1.
Americans
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Americans are citizens of the United States of America. The country is home to people of different national origins. As a result, Americans do not equate their nationality with ethnicity, although citizens make up the majority of Americans, non-citizen residents, dual citizens, and expatriates may also claim an American identity. See Names for United States citizens. S, virgin Islands and Northern Mariana Islands in the 20th century. It also includes influences of African-American culture, westward expansion integrated the Creoles and Cajuns of Louisiana and the Hispanos of the Southwest and brought close contact with the culture of Mexico. Large-scale immigration in the late 19th and early 20th centuries from Southern and Eastern Europe introduced a variety of elements, immigration from Asia, Africa, and Latin America has also had impact. A cultural melting pot, or pluralistic salad bowl, describes the way in which generations of Americans have celebrated and exchanged distinctive cultural characteristics, in addition to the United States, Americans and people of American descent can be found internationally. As many as seven million Americans are estimated to be living abroad, the United States of America is a diverse country, racially, and ethnically. Some other race is also an option in the census and other surveys, people of European descent, or White Americans, constitute the majority of the 308 million people living in the United States, with 72. 4% of the population in the 2010 United States Census. They are considered people who trace their ancestry to the peoples of Europe, the Middle East. Of those reporting to be White American,7,487,133 reported to be Multiracial, with largest combination being white, additionally, there are 29,184,290 White Hispanics or Latinos. Non-Hispanic Whites are the majority in 46 states, there are four minority-majority states, California, Texas, New Mexico, and Hawaii. In addition, the District of Columbia has a non-white majority, the state with the highest percentage of non-Hispanic White Americans is Maine. The largest continental ancestral group of Americans are that of Europeans who have origins in any of the peoples of Europe. This includes people via African, North American, Caribbean, Central American or South American and Oceanian nations that have a large European diaspora, the Spanish were the first Europeans to establish a continuous presence in what is now the United States. Martín de Argüelles born 1566, San Agustín, La Florida, was the first person of European descent born in what is now the United States. Twenty-one years later, Virginia Dare born 1587 Roanoke Island in present-day North Carolina, was the first child born in the Thirteen Colonies to English parents. 8% of the total population, Hispanic or Latino Americans constitute the largest ethnic minority in the United States. They form the second largest group after non-Hispanic Whites in the United States, hispanic/Latino Americans are very racially diverse, and as a result form an ethnic category, rather than a race
2.
Photography
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Typically, a lens is used to focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed exposure. With an electronic sensor, this produces an electrical charge at each pixel. A negative image on film is used to photographically create a positive image on a paper base, known as a print. The word photography was created from the Greek roots φωτός, genitive of φῶς, light and γραφή representation by means of lines or drawing, several people may have coined the same new term from these roots independently. Johann von Maedler, a Berlin astronomer, is credited in a 1932 German history of photography as having used it in an article published on 25 February 1839 in the German newspaper Vossische Zeitung. Both of these claims are now widely reported but apparently neither has ever been confirmed as beyond reasonable doubt. Credit has traditionally given to Sir John Herschel both for coining the word and for introducing it to the public. Photography is the result of combining several technical discoveries, later Greek mathematicians Aristotle and Euclid also independently described a pinhole camera in the 5th and 4th centuries BCE. Daniele Barbaro described a diaphragm in 1566, wilhelm Homberg described how light darkened some chemicals in 1694. The fiction book Giphantie, published in 1760, by French author Tiphaigne de la Roche, the discovery of the camera obscura that provides an image of a scene dates back to ancient China. Leonardo da Vinci mentions natural camera obscura that are formed by dark caves on the edge of a sunlit valley, a hole in the cave wall will act as a pinhole camera and project a laterally reversed, upside down image on a piece of paper. So the birth of photography was primarily concerned with inventing means to capture, renaissance painters used the camera obscura which, in fact, gives the optical rendering in color that dominates Western Art. The camera obscura literally means dark chamber in Latin and it is a box with a hole in it which allows light to go through and create an image onto the piece of paper. Around the year 1800, British inventor Thomas Wedgwood made the first known attempt to capture the image in a camera obscura by means of a light-sensitive substance and he used paper or white leather treated with silver nitrate. The shadow images eventually darkened all over, the first permanent photoetching was an image produced in 1822 by the French inventor Nicéphore Niépce, but it was destroyed in a later attempt to make prints from it. Niépce was successful again in 1825, in 1826 or 1827, he made the View from the Window at Le Gras, the earliest surviving photograph from nature. Because Niépces camera photographs required a long exposure, he sought to greatly improve his bitumen process or replace it with one that was more practical. With an eye to eventual commercial exploitation, the partners opted for total secrecy, Daguerres efforts culminated in what would later be named the daguerreotype process
3.
Snowflake
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A snowflake is either a single ice crystal or an aggregation of ice crystals which falls through the Earths atmosphere as snow. Each flake nucleates around a dust particle in supersaturated air masses by attracting supercooled water droplets. The main constituent shapes for ice crystals, from which combinations may occur, are needle, column, plate, Snowflakes appear white in color despite being made of clear ice. This is due to reflection of the whole spectrum of light by the small crystal facets. Once snowflakes land and accumulate, they undergo metamorphosis with changes in temperature, the characteristics of the snowpack reflect the changed nature of the constituent snow crystals. Snowflakes nucleate around mineral or organic particles in moisture-saturated, subfreezing air masses and they grow by net accretion to the incipient crystals in hexagonal formations. The cohesive forces are primarily electrostatic, in warmer clouds an aerosol particle or ice nucleus must be present in the droplet to act as a nucleus. The particles that make ice nuclei are very rare compared to nuclei upon which liquid droplets form, however. Clays, desert dust and biological particles may be effective, although to what extent is unclear, artificial nuclei include particles of silver iodide and dry ice, and these are used to stimulate precipitation in cloud seeding. Experiments show that homogeneous nucleation of cloud droplets only occurs at lower than −35 °C. Once a droplet has frozen, it grows in the supersaturated environment, the droplet then grows by deposition of water molecules in the air onto the ice crystal surface where they are collected. This process is known as the Wegener–Bergeron–Findeisen process, the corresponding depletion of water vapor causes the droplets to evaporate, meaning that the ice crystals grow at the droplets expense. These large crystals are an efficient source of precipitation, since they fall through the due to their mass. These aggregates are usually the type of ice particle that falls to the ground, guinness World Records list the worlds largest snowflakes as those of January 1887 at Fort Keogh, Montana, allegedly one measured 15 inches wide. Although this report by a farmer is doubtful, aggregates of three or four inches width have been observed, single crystals the size of a dime have been observed. Snowflakes encapsulated in rime form balls known as graupel, the exact details of the sticking mechanism remain controversial. Possibilities include mechanical interlocking, sintering, electrostatic attraction as well as the existence of a sticky layer on the crystal surface. The individual ice crystals often have hexagonal symmetry, the shape of the snowflake is determined broadly by the temperature and humidity at which it is formed
4.
Micrograph
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A micrograph or photomicrograph is a photograph or digital image taken through a microscope or similar device to show a magnified image of an item. This is opposed to an image, which is at a scale that is visible to the naked eye. Micrography is the practice or art of using microscopes to make photographs, a micrograph contains extensive details that form the features of a microstructure. The neuropathologist Solomon C. Fuller designed and created the first photomicrograph in 1900, micrographs are widely used in all fields of microscopy. A light micrograph or photomicrograph is a micrograph prepared using an optical microscope, at a basic level, photomicroscopy may be performed simply by hooking up a regular camera to a microscope, thereby enabling the user to take photographs at reasonably high magnification. Roman Vishniac was a pioneer in the field of photomicroscopy, specializing in the photography of living creatures in full motion and he also made major developments in light-interruption photography and color photomicroscopy. An electron micrograph is a micrograph prepared using an electron microscope, however, the term electron micrograph is not used in electron microscopy. Digital micrography is a digital picture obtained either directly with a microscope or by scanning of a photomicrograph, digital micrographs are now commonly obtained using a USB microscope attached directly to a home computer or laptop. Today, an add-on three-in-one macro lens which has capability to take wide-angle, fish-eye and macro with 7x, 14x, micrographs usually have micron bars, or magnification ratios, or both. Magnification is a ratio between size of object on a picture and its real size, unfortunately, magnification is somewhat a misleading parameter. It depends on a size of a printed picture. Editors of journals and magazines routinely resize a figure to fit the page, a scale bar, or micron bar, is a bar of known length displayed on a picture. The bar can be used for measurements on a picture, when a picture is resized a bar is also resized. If a picture has a bar, the magnification can be easily calculated, ideally, all pictures destined for publication/presentation should be supplied with a scale bar, the magnification ratio is optional. All but one of the micrographs presented on this page do not have a bar, supplied magnification ratios are likely incorrect. The microscope has been used for scientific discovery. It has also linked to the arts since its invention in the 17th century. At first scientists used the microscope to view and draw objects not visible with the unaided eye, early adopters of the microscope, such as Robert Hooke and Antonie van Leeuwenhoek, were excellent illustrators
5.
Crystal
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A crystal or crystalline solid is a solid material whose constituents are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions. In addition, macroscopic single crystals are usually identifiable by their geometrical shape, the scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification, the word crystal derives from the Ancient Greek word κρύσταλλος, meaning both ice and rock crystal, from κρύος, icy cold, frost. Examples of large crystals include snowflakes, diamonds, and table salt, most inorganic solids are not crystals but polycrystals, i. e. many microscopic crystals fused together into a single solid. Examples of polycrystals include most metals, rocks, ceramics, a third category of solids is amorphous solids, where the atoms have no periodic structure whatsoever. Examples of amorphous solids include glass, wax, and many plastics, Crystals are often used in pseudoscientific practices such as crystal therapy, and, along with gemstones, are sometimes associated with spellwork in Wiccan beliefs and related religious movements. The scientific definition of a crystal is based on the arrangement of atoms inside it. A crystal is a solid where the form a periodic arrangement. For example, when liquid water starts freezing, the change begins with small ice crystals that grow until they fuse. Most macroscopic inorganic solids are polycrystalline, including almost all metals, ceramics, ice, rocks, solids that are neither crystalline nor polycrystalline, such as glass, are called amorphous solids, also called glassy, vitreous, or noncrystalline. These have no periodic order, even microscopically, there are distinct differences between crystalline solids and amorphous solids, most notably, the process of forming a glass does not release the latent heat of fusion, but forming a crystal does. A crystal structure is characterized by its cell, a small imaginary box containing one or more atoms in a specific spatial arrangement. The unit cells are stacked in three-dimensional space to form the crystal, the symmetry of a crystal is constrained by the requirement that the unit cells stack perfectly with no gaps. There are 219 possible crystal symmetries, called space groups. These are grouped into 7 crystal systems, such as cubic crystal system or hexagonal crystal system, Crystals are commonly recognized by their shape, consisting of flat faces with sharp angles. Euhedral crystals are those with obvious, well-formed flat faces, anhedral crystals do not, usually because the crystal is one grain in a polycrystalline solid. The flat faces of a crystal are oriented in a specific way relative to the underlying atomic arrangement of the crystal. This occurs because some surface orientations are more stable than others, as a crystal grows, new atoms attach easily to the rougher and less stable parts of the surface, but less easily to the flat, stable surfaces
6.
Microscope
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A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy, microscopic means invisible to the eye unless aided by a microscope. There are many types of microscopes, the most common is the optical microscope, which uses light to image the sample. Other major types of microscopes are the microscope, the ultramicroscope. The earliest microscopes were single lens magnifying glasses with limited magnification which date at least as far back as the wide use of lenses in eyeglasses in the 13th century. Compound microscopes, which combine an objective lens with an eyepiece to view a real image, the actual inventor of the compound microscope is unknown although many claims have been made over the years. These include what may be a claim by the son of Zacharias Janssen that his father invented the microscope and telescope as early as 1590. Historians note the compound microscope did not appear in the Netherlands until the 1620s, giovanni Faber coined the name microscope for the compound microscope Galileo submitted to the Accademia dei Lincei in 1625. The first detailed account of the construction of living tissue based on the use of a microscope did not appear until 1644, in Giambattista Odiernas Locchio della mosca. It was not until the 1660s and 1670s that the microscope was used extensively for research in Italy, marcello Malpighi in Italy began the analysis of biological structures, beginning with the lungs. Robert Hookes Micrographia had an impact, largely because of its impressive illustrations. A significant contribution came from Antonie van Leeuwenhoek who achieved up to 300 times magnification using a single lens microscope. He sandwiched a very small glass ball lens between the holes in two metal plates riveted together, and with a needle attached to mount the specimen. Then, Van Leeuwenhoek re-discovered red blood cells and spermatozoa, on 9 October 1676, he reported the discovery of micro-organisms. The performance of light microscopy depends as much on how the sample is illuminated as on how it is observed, early instruments were limited until this principle was fully appreciated and developed, and until electric lamps were available as light sources. In 1893 August Köhler developed a key principle of sample illumination, Köhler illumination and this method of sample illumination produces even lighting and overcomes the limited contrast and resolution imposed by early techniques of sample illumination. In the early 20th century a significant alternative to light microscopy was developed, ernst Ruska started development of the first electron microscope in 1931 which was the transmission electron microscope. The transmission electron microscope works on the principle as an optical microscope but uses electrons in the place of light
7.
Blackboard
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A blackboard is a reusable writing surface on which text or drawings are made with sticks of calcium sulfate or calcium carbonate, known, when used for this purpose, as chalk. Blackboards were originally made of smooth, thin sheets of black or dark grey slate stone, a blackboard can simply be a piece of board painted with matte dark paint. Black plastic sign material, using the trade name sintra is also used to create custom chalkboard art, a more modern variation consists of a coiled sheet of plastic drawn across two parallel rollers, which can be scrolled to create additional writing space while saving what has been written. The highest grade blackboards are made of a rougher version porcelain enamelled steel, porcelain is very hard wearing and blackboards made of porcelain usually last 10–20 years in intensive use. Manufacturing of slate blackboards began by the 1840s, green chalkboards, generally made of porcelain enamel on a steel base, first appeared in the 1960s. Lecture theatres may contain a number of blackboards in a grid arrangement, the lecturer then moves boards into reach for writing and then moves them out of reach, allowing a large amount of material to be shown simultaneously. The chalk marks can be wiped off with a damp cloth. However, chalk marks made on some types of wet blackboard can be difficult to remove, sticks of processed chalk are produced especially for use with blackboards in white and also in various colours. These are often not from chalk rock but from calcium sulfate in its dihydrate form. Chalk sticks containing calcium carbonate typically contain 40-60% of CaCO3, as compared to whiteboards, blackboards have a variety of advantages, Chalk requires no special care, whiteboard markers must be capped or else they dry out. Chalk is an order of magnitude cheaper than whiteboard markers for a amount of writing. It is easier to draw lines of different weights and thicknesses with chalk than with whiteboard markers, dashed lines can be drawn very quickly using a technique involving the friction of the chalk and blackboard. Chalk has a smell, whereas whiteboard markers often have a pungent odor. Chalk writing often provides better contrast than whiteboard markers, Chalk can be easily erased, writing which has been left on a whiteboard for a prolonged period may require a solvent to remove. Chalk can be removed from most clothing, whiteboard markers often permanently stain fabric. On the other hand, chalk produces dust, the amount depending on the quality of chalk used, the dust also precludes the use of chalk in areas shared with dust-sensitive equipment such as computers. The writing on chalkboards is difficult to read in the dark, Chalk sticks are notorious for shrinking through use, and breaking in half unless inserted in a writing utensil designed to store chalk. According to a run by Michael Oehler, a professor at the University of Media and Communication in Cologne, Germany
8.
Microscope slide
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A microscope slide is a thin flat piece of glass, typically 75 by 26 mm and about 1 mm thick, used to hold objects for examination under a microscope. Typically the object is placed or secured on the slide, and this arrangement allows several slide-mounted objects to be quickly inserted and removed from the microscope, labeled, transported, and stored in appropriate slide cases or folders. Microscope slides are used together with a cover slip or cover glass. These sliders were popular in Victorian England until the Royal Microscopical Society introduced the standardized glass microscope slide, a standard microscope slide measures about 75 mm by 25 mm and is about 1 mm thick. A range of sizes are available for various special purposes, such as 75 x 50 mm and for geological use,46 x 27 mm for petrographic studies. Slides are usually made of glass and their edges are often finely ground or polished. Microscope slides are made of optical quality glass, such as soda lime glass or borosilicate glass. Fused quartz slides are used when ultraviolet transparency is important. While plain slides are the most common, there are specialized types. A concavity slide or cavity slide has one or more shallow depressions, designed to hold slightly thicker objects, if this system were used with a slide which did not incorporate these cut-off corners, the corners would chip and the slide could shatter. A graticule slide is marked with a grid of lines that allows the size of objects seen under magnification to be easily estimated, sometimes one square of the grid will itself be subdivided into a finer grid. Slides for specialized applications, such as counting, may have various reservoirs, channels. Various permanent markings or masks may be printed, sand-blasted, or deposited on the surface by the manufacturer, some slides have a frosted or enamel-coated area at one end, for labeling with a pencil or pen. Slides may have special coatings applied by the manufacturer, e. g. for chemical inertness or enhanced cell adhesion, the coating may have a permanent electric charge to hold thin or powdery samples. Common coatings include poly-L-lysine, silanes, epoxy resins, or even gold, the mounting of specimens on microscope slides is often critical for successful viewing. The problem has given much attention in the last two centuries and is a well-developed area with many specialized and sometimes quite sophisticated techniques. In a dry mount, the simplest kind of mounting, the object is placed on the slide. A cover slip may be placed on top to protect the specimen and this mounting can be successfully used for viewing specimens like pollen, feathers, hairs, etc
9.
Ephemerality
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Ephemerality is the concept of things being transitory, existing only briefly. Because different people may value the passage of time differently, the concept of ephemerality is a relative one, an ephemeral waterbody is a wetland, spring, stream, river, pond or lake that only exists for a short period following precipitation or snowmelt. They are not the same as intermittent or seasonal waterbodies, which exist for longer periods, examples of ephemeral streams are the Luni river in Rajasthan, India, Ugab River in Southern Africa, and a number of small ephemeral watercourses that drain Talak in northern Niger. Other notable ephemeral rivers include the Todd River and Sandover River in Central Australia as well as the Son River, Batha River, any endorheic basin, or closed basin, that contains a playa or dry lake at its drainage lowpoint can become an ephemeral lake. Examples include Lake Carnegie in Western Australia, Lake Cowal in New South Wales, Mystic Lake and Rogers Lake in California, even the driest and lowest place in North America, Death Valley, became flooded with a short-lived ephemeral lake in the spring of 2005. There are also ephemeral islands such as Banua Wuhu and Home Reef and these islands appear when volcanic activity increases their height above sea level, but disappear over several years due to wave erosion. Bassas da India, on the hand, is a near-sea level island that appears only at low tide. Many plants are adapted to a lifestyle, in which they spend most of the year or longer as seeds before conditions are right for a brief period of growth. The spring ephemeral plant mouse-ear cress is a well-known example, animals can be ephemeral, with brine shrimp and the mayfly being examples. The placenta is considered an ephemeral organ present during gestation and pregnancy, ephemeral can also be used as an adjective to refer to a fast-deteriorating importance or temporary nature of an object to a person. Brands are notoriously ephemeral assets, and magazine publishing was once much more ephemeral than it is today, a number of art forms can be considered ephemeral because of their temporary nature. Early land art and all sand sculptures, ice sculptures and chalk drawings on footpaths are examples of ephemeral art, G. Augustine Lynas and Duthain Dealbh create ephemeral sculptures. Ephemeroptera Christine Buci-Glucksmann, Esthetique De Lephemere, Galilee, ISBN 2-7186-0622-3
10.
Natural history
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Natural history is the research and study of organisms including animals, fungi and plants in their environment, leaning more towards observational than experimental methods of study. It encompasses scientific research but is not limited to it, with articles nowadays more often published in magazines than in academic journals. Grouped among the sciences, natural history is the systematic study of any category of natural objects or organisms. That is a broad designation in a world filled with many narrowly focused disciplines. For example, geobiology has a strong multi-disciplinary nature combining scientists, a person who studies natural history is known as a naturalist or natural historian. The English term natural history is a translation of the Latin historia naturalis and its meaning has narrowed progressively with time, while the meaning of the related term nature has widened. In antiquity, it covered essentially anything connected with nature or which used materials drawn from nature. For example, Pliny the Elders encyclopedia of this title, published circa 77 to 79 AD, covers astronomy, geography, man and his technology, medicine and superstition as well as animals and plants. Medieval European academics considered knowledge to have two divisions, the humanities and divinity, with science studied largely through texts rather than observation or experiment. In modern terms, natural philosophy roughly corresponded to modern physics and chemistry, natural history had been encouraged by practical motives, such as Linnaeus aspiration to improve the economic condition of Sweden. Similarly, the Industrial Revolution prompted the development of geology to help find useful mineral deposits, the astronomer, William Herschel was also a natural historian. Instead of working with plants or minerals he worked with the stars and he spent his time building telescopes to see the stars and the rest of the time watching the stars. In the beginning, he believed there to be a known as a nebulae. Herschel can be considered a natural historian because he observed the natural world, in the process he made charts of all the stars and kept records of all that he saw. S. Wilcove and T. Eisner, The close observation of organisms—their origins, their evolution, their behavior and it encompasses changes in internal states insofar as they pertain to what organisms do. Some definitions go further, focusing on observation of organisms in their environment. Bartholomew, A student of history, or a naturalist, studies the world by observing plants. A common thread in many definitions of natural history is the inclusion of a component, as seen in a recent definition by H. W. Greene
