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Talk:Marine Aerial Navigator insignia

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I'm sorry I identified this badge as "the same" as the previous Naval Aviation Observer (Navigation) wings; the information identifying this as the same badge came from Appendix 20 to United States Naval Aviation 1910–1995 published by the Naval Historical Center; this is generally a reliable source. By the way the wings pictured in the linked article Naval Navigation Observer Badge are non-standard as the standard--BuPers Circular Letter 88-45 of 31 March 1945--called for the compass rose in the center of the silver circle to be in gold. I am attempting to document my sources in the discussion pages on some of these insignia because they sometimes appear to conflict with information provided by other editors.

I changed the last line because the 2 MOSes that Marine Aerial Navigators serve in are sequential MOSes, i.e. after designation as an Aerial Navigator they serve in MOS 7371 while undergoing aircraft model-specific training and move into MOS 7372 upon completion of their training. Ray Trygstad 22:38, 20 Feb 2005 (UTC)

As it turns out, the badge pictured in this article is equally innacurate, as Para 4002.2.a.(3) of Marine Corps Uniform Regulations states that "The Marine aerial navigator insignia is a gold metal pin consisting of the basic wings with a central device of two fouled anchors surmounted by a replica of a mariner's compass, superimposed on a silver-colored (emphasis added) disk. The fouled anchors are 5/8 inch long; diameter of the disk, 1/2 inch; diameter of the compass, 3/8 inch". This DOES in fact mean that the current Marine badge is identical to the original Navy badge, and both badges shown in the photographs are inaccurate. How 'bout that? Ray Trygstad 23:00, 20 Feb 2005 (UTC)

title: Talk:Marine Aerial Navigator insignia


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Bioturbation

Bioturbation is defined as the reworking of soils and sediments by animals or plants. It includes burrowing, ingestion, and defecation of sediment grains. Bioturbating activities have a profound effect on the environment and are thought to be a primary driver of biodiversity. The formal study of bioturbation began in the 1800s by Charles Darwin experimenting in his garden. The disruption of aquatic sediments and terrestrial soils through bioturbating activities provides significant ecosystem services. These include the alteration of nutrients in aquatic sediment and overlying water, shelter to other species in the form of burrows in terrestrial and water ecosystems, and soil production on land.

Bioturbators are deemed ecosystem engineers because they alter resource availability to other species through the physical changes they make to their environments. This type of ecosystem change affects the evolution of cohabitating species and the environment, which is evident in trace fossils left in marine and terrestrial sediments. Other bioturbation effects include altering the texture of sediments (diagenesis), bioirrigation, and displacement of microorganisms and non-living particles. Bioturbation is sometimes confused with the process of bioirrigation, however these processes differ in what they are mixing; bioirrigation refers to the mixing of water and solutes in sediments and is an effect of bioturbation.

Walruses, salmon, and pocket gophers are examples of large bioturbators. Although the activities of these large macrofaunal bioturbators are more conspicuous, the dominant bioturbators are small invertebrates, such as earthworms, polychaetes, ghost shrimp, mud shrimp, and midge larvae. The activities of these small invertebrates, which include burrowing and ingestion and defecation of sediment grains, contribute to mixing and the alteration of sediment structure.

Functional groups
Bioturbators have been organized by a variety of functional groupings based on either ecological characteristics or biogeochemical effects. While the prevailing categorization is based on the way bioturbators transport and interact with sediments, the various groupings likely stem from the relevance of a categorization mode to a field of study (such as ecology or sediment biogeochemistry) and an attempt to concisely organize the wide variety of bioturbating organisms in classes that describe their function. Examples of categorizations include those based on feeding and motility, feeding and biological interactions, and mobility modes. The most common set of groupings are based on sediment transport and are as follows:
 * Gallery-diffusers create complex tube networks within the upper sediment layers and transport sediment through feeding, burrow construction, and general movement throughout their galleries. Gallery-diffusers are heavily associated with burrowing polychaetes, such as Nereis diversicolor and Marenzelleria spp.
 * Biodiffusers transport sediment particles randomly over short distances as they move through sediments. Animals mostly attributed to this category include bivalves such as clams, and amphipod species, but can also include larger vertebrates, such as bottom-dwelling fish and rays that feed along the sea floor. Biodiffusers can be further divided into two subgroups, which include epifaunal (organisms that live on the surface sediments) biodiffusers and surface biodiffusers. This subgrouping may also include gallery-diffusers, reducing the number of functional groups.
 * Upward-conveyors are oriented head-down in sediments, where they feed at depth and transport sediment through their guts to the sediment surface. Major upward-conveyor groups include burrowing polychaetes like the lugworm, Arenicola marina, and thalassinid shrimps.
 * Downward-conveyor species are oriented with their heads towards the sediment-water interface and defecation occurs at depth. Their activities transport sediment from the surface to deeper sediment layers as they feed. Notable downward-conveyors include those in the peanut worm family, Sipunculidae.

 * Regenerators are categorized by their ability to release sediment to the overlying water column, which is then dispersed as they burrow. After regenerators abandon their burrows, water flow at the sediment surface can push in and collapse the burrow. Examples of regenerator species include fiddler and ghost crabs.

Ecological roles

The evaluation of the ecological role of bioturbators has largely been species-specific. However, their ability to transport solutes, such as dissolved oxygen, enhance organic matter decomposition and diagenesis, and alter sediment structure has made them important for the survival and colonization by other macrofaunal and microbial communities.

Microbial communities are greatly influenced by bioturbator activities, as increased transport of more energetically favorable oxidants, such as oxygen, to typically highly reduced sediments at depth alters the microbial metabolic processes occurring around burrows. As bioturbators burrow, they also increase the surface area of sediments across which oxidized and reduced solutes can be exchanged, thereby increasing the overall sediment metabolism. This increase in sediment metabolism and microbial activity further results in enhanced organic matter decomposition and sediment oxygen uptake. In addition to the effects of burrowing activity on microbial communities, studies suggest that bioturbator fecal matter provides a highly nutritious food source for microbes and other macrofauna, thus enhancing benthic microbial activity. This increased microbial activity by bioturbators can contribute to increased nutrient release to the overlying water column. Nutrients released from enhanced microbial decomposition of organic matter, notably limiting nutrients, such as ammonium, can have bottom-up effects on ecosystems and result in increased growth of phytoplankton and bacterioplankton.

Burrows offer protection from predation and harsh environmental conditions. For example, termites (Macrotermes bellicosus) burrow and create mounds that have a complex system of air ducts and evaporation devices that create a suitable microclimate in an unfavorable physical environment. Many species are attracted to bioturbator burrows because of their protective capabilities. The shared use of burrows has enabled the evolution of symbiotic relationships between bioturbators and the many species that utilize their burrows. For example, gobies, scale-worms, and crabs live in the burrows made by innkeeper worms. Social interactions provide evidence of co-evolution between hosts and their burrow symbionts. This is exemplified by shrimp-goby associations. Shrimp burrows provide shelter for gobies and gobies serve as a scout at the mouth of the burrow, signaling the presence of potential danger. In contrast, the blind goby Typhlogobius californiensis lives within the deep portion of Callianassa shrimp burrows where there is not much light. The blind goby is an example of a species that is an obligate commensalist, meaning their existence depends on the host bioturbator and its burrow. Although newly hatched blind gobies have fully developed eyes, their eyes become withdrawn and covered by skin as they develop. They show evidence of commensal morphological evolution because it is hypothesized that the lack of light in the burrows where the blind gobies reside is responsible for the evolutionary loss of functional eyes.

Bioturbators can also inhibit the presence of other benthic organisms by smothering, exposing other organisms to predators, or resource competition. While thalassinidean shrimps can provide shelter for some organisms and cultivate interspecies relationships within burrows, they have also been shown to have strong negative effects on other species, especially those of bivalves and surface-grazing gastropods, because thalassinidean shrimps can smother bivalves when they resuspend sediment. They have also been shown to exclude or inhibit polychaetes, cumaceans, and amphipods. This has become a serious issue in the northwestern United States, as ghost and mud shrimp (thalassinidean shrimp) are considered pests to bivalve aquaculture operations. The presence of bioturbators can have both negative and positive effects on the recruitment of larvae of conspecifics (those of the same species) and those of other species, as the resuspension of sediments and alteration of flow at the sediment-water interface can affect the ability of larvae to burrow and remain in sediments. This effect is largely species-specific, as species differences in resuspension and burrowing modes have variable effects on fluid dynamics at the sediment-water interface. Deposit-feeding bioturbators may also hamper recruitment by consuming recently settled larvae.

Biogeochemical effects
Since its onset around 539 million years ago, bioturbation has been responsible for changes in ocean chemistry, primarily through nutrient cycling. Bioturbators played, and continue to play, an important role in nutrient transport across sediments.

For example, bioturbating animals are hypothesized to have affected the cycling of sulfur in the early oceans. According to this hypothesis, bioturbating activities had a large effect on the sulfate concentration in the ocean. Around the Cambrian-Precambrian boundary (539 million years ago), animals begin to mix reduced sulfur from ocean sediments to overlying water causing sulfide to oxidize, which increased the sulfate composition in the ocean. During large extinction events, the sulfate concentration in the ocean was reduced. Although this is difficult to measure directly, seawater sulfur isotope compositions during these times indicates bioturbators influenced the sulfur cycling in the early Earth.

Bioturbators have also altered phosphorus cycling on geologic scales. Bioturbators mix readily available particulate organic phosphorus (P) deeper into ocean sediment layers which prevents the precipitation of phosphorus (mineralization) by increasing the sequestration of phosphorus above normal chemical rates. The sequestration of phosphorus limits oxygen concentrations by decreasing production on a geologic time scale. This decrease in production results in an overall decrease in oxygen levels, and it has been proposed that the rise of bioturbation corresponds to a decrease in oxygen levels of that time. The negative feedback of animals sequestering phosphorus in the sediments and subsequently reducing oxygen concentrations in the environment limits the intensity of bioturbation in this early environment.

Organic contaminants
Bioturbation can either enhance or reduce the flux of contaminants from the sediment to the water column, depending on the mechanism of sediment transport. In polluted sediments, bioturbating animals can mix the surface layer and cause the release of sequestered contaminants into the water column. Upward-conveyor species, like polychaete worms, are efficient at moving contaminated particles to the surface. Invasive animals can remobilize contaminants previously considered to be buried at a safe depth. In the Baltic Sea, the invasive Marenzelleria species of polychaete worms can burrow to 35-50 centimeters which is deeper than native animals, thereby releasing previously sequestered contaminants. However, bioturbating animals that live in the sediment (infauna) can also reduce the flux of contaminants to the water column by burying hydrophobic organic contaminants into the sediment. Burial of uncontaminated particles by bioturbating organisms provides more absorptive surfaces to sequester chemical pollutants in the sediments.

Ecosystem impacts
Nutrient cycling is still affected by bioturbation in the modern Earth. Some examples in the terrestrial and aquatic ecosystems are below.

Terrestrial
Plants and animals utilize soil for food and shelter, disturbing the upper soil layers and transporting chemically weathered rock called saprolite from the lower soil depths to the surface. Terrestrial bioturbation is important in soil production, burial, organic matter content, and downslope transport. Tree roots are sources of soil organic matter, with root growth and stump decay also contributing to soil transport and mixing. Death and decay of tree roots first delivers organic matter to the soil and then creates voids, decreasing soil density. Tree uprooting causes considerable soil displacement by producing mounds, mixing the soil, or inverting vertical sections of soil.

Burrowing animals, such as earth worms and small mammals, form passageways for air and water transport which changes the soil properties, such as the vertical particle-size distribution, soil porosity, and nutrient content. Invertebrates that burrow and consume plant detritus help produce an organic-rich topsoil known as the soil biomantle, and thus contribute to the formation of soil horizons. Small mammals such as pocket gophers also play an important role in the production of soil, possibly with an equal magnitude to abiotic processes. Pocket gophers form above-ground mounds, which moves soil from the lower soil horizons to the surface, exposing minimally weathered rock to surface erosion processes, speeding soil formation. Pocket gophers are thought to play an important role in the downslope transport of soil, as the soil that forms their mounds is more susceptible to erosion and subsequent transport. Similar to tree root effects, the construction of burrows-even when backfilled- decreases soil density. The formation of surface mounds also buries surface vegetation, creating nutrient hotspots when the vegetation decomposes, increasing soil organic matter. Due to the high metabolic demands of their burrow-excavating subterranean lifestyle, pocket gophers must consume large amounts of plant material. Though this has a detrimental effect on individual plants, the net effect of pocket gophers is increased plant growth from their positive effects on soil nutrient content and physical soil properties.

Freshwater
Important sources of bioturbation in freshwater ecosystems include benthivorous (bottom-dwelling) fish, macroinvertebrates such as worms, insect larvae, crustaceans and molluscs, and seasonal influences from anadromous (migrating) fish such as salmon. Anadromous fish migrate from the sea into fresh-water rivers and streams to spawn. Macroinvertebrates act as biological pumps for moving material between the sediments and water column, feeding on sediment organic matter and transporting mineralized nutrients into the water column. Both benthivorous and anadromous fish can affect ecosystems by decreasing primary production through sediment re-suspension, the subsequent displacement of benthic primary producers, and recycling nutrients from the sediment back into the water column.

Lakes and ponds

The sediments of lake and pond ecosystems are rich in organic matter, with higher organic matter and nutrient contents in the sediments than in the overlying water. Nutrient re-regeneration through sediment bioturbation moves nutrients into the water column, thereby enhancing the growth of aquatic plants and phytoplankton (primary producers). The major nutrients of interest in this flux are nitrogen and phosphorus, which often limit the levels of primary production in an ecosystem. Bioturbation increases the flux of mineralized (inorganic) forms of these elements, which can be directly used by primary producers. In addition, bioturbation increases the water column concentrations of nitrogen and phosphorus-containing organic matter, which can then be consumed by fauna and mineralized.

Lake and pond sediments often transition from the aerobic (oxygen containing) character of the overlaying water to the anaerobic (without oxygen) conditions of the lower sediment over sediment depths of only a few millimeters, therefore, even bioturbators of modest size can affect this transition of the chemical characteristics of sediments. By mixing anaerobic sediments into the water column, bioturbators allow aerobic processes to interact with the re-suspended sediments and the newly exposed bottom sediment surfaces.

Macroinvertebrates including chironomid (non-biting midges) larvae and tubificid worms (detritus worms) are important agents of bioturbation in these ecosystems and have different effects based on their respective feeding habits. Tubificid worms do not form burrows, they are upward conveyors. Chironomids, on the other hand, form burrows in the sediment, acting as bioirrigators and aerating the sediments and are downward conveyors. This activity, combined with chironomid's respiration within their burrows, decrease available oxygen in the sediment and increase the loss of nitrates through enhanced rates of denitrification.

The increased oxygen input to sediments by macroinvertebrate bioirrigation coupled with bioturbation at the sediment-water interface complicates the total flux of phosphorus. While bioturbation results in a net flux of phosphorus into the water column, the bio-irrigation of the sediments with oxygenated water enhances the adsorption of phosphorus onto iron-oxide compounds, thereby reducing the total flux of phosphorus into the water column.

The presence of macroinvertebrates in sediment can initiate bioturbation due to their status as an important food source for benthivorous fish such as carp. Of the bioturbating, benthivorous fish species, carp in particular are important ecosystem engineers and their foraging and burrowing activities can alter the water quality characteristics of ponds and lakes. Carp increase water turbidity by the re-suspension of benthic sediments. This increased turbidity limits light penetration and coupled with increased nutrient flux from the sediment into the water column, inhibits the growth of macrophytes (aquatic plants) favoring the growth of phytoplankton in the surface waters. Surface phytoplankton colonies benefit from both increased suspended nutrients and from recruitment of buried phytoplankton cells released from the sediments by the fish bioturbation. Macrophyte growth has also been shown to be inhibited by displacement from the bottom sediments due to fish burrowing.

Rivers and streams
River and stream ecosystems show similar responses to bioturbation activities, with chironomid larvae and tubificid worm macroinvertebrates remaining as important benthic agents of bioturbation. These environments can also be subject to strong season bioturbation effects from anadromous fish.

Salmon function as bioturbators on both gravel to sand-sized sediment and a nutrient scale, by moving and re-working sediments in the construction of redds (gravel depressions or "nests" containing eggs buried under a thin layer of sediment) in rivers and streams and by mobilization of nutrients. The construction of salmon redds functions to increase the ease of fluid movement (hydraulic conductivity) and porosity of the stream bed. In select rivers, if salmon congregate in large enough concentrations in a given area of the river, the total sediment transport from redd construction can equal or exceed the sediment transport from flood events. The net effect on sediment movement is the downstream transfer of gravel, sand and finer materials and enhancement of water mixing within the river substrate.

The construction of salmon redds increases sediment and nutrient fluxes through the hyporheic zone (area between surface water and groundwater) of rivers and effects the dispersion and retention of marine derived nutrients (MDN) within the river ecosystem. MDN are delivered to river and stream ecosystems by the fecal matter of spawning salmon and the decaying carcasses of salmon that have completed spawning and died. Numerical modeling suggests that residence time of MDN within a salmon spawning reach is inversely proportional to the amount of redd construction within the river. Measurements of respiration within a salmon-bearing river in Alaska further suggest that salmon bioturbation of the river bed plays a significant role in mobilizing MDN and limiting primary productivity while salmon spawning is active. The river ecosystem was found to switch from a net autotrophic to heterotrophic system in response to decreased primary production and increased respiration. The decreased primary production in this study was attributed to the loss of benthic primary producers who were dislodged due to bioturbation, while increased respiration was thought to be due to increased respiration of organic carbon, also attributed to sediment mobilization from salmon redd construction. While marine derived nutrients are generally thought to increase productivity in riparian and freshwater ecosystems, several studies have suggested that temporal effects of bioturbation should be considered when characterizing salmon influences on nutrient cycles.

Marine
Major marine bioturbators range from small infaunal invertebrates to fish and marine mammals. In most marine sediments, however, they are dominated by small invertebrates, including polychaetes, bivalves, burrowing shrimp, and amphipods.

Shallow and coastal

Coastal ecosystems, such as estuaries, are generally highly productive, which results in the accumulation of large quantities of detritus (organic waste). These large quantities, in addition to typically small sediment grain size and dense populations, make bioturbators important in estuarine respiration. Bioturbators enhance the transport of oxygen into sediments through irrigation and increase the surface area of oxygenated sediments through burrow construction. Bioturbators also transport organic matter deeper into sediments through general reworking activities and production of fecal matter. This ability to replenish oxygen and other solutes at sediment depth allows for enhanced respiration by both bioturbators as well as the microbial community, thus altering estuarine elemental cycling.

The effects of bioturbation on the nitrogen cycle are well-documented. Coupled denitrification and nitrification are enhanced due to increased oxygen and nitrate delivery to deep sediments and increased surface area across which oxygen and nitrate can be exchanged. The enhanced nitrification-denitrification coupling contributes to greater removal of biologically available nitrogen in shallow and coastal environments, which can be further enhanced by the excretion of ammonium by bioturbators and other organisms residing in bioturbator burrows. While both nitrification and denitrification are enhanced by bioturbation, the effects of bioturbators on denitrification rates have been found to be greater than that on rates of nitrification, further promoting the removal of biologically available nitrogen. This increased removal of biologically available nitrogen has been suggested to be linked to increased rates of nitrogen fixation in microenvironments within burrows, as indicated by evidence of nitrogen fixation by sulfate-reducing bacteria via the presence of nifH (nitrogenase) genes.

Bioturbation by walrus feeding is a significant source of sediment and biological community structure and nutrient flux in the Bering Sea. Walruses feed by digging their muzzles into the sediment and extracting clams through powerful suction. By digging through the sediment, walruses rapidly release large amounts of organic material and nutrients, especially ammonium, from the sediment to the water column. Additionally, walrus feeding behavior mixes and oxygenates the sediment and creates pits in the sediment which serve as new habitat structures for invertebrate larvae.

Deep sea
Bioturbation is important in the deep sea because deep-sea ecosystem functioning depends on the use and recycling of nutrients and organic inputs from the photic zone. In low energy regions (areas with relatively still water), bioturbation is the only force creating heterogeneity in solute concentration and mineral distribution in the sediment. It has been suggested that higher benthic diversity in the deep sea could lead to more bioturbation which, in turn, would increase the transport of organic matter and nutrients to benthic sediments. Through the consumption of surface-derived organic matter, animals living on the sediment surface facilitate the incorporation of particulate organic carbon (POC) into the sediment where it is consumed by sediment dwelling animals and bacteria. Incorporation of POC into the food webs of sediment dwelling animals promotes carbon sequestration by removing carbon from the water column and burying it in the sediment. In some deep-sea sediments, intense bioturbation enhances manganese and nitrogen cycling.

Mathematical modelling
The role of bioturbators in sediment biogeochemistry makes bioturbation a common parameter in sediment biogeochemical models, which are often numerical models built using ordinary and partial differential equations. Bioturbation is typically represented as DB, or the biodiffusion coefficient, and is described by a diffusion and, sometimes, an advective term. This representation and subsequent variations account for the different modes of mixing by functional groups and bioirrigation that results from them. The biodiffusion coefficient is usually measured using radioactive tracers such as Pb210, radioisotopes from nuclear fallout, introduced particles including glass beads tagged with radioisotopes or inert fluorescent particles, and chlorophyll a. Biodiffusion models are then fit to vertical distributions (profiles) of tracers in sediments to provide values for DB.

Parameterization of bioturbation, however, can vary, as newer and more complex models can be used to fit tracer profiles. Unlike the standard biodiffusion model, these more complex models, such as expanded versions of the biodiffusion model, random walk, and particle-tracking models, can provide more accuracy, incorporate different modes of sediment transport, and account for more spatial heterogeneity.

Evolution
The onset of bioturbation had a profound effect on the environment and the evolution of other organisms. Bioturbation is thought to have been an important co-factor of the Cambrian Explosion, during which most major animal phyla appeared in the fossil record over a short time. Predation arose during this time and promoted the development of hard skeletons, for example bristles, spines, and shells, as a form of armored protection. It is hypothesized that bioturbation resulted from this skeleton formation. These new hard parts enabled animals to dig into the sediment to seek shelter from predators, which created an incentive for predators to search for prey in the sediment (see Evolutionary Arms Race). Burrowing species fed on buried organic matter in the sediment which resulted in the evolution of deposit feeding (consumption of organic matter within sediment). Prior to the development of bioturbation, laminated microbial mats were the dominant biological structures of the ocean floor and drove much of the ecosystem functions. As bioturbation increased, burrowing animals disturbed the microbial mat system and created a mixed sediment layer with greater biological and chemical diversity. This greater biological and chemical diversity is thought to have led to the evolution and diversification of seafloor-dwelling species.

An alternate, less widely accepted hypothesis for the origin of bioturbation exists. The trace fossil Nenoxites is thought to be the earliest record of bioturbation, predating the Cambrian Period. The fossil is dated to 555 million years, which places it in the Ediacaran Period. The fossil indicates a 5 centimeter depth of bioturbation in muddy sediments by a burrowing worm. This is consistent with food-seeking behavior, as there tended to be more food resources in the mud than the water column. However, this hypothesis requires more precise geological dating to rule out an early Cambrian origin for this specimen.

The evolution of trees during the Devonian Period enhanced soil weathering and increased the spread of soil due to bioturbation by tree roots. Root penetration and uprooting also enhanced soil carbon storage by enabling mineral weathering and the burial of organic matter.

Fossil record

Patterns or traces of bioturbation are preserved in lithified rock. The study of such patterns is called ichnology, or the study of "trace fossils", which, in the case of bioturbators, are fossils left behind by digging or burrowing animals. This can be compared to the footprint left behind by these animals. In some cases bioturbation is so pervasive that it completely obliterates sedimentary structures, such as laminated layers or cross-bedding. Thus, it affects the disciplines of sedimentology and stratigraphy within geology. The study of bioturbator ichnofabrics uses the depth of the fossils, the cross-cutting of fossils, and the sharpness (or how well defined) of the fossil to assess the activity that occurred in old sediments. Typically the deeper the fossil, the better preserved and well defined the specimen.

Important trace fossils from bioturbation have been found in marine sediments from tidal, coastal and deep sea sediments. In addition sand dune, or Eolian, sediments are important for preserving a wide variety of fossils. Evidence of bioturbation has been found in deep-sea sediment cores including into long records, although the act extracting the core can disturb the signs of bioturbation, especially at shallower depths. Arthropods, in particular are important to the geologic record of bioturbation of Eolian sediments. Dune records show traces of burrowing animals as far back as the lower Mesozoic (250 Million years ago), although bioturbation in other sediments has been seen as far back as 550 Ma.

Research history
Bioturbation's importance for soil processes and geomorphology was first realized by Charles Darwin, who devoted his last scientific book to the subject (The Formation of Vegetable Mould through the Action of Worms). Darwin spread chalk dust over a field to observe changes in the depth of the chalk layer over time. Excavations 30 years after the initial deposit of chalk revealed that the chalk was buried 18 centimeters under the sediment, which indicated a burial rate of 6 millimeters per year. Darwin attributed this burial to the activity of earthworms in the sediment and determined that these disruptions were important in soil formation. In 1891, geologist Nathaniel Shaler expanded Darwin's concept to include soil disruption by ants and trees. The term "bioturbation" was later coined by Rudolf Richter in 1952 to describe structures in sediment caused by living organisms. Since the 1980s, the term "bioturbation" has been widely used in soil and geomorphology literature to describe the reworking of soil and sediment by plants and animals.

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Bioturbation


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Banburismus

Banburismus was a cryptanalytic process developed by Alan Turing at Bletchley Park in Britain during the Second World War. It was used by Bletchley Park's Hut 8 to help break German Kriegsmarine (naval) messages enciphered on Enigma machines. The process used sequential conditional probability to infer information about the likely settings of the Enigma machine. It gave rise to Turing's invention of the ban as a measure of the weight of evidence in favour of a hypothesis. This concept was later applied in Turingery and all the other methods used for breaking the Lorenz cipher.

Overview
The aim of Banburismus was to reduce the time required of the electromechanical Bombe machines by identifying the most likely right-hand and middle wheels of the Enigma. Hut 8 performed the procedure continuously for two years, stopping only in 1943 when sufficient bombe time became readily available. Banburismus was a development of the "clock method" invented by the Polish cryptanalyst Jerzy Różycki.

Hugh Alexander was regarded as the best of the Banburists. He and I. J. Good considered the process more an intellectual game than a job. It was "not easy enough to be trivial, but not difficult enough to cause a nervous breakdown".

History
In the first few months after arriving at Bletchley Park in September 1939, Alan Turing correctly deduced that the message-settings of Kriegsmarine Enigma signals were enciphered on a common Grundstellung (starting position of the rotors), and were then super-enciphered with a bigram and a trigram lookup table. These trigram tables were in a book called the Kenngruppenbuch (K book). However, without the bigram tables, Hut 8 were unable to start attacking the traffic. A breakthrough was achieved after the Narvik pinch in which the disguised armed trawler Polares, which was on its way to Narvik in Norway, was seized by HMS Griffin (H31) in the North Sea on 26 April 1940. The Germans did not have time to destroy all their cryptographic documents, and the captured material revealed the precise form of the indicating system, supplied the plugboard connections and Grundstellung for 23 and 24 April and the operators' log, which gave a long stretch of paired plaintext and enciphered message for the 25th and 26th.

The bigram tables themselves were not part of the capture, but Hut 8 were able to use the settings-lists to read, retrospectively, all the Kriegsmarine traffic that had been intercepted from 22 to 27 April. This allowed them do a partial reconstruction of the bigram tables and start the first attempt to use Banburismus to attack Kriegsmarine traffic, from 30 April onwards. Eligible days were those where at least 200 messages were received, and for which the partial bigram-tables deciphered the indicators. The first day to be broken was 8 May 1940, thereafter celebrated as "Foss's Day" in honour of Hugh Foss, the cryptanalyst who achieved the feat.

This task took until November that year, by which time the intelligence was very out of date, but it did show that Banburismus could work. It also allowed much more of the bigram tables to be reconstructed, which in turn allowed 14 April and 26 June to be broken. However, the Kriegsmarine had changed the bigram tables on 1 July. By the end of 1940, much of the theory of the Banburismus scoring system had been worked out.

The First Lofoten pinch from the trawler Krebs on 3 March 1941 provided the complete keys for February – but no bigram tables or K book. The consequent decrypts allowed the statistical scoring system to be refined so that Banburismus could become the standard procedure against Kriegsmarine Enigma until mid-1943.

Principles
Banburismus utilised a weakness in the indicator procedure (the encrypted message settings) of Kriegsmarine Enigma traffic. Unlike the German Army and Airforce Enigma procedures, the Kriegsmarine used a Grundstellung provided by key lists, and so it was the same for all messages on a particular day (or pair of days). This meant that the three-letter indicators were all enciphered with the same rotor settings so that they were all in depth with each other. Normally, the indicators for two messages were never the same, but it could happen that, part-way through a message, the rotor positions became the same as the starting position of the rotors for another message, the parts of the two messages that overlapped in this way were in depth.

The principle behind Banburismus is relatively simple (and seems to be rather similar to the Index of Coincidence). If two sentences in English or German are written down one above the other, and a count is made of how often a letter in one message is the same as the corresponding letter in the other message; there will be more matches than would occur if the sentences were random strings of letters. For a random sequence, the repeat rate for single letters is expected to be 1 in 26 (around 3.8%), and for the German Navy messages it was shown to be 1 in 17 (5.9%). If the two messages were in depth, then the matches occur just as they did in the plaintexts. However, if the messages were not in depth, then the two ciphertexts will compare as if they were random, giving a repeat rate of about 1 in 26. This allows an attacker to take two messages whose indicators differ only in the third character, and slide them against each other looking for the giveaway repeat pattern that shows where they align in depth.

The comparison of two messages to look for repeats was made easier by punching the messages onto thin cards about 250 mm high by several metres (yards) wide, depending on the length of message. A hole at the top of a column on the card represented an 'A' at that position, a hole at the bottom represented a 'Z'. The two message-cards were laid on top of each other on a light-box and where the light shone through, there was a repeat. This made it much simpler to detect and count the repeats. The cards were printed in Banbury in Oxfordshire. They became known as 'banburies' at Bletchley Park, and hence the procedure using them: Banburismus.

The application of the scritchmus procedure (see below) gives a clue as to the possible right-hand rotor.

Example
Message with indicator "VFG": XCYBGDSLVWBDJLKWIPEHVYGQZWDTHRQXIKEESQSSPZXARIXEABQIRUCKHGWUEBPF

Message with indicator "VFX": YNSCFCCPVIPEMSGIZWFLHESCIYSPVRXMCFQAXVXDVUQILBJUABNLKMKDJMENUNQ

Hut 8 would punch these onto banburies and count the repeats for all valid offsets −25 letters to +25 letters. There are two promising positions: XCYBGDSLVWBDJLKWIPEHVYGQZWDTHRQXIKEESQSSPZXARIXEABQIRUCKHGWUEBPF YNSCFCCPVIPEMSGIZWFLHESCIYSPVRXMCFQAXVXDVUQILBJUABNLKMKDJMENUNQ - -- -   -          -  -   -- This offset of eight letters shows nine repeats, including two bigrams, in an overlap of 56 letters (16%).

The other promising position looks like this: XCYBGDSLVWBDJLKWIPEHVYGQZWDTHRQXIKEESQSSPZXARIXEABQIRUCKHGWUEBPF YNSCFCCPVIPEMSGIZWFLHESCIYSPVRXMCFQAXVXDVUQILBJUABNLKMKDJMENUNQ --- This offset of seven shows just a single trigram in an overlap of 57 letters.

Turing's method of accumulating a score of a number of decibans allows the calculation of which of these situations is most likely to represent messages in depth. As might be expected, the former is the winner with odds of 5:1 on, the latter is only 2:1 on.

Turing calculated the scores for the number of single repeats in overlaps of so many letters, and the number of bigrams and trigrams. Tetragrams often represented German words in the plaintext and their scores were calculated according to the type of message (from traffic analysis), and even their position within the message. These were tabulated and the relevant values summed by Banburists in assessing pairs of messages to see which were likely to be in depth.

Bletchley Park used the convention that the indicator plaintext of "VFX", being eight characters ahead of "VFG", or (in terms of just the third, differing, letter) that "X = G+8".

Scritchmus
Scritchmus was the part of the Banburismus procedure that could lead to the identification of the right-hand (fast) wheel. The Banburist might have evidence from various message-pairs (with only the third indicator letter differing) showing that "X = Q−2", "H = X−4" and "B = G+3". He or she would search the deciban sheets for all distances with odds of better than 1:1 (i.e. with scores ≥ +34). An attempt was then made to construct the 'end wheel alphabet' by forming 'chains' of end-wheel letters out of these repeats.

They could then construct a "chain" as follows: G--B-H---X-Q If this is then compared at progressive offsets with the known letter-sequence of an Enigma rotor, quite a few possibilities are discounted due to violating either the "reciprocal" property or the "no-self-ciphering" property of the Enigma machine: G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is possible

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (G enciphers to B, yet B enciphers to E)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (H apparently enciphers to H)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (G enciphers to D, yet B enciphers to G)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (B enciphers to H, yet H enciphers to J)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (Q apparently enciphers to Q)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (G apparently enciphers to G)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (G enciphers to H, yet H enciphers to M)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is possible

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is possible

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is possible

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (H enciphers to Q, yet Q enciphers to W)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (X enciphers to V, yet Q enciphers to X)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (B enciphers to Q, yet Q enciphers to Y)

G--B-H---X-Q ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (X enciphers to X)

Q             G--B-H---X-> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is possible

-Q             G--B-H---X-> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (Q enciphers to B, yet B enciphers to T)

X-Q             G--B-H---> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is possible

-X-Q             G--B-H--> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (X enciphers to B, yet B enciphers to V)

--X-Q             G--B-H-> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is possible

---X-Q             G--B-H-> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (X enciphers to D, yet B enciphers to X)

H---X-Q             G--B-> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (Q enciphers to G, yet G enciphers to V)

-H---X-Q             G--B-> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (H enciphers to B, yet Q enciphers to H)

B-H---X-Q             G--> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is possible (note the G enciphers to X, X enciphers to G property)

-B-H---X-Q             G-> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is impossible (B enciphers to B)

--B-H---X-Q             G-> ABCDEFGHIJKLMNOPQRSTUVWXYZ ......... is possible

The so-called "end-wheel alphabet" is already limited to just nine possibilities, merely by establishing a letter-chain of five letters derived from a mere four message-pairs. Hut 8 would now try fitting other letter-chains — ones with no letters in common with the first chain — into these nine candidate end-wheel alphabets.

Eventually they will hope to be left with just one candidate, maybe looking like this: NUP FA--D---O --X-Q             G--B-H-> ABCDEFGHIJKLMNOPQRSTUVWXYZ

Not only this, but such an end-wheel alphabet forces the conclusion that the end wheel is in fact "Rotor I". This is because "Rotor II" would have caused a mid-wheel turnover as it stepped from "E" to "F", yet that's in the middle of the span of the letter-chain "FA--D---O". Likewise, all the other possible mid-wheel turnovers are precluded. Rotor I does its turnover between "Q" and "R", and that's the only part of the alphabet not spanned by a chain.

That the different Enigma wheels had different turnover points was, presumably, a measure by the designers of the machine to improve its security. However, this very complication allowed Bletchley Park to deduce the identity of the end wheel.

Middle wheel
Once the end wheel is identified, these same principles can be extended to handle the middle rotor, though with the added complexity that the search is for overlaps in message-pairs sharing just the first indicator letter, and that the overlaps could therefore occur at up to 650 characters apart.

The workload of doing this is beyond manual labour, so BP punched the messages onto 80-column cards and used Hollerith machines to scan for tetragram repeats or better. That told them which banburies to set up on the light boxes (and with what overlap) to evaluate the whole repeat pattern.

Armed with a set of probable mid-wheel overlaps, Hut 8 could compose letter-chains for the middle wheel much in the same way as was illustrated above for the end wheel. That in turn (after Scritchmus) would give at least a partial middle wheel alphabet, and hopefully at least some of the possible choices of rotor for the middle wheel could be eliminated from turnover knowledge (as was done in identifying the end wheel).

Taken together, the probable right hand and middle wheels would give a set of bombe runs for the day, that would be significantly reduced from the 336 possible.

title: Banburismus


text:
Anacoenosis

Anacoenosis is a figure of speech in which the speaker poses a question to an audience in a way that demonstrates a common interest.

It can also be classified as a hyponym of rhetorical questions, where Anacoenosis notably invites the reader to cogitate on the subject at hand either through the formation of their own opinion or judgment.

Etymology
The term comes from the Greek ἀνακοινοῦν (anakoinoûn), meaning "to communicate, impart".

Discussion
Anacoenosis typically uses a rhetorical question, where no reply is really sought or required, thus softening what is really a statement or command.

Asking a question that implies one clear answer is to put others in a difficult position. If they disagree with you, then they risk conflict or derision. In particular if you state the question with certainty, then it makes disagreement seem rude.

Particularly when used in a group, this uses social conformance. If there is an implied agreement by all and one person openly disagrees, then they risk isolating themselves from the group, which is a very scary prospect.

If I am in an audience and the speaker uses anacoenosis and I do not agree yet do not speak up, then I may suffer cognitive dissonance between my thoughts and actions. As a result, I am likely to shift my thinking toward the speaker's views in order to reduce this tension.

Examples

 * Do you not think we can do this now?
 * Now tell me, given the evidence before us, could you have decided any differently?
 * What do you think? Are we a bit weary? Shall we stay here for a while?
 * "And now, O inhabitants of Jerusalem, and men of Judah, judge, I pray you, betwixt me and my vineyard. What could I have done more to my vineyard, that I have not done in it?" Isaiah 5:3-4
 * The entire speech of Marc Anthony in Shakespeare's Julius Caesar forms an extended example of anacoenosis. Marc Anthony begins by building common cause with the audience on stage, addressing them as "Friends, Romans, countrymen..." His speech then poses a number of rhetorical questions to them as part of his refutation of Brutus' words: "Did this in Caesar seem ambitious? / When that the poor have cried, Caesar hath wept: / Ambition should be made of sterner stuff: / Yet Brutus says he was ambitious;/ And Brutus is an honourable man. / You all did see that on the Lupercal / I thrice presented him a kingly crown, / Which he did thrice refuse: was this ambition?" (Act 3, Scene 2)

title: Anacoenosis


text:
No Depression (album)

No Depression is the first studio album by alternative country band Uncle Tupelo, released in June 1990. After its formation in the late 1980s, Uncle Tupelo recorded the Not Forever, Just for Now demo tape, which received a positive review by the College Media Journal in 1989. The review led to the band's signing with what would become Rockville Records later that year. The album was recorded with producers Sean Slade and Paul Q. Kolderie at Fort Apache Studios, on a budget of US$3,500.

No Depression was critically acclaimed and sold well for an independent release. Selling over 15,000 copies within a year of its release, the album's success inspired the roots music magazine No Depression. The record is considered one of the most important alternative country albums, and its title is often used as a synonym for the alternative country genre after being popularized by No Depression magazine. After regaining the rights to the album through a lawsuit, Uncle Tupelo released a remastered version in 2003 through Legacy Records, expanded to include six bonus tracks.

Background
Jay Farrar, Jeff Tweedy and Mike Heidorn began their musical careers in the 1980s playing in a garage band, The Plebes. After a few gigs, creative differences between the members led to the development of a punk rock sound for the band. As punk rock was unpopular in the St. Louis region, the band changed their style to blues-rock and renamed themselves Uncle Tupelo. At this point, they stopped performing covers and began to write their own songs.

The band discovered a musical niche around Washington University in St. Louis, where bands such as Brian Henneman's Chicken Truck performed in a similar style. The trio recorded its first professional tracks in Champaign, Illinois with future Chicago punk producer Matt Allison. The demo tape, Not Forever, Just for Now, contained early versions of several songs that would later appear on their debut album, including "Train", "Whiskey Bottle", "Flatness", "Screen Door", and "Before I Break".

That demo, as well as the band's rigorous touring schedule, attracted the attention of several music scouts. Record labels initially were wary of signing the band whom they perceived as straddling "the divide between the countrified punk of early 1980s such as Green on Red, Jason & the Scorchers, and X—none of whom had bum-rushed the charts—and the Pacific Northwest grunge of Mudhoney and Nirvana, which was still years from breaking out commercially". However, the influential CMJ New Music Report gave the demo tape a favorable review in 1989, praising its "mature, developed, seriously thought-out songwriting". This review prompted New York City-based distributor Dutch East India Trading to provide funding for the band to record an album on their Giant Records label, shortly before the label was renamed to Rockville Records.

Recording
Six months before signing a full contract with Giant/Rockville, Uncle Tupelo recorded the tracks for No Depression over ten days in January 1990 at Fort Apache South, a musician-run studio in the Roxbury neighborhood of Boston, Massachusetts. As the trio could not afford the cost of recording at a twenty-four track studio in nearby Cambridge, they settled on the cheaper Fort Apache studio. The album cost US$3,500 to produce, $1,000 of which went to in-house producers Sean Slade and Paul Q. Kolderie. The band was interested in working with Slade and Kolderie after hearing their production of Dinosaur Jr.'s album Bug. The producers allowed Farrar to use the same 1961 Gibson Les Paul guitar that J. Mascis used on Bug, which gave the power chords on No Depression a richer tone.

Slade and Kolderie suggested that the band deemphasize the roots rock influences heard on Not Forever, Just for Now and convinced them to replace the harmonica parts with pedal steel guitar. For this, Slade and Kolderie recruited guitarist Rich Gilbert of Human Sexual Response for the recording. The tracks were recorded using little overdubbing; only a few banjo and acoustic guitar parts were later added to the songs. At the suggestion of Slade and Kolderie, No Depression was recorded on eight-track, so "the music would compress and "jump" off the tape during playback". The recording sessions occurred before Uncle Tupelo officially became affiliated with Giant Records, so there was little input from the label.

Lyrically the songs reflected the band members' experiences growing up in Belleville. Farrar and Tweedy romanticized tales about unemployment, alcoholism, and the feeling of living in a small town in an effort to emulate the profundity of songwriters such as Woody Guthrie. Musically, No Depression was influenced by the start-stop musical pattern of the Minutemen. The cover of the album features a blurry photo of the band, taken by J. Hamilton, reminiscent of the albums released on Folkways Records.

Promotion and reception
No Depression was released by Rockville Records on June 21, 1990. The promotional tour for the album began at Cicero's Basement, a St. Louis bar associated with Washington University. The tour took Uncle Tupelo to both the East Coast and the Southwestern United States. Missouri radio stations KDHX and KCOU frequently played tracks off the album. By March 1991, No Depression had sold over 15,000 units, a hit by independent record standards. The proceeds from the album recuperated the $3,500 cost of the album, but Rockville refused to pay the band any royalties. Farrar and Tweedy later successfully sued Rockville CEO Barry Tenenbaum to attain the royalties. The surprise success of the album prompted Columbia Records to pay the band to record additional tracks with Slade and Kolderie at Fort Apache Studio in the summer of 1990, but the results were not released. Rolling Stone did not publish a review of the album upon its initial release, although the magazine later featured Uncle Tupelo in an article about rising stars alongside The Black Crowes. Rolling Stone later called the album "one of the loudest, loneliest wails in recent memory to arise from the Midwest's recession-plagued plains". Robert Christgau dismissed the album as a "dud".

After the lawsuit with Tenenbaum, Farrar and Tweedy received the rights to their first three albums (including No Depression), which were previously held by Rockville. In 2003, Uncle Tupelo remastered and re-released No Depression with six bonus tracks through Legacy Records, a Sony Music label. Among the bonus tracks were cover versions of the Flying Burrito Brothers' "Sin City", the Carter Family's "Blues Die Hard", and The Vertebrats' "Left in the Dark". The liner notes for the re-release featured an article written by Mike Heidorn about Uncle Tupelo's early days and the creation of No Depression. Upon re-release, AllMusic referred to the album as "Uncle Tupelo's landmark opening salvo", praising its "undeniable electricity" and remarking that it brought "new life" to the fusion of country and punk rock. Rolling Stone critic Tom Moon lauded "the band's impressive songwriting range", but noted that the bonus material was "pleasant but inconsequential". Pitchfork gave the subsequent 2014 re-issue an 8.4 rating out of 10, proclaiming "No Depression is a significant record".

No Depression is cited by RealNetworks as one of the most important albums in the alternative country genre. This was partly due to the success of the alternative country periodical No Depression, which took its name partly from the album. Due to the impact of the album on alternative country, "No Depression" is sometimes used as a synonym for the genre. AllMusic critic Jason Ankeny noted that the album helped the band "kick-start a revolution which reverberated throughout the American underground". In 1999, Spin listed the album at number 63 in their rankings of the "Top 90 Albums of the 90s".

Original release
All songs written by Jay Farrar, Jeff Tweedy, and Mike Heidorn except as indicated.

2014 Legacy Edition

 * Tracks 1-10 from 1989 demo tape "Not Forever, Just for Now", tracks 11-12 from 1988 demo tape "Live & Otherwise", and tracks 13-17 from 1987 demo tape "Colorblind and Rhymeless".

Personnel

 * Uncle Tupelo
 * Jay Farrar – vocals, guitar, banjo, mandolin, fiddle, harmonica
 * Mike Heidorn – drums, cymbals
 * Jeff Tweedy – vocals, acoustic guitar, bass guitar

 * Additional personnel
 * Rich Gilbert – pedal steel guitar
 * J. Hamilton – photography
 * Paul Q. Kolderie – production, audio engineering, sound effects
 * Sean Slade – production, piano, engineering, background vocals

title: No Depression (album)


text:
User:Veer

Veer is a not well known character in the Kingdom of Loathing forums. He has a strange obsession with Black Mages, and expresses a need to join the penguin mafia. He started Organized Chaos, and is ranked 13 in Postcount.

He did not make this article.

title: User:Veer


text:
Wikipedia:Articles for deletion/Naperville North High School

 This page is an archive of the discussion about the proposed deletion of the article below. This page is no longer live. Further comments should be made on the article's talk page rather than here so that this page is preserved as an historic record. The result of the debate was delete. Joyous 18:10, Feb 26, 2005 (UTC)

Naperville North High School
Article does not establish notability. RickK 22:44, Feb 20, 2005 (UTC)
 * Delete. Anyone up for another round of the inherent notability of schools discussion? Preisler 23:31, 20 Feb 2005 (UTC)
 * Delete as the article says, it does kinda suck --nixie 23:35, 20 Feb 2005 (UTC)
 * Delete. Gamaliel 01:02, 21 Feb 2005 (UTC)
 * Delete. No evidence of notability. I wasn't around during this debate about high schools some people have mentioned here before, but apparently no consensus was reached on this issue. If it was, please point to me to the discussion. JoaoRicardo 02:38, 21 Feb 2005 (UTC)
 * ONE touchstone is What's in, what's out. In general: 1) there is a wide range of opinion on high schools, from those who think only very notable high schools should be included to those who think all high schools are intrinsically notable and should be included; 2) the general topic has been argued interminably and there is currently no consensus; anyone stating otherwise is misinformed; 3) in practice VfD votes are strongly influenced by the quality of the article, and less strongly by the relative numbers and energy levels of inclusionists and deletionists on any given day.
 * Comment. Thank you, Dpbsmith. JoaoRicardo 23:52, 22 Feb 2005 (UTC)
 * Delete. We might as well suggest that Rambot create articles for every town reading "[name of town] High School is a high school in [name of town], [name of state];" most of them would be accurate, and VfD could always sort out the rest, right? Dpbsmith (talk) 02:54, 21 Feb 2005 (UTC)
 * Delete, non notable. -- Riffsyphon1024 03:36, 21 Feb 2005 (UTC)
 * Delete. Not notable. Jayjg (talk)  04:47, 21 Feb 2005 (UTC)
 * Keep all school articles. We apply a lower lower of notablity to trash culture than to the real world, which is absurd imo. Wincoote 07:15, 21 Feb 2005 (UTC)
 * Delete. Non-notable. Carrp | Talk 07:16, 21 Feb 2005 (UTC)
 * Keep. We have articles on fictional tank engines that only appear on one page of a book, why not a major school like this. Norman Rogers\talk 09:51, 21 Feb 2005 (UTC)
 * That's a ridiculous comparison given that Ivo Hugh is on vfd as well and will most likely be deleted. Gamaliel 16:49, 21 Feb 2005 (UTC)

 * Make mention in Naperville, Illinois and delete - Skysmith 11:16, 21 Feb 2005 (UTC)
 * Keep. Has potential to become encyclopedic. --Andylkl 14:08, Feb 21, 2005 (UTC)
 * Delete, high schools are not inherently encyclopedic. Note that the argument "all X are notable" is a fallacy, because for some X to be notable it must have some quality that sets it apart from other X (the obvious exception being when 'all X' is a field of study, such as ornithology that studies all birds). Radiant! 14:59, Feb 23, 2005 (UTC)
 * Keep, more notable than Pokemon - David Gerard 15:13, 23 Feb 2005 (UTC)
 * Come on, you've got to be kidding. Carrp | Talk 15:16, 23 Feb 2005 (UTC)
 * Comment. I don't understand what meaning of the word notable you are using here. The online Merriam-Webster defines it as "a: worthy of note: REMARKABLE b: DISTINGUISHED, PROMINENT" . I don't see how this applies to this school. It may be considered more important than the cartoon, because suposedly its function is to educate children and prepare them for life. But what are people more likely to type in our search bar? JoaoRicardo 02:50, 24 Feb 2005 (UTC)
 * Delete. Maybe it's actually more notable than Pokémon; then, we should delete all the Pokémon articles, because they aren't notable, in your opinion. After that, having no of such articles, this article won't be more notable than Pokémon and, thus, non-notable to you ;) --Neigel von Teighen 15:22, 23 Feb 2005 (UTC)
 * Delete. Ah, nothing like another salvo in the ongoing high school discussion.  If this was a detailed, fleshed-out stub, I'd likely vote "keep."  Instead, I'm voting on the merits of this non-article.  One lousy sentence is not an article.  Should have been a speedy for lack of content IMO. - Lucky 6.9 01:08, 24 Feb 2005 (UTC)

This page is now preserved as an archive of the debate and, like some other VfD subpages, is no longer 'live'. Subsequent comments on the issue, the deletion, or the decision-making process should be placed on the relevant 'live' pages. Please do not edit this page.


text: User talk:67.149.73.217

title: User talk:67.149.73.217


text: User talk:70.59.71.44

title: User talk:70.59.71.44


text:
Talk:Pseudo-Riemannian manifold

Don't understand
I don't understand one bit of this stuff! —Preceding unsigned comment added by Graham P. (talk • contribs) 22:46, 20 February 2005

Holy crap
No kidding. Articles generally should start out with a simple explanation. This starts out with no explanation and is therefore a terrible article. The only person capable of understanding the article will already know the content. Meaning that someone who simply wants to begin understanding it has nowhere to go except away from Wikipedia. My lowest rating. 1 of 10 stars. —Preceding unsigned comment added by 192.103.41.201 (talk) 23:36, 15 January 2006

Comment on Context Tag
I added the context tag. I had followed the Lorentzian manifold link (redirected to here) on the General relativity page hoping the get a better understanding of the subject. However, this article is difficult to follow and could use improvement. Judging by the comments above I'm not the only one. Ryan Roos 22:40, 1 December 2006 (UTC)

 * Do you have a specific question you wish to ask? If you haven't studied Riemannina geometry, you won't magically grok this article no matter how much "context" is added to it. FWIW, this article is nt well written, but it says nothing that is actually complicated, this is pretty introductory material. linas 23:41, 1 December 2006 (UTC)

 * I suspect most of the complaints regarding this page are coming from people who arrive here from a general relativity article looking for a definition of a Lorentzian manifold when they don't even know what a manifold is, much less a Riemannian one. Calabi-Yau manifold gets similar complaints. Perhaps its necessary to fork off Lorentzian manifold to its own page and start the discussion at a much lower level. -- Fropuff 00:27, 2 December 2006 (UTC)

 * linas and Fropuff thank you for your thoughtful replies. I found the discussion on the Talk:Calabi-Yau manifold of the technical tag that had been used there helped to resolve some of my problems with the article. The main basis of my concern was result my lack of knowledge of manifolds. (On a side note linas I enjoyed following several of the links on your user page) Ryan Roos 02:04, 3 December 2006 (UTC)

WikiProject class rating
This article was automatically assessed because at least one WikiProject had rated the article as stub, and the rating on other projects was brought up to Stub class. BetacommandBot 10:01, 10 November 2007 (UTC)

Lorentzian Manifold
I'd like to separate out an article about Lorentzian manifolds. This could emphasise their use in physics and in general relativity. It would link to pseudo-Riemannian manifold. What do people think? SJ 17.00 5 December 2007. —Preceding comment was added at 17:13, 5 December 2007 (UTC)

Oxymoron
A manifold must be locally Euclidean. A Pseudo-Riemannian metric cannot be used to form a family of neighborhoods of a point. We are in the business of clear communication in an encyclopedia. Occational misnomers are an unavoidable part of human communication when people race ahead of their understanding using inadequate vocabulary. In Minkowski space we have a few of these like Minkowski metric which is not a real metric (mathematics). The metric tensor article has been nuanced to avoid claiming to establish a metric. So far, so good. But this article is where general relativity is given too much license with the use of an oxymoron. Certainly it is a term in common use (though no references are yet produced), but our article needs to help readers. Learning should not be a continuous torture watching abuse of intellectual designations. The article must be clear on how the space is a manifold, not rely on presumption.Rgdboer (talk) 22:56, 5 July 2009 (UTC)

 * The page is correct: a pseudo-Riemannian manifold is a differentiable manifold with an additional structure, the pseudo-Riemannian metric. The manifold structure must be imposed prior to the choice of pseudometric. One might then wander if the topology is induced by the pseudo-Riemannian metric, and it is. For example, one can make the following construction in Minkowski space: Take the point about which you wish to construct a point, x. Construct two distinct null curves from the point. Pick two distinct points along the curves, y_1, y_2. The Lorentzian separation between x and and each of y_1 and y_2 is zero. The sets B(y_i,\epsilon), which consist of the points which have a separation less than \epsilon from y_i are open. Take the intersection of B(y_1,\epsilon_1) and B(y_2,\epsilon_2). This intersection is an open set containing x. Given any point z, there are values of \epsilon_1 and \epsilon_2 such that z is not in the intersection. The topology constructed this way is the standard one. 129.215.255.13 (talk) 20:24, 19 August 2009 (UTC)

 * In section two, one finds the definition that spells out the manifold hypothesis; section one apparently is necessary to lay the groundwork for the whole structure. Thank you computer 129.215.255.133 at Edinburgh University for pointing out the stipulation. As for your discussion of a topology generated by the pseudo-Riemannian metric, I'm not sure what you consider standard topology of spacetime.Rgdboer (talk) 20:47, 19 August 2009 (UTC)

 * Hi, you said on that page that you didn't understand what I meant by the standard topology. I'm not sure what the point of confusion is. If I start with things like second-countable and a base, would that make sense to you? —Preceding unsigned comment added by 129.215.255.13 (talk) 17:28, 20 August 2009 (UTC)

 * When you say, "Given any point z", you must mean "Given any event z with a non-zero separation from x". I note that such a topology does not separate events on the light-cone.
 * There is a significant alternative spacetime topology defined by Erik Christopher Zeeman in the journal Topology 6:161–170 (1966). The article is called "The topology of Minkowski space". Topology of spacetime continues to be an active investigative area; often writers just assume some Euclidean coordinates are around to make good. For pseudo-Euclidean metrics one often finds them built of a Euclidean metric with some minus signs thrown in, so the Euclidean metric is in the background. Zeeman's topology focuses on the important invariants in spacetime, so it contributes to an understanding of how the science of open sets can be applied in modern physics.
 * May I suggest, contributor in Edinburgh, that you log-on as a WP:User and gain the benefits including a User Talk, such as mine where you have been corresponding. I will respond here, since our focus is on the Pseudo-Riemannian manifold.Rgdboer (talk) 20:04, 20 August 2009 (UTC)
 * Hi, It's me again. Yes, registered user and talk page might make sense, but I prefer being anonymous. Sorry. You wrote: "When you say, 'Given any point z', you must mean 'Given any event z with a non-zero separation from x'." What I meant was take any event z which is distinct from x. There is no restriction on the separation between x and z. I will use the terms point (assumed to be in spacetime) and event interchangeably. Allow me to continue working in Minkowski space with the standard coordinates. I'm going to change the names of the points to P and Q so that I can use (t,x,y,z) as coordinates, and denote the separation between P1=(t1,x1,y1,z1) and P2=(t2,x2,y2,z2) by d(P1,P2) = -(t1-t2)^2 +(x1+x2)^2 +(y1-y2)^2 +(z1-z2)^2. With out loss of generality, I may assume that P is at the origin (Otherwise, I can translate the coordinates.) I may assume that Q lies in the t-x plane (Otherwise, I may rotate the axes until this is the case.). You were concerned about points on the light cone, so, to handle this case, let's assume the coordinates of P are (0,0,0,0) and for Q they are (a,a,0,0) for some positive number a. (P is at the origin. To get Q to have positive coordinates, I may apply reflections. This gives that the t and x coordinates are equal.)

To prove my claim it is sufficient that I construct an open set, defined by the separation, which contains P but not Q. The key point here is to construct the set about a different point. (I called such new points y_1 or y_2 previously. Now, I will call it R.) Let me introduce a new point R with coordinates (a,-a,0,0). Consider the new point R and the separation from P and Q. The separation from P is zero, but the separation from Q is 4a^2. Construct the set of points such that the separation from R is less than or equal to a^2, i.e. if Minkowskian separation is denoted d(M,N) for points M and N, the set is {S : d(S,R) a^2). Does that make sense? Does that convince you?

I'm not sure what the Zeeman paper says, but I'll try to look at it if I can. 86.177.228.248 (talk) 23:40, 3 September 2009 (UTC)

 * As stated above, now I see that you adequately define the concept since the manifold condition is specified in the second section. I retract the "oxymoron" label. There really is no convincing necessary.Rgdboer (talk) 21:25, 4 September 2009 (UTC)

This discussion comes to the point: For General Relativity we need the concept of a pseudo-Riemannian manifold. A reference to Euclidean spaces is inappropriate, since there is no Aether. So we need to define a manifold as something which is locally a (flat) real four-dimensional vector space (without every reference to a Euclidean structure thereupon). The structure, we must deal with, is the pseudo-Riemmannian one (i.e. the Minkowski-product locally). Any topology must be derived from there. Zeeman's topology fulfills this condition, but it is not known (to me) whether it is the only one. Perhaps there are other ones, equivalent or not in what sense whatsoever. Such a "Minkowkian"-topology should work inside, on and outside the null cone, giving an idea of neighborhood. Who has solved the problem, without which General Relativity is not well-based? — Preceding unsigned comment added by 141.89.80.203 (talk) 15:32, 4 October 2011 (UTC)

Special characters or symbols
There are a number of special characters or symbols that do not display correctly, or at all, in four different browsers I have tried: I have tried looking at the source code, editing the page within wikipedia, and copying the characters/symbols to a word processor. I cannot figure our what the writer intended. This requires the author of the text to fix this problem if it is desired to communicate completely with the reader. Colin.campbell.27 (talk) 21:08, 27 March 2011 (UTC)
 * Internet Explorer shows some as " " [box symbol for non-display characters] and some as a " " [a blank space]
 * Firefox and Safari show all as blank spaces, so it is not clear something is missing
 * Opera shows all as empty boxes, so it is clear something is not showing

copyvio?
This is odd. If I do a google search on '"locally non-decreasing" sylvester signature', http://www.google.com/#hl=en&sclient=psy-ab&q=%22locally+non-decreasing%22+sylvester+signature&oq=%22locally+non-decreasing%22+sylvester+signature&gs_l=hp.3...720.10192.0.10353.48.44.2.0.0.0.167.3998.30j14.44.0.les%3B..0.0...1c.1.W7Ns9Kjyc-0&pbx=1&bav=on.2,or.r_gc.r_pw.r_qf.&fp=a7217b4391070716&biw=1280&bih=905, I get a hit from google books for a book by Sussman and Wisdom, which contains text from this article. When I saw this, I assumed the article was plagiarized from the book. But when I click through on the google books link, I get a link that claims to be to a *different* book, by Kleppner and Kolenkow. And even this is wrong. I have the book by K&K, and what's in google books in not that book -- it's a compilation of wikipedia articles. Very mysterious.--75.83.64.6 (talk) 00:00, 2 October 2012 (UTC)

I took 3/4 of an undergraduate physics major and the introduction made my head hurt!
Seriously, I'm a biologist now, but when I write WP articles, I pretend that my readers are morons--seriously, it's hard to teach people if they can't understand what you're saying. Furthermore, drawing on experience explaining evolution to undergrads (an experience roughly analogous to skateboarding into the same giant stack of rusty nails and CMUs three hundred times in a row), I can safely say that the simpler language you use to explain a complex topic (even if it takes 300x longer to explain it that way than you could with the proper jargon) the more people (even people conversant in said jargon) will understand the points which you are trying to make. Seriously, explaining a topic in plain English does not reflect poorly on your knowledge of a given topic. Quite the opposite, it shows that you have an intuitive understanding of it.--99.112.106.168 (talk) 18:27, 15 September 2013 (UTC)
 * Seriously, I just noticed that I used the interjection "seriously" three times in a row. I hope that underscores just how serious I am!--99.112.106.168 (talk) 18:28, 15 September 2013 (UTC)

topological obstructions...
...to a manifold for admitting a Lorentzian metric. There is a large body of literature on this. Will be nice to add a word or two about it. - Subh83 (talk | contribs) 07:01, 10 November 2013 (UTC)

Meanwhile…
While the talk page is cluttered with pettifogging, the article states that a flat space with the
 * $$g = dx_1^2 + \cdots + dx_p^2 - dx_{p+1}^2 - \cdots - dx_{p+q}^2$$

metric is called… the Minkowski space. Can believe that nobody of you knows the correct name of this concept for general $p$ and $q$? Incnis Mrsi (talk) 19:12, 19 February 2014 (UTC)

 * It does not seem to say that; perhaps you misread? My guess is that pseudo-Euclidean space is reserved for the indefinite cases, and is thus not general. Flat space? —Quondum 21:53, 19 February 2014 (UTC)

First use?
Does anyone know what was the first use of pseudo-Riemannian manifold? David edwards — Preceding unsigned comment added by David edwards (talk • contribs) 15:47, 2 June 2018 (UTC)

My revert of a good-faith edit aimed at addressing WP:REDIR
I reverted an edit with the promise of elaborating here.

This is an article that deals with mathematical aspects of a metric tensor on a pseudo-Riemannian manifold, which need not be flat, even in the Lorentzian case, and example being general relativity. As such, defining even the separation between two points entails defining a curve along which to integrate, and this usually is taken to be a geodesic, the definition of which in turn requires a lot of theory based on the metric tensor. So in a sense, describing a Lorentzian metric tensor in terms of distances is inherently circular. In the flat case (a Minkowski space), a lot of short-cuts are possible and the circularity can be avoided, but that intuition does not work to define distances directly in this context. A second major point is that the ideas of a "time separation" and a "space distance" are ill-defined in this context, and even in the Minkowski space case need specification in terms of a selected frame of reference. Without mentioning this (in the Minkowski case, where it applies), one risks confusing the reader with Galilean intuitions of absolute time and space. Defining such frames in the Lorentzian case are not possible in general. One is left with building the concept of distances along curves from the concepts already stated, and one cannot start from the concept of distance or time separation: one cannot really appeal the intuitions of special relativity except in the limit of shrinking a region to a point.

A more productive approach might be to resolve the WP:REDIR problem by looking at where the redirect was used. Note that the redirect itself seems to be appropriate; a Lorentzian metric (which I presume "Lorentz metric" might be used in place of) is more general than a Minkowski metric: allowing non-flat space in addition to an arbitrary number of spatial dimensions; there should be no violation of the no-astonishment principle with this redirect. —Quondum 12:06, 19 August 2020 (UTC)

 * This is not the correct explanation. The metric is defined on the tangent space (of the spacetime manifold), where it is linear as in linear algebra. No appeal to geodesics is needed to define the metric. Quite the opposite: *after* defining the metric (on the tangent space), you can ask what the shortest distance between two points on a manifold. Be sure to read and grok manifold. The shortest distance is gotten via variational principles, solved by the Hamilton-Jacobi equations. These are partial differential equations, and when you integrate them, only then do you get the geodesics.  There aren't any circular definitions here. 67.198.37.16 (talk) 08:40, 18 November 2023 (UTC)

Lorentzian Metric ...again (1)
Currently (Aug 8, 2022), in the LM section of this article "... signature of the metric is (1, (-1)(n-1 occurrences) or (equivalently, (-1, 1(n-1 occurrences))" is a hot, stinking mess. My first suggestion is that the FULL signature (p,q, 0) be mentioned. (I assume that's what (p,q) means, as per convention). I also note that if p, q must be integers, that calling them numbers is just plain sloppy; no reason for that. Anyway, my suggested correction is "...signature of the metric is (1, (-1)(n-1)) ( or equivalently, (-1, 1(n-1)). (see Sign Convention)" but also include an explanation of n AND to explain how -1 is allowable when p and q are to be NON-NEGATIVE. So, that's like four things. 1. Easiest: clean up the parenthesis - "or (blah blah)" is wrong, should be "(or blah, blah)" 2.Most obvious: remove "occurrences" from formula, it is NO WHERE defined. 3. Almost as obvious: Before using n, DEFINE (or explain) it. 4.Lastly:YOU MUST EXPLAIN why negative (integers?) are allowable as a "special case" when non-negative integers are required in the more general case.174.131.48.89 (talk) 17:24, 8 August 2022 (UTC)

 * The dimension of space is always a (non-negative) integer, like "1D space and 2D space and 3D space" and its unfair to ask that an advanced article to stop and explain this first, before doing anything else. You will have an easier time of it all if you get a good book on special relativity and another on differential geometry and get through the basics, first. Also, Feynman "Lectures in Physics" are great. 67.198.37.16 (talk) 08:53, 18 November 2023 (UTC)

title: Talk:Pseudo-Riemannian manifold


text:
Juglans regia

Juglans regia, the Persian walnut, English walnut, Carpathian walnut, Madeira walnut, or, especially in Great Britain, common walnut, is an Old World walnut tree species native to the region stretching from the Caucasus eastward to the Kashmir region. It is widely cultivated across Asia, Northern America and Europe.

It is the origin of cultivated varieties which produce the edible walnut, consumed around the world. China is the major commercial producer of walnuts.

Description
Juglans regia is a large deciduous tree, attaining heights of 80-120 ft, and a trunk up to 2 m (6 ft) in diameter, commonly with a short trunk and broad crown.

The bark is smooth, olive-brown when young and silvery-grey on older branches, and features scattered broad fissures with a rougher texture. Like all walnuts, the pith of the twigs contains air spaces; this chambered pith is brownish in color. The leaves are alternately arranged, 25–40 cm (10 to 16 in) long, odd-pinnate with 5–9 leaflets, paired alternately with one terminal leaflet. The largest leaflets are the three at the apex, 10–18 cm (4 to 7 in) long and 6–8 cm (2 to 3 in) broad; the basal pair of leaflets are much smaller, 5–8 cm (2 to 3 in) long, with the margins of the leaflets entire. The male flowers are in drooping catkins 5–10 cm (2 to 4 in) long, and the female flowers are terminal, in clusters of two to five, ripening in the autumn into a fruit with a green, semifleshy husk and a brown, corrugated nut. The whole fruit, including the husk, falls in autumn; the seed is large, with a relatively thin shell, and edible, with a rich flavour.

Etymology

The Latin name for the walnut was nux Gallica, "Gallic nut"; the Gaulish region of Galatia in Anatolia lies in highlands at the western end of the tree's presumed natural distribution.

For the etymology and meaning of the word in English and other Germanic languages, see "walnut".

"Walnut" does not distinguish the tree from other species of Juglans. Other names include common walnut in Britain; Persian walnut in South Africa and Australia; and English walnut in North America and Great Britain, New Zealand, and Australia, the latter name possibly because English sailors were prominent in Juglans regia nut distribution at one time. Alternatively, Walter Fox Allen stated in his 1912 treatise What You Need to Know About Planting, Cultivating and Harvesting this Most Delicious of Nuts: "In America, it has commonly been known as English walnut to distinguish it from our native species."

In the Chinese language, the edible, cultivated walnut is called 胡桃 (hú táo in modern standard Chinese), which means literally "Hu peach", suggesting the ancient Chinese associated the introduction of the tree into East Asia with the Hu barbarians of the regions north and northwest of China. In Mexico, it is called nogal de Castilla, suggesting the Mexicans associated the introduction of the tree into Mexico with Spaniards from Castile (as opposed to the black walnuts native to North America).

The Old English term wealhhnutu is a late book-name (Old English Vocabularies, Wright & Wulker), so the remark that the Anglo-Saxons inherited the walnut tree from the Romans does not follow from this name. Old English: walhhnutu is wealh (foreign) + hnutu (nut). Etymologically it "meant the nut of the Roman lands (Gaul and Italy) as distinguished from the native hazel" according to the Oxford English Dictionary.

Original habitat
One of the centers of origin and diversity of Juglans regia is Iran. However, as with other old and widespread cultivated plants, it is not easy to reconstruct the original distribution and determine the borders of the past natural ranges. There are many reports concerning the earliest fossil pollen and nuts of J. regia, and the conclusions that various authors draw are somewhat contradictory. Taken together these finds suggest that J. regia possibly survived the last glaciations in several refugia, as the compilation of the data shows most likely southern Europe, the Near East, China, and the Himalaya.

The largest forests are in Kyrgyzstan, where trees occur in extensive forests at 1,000–2,000 m altitude, notably at Arslanbob in Jalal-Abad Province.

Introduction around the world
In the fourth century BC, Alexander the Great introduced this "Persian nut" (Theophrastus' καρυα ή Περσική ) in Macedonian, Ancient Greek ancestral forms with lateral fruiting from Iran and Central Asia. They hybridized with terminal-bearing forms to give lateral-bearing trees with larger fruit. These lateral-bearers were spread in southern Europe and northern Africa by Romans. Recent prospections in walnut populations of the Mediterranean Basin allowed to select interesting trees of this type. In the Middle Ages, the lateral-bearing character was introduced again in southern Turkey by merchants travelling along the Silk Road. J. regia germplasm in China is thought to have been introduced from Central Asia about 2,000 years ago, and in some areas has become naturalized. Cultivated J. regia was introduced into western and northern Europe very early, in Roman times or earlier, and to the Americas in the 17th century, by English colonists. Important nut-growing regions include California in the United States; France, Serbia, Greece, Bulgaria, Romania and Hungary in Europe; China in Asia; Baja California and Coahuila in Mexico; and Chile in Latin America. Lately, cultivation has spread to other regions, such as New Zealand and the southeast of Australia. It is cultivated extensively from 30° to 50° of latitude in the Northern Hemisphere and from 30° to 40° in the Southern Hemisphere. Its high-quality fruits are eaten both fresh or pressed for their richly flavored oil; numerous cultivars have been selected for larger nuts with thinner shells.

Ecology
It tends to grow taller and narrower in dense forest competition. It is a light-demanding species, requiring full sun to grow well.

Juglans regia is infested by Rhagoletis juglandis, commonly known as the walnut husk fly, which lays its eggs in the husks of walnut fruit.

Other plants often will not grow under walnut trees because the fallen leaves and husks contain juglone, a chemical which acts as a natural herbicide. Horses that eat walnut leaves may develop laminitis, a hoof ailment.

Cultivation

Walnut trees grow best in rich, deep soil with full sun and long summers, such as the California central valley. Juglans hindsii and J. hindsii × J. regia are often used as grafting stock for J. regia. Mature trees may reach 50 ft in height and width, and live more than 200 years, developing massive trunks more than 8 ft thick.

Cultivars
Walnut cultivars include:

• Purpurea

• Broadview

• Cascade

• Allegheny

• Bedco 1

• Coble #2

• Hansen

• Kaiser

• KY Giant

• Lake

• McKinster

• Somers

• Utah Giant

• Colby

• Greenhaven

• Reda

• Shiawassee

• Perry

• S-1

• Looking Glass

• China-B

• Champion

• Northern Prize

• Placentia

• Zijing

Pests
Particular cultivars of J. regia may be more infested by R. juglandis than others because of varying walnut husk softness or thickness. 'Eureka', 'Klondike', 'Payne', 'Franquette' and 'Ehrhardt' cultivars are among the most susceptible to infestation.

Production
In 2019, world production of shelled walnuts was 4.5 million tonnes, led by China with 56% of the total harvested (table). Secondary producers were the United States and Iran.

Allergy
Walnuts and other tree nuts are food allergen sources having potential to cause life-threatening, IgE-mediated allergic reactions in some individuals.

Nutrition
English walnut kernels are 4% water, 65% fat, 15% protein, and 14% carbohydrates. In a 100 gram reference amount providing 654 calories, the kernels supply several nutrients in "rich" amounts (20% or more of the Daily Value, DV), including the dietary minerals manganese (162% DV), phosphorus (49% DV), magnesium (45% DV), zinc (33% DV), and iron (22% DV), among others; B vitamins B6 (42% DV), thiamine (30% DV), and folate (25% DV); and dietary fiber.

One study of various cultivars of J. regia in Turkey showed the fatty acid composition included about 6% palmitic acid, 3% stearic acid, 30% oleic acid, 50% linoleic acid, and 9% linolenic acid (omega-3 alpha-linolenic acid vs. omega-6 gamma-linolenic acid content not specified).

Wood
Walnut heartwood is a heavy, hard, open-grained hardwood. Freshly cut live wood may be Dijon-mustard colour, darkening to brown over a few days. The dried lumber is a rich chocolate-brown to black, with cream to tan sapwood, and may feature unusual figures, such as "curly", "bee's wing", "bird's eye", and "rat tail", among others. It is prized by fine woodworkers for its durability, lustre and chatoyance, and is used for high-end flooring, guitars, furniture, veneers, knobs and handles as well as gunstocks.

Other uses
The Native American Navajo tribe has been documented using the hulls of the nut to create a brown dye.

Culture
In Skopelos, a Greek island in the Aegean Sea, local legend suggests whoever plants a walnut tree will die as soon as the tree can "see" the sea. Most planting is done by field rats (subfamily Murinae). In Flanders, a folk saying states: "By the time the tree is big, the planter surely will be dead." (Boompje groot, plantertje dood). These sayings refer to the relatively slow growth rate and late fruiting of the tree.

Benevento in southern Italy is the home of an ancient tradition of stregoneria. The witches of Benevento were reputed to come from all over Italy to gather for their sabbats under the sacred walnut tree of Benevento. In 1526, Judge Paolo Grillandi wrote of witches in Benevento who worship a goddess at the site of an old walnut tree. This legend inspired many cultural works, including the 1812 ballet Il Noce di Benevento (the walnut tree of Benevento) by Salvatore Viganò and Franz Xaver Süssmayr, a theme from which was adapted into a violin piece called Le Streghe by Niccolò Paganini. The Beneventan liqueur Strega depicts on its label the famous walnut tree with the witches dancing under it.

title: Juglans regia


text:
Waccamaw

The Waccamaw people were an Indigenous people of the Southeastern Woodlands, who lived in villages along the Waccamaw and Pee Dee rivers in North and South Carolina in the 18th century.

Name
The meaning of the name Waccamaw is unknown. Francisco of Chicora, a 16th-century Indian man kidnapped by Spanish colonists, wrote it as Guacaya.

Language
The Waccamaw language was not recorded and remains unattested. The language likely belonged to the Siouan language family. English explorer John Lawson published a 143-word vocabulary of the possibly related Woccon language in 1709.

Precontact
People in the area have built sedentary villages since at least 3,000 to 500 BP. Maize became a staple crop in the regions. Complex chiefdoms first arose in the area between 1150 to 1200 AD. Tribes neighboring the Waccamaw included the Sewees, Santees, Sampits (Sampa), Winyahs, and Pedees.

16th century
According to ethnographer John R. Swanton, the Waccamaw may have been one of the first mainland groups of Natives visited by the Spanish explorers in the 16th century. Within the second decade of the 16th century, Francisco Gordillo and Pedro de Quexos captured and enslaved several Native Americans, and transported them to the island of Hispaniola where they had a base. Most died within two years, although they were supposed to have been returned to the mainland.

One of the Native men kidnapped by the Spanish in 1521, Francisco de Chicora was baptized and learned Spanish. He worked for Lucas Vázquez de Ayllón. The explorer took him to Spain. Chicora told the court chronicler Peter Martyr about more than 20 Indigenous peoples who lived in present-day South Carolina, among which he mentioned the "Chicora" and the "Duhare". Their tribal territories comprised the northernmost regions.

Swanton believed that Chicora was referring to the peoples who became known as the Waccamaw and the Cape Fear Indians, respectively.

18th century
European contact decimated the Waccamaw. Having no natural immunity to endemic Eurasian infectious diseases, such as smallpox and measles, the Waccamaw, like many southeastern Native peoples, had high mortality rates from the new diseases. The 1715 Carolina colonial census listed their population as 610 total, with 210 men. The 1720 census recorded that they had 100 warriors.

By the early 18th century, the Cheraw, a related Siouan people of the Southeastern Piedmont, tried to recruit the Waccamaw to support the Yamasee and other tribes against English colonists during the Yamasee War in 1715. The Cheraw made peace with the English.

The English colonists founded a trading post in Euaunee, "the Great Bluff," in 1716. The Waccamaw engaged in a brief war against the South Carolina colony in 1720, and 60 Waccamaw men, women, and children were either killed or captured by the colonists as a result.

In 1755, John Evans noted in his journal that Cherokee and Natchez warriors killed some Waccamaw and Pedee "in the white people’s settlements."

19th century
The surviving Waccamaw grew corn for their own use. In the later 19th century, they cultivated tobacco and cotton as commodity crops, on a small scale, as did yeomen among the neighboring African-American freedmen and European-Americans. Waccamaw Siouan people in the late 19th century in North Carolina farmed diverse crops on inherited lands, but agriculture was depressed. They increasingly turned to wage labor by the end of the century. Men collected turpentine from pine trees to supplement their income, while women grew cash crops, including tobacco and cotton, and /or worked as domestic laborers and farm hands.

Population
While the Waccamaw were never populous, the arrival of settlers and their diseases in the 16th century resulted in devastating population loss and dispersal. Anthropologist James Mooney estimated the 1600 population of the "Waccamaw, Winyaw, Hook, &c" at 900 people, while the 1715 census records only one remaining Waccamaw village with a total population of 106 people, 36 of them men.

State-recognized tribes
In 1910, the Waccamaw Siouan Indians, one of eight state-recognized groups in North Carolina, organized a council to oversee community issues. A school funded by Columbus County to serve Waccamaw children opened in 1934. At the time, public education was still racially segregated in the state. Before this, the Waccamaw had been required to send their children to schools for African Americans.

North Carolina recognized the Waccamaw Siouan Tribe of North Carolina in 1971. The community is centered in Bladen and Columbus counties, North Carolina. They have unsuccessfully tried to gain federal recognition. They hold membership on the NC Commission of Indian Affairs as per NCGS 143B-407, and incorporated as a 501(c)(3) organization in 1977. Lumbee Legal Services, Inc., represents the Waccamaw Siouan Tribe in its administrative process for seeking federal recognition.

In 2005 South Carolina recognized the Waccamaw Indian People, a 501(c)(3) nonprofit organization in Conway, South Carolina. with an office in Aynor, South Carolina.

Both organizations claim to descend from the historic Waccamaw people.

Unrecognized organization
The Waccamaw Sioux Indian Tribe of Farmers Union is an unrecognized tribe based in Clarkton, North Carolina, that incorporated as a nonprofit organization in 2001.

title: Waccamaw