Solar neutrino problem - Solar neutrino problem The solar neutrino problem was a major discrepancy between observation and the theory of nuclear physics, lasting from the mid-1960s to about 2002. The discrepancy has since been resolved by new understanding of neutrino physics, requiring a modification of the Standard Model of particle physics. The sun is a natural nuclear fusion reactor, fusing hydrogen to helium. Our current understanding of physics is quite clear about what happens, four hydrogen nuclei (protons), with and without the help of catalysts are transformed into helium, neutrinos and energy. The energy is released as gamma rays and as kinetic energy of the particles, including the neutrinos. Neutrinos were originally theorized to make up the energy and angular momentum difference when a neutron decays into a proton.
Sudbury Neutrino Observatory - Sudbury Neutrino Observatory The Sudbury Neutrino Observatory, or SNO for short, is located over a mile underground in an old mine near Sudbury, Ontario, Canada. The detector, made of heavy water, is designed to detect cosmic neutrinos, with the objectives of understanding the solar neutrino problem and neutrino mass. The SNO site is http://www.sno.phy.queensu.ca/.
Neutrino - Neutrino The neutrino is an elementary particle. It has spin 1/2 and so it is a fermion. Its mass is very small, as recent experiments (see Super-Kamiokande) have shown it to be different from zero. It only interacts through the weak interaction and feels neither the strong nor the electromagnetic interaction(but it feels gravity, but since it is extremely small, when gravity is already the weakest force, it hardly matters). Because the neutrino only interacts weakly, when moving through ordinary matter its chance of interacting with it is very small. It would take a light year of lead to block half the neutrinos flowing through it. Neutrino detectors therefore typically contain hundreds of tons of a material constructed so that a few atoms per day would.
Helioseismology - of the interior conditions of the sun. See also Asteroseismology List of ologies Magneto-gravity Proton-proton chain Solar neutrino problem Solar tower.
Sun - composition Hydrogen 73.46 % Helium 24.85 % Oxygen 0.77 % Carbon 0.29 % Iron 0.16 % Neon 0.12 % Nitrogen 0.09 % Silicon 0.07 % Magnesium 0.05 % Sulphur 0.04 % The Sun, sometimes called Sol, is the star in our solar system. The planet Earth and all of her sister planets, both the other terrestrial planets and the gas giants, orbit the Sun. Other bodies that orbit the Sun include asteroids, meteoroids, comets, Trans-Neptunian objects, and, of course, dust. Physical and other characteristics The Sun is a main sequence star, with a spectral class of G2, meaning that it is somewhat bigger and hotter than the average star but far smaller than a red giant star. A G2 star has a main sequence lifetime of about 10 billion years, and.
Supernova 1987a - Since 50 kiloparsecs is approximately 164,000 light-years, the cosmic event itself happened approximately 164,000 years ago. 1987a supernova remnant near the center Approximately three hours before the visible light from SN 1987a reached the Earth, a burst of neutrinos was observed at two separate neutrino observatories, which had originally been built to study the solar neutrino problem. Although the actual neutrino count was small - fewer than twenty in all - it was a significant rise from the previously-observed background level. This was the first time neutrinos emitted from a supernova had been observed directly, and the observations were consistent with theoretical supernova models in which most of the energy of the collapse is radiated away in neutrinos. It is a source of regret to astrophysicists and particle physicists that two.
Physics - -- Antimatter -- Elementary particle -- Boson -- Fermion Symmetry -- Motion -- Conservation law -- Mass -- Energy -- Momentum -- Angular momentum -- Spin Time -- Space -- Dimension -- Spacetime -- Length -- Velocity -- Force -- Torque Wave -- Wavefunction -- Quantum entanglement -- Harmonic oscillator -- Magnetism -- Electricity -- Electromagnetic radiation -- Temperature -- Entropy -- Physical information Phase transitions -- Critical phenomena -- Self-organization -- Spontaneous symmetry breaking -- Superconductivity -- Superfluidity -- Quantum phase transitions Fundamental forces Gravitational -- Electromagnetic -- Weak -- Strong Particles Main article: Particless Atom -- Proton -- Neutron -- Electron -- Quark -- Photon -- Gluon -- W boson -- Z boson -- Graviton -- Neutrino -- Particle radiation--Phonon--Roton Subfields of physics Accelerator physics -- Acoustics -- Astrophysics.
Proton-proton chain - first step involves the fusion of two hydrogen nuclei 1H (protons) into deuterium 2H, releasing a positron as one proton changes into a neutron, and a neutrino. To overcome the electromagnetic repulsion between two hydrogen nuclei requires a large amount of energy, and this reaction takes an average of 10 billion years to complete. It is because of the slowness of this reaction that the Sun is still shining; if it where faster, the Sun would have exhausted its hydrogen long ago. The neutrinos detected from the sun are signficantly below what the the proton-proton calculations predict resulting in what is known as the solar neutrino problem. Observations of pressure waves in the sun, known as helioseismology have indicated the the pressures and temperatures in the sun are very close to.
List of astronomical topics - of Bath -- Adhara -- Adler Planetarium -- Adrastea -- Aether theory -- Afterglow -- Age of the Earth -- Age of the Universe -- Airglow -- Airy disc -- Airy, George -- Aitken, Robert -- Al-Batani -- Albategnius -- Albedo -- Albireo -- Alcor -- Aldebaran -- Aldhelm, Bishop of Sherborne -- d'Alembert, Jean le Rond -- Alfonsine tables -- Alfonso X of Castile -- Alfvén, Hannes Olof Gösta -- Alfven universe -- Algieba -- Algol -- ALH84001 -- Alioth -- Alkaid -- Al-Khwarizmi -- Allegheny Observatory -- Almach -- Almagest -- Alnilam -- Alnitak -- Alniyat -- Alpha Centauri -- Alpha Centauri B -- Alpha particle -- Alpha Persei -- Alpha process -- Alpher-Bethe-Gamow theory -- Alpheratz -- Alphonsine tables -- Al Sufi -- Al Sufi, 'Abd Al-Rahman --.
List of physics topics R-Z - the universe Shock wave Shockley, William Bradford Shull, Clifford G SI base unit SI derived unit SI prefix Siegbahn, Kai M Siegbahn, Karl Manne Georg Simple harmonic motion Simultaneity Sine wave Singular-value decomposition Slope Snell's law Snell, Willebrord SO(3) Solar cell Solar neutrino problem Solar power Solid Solid state Solid state physics Soliton Sommerfeld, Arnold Sound Space Space group Space-time Spacetime Special linear group Special relativity Specific gravity Spectral line Spectroscope Spectroscopy Electromagnetic spectrum Optical spectrum Spectrum of a matrix Spectrum of an operator Speed Speed of gravity Speed of light Spherical coordinate system Spherical geometry Spin (physics) Spin glass Spin network Spin-statistics theorem Spinor Spinor field Spontaneous symmetry breaking Standard Model Stark, Johannes Stark effect Statcoulomb Statics Statistical Mechanics Statistical physics Statistics Stefan-Boltzmann constant Stefan-Boltzmann law Stefan electromagnetic equation Stefan's.
Galaxy rotation problem - Galaxy rotation problem The galaxy rotation problem is the discrepancy between the observed rotation of galaxies and the predictions of current physical theories. Attempts to resolve the galaxy rotation problem have included the hypothesis of dark matter and the hypothesis known as Modified Newtonian Dynamics. In the beginning of the 1980s, the first observational evidence was reported that galaxies do not spin as expected according to then current theories. A galaxy is a collection of stars orbiting the bulge (the center of the galaxy). Since the orbit of stars is driven solely by the gravitational force, it was expected that stars at the edge would have an orbital period much larger than those near the bulge. For example, the Earth which is 150 million kilometers away from the.
Complexity, Problem Solving, and Sustainable Societies - Complexity, Problem Solving, and Sustainable Societies Complexity, Problem Solving, and Sustainable Societies is an extremely influential 1996 paper in energy economics by Joseph Tainter. It focuses on the energy cost of problem solving, and the energy-complexity relation in manmade systems. This is a mirror of the negentropic tendencies of natural evolution, according to ecological economics, notably the arguments of Donella Meadows and her colleagues on the economic constraints of contemporary problem solving: The Limits to Growth, 1972, argued that "to raise world food production from 1951-1966 by 34%, for example, required increasing expenditures on tractors of 63%, on nitrate fertilizers of 146%, and on pesticides of 300%. To remove all organic wastes from a sugar-processing plant costs 100 times more than removing 30%. To reduce sulfur dioxide.
Solar power satellite - Solar power satellite A solar power satellite, or SPS, is a satellite built in high-orbit over the Earth that uses microwaves to beam solar power to a large antenna on Earth where it can be used in place of conventional power sources. The advantage to placing the solar collectors in space is the unobstructed view of the Sun, unaffected by the day/night cycle, weather, or seasons. However, the costs of construction are very high, so it is unlikely the SPS will be able to compete with conventional sources unless some form of dramatically less expensive space transport system is constructed first. Table of contents showTocToggle("show","hide") 1 History 2 Description 3 Problems 4 SPS's Economic Feasibility History This SPS concept has been floating around since late 1968,.
Karl Guthe Jansky - of static: nearby thunderstorms, distant thunderstorms, and a faint steady hiss of unknown origin. Jansky spent over a year investigating the third type of static. It rose and fell once a day, leading Jansky to think at first that he was seeing radiation from the Sun. But after a few months of following the signal, the brightest point moved away from the position of the Sun. The signal repeated not every 24 hours, but every 23 hours and 56 minutes. This is characteristic of the fixed stars, and other objects far from our solar system (sidereal day). He eventually figured out that the radiation was coming from the Milky Way and was strongest in the direction of the center of our Milky Way galaxy, in the constellation of Sagittarius. The discovery.
Jumpstart 3rd-6th Grade - Hall must be unlocked. The door to the Music Hall opens with a password. To discover the password, student rearenge 4 words on the left side of the door. After completing each one, at least one letter from the password will appear on the other side, it that letter(s) will always appear. For example: Rain Snow Heat Sleet Weather When the letters of the password are reorganized, the door will open. Students are helpped in this activity by Bothoven, the door-knocker-robot. Inside the Music Hall, the user meets Maestro Trumbot[spelling not certain] the head of the All-Winning, All-Robot Courus. Here we find out that Polly wants us to play a particular song for her. However she has organized the chips. The user must reorganize them, when they are correct, the Maestro.
Interstellar travel - generations of people are born, live and die onboard a massive star ship as it travels to its destination. Alternately, the crew of a starship could spend the bulk of the journey frozen in suspended animation on board a sleeper ship, leaving the tedium of interstellar travel to automated systems and awakening unaged at their destination. While manned interstellar travel may prove difficult or impossible to accomplish, manned interplanetary travel (travel between the planets of the solar system) is technically feasible, though economic factors, health and other risks regarding a person's continueous stay in space, and other motivational factors may suspend the achivement. Many scientific papers have been published about related concepts. Given sufficient travel time and engineering work, interstellar travel is certainly possible. NASA has been engaging in research into.
International broadcasting - 1933, shortwave, under the Rundfunk Ausland (Foreign Radio Section), was regarded as a vital element of Nazi propaganda. German shortwave hours were increased from two hours a day to 118 per day, and eventually twelve languages were broadcast on a 24 hour basis, including English. A 100 kilowatt transmitter and antenna complex was built at Zeesen, a suburb of Berlin. Specialty target programming to the United States began in 1933, to South Africa, South America, and East Asia in 1934, and South Asia and Central America in 1938. Mediumwave transmitters on the periphery of the Third Reich provided specialty programs to listeners in neighboring countries. Nevertheless, the Germans always had a problem staffing their foreign services with announcers who were both technically competent and loyal to Nazi ideas. Several announcers who.
Intellectual history of time - (socially) and measure time has evolved. By way of the changing tempo and structure of our lives through the passing generations, contorted by inventions, ideas, art, and altogether changing paradigms and philosophies, we have consistently found new ways to remedy time's obscure procession with our changing modes of measurement and interaction. Our conceived notions of time have developed in accordance with our art, our science, and our social infrastructure. The intellectual history of time is a subtle progression that weaves through the collective experience of generations, as it weaves through each individual's emotional and intellectual lives. Table of contents showTocToggle("show","hide") 1 Overture 2 An Outline of the History of Time 2.1 Irregular time 2.2 Isochronous time 2.3 Global time 2.4 Relative time 2.5 Chaotic time 3 Time in Physics 3.6 Aristotle's.
Interstellar communication - interstellar communication is possible at this time. Radio The SETI project has for the past several decades been conducting a search for signals being transmitted by extraterrestrial life located outside the solar system, primarily in the radio frequencies of the electromagnetic spectrum. Special attention has been given to the "water hole", the frequency of one of neutral hydrogen's absorption lines, due to the low background noise at this frequency and its symbolic association with the basis for what is likely to be the most common system of biochemistry (see carbon chauvinism for a discussion of potential alternatives). The regular radio pulses emitted by pulsars were briefly thought to be potential intelligent signals; the first pulsar to be discovered was originally designated "LGM-1", for "Little Green Men." They were quickly determined to.
Henri Poincaré - formulating the Poincaré Conjecture, one of the most famous problems in mathematics. In his research on the three-body problem, Poincaré became the first person to discover a chaotic deterministic system and laid the foundations of modern Chaos theory. Poincaré anticipated Albert Einstein’s work and sketched a preliminary version of the special theory of relativity. Table of contents showTocToggle("show","hide") 1 Work 2 Life 3 Character 4 Quotations 5 Related articles 6 Publications 7 References 8 External Links Work Among the specific topics he contributed to are the following: algebraic topology the theory of analytic functions of several complex variables the theory of abelian functions algebraic geometry number theory the three-body problem the theory of diophantine equations the theory of electromagnetism the special theory of relativity Life Poincaré was born on April 29,1854.
