These are Good articles, which meet a core set of high editorial standards.
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Image 118th-century glassmaking in the United States began before the country existed. During the previous century, several attempts were made to produce glass, but none were long-lived. By 1700, it is thought that little or no glass was being produced in the
British colonies that would eventually become the United States. The first American glass factory operated with long–term success was started by
Caspar Wistar in 1745—although two glass works in
New Amsterdam that operated in the previous century deserve honorable mention. Wistar's glass works was located in the English colony known as the
Province of New Jersey. In the southeastern portion of the
Province of Pennsylvania,
Henry Stiegel was the first American producer of high–quality glassware known as
crystal. Stiegel's first glass works began in 1763, and his better quality glassmaking began in 1769. In the United States, the first use of coal as a fuel for glassmaking furnaces is believed to have started in 1794 at a short-lived factory on the
Schuylkill River near Philadelphia. In 1797 Pittsburgh's O'Hara and Craig glass works was also powered by coal, and it contributed to the eventual establishment of Pittsburgh as a leading glassmaking center in the 19th century.
Many of the skilled glass workers in the United States during the 17th and 18th centuries came from the German-speaking region of Europe. German–born Johann Friedrich Amelung (later renamed
John Frederick Amelung) employed 342 people in 1788 at his New Bremen glass works located in
Frederick County, Maryland. His skilled workers were German. Other prominent glass makers such as Wistar, Stiegel, and the Stanger brothers were also German. In many cases, as a glass works failed, the skilled workers found work at another factory. (
Full article...)
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Image 2
Wilson at the Fermilab groundbreaking ceremony
(March 4, 1914 – January 16, 2000) was an American
physicist known for his work on the
Manhattan Project during
World War II, as a
sculptor, and as an architect of the
Fermi National Accelerator Laboratory (Fermilab), where he was the first director from 1967 to 1978.
A graduate of the
University of California, Berkeley, Wilson received his doctorate under the supervision of
Ernest Lawrence for his work on the development of the
cyclotron at the Berkeley
Radiation Laboratory. He subsequently went to
Princeton University to work with
Henry DeWolf Smyth on
electromagnetic separation of the
isotopes of uranium. In 1943, Wilson and many of his colleagues joined the
Manhattan Project's
Los Alamos Laboratory, where Wilson became the head of its Cyclotron Group (R-1), and later its Research (R) Division. (
Full article...)
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Image 4A
frog battery is an
electrochemical battery consisting of a number of dead frogs (or sometimes live ones), which form the
cells of the battery connected in a
series arrangement. It is a kind of
biobattery. It was used in early scientific investigations of electricity and academic demonstrations.
The principle behind the battery is the
injury potential created in a muscle when it is damaged, although this was not fully understood in the 18th and 19th centuries; the
potential being caused incidentally due to the dissection of the frog's muscles. (
Full article...)
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Image 5The
physics of a bouncing ball concerns the physical behaviour of
bouncing balls, particularly its
motion before, during, and after
impact against the surface of another
body. Several aspects of a bouncing ball's behaviour serve as an introduction to
mechanics in
high school or
undergraduate level physics courses. However, the exact modelling of the behaviour is complex and of interest in
sports engineering.
The motion of a ball is generally described by
projectile motion (which can be affected by
gravity,
drag, the
Magnus effect, and
buoyancy), while its impact is usually characterized through the
coefficient of restitution (which can be affected by the nature of the ball, the nature of the impacting surface, the impact velocity, rotation, and local conditions such as
temperature and
pressure). To ensure
fair play, many
sports governing bodies set limits on the bounciness of their ball and forbid tampering with the ball's aerodynamic properties. The bounciness of balls has been a feature of sports as ancient as the
Mesoamerican ballgame. (
Full article...)
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Image 6Electrical elastance is the
reciprocal of
capacitance. The
SI unit of elastance is the inverse
farad (F
−1). The concept is not widely used by electrical and electronic engineers, as the value of
capacitors is typically specified in units of capacitance rather than inverse capacitance. However, elastance is used in theoretical work in network analysis and has some niche applications, particularly at
microwave frequencies.
The term
elastance was coined by
Oliver Heaviside through the analogy of a capacitor to a spring. The term is also used for analogous quantities in other energy domains. In the mechanical domain, it corresponds to
stiffness, and it is the inverse of
compliance in the fluid flow domain, especially in
physiology. It is also the name of the generalized quantity in
bond-graph analysis and other schemes that analyze systems across multiple domains. (
Full article...)
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Image 7Donald William Kerst (November 1, 1911 – August 19, 1993) was an American
physicist who worked on advanced
particle accelerator concepts (
accelerator physics) and
plasma physics. He is most notable for his development of the
betatron, a novel type of particle accelerator used to accelerate
electrons.
A graduate of the
University of Wisconsin–Madison, Kerst developed the first betatron at the
University of Illinois at Urbana Champaign, where it became operational on July 15, 1940. During
World War II, Kerst took a leave of absence in 1940 and 1941 to work on it with the engineering staff at
General Electric, and he designed a portable betatron for inspecting
dud bombs. In 1943 he joined the
Manhattan Project's
Los Alamos Laboratory, where he was responsible for designing and building the Water Boiler, a
nuclear reactor intended to serve as a laboratory instrument. (
Full article...)
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Image 8Magnetic resonance imaging (
MRI) is a
medical imaging technique used in
radiology to generate pictures of the
anatomy and the
physiological processes inside the body.
MRI scanners use strong
magnetic fields, magnetic field gradients, and
radio waves to form images of the organs in the body. MRI does not involve
X-rays or the use of
ionizing radiation, which distinguishes it from
computed tomography (CT) and
positron emission tomography (PET) scans. MRI is a
medical application of
nuclear magnetic resonance (NMR) which can also be used for imaging in other
NMR applications, such as
NMR spectroscopy.
MRI is widely used in hospitals and clinics for
medical diagnosis,
staging and follow-up of disease. Compared to CT, MRI provides better
contrast in images of soft tissues, e.g. in the
brain or abdomen. However, it may be perceived as less comfortable by patients, due to the usually longer and louder measurements with the subject in a long, confining tube, although "open" MRI designs mostly relieve this. Additionally,
implants and other non-removable metal in the body can pose a risk and may exclude some patients from undergoing an MRI examination safely. (
Full article...)
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Image 9
Wheeler lecturing on "Beyond the End of Time" at the University of Missouri
(July 9, 1911 – April 13, 2008) was an American
theoretical physicist. He was largely responsible for reviving interest in
general relativity in the United States after
World War II. Wheeler also worked with
Niels Bohr to explain the basic principles of
nuclear fission. Together with
Gregory Breit, Wheeler explored positron-electron pair production from the collision of two photons, now known as the
Breit–Wheeler process. He is known for popularizing the term "
black hole" to describe the gravitationally completely collapsed objects predicted by general relativity. He also coined "
quantum foam", "
neutron moderator", "
wormhole" and "it from bit", and hypothesized the "
one-electron universe".
Stephen Hawking called Wheeler the "hero of the black hole story".
At 21, Wheeler earned his doctorate at
Johns Hopkins University under the supervision of
Karl Herzfeld. He studied under Breit and Bohr on a
National Research Council fellowship. In 1939 he collaborated with Bohr on a series of papers using the
liquid drop model to explain the mechanism of fission. During World War II, he worked with the
Manhattan Project's
Metallurgical Laboratory in Chicago, where he helped design
nuclear reactors, and then at the
Hanford Site in
Richland, Washington, where he helped
DuPont build them. He returned to Princeton after the war but returned to government service to help design and build the
hydrogen bomb in the early 1950s. He and
Edward Teller were the main civilian proponents of thermonuclear weapons. (
Full article...)
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Image 10The
Wu experiment was a
particle and
nuclear physics experiment conducted in 1956 by the
Chinese-American physicist
Chien-Shiung Wu in collaboration with the Low Temperature Group of the US
National Bureau of Standards. The experiment's purpose was to establish whether conservation of
parity, which was previously established in the
electromagnetic and
strong interactions, also applied to
weak interactions. If parity conservation were universal, particle decays governed by the weak interaction would behave similarly to particle decays involving the other interactions. A parity transformation negates the coordinates in a theory. If the predictions of the theory are not altered, it is said to "conserve parity". A parity transformation creates a mirror image. In mirror images, objects spinning clockwise appear to spin counterclockwise. The Wu experiment created an atomic system with spin, then compared weak-interaction particle decay for spins clockwise and anti-clockwise.
The experiment established that conservation of parity was violated by the weak interaction, thus providing a way to
operationally define left and right. This result was not expected by the physics community, which had previously regarded parity as a symmetry that applied to all forces of nature.
Tsung-Dao Lee and
Chen-Ning Yang, the theoretical physicists who originated the idea of parity nonconservation and proposed the experiment, received the 1957
Nobel Prize in Physics for this result. While not awarded the Nobel Prize,
Chien-Shiung Wu's role in the discovery was mentioned in the Nobel Prize acceptance speech of Yang and Lee, but she was not honored until 1978, when she was awarded the first
Wolf Prize. (
Full article...)
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Image 12Pythagoras of Samos (
Ancient Greek:
Πυθαγόρας;
c. 570 – c.
495 BC) was an ancient
Ionian Greek philosopher,
polymath, and the eponymous founder of
Pythagoreanism. His political and religious teachings were well known in
Magna Graecia and influenced the philosophies of
Plato,
Aristotle, and, through them,
Western philosophy. Modern scholars disagree regarding Pythagoras's education and influences, but most agree that he travelled to
Croton in southern Italy around 530 BC, where he founded a school in which initiates were allegedly sworn to secrecy and lived a communal,
ascetic lifestyle.
In antiquity, Pythagoras was credited with
mathematical and scientific discoveries, such as the
Pythagorean theorem,
Pythagorean tuning, the
five regular solids, the
theory of proportions, the
sphericity of the Earth, the identity of the
morning and
evening stars as the planet
Venus, and the division of the globe into
five climatic zones. He was reputedly the first man to call himself a philosopher ("lover of wisdom"). Historians debate whether Pythagoras made these discoveries and pronouncements, as some of the accomplishments credited to him likely originated earlier or were made by his colleagues or successors, such as
Hippasus and
Philolaus. (
Full article...)
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Image 13Ice is
water that is
frozen into a
solid state, typically forming at or below temperatures of 0 °
C, 32 °
F, or 273.15
K. It occurs naturally on
Earth, on other planets, in
Oort cloud objects, and as
interstellar ice. As a naturally occurring crystalline inorganic solid with an ordered structure, ice is considered to be a
mineral. Depending on the presence of
impurities such as particles of
soil or bubbles of
air, it can appear transparent or a more or less
opaque bluish-white color.
Virtually all of the ice on Earth is of a
hexagonal crystalline structure denoted as
ice Ih (spoken as "ice one h"). Depending on temperature and pressure, at least nineteen
phases (
packing geometries) can exist. The most common
phase transition to ice I
h occurs when liquid water is cooled below
0 °C (
273.15 K,
32 °F) at
standard atmospheric pressure. When water is cooled rapidly (
quenching), up to three types of amorphous ice can form. Interstellar ice is overwhelmingly low-density amorphous ice (LDA), which likely makes LDA ice the most abundant type in the universe. When cooled slowly, correlated proton tunneling occurs below
−253.15 °C (
20 K,
−423.67 °F) giving rise to
macroscopic quantum phenomena. (
Full article...)
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Image 14
Police photograph of Fuchs (
c. 1940)
(29 December 1911 – 28 January 1988) was a German
theoretical physicist,
atomic spy, and communist who supplied information from the American, British, and Canadian
Manhattan Project to the
Soviet Union during and shortly after
World War II. While at the
Los Alamos Laboratory, Fuchs was responsible for many significant theoretical calculations relating to the first
nuclear weapons and, later, early models of the
hydrogen bomb. After his conviction in 1950, he served nine years in prison in the United Kingdom, then migrated to
East Germany where he resumed his career as a physicist and scientific leader.
The son of a
Lutheran pastor, Fuchs attended the
University of Leipzig, where his father was a professor of
theology, and became involved in student politics, joining the student branch of the
Social Democratic Party of Germany (SPD), and the
Reichsbanner Schwarz-Rot-Gold, an SPD-allied
paramilitary organisation. He was expelled from the SPD in 1932, and joined the
Communist Party of Germany (KPD). He went into hiding after the 1933
Reichstag fire and the subsequent persecution of communists in Nazi Germany, and fled to the United Kingdom, where he received his
PhD from the
University of Bristol under the supervision of
Nevill Francis Mott, and his
DSc from the
University of Edinburgh, where he worked as an assistant to
Max Born. (
Full article...)
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Image 15The
metric system is a
system of measurement that
standardises a set of base units and a
nomenclature for describing relatively large and small quantities using
decimal-based multiplicative
unit prefixes. Though the rules governing the metric system have changed over time, the modern definition, the
International System of Units (SI), defines the
metric prefixes and seven base units:
metre (m),
kilogram (kg),
second (s),
ampere (A),
kelvin (K),
mole (mol), and
candela (cd).
An
SI derived unit is a named combination of base units, such as the
hertz (cycles per second),
newton (kg⋅m/s
2), and
tesla (1 kg⋅s
−2⋅A
−1). In the case of degrees
Celsius, it is a shifted scale derived from the kelvin. Certain units have been
officially accepted for use with the SI. Some of these are decimalised, like the
litre and
electronvolt, and are considered "metric". Others, like the
astronomical unit are not. Ancient non-metric but SI-accepted multiples of time,
minute and
hour, are base 60 (
sexagesimal). Similarly, the angular measure
degree and submultiples,
arcminute, and
arcsecond, are also sexagesimal and SI-accepted. (
Full article...)
The following are images from various physics-related articles on Wikipedia.
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Image 1The Hindu-Arabic numeral system. The inscriptions on the
edicts of Ashoka (3rd century BCE) display this number system being used by the Imperial
Mauryas. (from
History of physics)
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Image 2Johannes Kepler's first
law of planetary motion states that planets move in elliptical orbits about the Sun. (from
History of physics)
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Image 3The
quantum Hall effect: Components of the Hall resistivity as a function of the external magnetic field (from
Condensed matter physics)
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Image 6Magdeburg hemispheres, an experiment by
Otto von Guericke where two metal hemispheres are held together by vacuum and cannot be separated even if large forces are applied. (from
History of physics)
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Image 7The ancient Greek mathematician
Archimedes, developer of ideas regarding
fluid mechanics and
buoyancy. (from
History of physics)
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Image 8Marie Skłodowska-Curie(1867–1934) received Nobel prizes in physics (1903) and chemistry (1911). (from
History of physics)
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Image 10Christiaan Huygens (1629–1695) (from
History of physics)
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Image 11James Prescott Joule's apparatus for measuring the
mechanical equivalent of heat which the "
work" of the falling weight is converted into the "
heat" of agitation in the water. (from
History of physics)
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Image 13Newton's cannonball, a though experiment by Newton relating the motion of a projectile and orbiting of planets. (from
History of physics)
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Image 14Chien-Shiung Wu worked on parity violation in 1956 and announced her results in January 1957. (from
History of physics)
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Image 15Richard Feynman's Los Alamos ID badge (from
History of physics)
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Image 16Classical physics is usually concerned with everyday conditions: speeds are much lower than the
speed of light, sizes are much greater than that of atoms, yet very small in astronomical terms. Modern physics, however, is concerned with high velocities, small distances, and very large energies. (from
Modern physics)
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Image 20The first
Bose–Einstein condensate observed in a gas of ultracold
rubidium atoms. The blue and white areas represent higher density. (from
Condensed matter physics)
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Image 23Composite montage comparing
Jupiter (
left) and its four
Galilean moons (
from top:
Io,
Europa,
Ganymede,
Callisto) (from
History of physics)
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Image 24Star maps by the 11th century Chinese
polymath Su Song are the oldest known
woodblock-printed star maps to have survived to the present day. This example, dated 1092, employs the cylindrical
equirectangular projection. (from
History of physics)
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Image 25One possible signature of a Higgs boson from a simulated
proton–proton collision. It decays almost immediately into two jets of
hadrons and two electrons, visible as lines. (from
History of physics)
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Image 26Einstein proposed that
gravitation results from
masses (or their equivalent energies)
curving ("bending") the
spacetime in which they exist, altering the paths they follow within it. (from
History of physics)
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Image 27A
Feynman diagram representing (left to right) the production of a photon (blue
sine wave) from the
annihilation of an electron and its complementary
antiparticle, the
positron. The photon becomes a
quark–
antiquark pair and a
gluon (green spiral) is released. (from
History of physics)
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Image 28Hydrogen
emission spectrum is discrete (here in log scale). The lines can only be explained with quantum mechanics. (from
History of physics)
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Image 29Albert Einstein (1879–1955), ca. 1905 (from
History of physics)
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Image 30Classical physics (
Rayleigh–Jeans law, black line) failed to explain
black-body radiation – the so-called
ultraviolet catastrophe. The quantum description (
Planck's law, colored lines) is said to be
modern physics. (from
Modern physics)
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Image 31Galileo Galilei (1564–1642), early proponent of the modern scientific worldview and method (from
History of physics)
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Image 32Crookes tube used to study
cathode rays. It led to the discovery of the
electron by
J. J. Thomson. (from
History of physics)
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Image 33Computer simulation of
nanogears made of
fullerene molecules. It is hoped that advances in nanoscience will lead to machines working on the molecular scale. (from
Condensed matter physics)
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Image 34The
Voltaic pile, the first battery was invented by
Alessandro Volta in 1800 (from
History of physics)
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Image 36Image of X-ray diffraction pattern from a
protein crystal (from
Condensed matter physics)
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Image 37Replica of
William Herschel's telescope used to discover
Uranus (from
History of physics)
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Image 38Maxwell's demon, thought experiment by
James Clerk Maxwell to describe the
kinetic theory of gases and describe how a microscopic creature could lead to violations of the
second law of thermodynamics. (from
History of physics)
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Image 39A
magnet levitating above a
high-temperature superconductor. Today some physicists are working to understand high-temperature superconductivity using the AdS/CFT correspondence. (from
Condensed matter physics)
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Image 40Sir Isaac Newton (1642–1727) (from
History of physics)
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