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Oceanography In 1881 the geographer John Francon Williams published a seminal book, "Geography of the Oceans". Between 1907 and 1911 Otto Krümmel published the "Handbuch der Ozeanographie", which became influential in awakening public interest in oceanography. The four-month 1910 North Atlantic expedition headed by Joh... | https://en.wikipedia.org/wiki?curid=44044 |
Oceanography In the 1950s, Auguste Piccard invented the bathyscaphe and used the bathyscaphe to investigate the ocean's depths. The United States nuclear submarine made the first journey under the ice to the North Pole in 1958. In 1962 the FLIP (Floating Instrument Platform), a spar buoy, was first deployed. From the 1... | https://en.wikipedia.org/wiki?curid=44044 |
Oceanography Further understanding of the worlds oceans permit scientists to better decide weather changes which in addition guides to a more reliable utilization of earths resources. The study of oceanography is divided into these four branches: Biological oceanography investigates the ecology of marine organisms in t... | https://en.wikipedia.org/wiki?curid=44044 |
Oceanography Calcium carbonate becomes more soluble at lower pH, so ocean acidification is likely to affect marine organisms with calcareous shells, such as oysters, clams, sea urchins and corals, and the carbonate compensation depth will rise closer to the sea surface. Affected planktonic organisms will include pterop... | https://en.wikipedia.org/wiki?curid=44044 |
Oceanography The tides, the Coriolis effect, changes in direction and strength of wind, salinity and temperature are the main factors determining ocean currents. The thermohaline circulation (THC) ("thermo-" referring to temperature and "-haline" referring to salt content) connects the ocean basins and is primarily dep... | https://en.wikipedia.org/wiki?curid=44044 |
Oceanography In 1903 the Scripps Institution of was founded, followed by Woods Hole Oceanographic Institution in 1930, Virginia Institute of Marine Science in 1938, and later the Lamont-Doherty Earth Observatory at Columbia University, and the School of at University of Washington. In Britain, the National Centre (an i... | https://en.wikipedia.org/wiki?curid=44044 |
Biomimetics or biomimicry is the imitation of the models, systems, and elements of nature for the purpose of solving complex human problems. The terms "biomimetics" and "biomimicry" derive from ("bios"), life, and μίμησις ("mīmēsis"), imitation, from μιμεῖσθαι ("mīmeisthai"), to imitate, from μῖμος ("mimos"), actor. A ... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics During his doctoral research he developed the Schmitt trigger by studying the nerves in squid, attempting to engineer a device that replicated the biological system of nerve propagation. He continued to focus on devices that mimic natural systems and by 1957 he had perceived a converse to the standard view ... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Because the term "bionic" took on the implication of supernatural strength, the scientific community in English speaking countries largely abandoned it. The term "biomimicry" appeared as early as 1982. Biomimicry was popularized by scientist and author Janine Benyus in her 1997 book "Biomimicry: Innovation ... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Biorobots based on the physiology and methods of locomotion of animals include BionicKangaroo which moves like a kangaroo, saving energy from one jump and transferring it to its next jump. Kamigami Robots, a children's toy, mimic cockroach locomotion to run quickly and efficiently over indoor and outdoor su... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics This design of façade is able to induce air flow due to the Venturi effect and continuously circulates rising air in the ventilation slot. Significant transfer of heat between the building’s external wall surface and the air flowing over it was observed. The design is coupled with greening of the façade. Gr... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Analysis of the elastic deformation happening when a pollinator lands on the sheath-like perch part of the flower "Strelitzia reginae" (known as Bird-of-Paradise flower) has inspired architects and scientists from the University of Freiburg and University of Stuttgart to create hingeless shading systems tha... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Understanding the highly diverse and multi functional biological materials and discovering approaches to replicate such structures will lead to advanced and more efficient technologies. Bone, nacre (abalone shell), teeth, the dactyl clubs of stomatopod shrimps and bamboo are great examples of damage toleran... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Freeze casting (Ice templating), an inexpensive method to mimic natural layered structures was employed by researchers at Lawrence Berkeley National Laboratory to create alumina-Al-Si and IT HAP-epoxy layered composites that match the mechanical properties of bone with an equivalent mineral/ organic content... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Engineers could in principle use such a material, if it could be reengineered to have a long enough life, for parachute lines, suspension bridge cables, artificial ligaments for medicine, and other purposes. The self-sharpening teeth of many animals have been copied to make better cutting tools. New ceramic... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Efforts have been made to produce fabric that emulates shark skin. Surface tension biomimetics are being researched for technologies such as hydrophobic or hydrophilic coatings and microactuators. Some amphibians, such as tree and torrent frogs and arboreal salamanders, are able to attach to and move over w... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Other research has proposed adhesive glue from mussels. Leg attachment pads of several animals, including many insects (e.g. beetles and flies), spiders and lizards (e.g. geckos), are capable of attaching to a variety of surfaces and are used for locomotion, even on vertical walls or across ceilings. Attach... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics These fruits show iridescent colors in the blue-green region of the visible spectrum which gives the fruit a strong metallic and shiny visual appearance. The structural colours come from the organisation of cellulose chains in the fruit's epicarp, a part of the fruit skin. Each cell of the epicarp is made o... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Phase-separation has been used to fabricate ultra-white scattering membranes from polymethylmethacrylate, mimicking the beetle "Cyphochilus". LED lights can be designed to mimic the patterns of scales on fireflies' abdomens, improving their efficiency. "Morpho" butterfly wings are structurally coloured to p... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics The natural system being mimicked and used as a template is grazing animals concentrated by pack predators that must move on after eating, trampling, and manuring an area, and returning only after it has fully recovered. Developed by Allan Savory, who in turn was inspired by the work of André Voisin, this m... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics " The functions and significance of vacuoles are fractal in nature, the organelle has no basic shape or size; its structure varies according to the requirements of the cell. Vacuoles not only isolate threats, contain what's necessary, export waste, maintain pressure -- they also help the cell scale and grow... | https://en.wikipedia.org/wiki?curid=45784 |
Biomimetics Tubular virus particles such as the tobacco mosaic virus (TMV) can be used as templates to create nanofibers and nanotubes, since both the inner and outer layers of the virus are charged surfaces which can induce nucleation of crystal growth. This was demonstrated through the production of platinum and gold... | https://en.wikipedia.org/wiki?curid=45784 |
National Institutes of Health The (NIH) () is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late 1880s and is now part of the United States Department of Health and Human Services. The majority of NIH facilities are located in Bethesda, M... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health NIH's roots extend back to the Marine Hospital Service in the late 1790s that provided medical relief to sick and disabled men in the U.S. Navy. By 1870, a network of marine hospitals had developed and was placed under the charge of a medical officer within the Bureau of the Treasury Depar... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health In the 1960s, virologist and cancer researcher Chester M. Southam injected HeLa cancer cells into patients at the Jewish Chronic Disease Hospital. When three doctors resigned after refusing to inject patients without their consent, the experiment gained considerable media attention. The NI... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health Funding for the NIH has often been a source of contention in Congress, serving as a proxy for the political currents of the time. In 1992, the NIH encompassed nearly 1 percent of the federal government's operating budget and controlled more than 50 percent of all funding for health researc... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health The Bayview Campus in Baltimore, Maryland houses the research programs of the National Institute on Aging, National Institute on Drug Abuse, and National Human Genome Research Institute with nearly 1,000 scientists and support staff. The Frederick National Laboratory in Frederick, MD and t... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health , the extramural funding consisted of about 50,000 grants to more than 325,000 researchers at more than 3000 institutions. , this rate of granting remained reasonably steady, at 47,000 grants to 2,700 organizations. , NIH spent (not including temporary funding from the American Recovery an... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health In 2000, the Joint Economic Committee of Congress reported NIH research, which was funded at $16 billion a year in 2000, that some econometric studies had given a rate of return of 25 to 40 percent per year by reducing the economic cost of illness in the US. It found that of the 21 drugs w... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health To allocate funds, the NIH must first obtain its budget from Congress. This process begins with institute and center (IC) leaders collaborating with scientists to determine the most important and promising research areas within their fields. IC leaders discuss research areas with NIH manag... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health Over the last century, the responsibility to allocate funding has shifted from the OD and Advisory Committee to the individual ICs and Congress increasingly set apart funding for particular causes. In the 1970s, Congress began to earmark funds specifically for cancer research, and in the 1... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health 2 billion in 2000. In 2009 Congress again increased the NIH budget to $31 billion in 2010. In 2017 and 2018, Congress passed laws with bipartisan support that substantially increasing appropriations for NIH, which was 37.3 billion dollars annually in FY2018. Researchers at universities or ... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health Similarly, the 13,000 to 14,000 R21 applications had a funding success of 13-14% during the same period. In FY 2016, the total number of grant applications received by the NIH was 54,220, with approximately 19% being awarded funding. Institutes have varying funding rates. The National Canc... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health In 2014, it was announced that the NIH is directing scientists to perform their experiments with both female and male animals, or cells derived from females as well as males if they are studying cell cultures, and that the NIH would take the balance of each study design into consideration ... | https://en.wikipedia.org/wiki?curid=46174 |
National Institutes of Health Policy changes on who receives funding significantly affect researchers. For example, the NIH has recently attempted to approve more first-time NIH R01 applicants or the research grant applications of young scientists. To encourage the participation of young scientists, the application pro... | https://en.wikipedia.org/wiki?curid=46174 |
Azimuth An azimuth (; from Arabic اَلسُّمُوت "as-sumūt", 'the directions', the plural form of the Arabic noun السَّمْت "as-samt", meaning 'the direction') is an angular measurement in a spherical coordinate system. The vector from an observer (origin) to a point of interest is projected perpendicularly onto a reference... | https://en.wikipedia.org/wiki?curid=47487 |
Azimuth Moving clockwise on a 360 degree circle, east has azimuth 90°, south 180°, and west 270°. There are exceptions: some navigation systems use south as the reference vector. Any direction can be the reference vector, as long as it is clearly defined. Quite commonly, azimuths or compass bearings are stated in a sys... | https://en.wikipedia.org/wiki?curid=47487 |
Azimuth If the azimuth becomes negative, one can always add 360°. The formula in radians would be slightly easier: Note the swapped formula_3 in contrast to the normal formula_4 atan2 input order. When the coordinates ("X", "Y") of one point, the distance "D", and the azimuth "α" to another point ("X", "Y") are known, ... | https://en.wikipedia.org/wiki?curid=47487 |
Azimuth Normal-section azimuth is simpler to calculate; Bomford says Cunningham's formula is exact for any distance. If "f" is the flattening, and "e" the eccentricity, for the chosen spheroid (e.g., for WGS84) then If "φ" = 0 then To calculate the azimuth of the sun or a star given its declination and hour angle at ou... | https://en.wikipedia.org/wiki?curid=47487 |
Azimuth If, instead of measuring from and along the horizon, the angles are measured from and along the celestial equator, the angles are called right ascension if referenced to the Vernal Equinox, or hour angle if referenced to the celestial meridian. In the horizontal coordinate system, used in celestial navigation a... | https://en.wikipedia.org/wiki?curid=47487 |
Azimuth It originates from medieval Arabic "al-sumūt", pronounced "as-sumūt" in Arabic, meaning "the directions" (plural of Arabic "al-samt" = "the direction"). The Arabic word entered late medieval Latin in an astronomy context and in particular in the use of the Arabic version of the astrolabe astronomy instrument. T... | https://en.wikipedia.org/wiki?curid=47487 |
Cloud albedo is a measure of the albedo of a cloud. Higher values indicate that a cloud reflects a larger amount of solar radiation and transmits a smaller amount of radiation. depends on the total mass of water, the size and shape of the droplets or particles and their distribution in space. Cloud albedo, along with t... | https://en.wikipedia.org/wiki?curid=47514 |
Cloud albedo In macrophysically identical clouds, a cloud with few larger drops will have a lower albedo than a cloud with more smaller drops. The cloud albedo increases with the total water content or depth of the cloud and with the solar zenith angle. The variation of albedo with zenith angle is most rapid when the s... | https://en.wikipedia.org/wiki?curid=47514 |
Planetary body A planetary body or planetary object is any secondary body in the Solar System that is geologically differentiated or in hydrostatic equilibrium and thus has a planet-like geology: a planet, dwarf planet, or planetary-mass moon. In 2002, planetary scientists Alan Stern and Harold Levison proposed the fol... | https://en.wikipedia.org/wiki?curid=47517 |
Cryosphere The cryosphere (from the Greek "kryos", "cold", "frost" or "ice" and "sphaira", "globe, ball") is an all-encompassing term for those portions of Earth's surface where water is in solid form, including sea ice, lake ice, river ice, snow cover, glaciers, ice caps, ice sheets, and frozen ground (which includes ... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere Most of the world's ice volume is in Antarctica, principally in the East Antarctic Ice Sheet. In terms of areal extent, however, Northern Hemisphere winter snow and ice extent comprise the largest area, amounting to an average 23% of hemispheric surface area in January. The large areal extent and the importa... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere It is the ratio of reflected to incident solar radiation, commonly referred to as albedo. Climatologists are primarily interested in albedo integrated over the shortwave portion of the electromagnetic spectrum (~300 to 3500 nm), which coincides with the main solar energy input. Typically, albedo values for n... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere Snow cover insulates the ground surface, and sea ice insulates the underlying ocean, decoupling the surface-atmosphere interface with respect to both heat and moisture fluxes. The flux of moisture from a water surface is eliminated by even a thin skin of ice, whereas the flux of heat through thin ice continu... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere Gutzler and Preston (1997) recently presented evidence for a similar snow-summer circulation feedback over the southwestern United States. The role of snow cover in modulating the monsoon is just one example of a short-term cryosphere-climate feedback involving the land surface and the atmosphere. From Figur... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere However, the available satellite data show that the hemispheric winter snow cover has exhibited little interannual variability over the 1972–1996 period, with a coefficient of variation (COV=s.d./mean) for January Northern Hemisphere snow cover of < 0.04. According to Groisman "et al." Northern Hemisphere sp... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere Snowmelt runoff from the Earth's mountains fills the rivers and recharges the aquifers that over a billion people depend on for their water resources. Furthermore, over 40% of the world's protected areas are in mountains, attesting to their value both as unique ecosystems needing protection and as recreation... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere The seasonal variation is much less in the Northern Hemisphere where the confined nature and high latitudes of the Arctic Ocean result in a much larger perennial ice cover, and the surrounding land limits the equatorward extent of wintertime ice. Thus, the seasonal variability in Northern Hemisphere ice exte... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere The Intergovernmental Panel on Climate Change publication "Climate change 2013: The Physical Science Basis" stated that sea ice extent for the Northern Hemisphere showed a decrease of 3.8% ± 0.3% per decade from November 1978 to December 2012. Ice forms on rivers and lakes in response to seasonal cooling. Th... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere " 1975) and spaceborne optical imagery during summer (Duguay and Lafleur 1997). The timing of breakup is modified by snow depth on the ice as well as by ice thickness and freshwater inflow. Frozen ground (permafrost and seasonally frozen ground) occupies approximately 54 million km of the exposed land areas ... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere Washburn (1973) concluded that most continuous permafrost is in balance with the present climate at its upper surface, but changes at the base depend on the present climate and geothermal heat flow; in contrast, most discontinuous permafrost is probably unstable or "in such delicate equilibrium that the slig... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere Gold and Lachenbruch (1973) infer a 2–4 °C warming over 75 to 100 years at Cape Thompson, Alaska, where the upper 25% of the 400-m thick permafrost is unstable with respect to an equilibrium profile of temperature with depth (for the present mean annual surface temperature of −5 °C). Maritime influences may ... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere The latter results from gravity-driven creep flow ("glacial flow") within the ice body and sliding on the underlying land, which leads to thinning and horizontal spreading. Any imbalance of this dynamic equilibrium between mass gain, loss and transport due to flow results in either growing or shrinking ice b... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere While glacier variations are likely to have minimal effects upon global climate, their recession may have contributed one third to one half of the observed 20th Century rise in sea level (Meier 1984; IPCC 1996). Furthermore, it is extremely likely that such extensive glacier recession as is currently observe... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere (roughly 1 mm/y or less) is similar to the modeled imbalance in the Antarctic (roughly 1 mm/y of sea-level rise; Huybrechts 1990), suggesting a contribution of sea-level rise from the Antarctic. Relationships between global climate and changes in ice extent are complex. The mass balance of land-based glacier... | https://en.wikipedia.org/wiki?curid=47527 |
Cryosphere Opinions differ as to the present mass balance of these systems (Bentley 1983, 1985), principally because of the limited data. The West Antarctic Ice Sheet is stable so long as the Ross Ice Shelf is constrained by drag along its lateral boundaries and pinned by local grounding. | https://en.wikipedia.org/wiki?curid=47527 |
Celestial coordinate system In astronomy, a celestial coordinate system (or celestial reference system) is a system for specifying positions of satellites, planets, stars, galaxies, and other celestial objects. Coordinate systems can specify an object's position in three-dimensional space or plot merely its direction o... | https://en.wikipedia.org/wiki?curid=48381 |
Celestial coordinate system The origin is the zero distance point, the "center of the celestial sphere", although the definition of celestial sphere is ambiguous about the definition of its center point. The "horizontal", or altitude-azimuth, system is based on the position of the observer on Earth, which revolves arou... | https://en.wikipedia.org/wiki?curid=48381 |
Celestial coordinate system Popular choices of pole and equator are the older B1950 and the modern J2000 systems, but a pole and equator "of date" can also be used, meaning one appropriate to the date under consideration, such as when a measurement of the position of a planet or spacecraft is made. There are also subdi... | https://en.wikipedia.org/wiki?curid=48381 |
Celestial coordinate system Galactic latitude resembles the elevation above the galactic plane and galactic longitude determines direction relative to the center of the galaxy. The supergalactic coordinate system corresponds to a fundamental plane that contains a higher than average number of local galaxies in the sky ... | https://en.wikipedia.org/wiki?curid=48381 |
Celestial coordinate system Thus, consistent with the convention of azimuth being measured from the south and opening positive to the west, where If the above formula produces a negative value for , it can be rendered positive by simply adding 360°. Again, in solving the equation for , use of the two-argument arctangen... | https://en.wikipedia.org/wiki?curid=48381 |
Volatilisation Volatilization is the process whereby a dissolved sample is vaporised. In atomic spectroscopy this is usually a two-step process. The analyte is turned into small droplets in a nebuliser which are entrained in a gas flow which is in turn volatilised in a high temperature flame in the case of AAS or volat... | https://en.wikipedia.org/wiki?curid=49484 |
Volatilisation 7b01224"></ref>, since herbicidal ionic systems express lower susceptibility to volatilisation. <ref name="10.1002/cplu.201800251"></ref> | https://en.wikipedia.org/wiki?curid=49484 |
Interacting boson model The interacting boson model (IBM) is a model in nuclear physics in which nucleons (protons or neutrons) pair up, essentially acting as a single particle with boson properties, with integral spin of 0, 2 or 4. It is sometimes known as the Interacting boson approximation (IBA). The IBM1/IBM-I mode... | https://en.wikipedia.org/wiki?curid=50604 |
Astronomy (from ) is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bu... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Theoretical astronomy seeks to explain observational results and observations are used to confirm theoretical results. Amateurs play an active role in astronomy. It is one of the few sciences in which this is the case. This is especially true for the discovery and observation of transient events. Amateur astr... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy However, since most modern astronomical research deals with subjects related to physics, modern astronomy could actually be called astrophysics. Some fields, such as astrometry, are purely astronomy rather than also astrophysics. Various departments in which scientists carry out research on this subject may u... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Most early astronomy consisted of mapping the positions of the stars and planets, a science now referred to as astrometry. From these observations, early ideas about the motions of the planets were formed, and the nature of the Sun, Moon and the Earth in the Universe were explored philosophically. The Earth w... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Hipparchus also created a comprehensive catalog of 1020 stars, and most of the constellations of the northern hemisphere derive from Greek astronomy. The Antikythera mechanism (c. 150–80 BC) was an early analog computer designed to calculate the location of the Sun, Moon, and planets for a given date. Technol... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy This led to the emergence of the first astronomical observatories in the Muslim world by the early 9th century. In 964, the Andromeda Galaxy, the largest galaxy in the Local Group, was described by the Persian Muslim astronomer Abd al-Rahman al-Sufi in his "Book of Fixed Stars". The SN 1006 supernova, the bri... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy His work was defended by Galileo Galilei and expanded upon by Johannes Kepler. Kepler was the first to devise a system that correctly described the details of the motion of the planets around the Sun. However, Kepler did not succeed in formulating a theory behind the laws he wrote down. It was Isaac Newton, w... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Joseph von Fraunhofer discovered about 600 bands in the spectrum of the Sun in 1814–15, which, in 1859, Gustav Kirchhoff ascribed to the presence of different elements. Stars were proven to be similar to the Earth's own Sun, but with a wide range of temperatures, masses, and sizes. The existence of the Earth'... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Observational astronomy may be categorized according to the corresponding region of the electromagnetic spectrum on which the observations are made. Some parts of the spectrum can be observed from the Earth's surface, while other parts are only observable from either high altitudes or outside the Earth's atmo... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy The infrared spectrum is useful for studying objects that are too cold to radiate visible light, such as planets, circumstellar disks or nebulae whose light is blocked by dust. The longer wavelengths of infrared can penetrate clouds of dust that block visible light, allowing the observation of young stars emb... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Although visible light itself extends from approximately 4000 Å to 7000 Å (400 nm to 700 nm), that same equipment can be used to observe some near-ultraviolet and near-infrared radiation. Ultraviolet astronomy employs ultraviolet wavelengths between approximately 100 and 3200 Å (10 to 320 nm). Light at those ... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Notable X-ray sources include X-ray binaries, pulsars, supernova remnants, elliptical galaxies, clusters of galaxies, and active galactic nuclei. Gamma ray astronomy observes astronomical objects at the shortest wavelengths of the electromagnetic spectrum. Gamma rays may be observed directly by satellites suc... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Cosmic rays, which consist of very high energy particles (atomic nuclei) that can decay or be absorbed when they enter the Earth's atmosphere, result in a cascade of secondary particles which can be detected by current observatories. Some future neutrino detectors may also be sensitive to the particles produc... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Careful measurement of the positions of the planets has led to a solid understanding of gravitational perturbations, and an ability to determine past and future positions of the planets with great accuracy, a field known as celestial mechanics. More recently the tracking of near-Earth objects will allow for p... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Theorists in astronomy endeavor to create theoretical models and from the results predict observational consequences of those models. The observation of a phenomenon predicted by a model allows astronomers to select between several alternate or conflicting models as the one best able to describe the phenomena... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy A few examples of this process: Along with Cosmic inflation, dark matter and dark energy are the current leading topics in astronomy, as their discovery and controversy originated during the study of the galaxies. Astrophysics is the branch of astronomy that employs the principles of physics and chemistry "to... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Topics also studied by theoretical astrophysicists include Solar System formation and evolution; stellar dynamics and evolution; galaxy formation and evolution; magnetohydrodynamics; large-scale structure of matter in the universe; origin of cosmic rays; general relativity and physical cosmology, including st... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy The term exobiology is similar. Astrobiology makes use of molecular biology, biophysics, biochemistry, chemistry, astronomy, physical cosmology, exoplanetology and geology to investigate the possibility of life on other worlds and help recognize biospheres that might be different from that on Earth. The origi... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy 8 billion years to its present condition. The concept of the Big Bang can be traced back to the discovery of the microwave background radiation in 1965. In the course of this expansion, the Universe underwent several evolutionary stages. In the very early moments, it is theorized that the Universe experienced... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Over time, these pulled in more matter, and were often organized into groups and clusters of galaxies, then into larger-scale superclusters. Various fields of physics are crucial to studying the universe. Interdisciplinary studies involve the fields of quantum mechanics, particle physics, plasma physics, cond... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Elliptical galaxies are more commonly found at the core of galactic clusters, and may have been formed through mergers of large galaxies. A spiral galaxy is organized into a flat, rotating disk, usually with a prominent bulge or bar at the center, and trailing bright arms that spiral outward. The arms are dus... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy This structure is organized into a hierarchy of groupings, with the largest being the superclusters. The collective matter is formed into filaments and walls, leaving large voids between. The Solar System orbits within the Milky Way, a barred spiral galaxy that is a prominent member of the Local Group of gala... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy The stellar wind and supernova explosions from these stars eventually cause the cloud to disperse, often leaving behind one or more young open clusters of stars. These clusters gradually disperse, and the stars join the population of the Milky Way. Kinematic studies of matter in the Milky Way and other galaxi... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy A star with a high enough core temperature will push its outer layers outward while increasing its core density. The resulting red giant formed by the expanding outer layers enjoys a brief life span, before the helium fuel in the core is in turn consumed. Very massive stars can also undergo a series of evolut... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy This is an 11-year oscillation in sunspot number. Sunspots are regions of lower-than- average temperatures that are associated with intense magnetic activity. The Sun has steadily increased in luminosity by 40% since it first became a main-sequence star. The Sun has also undergone periodic changes in luminosi... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy As the solar wind passes the Earth, it interacts with the Earth's magnetic field (magnetosphere) and deflects the solar wind, but traps some creating the Van Allen radiation belts that envelop the Earth. The aurora are created when solar wind particles are guided by the magnetic flux lines into the Earth's po... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy The radiation pressure of the solar wind then expelled most of the unaccreted matter, and only those planets with sufficient mass retained their gaseous atmosphere. The planets continued to sweep up, or eject, the remaining matter during a period of intense bombardment, evidenced by the many impact craters on... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Archaeoastronomy is the study of ancient or traditional astronomies in their cultural context, utilizing archaeological and anthropological evidence. Astrobiology is the study of the advent and evolution of biological systems in the Universe, with particular emphasis on the possibility of non-terrestrial life... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy clubs are located throughout the world and many have programs to help their members set up and complete observational programs including those to observe all the objects in the Messier (110 objects) or Herschel 400 catalogues of points of interest in the night sky. One branch of amateur astronomy, amateur ast... | https://en.wikipedia.org/wiki?curid=50650 |
Astronomy Improvements in digital technology have allowed amateurs to make impressive advances in the field of astrophotography. Although the scientific discipline of astronomy has made tremendous strides in understanding the nature of the Universe and its contents, there remain some important unanswered questions. Ans... | https://en.wikipedia.org/wiki?curid=50650 |
Conventional superconductor Conventional superconductors are materials that display superconductivity as described by BCS theory or its extensions. This is in contrast to unconventional superconductors, which do not. Conventional superconductors can be either type-I or type-II. Most elemental superconductors are conven... | https://en.wikipedia.org/wiki?curid=51070 |
Giant-impact hypothesis The giant-impact hypothesis, sometimes called the Big Splash, or the Theia Impact, suggests that Luna (the Moon) formed from the ejecta of a collision between the proto-Earth and a Mars-sized planetesimal, approximately 4.5 billion years ago, in the Hadean eon (about 20 to 100 million years afte... | https://en.wikipedia.org/wiki?curid=51143 |
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