"Where word breaks off no thing may be": this is the line from a poem by Stefan George repeatedly cited by Martin Heidegger to indicate his version of the linguistic turn, which affected many philosophers in the early twentieth century—literary scholars already having made the turn, whether consciously or not (Heidegger, p. 60). The phrase "linguistic turn" is ac…
Lipids are a class of natural, organic compounds in plants and animals, defined by a specific way they behave: they are soluble in non-polar solvents. That is, lipids are not soluble in water but dissolve in solvents like gasoline, ether, carbon tetrachloride, or oil. The vast majority of lipids are colorless and mostly fats and oils. Lipids comprise one of the three broad classifications into whi…
Liquid crystals are pure substances in a state of matter that shows properties of both liquids and solids over a specific temperature range. At temperatures lower than this range, the liquid crystals are only like solids. They do not flow and their molecules maintain a regular arrangement. At temperatures above this range, the liquid crystals behave only like liquids. They can flow and the molecul…
When the definitive account of post-1960s intellectual technologies is written, the history of literary movements will constitute a key chapter. Perhaps paradigmatic of the closing decades of the twentieth century in its dramatic shifts and realignments, literary criticism at the opening of the twenty-first century shows all the earmarks of specialized knowledge, professionalization, and market ma…
History traces the passage of men and women through time. Literary history charts their developments and experiments in writing in the hope that global discourse will be stimulated and cultures come to understand one another. It relates, compares, and categorizes the poetry, prose, drama, and reportage of authors at various periods. The process started when the artistic deployment of language (poe…
Lithium has been the treatment of choice for manic-depressive illness for several decades. Lithium is a trace element found in plants, mineral rocks, and in the human body. Today, the major source of medical lithium is mines in North Carolina. Lithium is classified as an antimonic medication because of its ability to reverse mania, a mood disorder characterized by extreme excitement and activity. …
Lithography is a method of printing an image by applying patterned layers of color to paper with a series of etched metal or stone plates. This is the process used to print many newspapers and multi-colored lithographs. It is also the general name for the techniques used to fabricate integrated circuits (ICs). In the manufacture of integrated circuits, the silicon wafer that acts as the base and a…
The word lithosphere is derived from the word "sphere," combined with the Greek word "lithos" which means rock. The lithosphere is the solid outer section of Earth which includes Earth's crust (the "skin" of rock on the outer layer of planet Earth), as well as the underlying cool, dense, and fairly rigid upper part of the upper mantle. The lithosphe…
Lithotripsy, extracorporeal shock wave (ESWL), is the first non-invasive (not requiring surgical opening of the body) treatment for eliminating kidney stones by breaking them into sand-like particles, usually by means of high pressure waves generated in water. The particles are then eliminated from the body during urination. The ESWL machine, called a lithotripter, generates shock waves in a reser…
Livestock is a collective term for domesticated animals that are kept, mostly for the production of meat, milk, wool, or other products. The most common species are cattle, pigs, sheep, goats, horses, and chickens. The term is not used in reference to animals that are kept as pets or companions. Livestock are domesticated species, which have been genetically modified over time through the artifici…
Lobsters are large crustaceans in the order Decapoda, which also includes about 10,000 species of crayfish, crabs, and shrimps. Decapods are characterized by having their carapace fused with their thoracic segments to form a gill chamber above where the legs join the body, and the first three of their eight pairs of thoracic legs are modified into grasping, clawlike structures known as maxillipeds…
A lock or water lock is an enclosed, rectangular chamber with gates at each end, within which water is raised or lowered to allow boats or ships to overcome differences in water level. Locks have a history of over 2,000 years, and although they are most often used by boats on canals, they also are used to transport massive ships between seas. All locks operate on the simple buoyancy principle that…
A locus is a set of points that contains all the points, and only the points, that satisfy the condition, or conditions, required to describe a geometric figure. The word locus is Latin for place or location. A locus may also be defined as the path traced out by a point in motion, as it moves according to a stated set of conditions, since all the points on the path satisfy the stated conditions. T…
Because logarithms are exponents, they have an intimate connection with exponential functions and with the laws of exponents. The major laws of logarithms and the exponential laws from which they are derived are shown in Table 1. In all these rules, the bases a and b and the arguments x and y are limited to positive numbers. The exponents m, n, p, and r and the logarithms can be positive, negative…
Loons are the only surviving members of an ancient order of birds, the Gaviiformes, which has a fossil record extending back to the Lower Cretaceous, more than 100 million years ago. Loons comprise their own family, the Gaviidae, which consists of 12 extinct and five surviving (extant) species. All of the extant species of loons live in the Northern Hemisphere, where they breed on lakes and ponds,…
LORAN (Long Range Navigation) is a radio-based navigational aid first used during World War II to locate ships and planes with greater accuracy than could be achieved with conventional techniques. LORAN determines location by comparing accurately-synchronized powerful radio pulses originating from different reference transmitter sites. Pulses from nearby transmitters arrive earlier than pulses fro…
The loris or bushbaby family, Lorisidae, includes 14 species of Asian and African primates. Loris is a Dutch word for clown, given to these amusing creatures by European seaman who saw them. With the lemurs, these attractive little primates make up the group called prosimians, or "pre-monkeys." All lemurs are found on the big island of Madagascar; other members of the loris family ca…
Bony fish are divided into two major groups: rayfinned and fleshy-finned fish. The fleshy-finned fish are further subdivided into two orders: the lungfish, or Dipnoi, and the lobe-finned fish, or Crossopterygii. Although crossopterygian fish are the group that is thought to be close to the ancestors of the land vertebrates, lungfish also display many of these characteristics. In the early stages o…
Lycophytes are vascular plants in the class Lycopodiopsida, a division of vascular plants known as Pteridophytes (the ferns and their allies). The class Lycopodiopsida is divided into three subclasses: the Lycopodiidae, Selaginellidae, and Isoetidae. Like other pteridophytes, the lycophytes have an alternation of generations, consisting of two generations of morphologically different plants. The l…
Lyme disease is an infection transmitted by the bite of ticks carrying the spiral-shaped bacterium Borrelia burgdorferi (Bb). The disease was named for Lyme, Connecticut, the town where it was first diagnosed in 1975, after a puzzling outbreak of arthritis. The organism was named for its discoverer, Willy Burgdorfer. The effects of this disease can be long-term and disabling unless it is recognize…
The lymphatic system is the body's network of organs, ducts, and tissues that filter harmful substances out of the fluid that surrounds body tissues. Lymphatic organs include the bone marrow, thymus, spleen, appendix, tonsils, adenoids, lymph nodes, and Peyer's patches (in the small intestine). The thymus and bone marrow are called primary lymphatic organs, because lymphocytes are pr…
Lyrebirds are named for the male's magnificent tail, which spreads in a fan-like display, resembling a lyre, an ancient Greek stringed instrument. The male's body is little longer than 12 in (30.5 cm), but the tail may be longer than 16 in (40.5 cm). The only two species of lyrebird in the world are indigenous to a strip of rugged, hilly bushland along the east coast of the Australia…
A Möbius strip is a twisted surface in space that is made by starting with a rectangular piece of paper, twisting one side through 180° (relative to the opposite side), and then joining it to the opposite side. That is, Figure 2. Illustration by Hans & Cassidy. Courtesy of Gale Group. Figure 1. Illustration by Hans & Cassidy. Courtesy of Gale Group. using the …
Mössbauer effect was first reported by Rudolph Mössbauer in 1958. Three years later, he won the Nobel Prize with his discovery. Since then, it is believed that nuclear γ-ray emission and absorption process can take place in recoil-free fashion. In reality, of course we have both recoil and recoil-free events. Mössbauer also utilized the Doppler (velocity) shift to modu…
Macaques are medium to large-sized monkeys native to Asia and Africa belonging to the genus Macaca, family Cercopithecidae, order Primates. Macaques are usually various shades of brown, gray, or black in fur color, although golden and white color phases occur rarely. Approximately 20 species are known. Locomotion is mainly quadrupedal, and most species are terrestrial in habit, although they take …
The Mach number is used in fluid mechanics and is especially useful in studies involving supersonic aerodynamics. It is named after Ernst Mach (1838-1916), the Austrian physicist and philosopher who pioneered the study of supersonic projectiles. The Mach number is the ratio of the velocity of a fluid to the velocity of sound in that same fluid. In the case of a body moving through a fluid, the Mac…
Machiavellism, a word that goes back to the late sixteenth century, is a name for the theory and practice of amoral politics. In its ideal, simply abstract sense, it is not meant to coincide exactly with the views or practices of any historical individual, even Niccolò Machiavelli (1469–1527) himself. When Machiavelli praises the citizens of the ancient republic of Rome as noble and pu…
A machine tool is an electrically powered tool which is used to remove material, usually metal, at a controlled rate to achieve a desired shape or finish. A machine tool typically holds the workpiece and a cutting tool, and moves either the workpiece, tool or both to provide a means of machining the material to the desired shape. Machining, another term for metalcutting, is performed by shaving aw…
Machine vision, also referred to as computer or robot vision, is a term that describes the many techniques by which machines visually sense the physical world. These techniques, used primarily for monitoring industrial manufacturing, are becoming increasingly popular as today's manufacturing environments become more automated and quality control standards increase. Whether the task is to so…
Machos are not born; they are made. For the same reason, the term machismo refers to a concept that has been invented and not to a primordial cultural trait of any particular group of people. In the United States, machismo was "discovered" by social scientists and feminists much as the New World was "discovered" by Europeans five centuries earlier: U.S. scholars and fem…
The Atlantic mackerel, Somber scombrus, supports one of the most important commercial fisheries and supports a significant sport fishing interest. The fish is a close relative of the tuna. The attraction of mackerel as sport fish is due primarily to the streamlined body, forked tail, pointed head, and high-speed swimming. An unusual characteristic of the mackerel is that it does not possess a swim…