliet is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 3, 1986 and was given the temporary designation S/1986 U 2.

1986 Discovery of Cressida

Cressida is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 9, 1986 and was given the temporary designation S/1986 U 3.

1986 Discovery of Rosalind

Rosalind is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 13, 1986 and was given the temporary designation S/1986 U 4.

1986 Discovery of Belinda

Belinda is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 13, 1986 and was given the temporary designation S/1986 U 5.

1986 Discovery of Desdemona

Desdemona is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 13, 1986 and was given the temporary designation S/1986 U 6.

1986 Discovery of Cordelia

Cordelia is the inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 20, 1986 and was given the temporary designation S/1986 U 7.

1986 Discovery of Ophelia

Ophelia is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 20, 1986 and was given the temporary designation S/1986 U 8.

1986 Discovery of Bianca

Bianca is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 23, 1986 and was given the temporary designation S/1986 U 9.

1989 Discovery of the rings of Neptune

The rings of Neptune were discovered in 1989 by the Voyager 2 spacecraft.

1989 Discovery of Proteus

Proteus, also known as Neptune VIII, is Neptune’s largest inner satellite. Proteus was discovered from the images taken by Voyager 2 during the Neptune flyby in 1989.

1989 Discovery of Despina

Despina, also known as Neptune V, is the third closest inner satellite of Neptune. Despina was discovered in late July 1989 from the images taken by the Voyager 2. It was given the temporary designation S/1989 N 3.

1989 Discovery of Galatea

Galatea, also known as Neptune VI, is the fourth closest inner satellite of Neptune. Galatea was discovered in late July 1989 from the images taken by the Voyager 2. It was given the temporary designation S/1989 N 4.

1989 Discovery of Thalassa

Thalassa, also known as Neptune IV, is the second inner satellite of Neptune. It was discovered sometime before mid-September 1989 from the images taken by the Voyager 2. It was given the temporary designation S/1989 N 5.

1989 Discovery of Naiad

Naiad, also known as Neptune III, is the inner satellite of Neptune. It was discovered sometime before mid-September 1989 from the images taken by the Voyager 2. The last moon to be discovered during the flyby, it was designated S/1989 N 6.

1995 Discovery of the top quark

The top quark is the third-generation up-type quark with a charge of +(2/3)e. It was discovered in 1995 by the CDF and D0 experiments at Fermilab and is the most massive of known elementary particles.

1995 Discovery of the Hale-Bopp comet

Comet Hale-Bopp was arguably the most widely observed comet of the twentieth century, and one of the brightest seen for many decades and it was visible to the naked eye for a record 18 months when it passed near planet Earth. Hale-Bopp was discovered by Alan Hale and Thomas Bopp on July 23, 1995 at a great distance from the Sun, raising expectations that the comet would brighten considerably by the time it passed close to Earth. Although predicting the brightness of comets with any degree of accuracy is very difficult, Hale-Bopp met or exceeded most predictions when it passed perihelion on April 1, 1997.

1998 Discovery of the embryonic stem cell line

A breakthrough in human embryonic stem cell research came in November 1998 when a group led by Dr. James Thomson at the University of Wisconsinadison first discovered a technique in order to isolate and grow cells which derived from human blastocysts, could one day lead to major medical advancements in organ transplantation as well as gene therapy and treatment of maladies such as paralysis, diabetes, cancer, and AIDS.

2001 Discovery of interstellar vinyl alcohol

Between May and June 2001, astronomers A. J. Apponi and Barry Turner discovered vinyl alcohol in the molecular cloud Sagittarius B using the National Science Foundation’s 12-meter radio telescope at the Kitt Peak National Observatory.

2003 Discovery of Psamathe

Psamathe, also known as Neptune X, is a retrograde irregular satellite of Neptune. Psamathe was discovered by Scott S. Sheppard and David C. Jewitt in 2003.

2003 Discovery of Mab

Mab is an inner satellite of Uranus. It was discovered by Mark R. Showalter and Jack J. Lissauer in 2003 using the Hubble Space Telescope.

2003 Discovery of Perdita

Perdita is an inner satellite of Uranus. Perdita’s discovery was complicated. The first photographs of Perdita were taken by the Voyager 2 spacecraft in 1986, but it was not recognized from the photographs for more than a decade. In 1999, the moon was noticed by Erich Karkoschka and reported. But because no further pictures could be taken to confirm its existence, it was officially demoted in 2001. However, in 2003, pictures taken by the Hubble Space Telescope managed to pick up an object where Perdita was supposed to be, finally confirming its existence.

2003 Discovery of Cupid

Cupid is an inner satellite of Uranus. It was discovered by Mark Showalter and Jack J. Lissauer in 2003 using the Hubble Space Telescope.

2005 Discovery of Hydra

Hydra is the outer-most natural satellite of Pluto. It was discovered along with Nix in June 2005 by the Hubble Space Telescope’s Pluto Companion Search Team, which is composed of Hal A. Weaver, Alan Stern, Max J. Mutchler, Andrew J. Steffl, Marc W. Buie, William J. Merline, John R. Spencer, Eliot F. Young, and Leslie A. Young.

2005 Discovery of Nix

Nix is a natural satellite of Pluto. It was discovered along with Hydra in June 2005 by the Hubble Space Telescope’s Pluto Companion Search Team, composed of Hal A. Weaver, S. Alan Stern, Max J. Mutchler, Andrew J. Steffl, Marc W. Buie, William J. Merline, John R. Spencer, Eliot F. Young, and Leslie A. Young.

2007 Discovery of human genome and variation mapping

The human genome is the genome of Homo sapiens, which is stored on 23 chromosome pairs. Whereas a genome sequence lists the order of every DNA base in a genome, a genome map identifies the landmarks. A genome map is less detailed than a genome sequence and aids in navigating around the genome. While working at the National Institute of Health, Craig Venter discovered a technique for rapidly identifying all of the mRNAs present in a cell, and began to use it to identify human brain genes. The short cDNA sequence fragments discovered by this method are called expressed sequence tags. Through his scientific research of bringing the world one step closer to personalized medicine, Craig Venter was listed on Time Magazine’s 2007 and 2008 Time 100 list of the most influential people in the world.

2007 Discovery of the di-positronium

The di-positronium is a molecule consisting of two atoms of positronium. It was predicted to exist in 1946 by John Archibald Wheeler and subsequently studied theoretically, but was not observed until 2007 in an experiment done by David Cassidy and Allen Mills at the University of California, Riverside.

See also

List of African American inventors and scientists

NASA spinoff

National Inventors Hall of Fame

Science and technology in the United States

Technological and industrial history of the United States

Timeline of United States inventions

United States Patent and Trademark Office

Yankee ingenuity

Footnotes

^ “Chloroform”. BBC Radio 4. http://www.bbc.co.uk/radio4/science/thematerialworld_20050728.shtml. 

^ “Vaseline”. Unilever. http://www.unileverusa.com/ourbrands/personalcare/vaseline.asp. 

^ “J. Willard Gibbs”. American Physical Society. http://www.aps.org/programs/outreach/history/historicsites/gibbs.cfm. 

^ “Under the Moons of Mars”. NASA. http://www.nasa.gov/exploration/whyweexplore/Why_We_27_prt.htm. 

^ “Nasa probe pictures Phobos moon”. BBC News. http://news.bbc.co.uk/2/hi/science/nature/7340670.stm. 

^ “Amalthea”. Encyclopaedia Britannica. http://www.britannica.com/EBchecked/topic/18395/Amalthea. 

^ “Phoebe”. Encyclopaedia Britannica. http://www.britannica.com/EBchecked/topic/457103/Phoebe. 

^ “Seyfert Galaxies”. Illinois Mathematics and Science Academy. http://alumni.imsa.edu/~truvett/astrophysics/seyferts.html. 

^ “The History of Propane”. National Propane Gas Association. http://www.npga.org/i4a/pages/index.cfm?pageid=634. 

^ “”Primary Malignant Growth of the Lung and Bronchi”". A Cancer Journal for Clinicians. http://caonline.amcancersoc.org/cgi/reprint/30/5/295.pdf. 

^ “Discovery of the Ninth Satellite of Jupiter”. Publications of the Astronomical Society of the Pacific. http://adsabs.harvard.edu//full/seri/PASP./0026//0000197.000.html. 

^ “Gilbert N. Lewis”. Encyclopaedia Britannica. http://www.britannica.com/EBchecked/topic/338142/Gilbert-N-Lewis. 

^ “Heparin used as an anticoagulant”. AnimalResearch.info. http://www.animalresearch.info/en/medical/timeline/anticoagulants#ref1. 

^ “Vitamin A”. Hyper Physics. http://hyperphysics.phy-astr.gsu.edu/HBASE/organic/vitamina.html. 

^ “Extragalactic Astronomy and Cosmology”. University of Bonn. http://www.astro.uni-bonn.de/~peter/inE.html. 

^ The Realm of the Nebulae. Yale University Press. http://books.google.com/books?id=kgiXdDGLpFUC. 

^ “Finding Pluto: Tough Task, Even 75 Years Later”. Imaginova Corp.. http://www.space.com/spacewatch/050311_pluto_guide.html. 

^ “Harold C. Urey”. Nobelprize.org. http://nobelprize.org/nobel_prizes/chemistry/laureates/1934/urey-bio.html. 

^ “Karl Jansky and the Discovery of Cosmic Radio Waves”. The National Radio Astronomy Observatory. http://www.nrao.edu/whatisra/hist_jansky.shtml. 

^ “Carl D. Anderson”. Encyclopaedia Britannica. http://student.britannica.com/comptons/article-9316287/Carl-D-Anderson. 

^ “Walter Bradford Cannon”. American Public Health Association. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1447286. 

^ “Gilbert Newton Lewis”. Massachusetts Institute of Technology. http://web.mit.edu/invent/iow/lewis.html. 

^ “History of Plastics”. Plastics Federation of South Africa. http://www.plasticsinfo.co.za/plastics-the-material.asp. 

^ Hubble, E. P. (1936). The Realm of the Nebulae. New Haven: Yale University Press. ISBN 36018182. 

^ “Muon Lifetime Experiment Purpose Introduction”. Ohio State University. http://www.physics.ohio-state.edu/~klaus/phys780.05/projects/Muon.pdf. 

^ “Vitamin E”. Time Magazine. http://www.time.com/time/magazine/article/0,9171,730521,00.html. 

^ “General Anesthetic Pentothal”. Massachusetts Institute of Technology. http://web.mit.edu/invent/iow/volwiler_tabern.html. 

^ “Niacin Augments the Benefits of Statins”. Life Enhancement Products, Inc.. http://www.life-enhancement.com/article_template.asp?id=1016. 

^ “Michael Sveda, the Inventor Of Cyclamates, Dies at 87″. Nobel The New York Times. http://query.nytimes.com/gst/fullpage.html?res=9507EFD61238F932A1575BC0A96F958260. 

^ “DuPont Fluoropolymer Solutions”. DuPont. http://www2.dupont.com/Teflon_Plunkett/en_US/assets/downloads/k20165.pdf. 

^ “Donald R. Griffin”. The National Academies Press. http://www.nap.edu/readingroom.php?book=biomems&page=dgriffin.html. 

^ “Two New Satellites of Jupiter”. Publications of the Astronomical Society of the Pacific. http://adsabs.harvard.edu//full/seri/PASP./0050//0000292.000.html. 

^ “Science Engineering and Technology timeline”. Intute. http://www.intute.ac.uk/sciences/timeline8.html. 

^ “Time, and the great healer”. Guardian News and Media Limited. http://www.guardian.co.uk/education/2002/nov/02/research.highereducation. 

^ “Jacob Marinsky; co-discoverer of promethium”. Boston Globe. http://www.boston.com/news/globe/obituaries/articles/2005/09/09/jacob_marinsky_co_discoverer_of_promethium/. 

^ “Warfarin: almost 60 years old and still causing problems”. University of Liverpool. http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1885167. 

^ “Miranda”. Sea and Sky. http://www.seasky.org/solarsystem/sky3h2.html. 

^ “Irvine Heinly Page”. The National Academies Press. http://www.nap.edu/readingroom.php?book=biomems&page=ipage.html. 

^ “California Megan’s Law – California Department of Justice – Office of the Attorney General”. California Department of Justice. http://www.dhh.louisiana.gov/offices/miscdocs/docs-249/vet/Tetracyclines.pdf. 

^ “The barium stars in the Hertzsprung-Russel diagram”. Harvard University. http://adsabs.harvard.edu/full/1997A&A…321L…9B. 

^ “An unidentified object near Jupiter, probably a new satellite”. Publications of the Astronomical Society of the Pacific. http://adsabs.harvard.edu//full/seri/PASP./0063//0000297.000.html. 

^ “Rapid Eye Movement”. Stanford University. http://www.stanford.edu/home/welcome/research/rem.html. 

^ “The elementary DNA of Dr Watson”. Times Newspapers Ltd.. http://entertainment.timesonline.co.uk/tol/arts_and_entertainment/books/article2630748.ece. 

^ “Antiproton”. Encyclopedia Britannica. http://www.britannica.com/EBchecked/topic/28507/antiproton. 

^ “A brief overview of porous silicon”. Duke University. http://people.ee.duke.edu/~flu/index_files/A brief overview of porous silicon.pdf. 

^ “Leon Lederman, the K-meson, the Muon Neutrino, and the Bottom Quark”. US Department of Energy. http://www.osti.gov/accomplishments/lederman.html. 

^ “2. New Directions and New Machines”. UC Berkeley. http://bancroft.berkeley.edu/Exhibits/physics/extending02.html. 

^ “The First Detection of The Neutrino by Frederick Reines and Clyde Cowan”. University of California at Irvine. http://www.ps.uci.edu/physics/news/nuexpt.html. 

^ “Scientists celebrate 50 years since key RNA discovery”. Massachusetts Institute of Technology. http://web.mit.edu/newsoffice/2007/rna-history.html. 

^ “The Van Allen Belt”. NASA. http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970228a.html. 

^ “Owen Chamberlain, 85, Dies; Discovered Antiproton”. New York Times. http://www.nytimes.com/2006/03/02/science/02chamberlain.html. 

^ “Seafloor spreading”. Encyclopaedia Britannica. http://www.britannica.com/EBchecked/topic/530828/seafloor-spreading-hypothesis. 

^ “Interaction of the eta-meson with light nuclei”. University of South Africa. http://etd.unisa.ac.za/ETD-db/theses/available/etd-04212006-152252/unrestricted/dissertation.pdf. 

^ The Xi Baryon

^ “Fighting talk on the front line”. The Daily Telegraph 4. http://www.telegraph.co.uk/connected/main.jhtml?xml=/connected/2000/10/19/ecfqark19.xml. 

^ “Desert Island Discs”. BBC Radio 4. http://www.bbc.co.uk/radio4/factual/desertislanddiscs_20030119.shtml. 

^ “History”. The Aspartame Information Service. http://www.aspartame.net/Aspartame_history.asp. 

^ “A New Short-Period Blue Variable”. Harvard University. http://adsabs.harvard.edu/abs/1968ApJ…153..151L. 

^ “Two Professors Share 1990 Physics Nobel”. Massachusetts Institute of Technology. http://web.mit.edu/newsoffice/tt/1990/oct24/nobelsmain.html. 

^ “What is matter?”. Jefferson Lab. http://education.jlab.org/beamsactivity/6thgrade/whatismatter/whatismatter.pdf. 

^ “A versatile reagent for the determination of enantiomeric composition of alcohols and amines”. Journal of Organic Chemistry. http://pubs.acs.org/doi/abs/10.1021/jo01261a013. 

^ “EVENTS IN SCIENCE AND MATHEMATICS”. Ohio State University. http://www.physics.ohio-state.edu/~wilkins/science/sciehist.html. 

^ “Reverse Transcriptase and the Generation of Retroviral DNA”. National Center for Biotechnology Information. http://www.ncbi.nlm.nih.gov/books/bv.fcgi?indexed=google&rid=rv.chapter.1053. 

^ “Meson”. Britannica Online Encyclopedia. http://www.britannica.com/EBchecked/topic/376781/meson. 

^ “Structure of Matter”. Nobelprize.org. http://nobelprize.org/educational_games/physics/matter/18.html. 

^ “Binary pulsar”. Encyclopaedia Britannica. http://www.britannica.com/EBchecked/topic/65555/binary-pulsar. 

^ “Press Information Sheet: New Outer Satellite of Jupiter Discovered”. Harvard University. http://www.cfa.harvard.edu/iau/pressinfo/S1999J1.html. 

^ “JUPITER SATELLITE (2000 J1 = S/1975 J1)”. University of Hawaii. http://www.ifa.hawaii.edu/faculty/jewitt/2000J1/jovs.html. 

^ “Timelines of Events in Science, Mathematics, and Technology”. Ohio State University. http://www.physics.ohio-state.edu/~wilkins/science/sctmln.html. 

^ “Uranus”. BBC. http://www.bbc.co.uk/dna/h2g2/A396713. 

^ “Upsilon meson”. Britannica Encyclopaedia. http://www.britannica.com/EBchecked/topic/618905/upsilon-meson. 

^ “Leon Lederman, the K-meson, the Muon, Neutrino, and the Bottom Quark”. US Department of Energy. http://www.osti.gov/accomplishments/lederman.html. 

^ “The Nobel Prize in Physiology or Medicine 1978″. Nobel Foundation. http://nobelprize.org/nobel_prizes/medicine/laureates/1978/press.html. 

^ “Charon”. BBC – Science & Nature – Space. http://www.bbc.co.uk/science/space/solarsystem/pluto/charon.shtml. 

^ “Metis”. The University Corporation of Atmospheric Research. http://www.windows.ucar.edu/tour/link=/jupiter/moons/metis.html. 

^ “1979J2: The Discovery of a Previously Unknown Jovian Satellite”. ScienceMag. http://www.sciencemag.org/cgi/content/abstract/210/4471/786. 

^ “The Jupiter System through the Eyes of Voyager 1″. Harvard University. http://adsabs.harvard.edu/abs/1979Sci…204..951S. 

^ “IAUC 3539: 1980 S 28″. Harvard University. http://cfa-www.harvard.edu/iauc/03500/03539.html. 

^ “IAUC 3532: SN IN NGC 6946; Sats OF SATURN; HD 44179; W Hya”. Harvard University. http://cfa-www.harvard.edu/iauc/03500/03532.html. 

^ “Saturn: Moons: Atlas”. NASA. http://solarsystem.nasa.gov/planets/profile.cfm?Object=Sat_Atlas. 

^ “Larissa”. Aristotle University of Thessaloniki. http://www.astro.auth.gr/ANTIKATOPTRISMOI/nineplanets/nineplanets/larissa.html. 

^ a b c d e f g h i j “The Moons of Uranus”. Smithsonian Institution. http://www.nasm.si.edu/research/ceps/etp/uranus/uran_moons.html. 

^ “Voyager 2 Finds Rings at Neptune (But Not All the Way Around It)”. The New York Times. http://query.nytimes.com/gst/fullpage.html?res=950DE3DE1338F931A2575BC0A96F948260. 

^ “Proteus – Voyager 2″. NASA. http://nssdc.gsfc.nasa.gov/imgcat/html/object_page/vg2_1138920.html. 

^ a b c d “Neptune in 3D”. CSU Hayward. http://www.mcs.csuhayward.edu/~malek/Space/Solar08.html. 

^ “Inquiring Minds”. Fermni National Accelerator Laboratory. http://www.fnal.gov/pub/inquiring/physics/discoveries/top_quark.html. 

^ “THE DISCOVERY OF COMET HALE-BOPP”. NASA. http://www2.jpl.nasa.gov/comet/discovery.html. 

^ “James Thomson: shifts from embryonic stem cells to induced pluripotency”. Nature. http://www.nature.com/stemcells/2008/0808/080814/full/stemcells.2008.118.html. 

^ “Scientists Toast the Discovery of Vinyl Alcohol in Interstellar Space”. National Radio Astronomy Observatory. http://www.nrao.edu/pr/2001/vinylalco/. 

^ “Psamathe”. AstroWWW. http://ksiezyce.astrowww.pl/neptune/psamathe_en.html. 

^ “NASA’s Hubble Discovers New Rings And Moons Around Uranus”. Science Daily. http://www.sciencedaily.com/releases/2005/12/051223085800.htm. 

^ “Perdita”. AstroWWW. http://ksiezyce.astrowww.pl/uranus/perdita_en.html. 

^ “IAU Circular No. 8209″. Harvard University. http://cfa-www.harvard.edu/iauc/08200/08209.html. 

^ a b “New names for Pluto’s moons”. PhysicsWorld. http://physicsworld.com/cws/article/news/25196. 

^ “Top 10 Scientific Discoveries”. Time Inc.. http://www.time.com/time/specials/2007/top10/article/0,30583,1686204_1686252_1690928,00.html. 

^ “Molecules made with antimatter”. Royal Society of Chemistry. http://www.rsc.org/chemistryworld/News/2007/September/13090701.asp. 

v  d  e

United States topics

History

Timeline

Pre-Columbian era  Colonial era (Thirteen Colonies) (Colonial American military history)   American Revolution (War)  Federalist Era War of 1812  Territorial changes  Mexican-American War  American Civil War  Reconstruction era  American Indian Wars  Gilded Age  African-American Civil Rights Movement (18961954)  Spanish-American War  World War I  Roaring Twenties  Great Depression  World War II (Home front)  Cold War  Korean War  Space Race  African-American Civil Rights Movement (19551968)  Feminist Movement  Vietnam War  Post-Cold War (1991resent)  War on Terrorism (War in Afghanistan  Iraq War)

Topics

Demographic  Economic  Military  Postal  Technological and industrial  Inventions  Discoveries

Federal

government

   

Law

Constitution

Bill of Rights

Civil liberties

Federalism

Separation of powers

Law enforcement

Department of Justice

Federal Bureau of Investigation

Legislature – Congress

House of Representatives  Speaker of the House

Senate  President of the Senate

Executive – President

Vice President

Executive Office

Cabinet / executive departments

Independent agencies

Civil service  Policies

Judiciary – Supreme Court

Federal courts

Courts of appeal

District courts

Intelligence

Intelligence Community

Central Intelligence Agency

Defense Intelligence Agency

National Security Agency

Armed Forces

Army

Marine Corps

Navy

Air Force

Coast Guard

Politics

State governments  Local governments  Elections (Electoral College)  Divisions  Ideologies  Parties (Democratic Party  Republican Party  Third parties)  Scandals  Political status of Puerto Rico  Red states and blue states  Uncle Sam

Geography

Cities, towns, and villages  Counties  Extreme points  Islands  Mountains (Peaks  Appalachian  Rocky)  National Park System  Regions (Great Plains  Mid-Atlantic  Midwestern  New England  Northern  Northwestern  Southern  Southwestern  Pacific  Western)  Rivers (Colorado  Mississippi  Missouri)  States  Territory  Water supply and sanitation

Economy

Agriculture  Banking  Communications  Companies  Dollar  Energy  Federal Budget  Federal Reserve System  Insurance  Standard of living (Personal income  Household income  Homeownership  Income inequality)  Mining  Public debt  Taxation  Tourism  Trade  Transportation  Wall Street

Society

Adolescent sexuality  Crime  Demographics  Education  Health care  Health insurance  Incarceration  Languages (American English  Spanish)  Media  People  Public holidays  Religion  Social class (Affluence  American Dream  Middle class  Educational attainment  Poverty  Professional and working class conflict)  Sports

Culture

Literature  Philosophy  Architecture  Cuisine  Dance  Fashion  Flag  Folklore  Music  Radio  Television / Cinema  Visual arts

Issues

Abortion  Affirmative action  Anti-Americanism  Capital punishment  Drug policy  Exceptionalism  Energy policy  Environmental movement  Gun politics  Health care reform  Human rights  Immigration   LGBT rights (Same-sex marriage)  Obesity  Racism  Terrorism

Portal

Categories: American inventions | History of science and technology in the United States | Technology-related lists | Lists of inventions or discoveries | United States-related listsHidden categories: Wikipedia articles needing clarification from April 2009