text:
Vashon, Washington

Vashon is a census-designated place (CDP) in King County, Washington, United States. It covers an island alternately called Vashon Island or Vashon–Maury Island, the largest island in Puget Sound south of Admiralty Inlet. The population was 11,055 at 2020, up from 10,624 at the 2010 census and the size is 95.6 sqkm.

The island is connected to West Seattle and the Kitsap Peninsula to the north and Tacoma to the south via the Washington State Ferries system, as well as to Downtown Seattle via the King County Water Taxi. The island has resisted the construction of a fixed bridge to preserve its relative isolation and rural character. Vashon Island is also known for its annual strawberry festival, sheepdog trials, and agriculture.

History
Vashon Island sits in the midpoint of southern Puget Sound, between Seattle and Tacoma, Washington. In the nearby Pacific Ocean, roughly 170 mi west of Vashon Island, lies the 700 mi tectonic boundary known as the Cascadia Subduction Zone, and as such, Vashon Island is one of many areas at risk for earthquakes or related natural disasters. The Cascadia Subduction Zone last saw a major rupture in 1700, but the potential of the zone could cause one of the worst natural disasters in the history of North America.

Native American inhabitants
Up until the late 1700s, Vashon and Maury Islands were inhabited solely by American Indians, and there is evidence of human activity on Vashon Island dating back 10,000 to 12,000 years. Historical data from the era when the first Native Americans settled Vashon–Maury Island is limited. Some of the Native peoples known to have lived on Vashon Island were the Marpole culture from about 7,000 years ago, the Salish about 1,000 years ago, and the Sqababsh (known in Chinook Wawa as the S'Homamish) starting about 500 years ago, the latter of which established 5 known major village sites. The Tulalip Indians is another tribe that populated the villages along the shores of both islands. Fishing was abundant in the cold saltwater of the central Puget Sound basin, helping Native American tribes to thrive. Moreover, the many waterways and inlets provided easy travel by way of canoe.

Euramerican settlement
The first non–Native American to explore and the first to chart this island was Captain George Vancouver, during his surveys of the Puget Sound area with the British Royal Navy. The island was named on May 28, 1792, by Vancouver after his friend James Vashon of the Royal Navy. Starting in 1824, different explorer and settler groups stayed on Vashon Island.

Maury Island, immediately to the southeast of Vashon, was named in 1841 by then Lt. Charles Wilkes in honor of William Lewis Maury, an officer in the United States Exploring Expedition. Maury was naturally separated from Vashon by a narrow passage, until local landowners decided to build an earth bridge, or isthmus, linking them together in 1916, thus creating the hamlet of Portage. Therefore, the two-piece isle was renamed Vashon-Maury Island. Between the two sections, it covers nearly 37 sqmi.

The first logging on the island began in 1852. By 1855–1856, the S'Homamish people were interned at Fox Island. European-Americans settled Vashon Island between 1865 and 1890. During that time the main economies on the island were fishing and logging.

In 1890, Japanese Americans started growing strawberries for sale. Denichiro Mukai came to the island in 1910 and became renowned for barreling fresh strawberries using a special method that concentrated flavor and moisture in the fruit and permitted long-distance shipping. In time, Mukai designed and built his own home and elaborate garden and then constructed a sturdy timber framed barreling plant. During the peak years, ice cream, jam and preserve makers across the West were customers of Mukai, relishing the oak barrels for their lingering flavor and mythologizing about the island of strawberry fields. This became an important part of the island economy during the next 50 years, until the Japanese American population was forcibly relocated into internment camps as a response to Japanese/American tension caused by WWII.

In 1892, Vashon College opened in the Burton section of Vashon. During its operation, it was one of the leading colleges in the area. It burned down in 1910.

Geography
According to the United States Census Bureau, the Vashon CDP has a total area of 209.3 sqkm, of which 95.6 sqkm comprise the island and 113.6 sqkm are the waters of Puget Sound surrounding the island.

To the west Vashon Island is separated from the Kitsap Peninsula by the Colvos Passage. The Dalco Passage separates Vashon Island from Tacoma to the south. Neighborhoods of Vashon Island include Magnolia Beach, which had a post office from 1908 to 1953, and Raeco, with a post office from 1907 to 1911.

Climate
This region experiences warm (but not hot) and dry summers, with no average monthly temperatures above 71.6 °F. According to the Köppen Climate Classification system, Vashon has a warm-summer Mediterranean climate, abbreviated "Csb" on climate maps.

Demographics
As of the census of 2000, there were 10,123 people, 4,193 households, and 2,838 families residing in the CDP. The population density was 273.9 people per square mile (105.7/km2). There were 4,867 housing units at an average density of 131.7/sq mi (50.8/km2). The racial makeup of the CDP was 93.61% White, 0.45% Black or African American, 0.70% Native American, 1.56% Asian, 0.06% Pacific Islander, 0.87% from other races, and 2.75% from two or more races. Hispanic or Latino of any race were 2.56% of the population.

There were 4,193 households, out of which 30.9% had children under the age of 18 living with them, 56.2% were married couples living together, 7.9% had a female householder with no husband present, and 32.3% were non-families. 23.8% of all households were made up of individuals, and 8.0% had someone living alone who was 65 years of age or older. The average household size was 2.40 and the average family size was 2.86.

In the CDP, the population was spread out, with 23.2% under the age of 18, 4.6% from 18 to 24, 25.1% from 25 to 44, 34.0% from 45 to 64, and 13.1% who were 65 years of age or older. The median age was 44 years. For every 100 females, there were 94.5 males. For every 100 females age 18 and over, there were 91.0 males.

The median income for a household in the CDP was $58,261, and the median income for a family was $67,010. Males had a median income of $50,201 versus $36,426 for females. The per capita income for the island was $31,983. About 4.6% of families and 6.0% of the population were below the poverty line, including 5.2% of those under the age of 18 and 2.2% of those 65 and older.

Based on per capita income, Vashon ranks 32nd of 522 areas in the state of Washington to be ranked.

Government
In 1994 the Vashon Island Committee for Self-Government circulated a petition calling for the incorporation of Vashon and Maury Islands. At the time only some 448 residents of about 10,000 signed the petition which was then filed with the King County Auditor.

The Vashon-Maury Island Community Council was a body whose purpose was to advise the King County Council on matters relating to Vashon Island and Maury Island. In 2013, it collapsed due to a requirement that it comply with the state's public records act and threats of lawsuits undermined the function of the organization. However, with the adoption of formal bylaws on June 15, 2020, a new Vashon-Maury Island Community Council was officially created by island residents. The new group was formed as a non-profit to help island residents address important issues facing their community.

Public safety
Vashon Fire is led by Matt Vinci and is a combination professional-volunteer department. There is one staffed station, Station 55, which houses a minimum staffing of three firefighter/EMTs and two King County paramedics. Station 55 contains four aid units, one engine, one quint, one brush truck, two water tenders, one boat, one ATV, and one support unit. Vashon Fire uses ValleyCom as its dispatch center. There are two outlying stations that contain water tenders and backup engines: Station 56 located in Burton and Station 58 located in Dockton. The department is primarily funded by a property tax levy which last had a voter approved lid lift in 2017.

The island has an established emergency operations center manager who runs emergency drills with members of the community emergency response team (CERT) in order to provide the best response in times of emergencies such as earthquakes. The drills were established as routine through the group VashonBePrepared, a nonprofit, FEMA-sanctioned coalition of disaster preparedness organizations that were previously established on the island. Sometimes the drills have members of the Washington Army National Guard participating and supporting the volunteers.

Crime
There are some claims that the island is home to various drug houses, a claim which has caused the Vashon Youth & Family Services to offer substance abuse counseling as part of the regular assembly of social services.

Homicide rates on the island are extremely low, with only two homicides reported in the last twenty years and other forms of crime are also largely not seen. In 2005 the Sheriff's Office investigated one rape, six assaults, and forty-nine burglaries, in 2006 they investigated three rapes, eight assaults, and sixty-three burglaries.

Major crimes on the Island include a serial rapist who operated from 2003 through 2010 until he was arrested and charged due to DNA evidence, and a police officer who pleaded guilty to incest and other sex crimes involving his underage stepdaughter.

Agriculture
While orchards and strawberry farms formerly played a major role in the Vashon economy, the pressures of suburban residential development have all but eliminated any major commercial agriculture on the island. However, many small farms operate on the island, providing locals with fresh organic produce, milk, and eggs.

Despite the changes, the island continues to observe the tradition of holding a Strawberry Festival every July. In certain areas like Dockton, a significant amount of private property was occupied and subsequently seized from Japanese-American citizens who farmed strawberries on that land until World War II, when they were moved to internment camps away from the island.

Local orchards and wineries are established on the island, with some focusing on developing perry, an alcoholic beverage derived from pear juice instead of grapes. There are at least three wineries that produce 100% locally produced wines and other alcoholic-based beverages.

Manufacturing and industry
Vashon has lost two of its major industrial employers: K2 Sports moved its manufacturing to China, and the Seattle's Best Coffee roastery operation was closed shortly after SBC was bought by Starbucks. Currently, the largest manufacturer on Vashon is Pacific Research Laboratories, locally referred to as "The Bone Factory".

In 2014 it was reported that the company Edipure was to purchase the old K2 ski plant to manufacture more than 60 marijuana-based snacks including crackers, candy and gummy bears.

Transportation
There are no bridges to Vashon Island, so all access to the island is by sea or by air. Most travel on and off the island is on the Washington State Ferry system. A bridge connecting Vashon to Seattle and Kitsap County was planned in 1959, but was ultimately not funded. A second bridge proposal from the Washington State Transportation Commission was withdrawn in 1992 after objections from island residents.

Vashon Municipal Airport is on the northern half of the island. There is no regularly scheduled air service to the airport.

King County Metro provides bus service down the length of the island daily. During peak commute times on weekdays, the buses drive on to the ferry to Seattle. On September 10, 2016, on-island Sunday service returned to Vashon. Route 118 provides islanders with Sunday service for the first time in many years, mirroring Saturday schedules and helping riders connect with both ferry terminals and other destinations in between.

Ferries
The southern terminus of the Vashon Highway is the Tahlequah Ferry Terminal in the Tahlequah neighborhood, connected to the Point Defiance neighborhood of Tacoma by the Point Defiance–Tahlequah ferry. The northern terminus of the Vashon Highway is the Heights Dock at Point Vashon, serving the state ferry docks at Southworth, and Fauntleroy in West Seattle. Passenger-only service from Heights Dock to Colman Dock in Downtown Seattle is provided by the King County Ferry District, with three sailings in each direction during the morning and afternoon, Monday through Friday.

The island previously had ferries that were run by private companies, including the Puget Sound Navigation Company (also known as the Black Ball Line). After a six-day strike by workers in February 1947 left Vashon Island without service, a group of residents acquired three passenger ferries and operated them on their own the following year under the King County Ferry District. The Black Ball Line planned to restart service on May 15, 1948, but were blocked by a mob of Vashon Island residents who rushed the MV Illahee when it attempted to dock. The ferry district remained without private competition until it was dissolved in 1951 and replaced by Washington State Ferries.

Health care
In 2016 it was reported that the medical clinic on the island had closed after CHI Franciscan Health had left the clinic, claiming financial concerns. Another provider, the non-profit NeighborCare Health, pledged to open a new clinic later in the year, alleviating the issue of transporting patients to hospitals off the island via the ferry, which can take upwards of three hours. NeighborCare's lease on the island's clinic expired in 2020, and as of 2021 the clinic was operated by Sea Mar.

During the 2020 COVID-19 pandemic, Vashon faced a shortage of tests, medical resources, and protective equipment. A team of local doctors created their own response plan, dubbed the "Rural Test & Trace Toolkit", with the hopes of creating a model for other isolated communities.

Vaccination concerns
Many of those who live on the island choose not to vaccinate their children due to vaccine hesitancy. It was reported in 2015 that 23.1% of kindergartners in the Vashon Island School District legally opted out of vaccinations against diphtheria and tetanus, whooping cough, measles, mumps, rubella, polio, varicella, and hepatitis B. The number, at the time, was five times the state average. Of those who do not vaccinate, more than 98% cite "Personal" rather than "Religious" or "Medical" as exemptions. Their failure to vaccinate has caused resentment in the community.

Due to expanded access to vaccines, media coverage of the measles outbreaks, and education about the benefits of vaccination, the vaccine rate for the Vashon Island School District has risen over the years, even though it is still one of the lowest in the United States. The district's rates of fully immunized students rose 31% over six years, from 56% to 74% as of the 2017–2018 school year; although still below the 95% target rate for the rest of the country. In 2019, it was reported that some 11.6% of families on the island had failed to vaccinate their children.

Education
Public schools: There are three public schools provided by the Vashon Island School District
 * Chautauqua Elementary School
 * McMurray Middle School
 * Vashon Island High School

Private schools: There are two private schools in Vashon.
 * The Harbor School (grades 4 to 8). 65 students were enrolled as of September 2013.
 * Carpe Diem Primary School (Kindergarten to 3rd grade). 26 students were enrolled as of September 2013.

Arts and culture
The annual studio tour was created in the late 1970s by some of the potters who lived on the island. The group was rebranded in February 2018 as the Vashon Island Visual Artists, and they applied for non-profit status in 2015. The group now operates semi-annual tours of studios of local artists, classes, workshops, salons, exhibits, and social activities for artists, with membership around 300. The island is home to a choral group established in 1989 under the name Island Singers, and now known as the Vashon Island Chorale.

On the first Friday of every month, there is a gallery walk where the art galleries in town open for visitors. The Vashon Center for the Arts along with cafés are also open during the First Friday gallery walk which have shown the work of local artists including Ann Leda Shapiro.

Broadcast radio stations
In 2014, a small media outlet, the Voice of Vashon, acquired a low-power FM radio broadcast license from the FCC. KVSH-FM went live on 101.9 FM in October 2014, and is also still available for live streaming. The Voice of Vashon started filing as a non-profit starting from the 2015 tax year. The Voice of Vashon records and broadcasts community arts events with support from King County 4Culture grants. The Voice of Vashon's board includes director and producer Rick Wallace. The Voice of Vashon also operates a television station, Comcast Channel 21, and its emergency broadcast system at 1650AM. Each of these outlets serves Vashon and Maury Islands year round, 24 hours/day, 7 days/week, with island-generated or specific information, entertainment and emergency alerts.

Maury Island is home to numerous AM transmitters. KIRO 710 (built in 1941) has two massive towers for its 50,000-watt day/night transmitter. KTTH 770, which transmits 50,000 watts during the day and 5,000 watts at night, shares towers with KPTR. KIRO and KTTH are owned by Bonneville International.

There was a tower originally built in 1946 for KEVR 1090AM, which later became KING radio, and is now KPTR, owned by iHeartMedia. It transmits 50,000 watts day/night and operates three towers. This site is shared with KTTH.

On Vashon Island, radio station KVI 570 has a single tower on a beach in Tramp Harbor, nicknamed "KVI Beach". KVI transmits 24 hours a day at 5,000 watts. KNWN 1000 transmits 50,000 watts day/night and has a three-tower setup on the northeast corner of the island. Both KVI and KNWN are owned by Lotus Communications.

KGNW AM 820 propagates its signal from three towers in the center of the island. It operates 50,000 watts during the day and 5,000 at night. It is owned by Salem Media Group. KJR 950 shares the towers at the KGNW site, transmits 50,000 watts day/night, and is owned by iHeartMedia.

These stations have located their transmitters on Vashon and Maury Islands because local soil conductivity, important for signal propagation in the megawatt broadcast frequency range, is greater than elsewhere in the Puget Sound area. The surrounding sea water is also helpful for radio propagation.

Sports and recreation
The island is home to the Vashon Island Rowing Club and Burton Beach Rowing Club, both of which participate in many events such as the Opening Day celebrations on Seattle's Montlake Cut. The island is also home to the Vashon Island Golf & Country Club.

The Vashon Sheepdog Classic occurs each year at the Misty Isle Farms, with local food and merchandise vendors, with all profits going to area nonprofits. The trials are completed by a team composed of a dog and its handler who are released into a shedding ring and work to herd the sheep into specific areas.

Notable people

 * Matt Alber, musician
 * Ian Moore, American guitarist and singer-songwriter
 * Gene Amondson, Prohibition Party presidential candidate
 * Gene "Bean" Baxter, co-host of KROQ's Kevin and Bean radio morning show
 * Steve Berlin, of the Grammy Award-winning band Los Lobos
 * Alex Borstein, actress noted especially for her work on Fox's MADtv and as the voice of Family Guy's Lois Griffin
 * Berkeley Breathed, author of the political satire comic strip Bloom County, resided on Vashon for some time. He wrote a children's book based on a bicycle in a tree. The real-life tree, growing around a bicycle, can be seen on the island.
 * Michael Chabon, writer and 2001 Pulitzer winner. His novel Summerland (2002) is set on fictional Clam Island, WA, which Chabon has acknowledged having modeled on Vashon. Some of the stories in his collection Werewolves In Their Youth (1999) are also set on an island that strongly resembles Vashon.
 * Donald Cole, abstract expressionist painter
 * Heather Corinna, feminist sex educator
 * Karen Cushman, young adult fiction author
 * Pete Droge, musician
 * Booth Gardner, former Washington state governor
 * Mary Matsuda Gruenewald, memoirist
 * Art Hansen, painter and lithographer
 * Rob Hotchkiss, founding member of Train
 * Eyvind Kang, modern composer
 * Amanda Knox, author and activist
 * Michael Leavitt (artist), sculptor
 * Betty MacDonald, author who specialized in humorous autobiographical tales; lived on Vashon and used the island as the setting of her book Onions in the Stew
 * Zach Mann, reality TV star from MTV's The Real World
 * Robert Miskimon, author
 * Susan Nattrass, a former world champion shooter from Canada
 * Kaitlin Olson, actor best known for playing Deandra Reynolds in FX hit comedy It's Always Sunny in Philadelphia and playing Micky Molng in The Mick; lived here until the age of 8
 * Frank Peretti, Christian fiction writer, grew up on Vashon Island
 * Basil Poledouris, film composer, spent the last four years of his life on Vashon Island
 * Austin Post, aerial photographer and glaciologist
 * John Ratzenberger, who played Clifford C. Clavin, Jr. on the television show Cheers, and also played varying roles in many Pixar films, once lived on and still owns land on connected Maury Island. He also helped to start a school on the island.
 * Peter Rinearson, Pulitzer Prize winner and entrepreneur
 * Dan Savage, editor of The Stranger and the author of "Savage Love," a syndicated sex advice column, formerly lived on Vashon Island with his partner and adopted son. By his own account, he moved from Vashon because he was unsure that the local public schools would welcome the adopted son of gay partners.
 * Josh Tillman, singer-songwriter, drummer with the Fleet Foxes, also performs as Father John Misty
 * Aaron Turner, Hydra Head Records and SIGE Records owner, musician
 * Edith Derby Williams, historian, granddaughter of former President Theodore Roosevelt, lived on Vashon Island from 1949 until her death in 2008
 * Benjamin F. Wilson, recipient of the Medal of Honor for his actions in the Korean War
 * Abe Koogler, playwright

Historic landmarks
Vashon Island has a number of buildings and sites that are listed on the King County Historic Register:

Other points of interest

 * The bike in the tree. A bicycle placed in the fork of a tree, allegedly when a child chained a bike to the tree decades ago and never picked it up, and the tree subsequently grew around it. This is a common local and tourist attraction, and has been subject to vandalism in recent years. The bike in the tree served as the inspiration for the Christmas book Red Ranger Came Calling by Berkeley Breathed.
 * Point Robinson Lighthouse. Point Robinson Beach on the east shore of Maury Island has been the site of a lighthouse since 1885. The current Point Robinson lighthouse has been fully automated since 1978.
 * Fisher Pond, a 90-acre terrestrial and freshwater conservancy, the largest on Vashon Island
 * Jesus Barn Farm, a farmstead founded in 1893. During the 1960s it was turned into an agrarian lifestyle commune. Local lore suggests this is when the iconic "Jesus" was first painted on the side of the barn.
 * All-Merciful Saviour Monastery, a Russian Orthodox monastery on Maury Island
 * Glen Acres, Washington, a community on Vashon Island

title: Vashon, Washington


text:
Talk:Ley line/Archive 1

Here's a handwaving order-of-magnitude argument for the probability of ley lines.

Consider a set on n points in an area with approximate diameter d. Consider a valid line to be one where every point is within distance w/2 of the line (that is, lies on a track of width w.

Consider all the unordered sets of k points from the n points, of which there are

$$ \frac {n!} {(n-k)!k!} $$

What is the probability that any given set of points is co-linear in this way? Let's very roughly consider the line between the "leftmost" and "rightmost" two points of the k selected points (for some arbitary left/right axis: we can choose top and bottom for the exceptional vertical case). For each of the remaining points, the probability that the point is "near enough" to the line is roughly w/d. Write ε = w/d

So, the expected number of k-point ley lines is very roughly

$$ \frac {n!} {(n-k)!k!} \epsilon^{k-2}$$

So, set w = 50m, d = 30 km, (pencil line on an OS map) thus ε = 0.001666...

Then, we can tabulate the expected number of k-point lines found in a single map as follows:

w = 50m, d = 30 km

k      n      expected points

3 from 10:    0.20 4 from 10:    0.00 5 from 10:    0.00 6 from 10:    0.00 7 from 10:    0.00

3 from 20:    1.90

4 from 20:    0.01 5 from 20:    0.00 6 from 20:    0.00 7 from 20:    0.00

3 from 50:   32.67 4 from 50:    0.64 5 from 50:    0.01 6 from 50:    0.00 7 from 50:    0.00

3 from 60:   57.03 4 from 60:    1.35 5 from 60:    0.03 6 from 60:    0.00 7 from 60:    0.00

3 from 70:   91.23 4 from 70:    2.55 5 from 70:    0.06 6 from 70:    0.00 7 from 70:    0.00

3 from 100: 269.50 4 from 100:  10.89 5 from 100:   0.35 6 from 100:   0.01 7 from 100:   0.00

3 from 200: 2189.00 4 from 200: 179.68 5 from 200:  11.74 6 from 200:   0.64 7 from 200:   0.03

Notice the rapid increase of the number of expected lines with n.

Ley line proponents generally view five point ley lines as definitive proof that a line is real. Note that as there are roughly 400 OS maps covering the UK, if there were 50 points in each, there would be an expected 256 4-point leys and 4 five-point leys found nationally.

Increasing the value of w dramatically increases the number of expected lines on a single map, with effects that increase with the value of k.

Increasing the size of a map will increase d, thus reducing ε, but will increase n: for example, if a 30 km map has 50 points, a 60 km map with the equivalent density of significant points will have 200, although it will have a value of ε that is half of that for the 30 km map.

w = 50m, d = 60 km

3 from 100: 134.75 4 from 100:   2.72 5 from 100:   0.04 6 from 100:   0.00 7 from 100:   0.00

3 from 150: 459.42 4 from 150:  14.07 5 from 150:   0.34 6 from 150:   0.01 7 from 150:   0.00

3 from 200: 1094.50 4 from 200:  44.92 5 from 200:   1.47 6 from 200:   0.04 7 from 200:   0.00

3 from 250: 2144.17 4 from 250: 110.34 5 from 250:   4.52 6 from 250:   0.15 7 from 250:   0.00

3 from 300: 3712.58 4 from 300: 229.72 5 from 300:  11.33 6 from 300:   0.46 7 from 300:   0.02

Note how the probability of finding a 5-point ley on the 60km map with n=200 is much more than four times that of finding a 5-point ley on the 30km map with n=50. With 100 such maps nationally, the expected national number of 4-point leys would be 4492, with 147 5-point leys.

Combining all these 100 maps into a single national map 600 km in "diameter" containing 20,000 points gives the following expected number of leys:

3 from 20000: 111094445.00 4 from 20000: 46282408.68 5 from 20000: 15424384.07 6 from 20000: 4283479.99 7 from 20000: 1019570.23 8 from 20000: 212336.12 9 from 20000: 39305.78 10 from 20000: 6548.01 11 from 20000: 991.63 12 from 20000: 137.65

Conclusion
Finding leys gets enormously easier, the bigger the area you consider, for a given density of points. Thus, finding leys with many points over long distances is disproportionately easy, not disproportionately hard as intuition might suggest.

Code
Python code for the above: def factorial(x): prod = 1L for y in range(1, x+1): prod = prod * y   return prod

def combin(k, n): return factorial(n) / (factorial(n-k) * factorial(k))

w = 50.0 d = (60000*10) eps = w/d for n in [20000]: print for k in [3, 4, 5, 6, 7, 8, 9]: print " %d from %3d: %7.2f" % (k, n, combin(k, n)*(eps**(k-2)))

Hm. The computation on the main ley line page should be computed using the exact data, not the approximation. User:The Anome

Is all this mathematical content original research by a Wikipedian? If it is, I don't think it should be included. (See What Wikipedia is not, under "What Wikipedia entries are not", point no. 10.) If it isn't, you need to attribute it to its source. We're supposed to summarise what other people have reported about things, you see, rather than come up with novel content ourselves. -- Oliver P. 11:26 8 Jul 2003 (UTC)

---

Feel free to take it out, but please transfer it to the talk page if you do: I'm sure it can be made citable if needed. I'm not sure it's "novel" work: it's just a back-of-envelope computation that I could not track down an online source for. The results tie in with the extlinked computer simulation and the observed real-world results, which is a pretty good sanity check. -- The Anome 11:53 8 Jul 2003 (UTC)

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

title: Talk:Ley line/Archive 1


text:
User:Smacdonald

Real Name: Stewart Macdonald

Location: Townsville, Queensland, Australia

Occupation: Ecologist

Interests: Reptiles, Sharks, Chocolate

Hobbies: Rock climbing, SCUBA diving

Blog: Stewed Thoughts

I live in Townsville, Queensland, Australia. I'm an ecologist.

I have a web page called AROD.com.au, the Australian Reptile Online Database.

This is a list of the pages to which I've contributed.

My Photos
I've uploaded the following reptile photos to Wikipedia (I have some more on my Flickr site):

 * Stimson's python
 * Spotted python
 * Children's python
 * Pygmy python
 * Ornamental snake
 * Burton's legless lizard
 * Mulga snake
 * Arafura file snake

More information about my photography is available at ugmedia.com.au.

title: User:Smacdonald


text:
Guimaras

Guimaras, officially the Province of Guimaras (Kapuoran sang Guimaras; Lalawigan ng Guimaras), is an island province in the Philippines located in the Western Visayas region. The capital is Jordan, while the largest local government unit is the municipality of Buenavista. The province is situated in Panay Gulf, between the islands of Panay and Negros. To the northwest is the city and province of Iloilo and to the southeast is Negros Occidental. The whole island is part of the Metro Iloilo–Guimaras, one of the twelve metropolitan areas of the Philippines.

The province consists primarily of Guimaras Island, and also includes Inampulugan, Guiwanon (or Guiuanon), Panobolon, Natunga, Nadulao, and many surrounding islets.

Guimaras, formerly known as Himal-os, was a sub-province of Iloilo until it was made an independent province on May 22, 1992.

Spanish colonial era
About 1581, Gonzalo Ronquillo de Peñalosa, Spanish governor and Captain-General of the Philippine Islands, established a settlement in Guimaras for the purpose of Christianizing the island's natives. He and his subordinates organized the pueblicitos or villages of Nayup under the patronage of Saint Peter the Apostle, and Igang with Saint Anne as patroness.

Evangelization of Guimaras occurred around the same time the friars were making inroads in Panay. The Augustinians established the visitas (chapelries) of Nayup and Igang as subordinate to Oton, Iloilo. Gómez Pérez Dasmariñas, the 7th Spanish Governor-General, noted in a June 20, 1591, report to King Philip II that the friars of Oton made regular visits to the island.

In 1742, the island came under the jurisdiction of Dumangas – now known as Iloilo, until 1751 when the Augustinian Order was replaced by the Jesuits, after which the Dominican order took over Guimaras. The Jesuits, who had established a school in Iloilo and had missions in Molo and Arevalo, took charge of the island. By 1755, it was organized into a regular parish. When the population increased considerably, the island was given its municipal status with a seat of government at Tilad (today Buenavista).

American invasion era
Under American rule, the Guimarasnons were given the opportunity to elect their municipal president in 1908.

Douglas MacArthur, a fresh graduate from West Point as a Second Lieutenant at the age of 23, came to Iloilo as the head of the company of U.S. Army Corps of Engineers. They constructed roads and the Santo Rosario Wharf, presently named MacArthur's Wharf, which are still in use today. In November 1903, while working on Guimaras, he was ambushed by a pair of Filipino brigands or guerrillas; he shot and killed both with his pistol.

Japanese occupation era
In 1942, Japanese Imperial forces landed on Guimaras Island as the Empire of Japan began its occupation of the country during the Second World War. The Japanese controlled almost every island between the Philippines and Hawaii. The U.S. Forces needed these islands to run aircraft to and from the Philippines, while denying Japan usage. The U.S. Army and Navy planned indirect attacks that would eventually lead them to Luzon.

In 1945, 10 U.S. divisions and 5 independent regiments would battle for Luzon, making it the largest campaign of the war and involving more troops than the United States had used in North Africa, Italy or southern France. The combined United States and Philippine Commonwealth forces landed on Guimaras Island, attacking the Japanese and defeating them in the Battle of Guimaras, which led to the liberation of the island.

Provincial status
Guimaras gained its status as a sub-province of Iloilo through Republic Act 4667, which was enacted by Congress on June 18, 1966. It was proclaimed as a regular and full-fledged province on May 22, 1992, after a plebiscite was conducted to ratify the approval of its conversion pursuant to Section 462 of R.A. 7160.

Shortly after Guimaras acquired its provincial status, President Fidel V. Ramos appointed Emily Relucio-López as its first Governor.

The province of Guimaras was originally composed of three municipalities: Buenavista, Jordan, and Nueva Valencia. In 1995, through Republic Act No. 7896 and Republic Act No. 7897, the municipalities of Sibunag and San Lorenzo were created. The two new municipalities officially acquired their municipal status after the May 8, 1995, plebiscite held simultaneously with the local election.

Ernesto L. Gedalanga was the first appointed mayor of Sibunag and Arsenio Zambarrano was also appointed mayor of San Lorenzo. The temporary seat of government of the Municipality of Sibunag is at Barangay Dasal while the temporary seat of Government of the Municipality of San Lorenzo is at Barangay Cabano.

Guimaras oil spill
In August 2006, the Guimaras oil spill occurred. The 998-ton MT Solar 1, chartered by Petron (the Philippines' largest oil refiner), carrying 2.4 million litres of bunker fuel, sank 17 km off the island's southern coast, contaminating 24 km2. The Philippine Coast Guard called this the worst oil spill in the country's history. According to officials, 1,100 ha of mangroves were affected, including parts of the Taklong Island National Marine Reserve.

Geography
Guimaras comprises primarily of Guimaras Island, and numerous minor islets, prominent among which are Inampulugan, Guiwanon (or Guiuanon), Panobolon, Natunga and Nadulao. The province covers a total area of 604.57 km2 occupying the southeastern section of the Western Visayas region.

Sibunag River is the longest river in Guimaras with a total length of 28.8 km in municipality of Sibunag, followed by Cabano River 23.7 km long in San Lorenzo, Mantangingi River 17.4 km in Buenavista.

Mount Bontoc is the highest point in the province of Guimaras with an elevation of 892 ft above sea level, located in municipality of Sibunag. Mount Dinulman is the second highest mountain with an elevation of 879 ft also located in Sibunag.

The province has 5 municipalities. There is only one legislative district of Guimaras which encompasses all five towns.

Demographics

The population of Guimaras in the 2020 census was 187,842 people, with a density of undefined PD/km2.

The people of the province, called Guimarasnon, speak Hiligaynon as the primary language, as it was once a sub-province of Iloilo. Filipino and English are widely spoken and understood.

Catholicism
The two predominant religions in the municipality are the Roman Catholic Church and the Iglesia Filipina Independiente (Philippine Independent Church). The St. Paul's Theological Seminary (SPTS) in Jordan is the regional seminary of the Philippine Independent Church serving its Visayas and Mindanao dioceses.

Economy
The sectors having the most potential to support Guimaras' economic development are mangoes, tourism, cashew cultivation, and food processing. Another expanding sector is fishery, which includes growing seaweed. Infrastructure, capacity-building initiatives, more favorable legislation, and higher investments are just a few examples of local variables that have boosted the potential growth of these industries.

Guimaras is well known for its agricultural crops, particularly the mangoes, half of all exported mangoes come from this island. The island province is famous for producing one of the sweetest mangoes in the world, thus earning the nickname "Mango Capital of the Philippines" from local and foreign tourists. Guimaras mangoes are reportedly served at the White House and Buckingham Palace. Guimaras' largest event of the year is the Manggahan Festival (the Mango Festival). The variety of mangoes produced are also best for making dried mangoes, jam and other special delicacies. They also produce other fruits and vegetables such as bananas, tomatoes, and eggplants among others.

Transportation
Steel or Fiberglass Ferry boats ply regularly from Iloilo-Guimaras Ferry Terminal in Iloilo City Proper to Jordan, Guimaras and Buenavista, Guimaras, taking about 15 to 20 minutes per journey. RORO or roll-on/roll-off vessels sail from Lapuz, Iloilo City to Jordan Port in Jordan, Guimaras, every 30 minutes to one hour starting at 4:30AM to 6:30PM, taking about 30mins per way.

There is also a Ferry plying from Sibunag Port to Pulupandan in Negros Occidental.

Government
The Governor of Guimaras is Joaquin Carlos Rahman A. Nava, a member of the National Unity Party. The province's Vice Governor is John Edward G. Gando, a member of PDP–Laban. Guimaras is represented in the Philippine House of Representatives by Lucille Nava, also a member of PDP–Laban.

Tourism
Guimaras attracts tourists particularly in May, when the Manggahan Festival takes place. In the festival, locals wear mango-inspired costumes and design mango-themed floats in a parade that makes its way around the island. Pastries and confectionery with mango ingredients, as well unprepared mangoes, are also sold in relatively large quantities. Tourism also includes visits to agricultural areas across the island, such as the Oro Verde Mango Plantation. The island is also a growing destination for ecotourism. Talkong Island, off Guimaras' south coast, is a area of natural beauty recognized by the Philippine government. Tourists frequently visit areas such as the Guisi, Alubihod, Tatlong Pulo, and Natago beaches. Ave Maria Island is another ecological destination near Jordan. Some tourists also choose to visit the San Lorenzo Wind Farm, a series of turbines located near the island's eastern coast.

Guimaras is also a site for religious tourism. The Balaan Bukid Shrine hosts twelve markers of the Way of the Cross as individuals make an ascent towards a hilltop where the main shrine rests. Navalas Church, built between 1880 and 1885, bears one of the few remaining sites of Roman Catholic Spanish heritage on the island. The Trappist Monastery is located near the center of the island, providing a retreat center for visitors in addition to selling various mango-based foodstuffs to help support the monks of the monastery.

title: Guimaras


text:
User:Bonobo~enwiki

Bonobo lives in the Lueneburg Heath in Northern Germany, teaches Media Design/Prepress Magic, keeps bees, plays Go, uses a Mac, loves psychology and philosophy

title: User:Bonobo~enwiki


text:
Castilleja

Castilleja, commonly known as paintbrush, Indian paintbrush, or prairie-fire, is a genus of about 200 species of annual and perennial mostly herbaceous plants native to the west of the Americas from Alaska south to the Andes, northern Asia, and one species as far west as the Kola Peninsula in northwestern Russia. These plants are classified in the broomrape family Orobanchaceae (following major rearrangements of the order Lamiales starting around 2001; sources which do not follow these reclassifications may place them in the Scrophulariaceae). They are hemiparasitic on the roots of grasses and forbs. The generic name honors Spanish botanist Domingo Castillejo.

Taxonomy
Castilleja was scientifically described by Carl Linnaeus the Younger using a partial description by José Celestino Bruno Mutis in 1782. The type species was Castilleja fissifolia from Columbia. The genus as a whole has never been renamed, however five others were described and named that are considered to be synonyms of Castilleja. For example, in 1818 Thomas Nuttall described a genus that he named Euchroma meaning finely colored, moving the species now known as Castilleja coccinea out of Bartsia where it had been placed by Carl Linnaeus and also named another species as Euchroma grandiflora. However, Nutttall's Euchroma grandiflora had already been named and correctly placed as Castilleja sessiliflora by Frederick Traugott Pursh in 1813.

Species
There are 216 species that are considered valid by Plants of the World Online. More than half, 119 species, are native to North America north of Mexico.

Description
The species in Castilleja are quite varied in form and lifecycle. The genus includes many species that are completely herbaceous, lacking woody material in their above-ground parts. Though it also includes some slightly woody subshrubs and even a few woody shrubs. They may grow as annual plants, but most of the species are perennial. Their roots are equally diverse in structure ranging from taproots to fibrous root systems. Some species also have modified underground stems called rhizomes to spread short distances.

Stem lengths range from a minute 1 centimeter to as much as 2 meters. In almost all species the leaves are attached to the stems and alternating. The inflorescences are always at the ends of the stems, which may or may not branch. The inflorescence usually have bracts that are brightly colored for the whole length or towards their ends.

Ecology
Castilleja species are eaten by the larvae of some lepidopteran species, including Schinia cupes (which has been recorded on C. exserta) and Schinia pulchripennis (which feeds exclusively on C. exserta), and checkerspot butterflies, such as Euphydryas species. Pollinators aid these plants in reproduction, with insects visiting the flowers, as well as hummingbirds for some species.

Castilleja species can play an important role in plant community dynamics and multitrophic interactions. For example, Castilleja hemiparasitic reliance on other plant species may affect competition and dominance among other plant species in its community. Additionally, the foliage of some Castilleja species naturally contains defensive compounds that are sequestered in the tissues of larvae of specialist insect species that have developed a tolerance for these compounds and are able to consume the foliage. These sequestered compounds then confer chemical protection against predators to larvae.

Hybridization
Some species in the Castilleja genus are able to hybridize, especially when ploidy levels match, and hybrids may produce viable seed. This hybridization potential has been identified as a threat to the genetic integrity of certain endangered Castilleja species.

Uses
The author Gregory L. Tilford claims that the flowers of Indian paintbrush are edible. However, these plants have a tendency to absorb and concentrate selenium in their tissues from the soils in which they grow, and can be potentially very toxic if the roots or green parts of the plant are consumed. Highly alkaline soils increase the selenium levels in the plants. In addition Castilleja species will take up alkaloids from other plants when parasitizing them.

Symbolism
Castilleja linariifolia is the state flower of Wyoming.

title: Castilleja


text:
Postage stamp reuse

Postage stamp reuse is the technique of fraudulently reusing postage stamps from sent mail to avoid paying the cost of postage.

Reuse
A postage stamp is a small piece of paper attached to mail that indicates that the postage (the cost of sending the mail) has been paid. Because stamps are sent on most mail, the stamp on a received item can be removed and placed on a different piece of mail to be sent, thus reusing the stamp without paying the proper postage.

In many countries, such as the United States, reuse of used stamps, whether cancelled or not, is illegal.

Mute cancellation (killer)
After use, many stamps are marked with a cancellation by the postal system, which defaces the stamp and prevents its reuse. The cancellation usually includes a killer placed on the stamp that has black bars, cork impressions or other obstructive shapes to deface the stamp. Instead of using an entirely separate mark, some countries use their postmark, placed on the stamp, to cancel mail.

Grilling
In the United States, the experiment of grilling was tried in 1867, where tiny squares were embossed into the paper after the stamp was printed, the idea being that this would break up the paper fibers and let more ink be absorbed into the paper. Grilling was abandoned around 1871 due to the stamps being more likely to tear. Unusual types of grills are typically found on rare U.S. stamps.

Design with water-soluble inks
In the 1880s in Great Britain, the use of inks which were water-soluble, thus preventing successful washing, was used. Only lilac and green colors were available. This scheme was abandoned after a few years, and the few surviving unwashed stamps have become collectibles.

Surface coating
Later experiments involved surface coatings. Between 1901 and 1907 Austria applied varnish bars, thin diagonal strips of varnish, to the paper before printing the design. Russia did the same between 1909 and 1915, applying the varnish in a pattern of lozenges. In both cases the theory was the same; the ink of the printed design would not soak into the varnish, so that in the washing process the design would tend to flake off, forming a telltale pattern on the washed stamp. The United States also coated a few of their $1 revenue stamps with varnish around the turn of the 20th century.

Perfin
A perfin is a stamp that has had initials or a name perforated across it to discourage theft. By agreement with postal authorities, a perfin stamp on a letter could be used only by the owner of the perfin. Therefore, a stolen perforated stamp would be of no value to the unauthorized bearer.

Varia
More unusual methods have included tearing or slicing the stamp, but this is a slower process and can easily damage the contents, and was only occasionally used. An example is 19th century Afghanistan, where cancellation involved the removal of part of the stamp rather than applying ink or other surface marking.

title: Postage stamp reuse


text:
Indian Paintbrush

Indian Paintbrush may refer to:
 * Indian Paintbrush (company), American film production company
 * Indian Paintbrush Book Award, award given annually to books nominated and voted on by children in Wyoming
 * Castilleja, a genus of annual and perennial herbaceous plants
 * Butterfly weed (Asclepias tuberosa), North American milkweed
 * Hawkweed (Hieracium)

title: Indian Paintbrush


text:
World Rugby

World Rugby is the governing body for the sport of rugby union. World Rugby organises the Rugby World Cup every four years, the sport's most recognised and most profitable competition. It also organises a number of other international competitions, such as the World Rugby Sevens Series, the Rugby World Cup Sevens, the World Under 20 Championship, and the Pacific Nations Cup.

World Rugby's headquarters are in Dublin, Ireland. Its membership now comprises 130 national unions. Each member country must also be a member of one of the six regional unions into which the world is divided: Africa, North America, Asia, Europe, South America, and Oceania.

World Rugby was founded as the International Rugby Football Board (IRFB) in 1886 by, and , with  joining in 1890. , and  became full members in 1949. became a member in 1978 and a further 80 members joined from 1987 to 1999. The body was renamed the International Rugby Board (IRB) in 1998, and took up its current name of World Rugby in November 2014. In 2009, the International Olympic Committee (IOC) voted to include rugby sevens in the 2016 Summer Olympics. World Rugby gained membership of the Association of Summer Olympic International Federations (ASOIF) in 2010.

History
Until 1885 the laws of rugby football were made by England as the founder nation. However, following a disputed try in an international between Scotland and England in 1884, letters were exchanged in which England claimed that they made the laws, and the try should stand. Scotland refused to play England in the 1885 Home Nations Championship. Following the dispute, the home unions of Scotland, Ireland and Wales decided to form an international union whose membership would agree on the standard rules of rugby football. The three nations met in Dublin in 1886, though no formal regulations were agreed upon.

On 5 December 1887, committee members of the Irish Rugby Football Union, Scottish Rugby Union (named the Scottish Football Union at the time) and Welsh Rugby Union met in Manchester and wrote up the first four principles of the International Rugby Football Board. England refused to take part in the founding of the IRFB, stating that they should have greater representation, as they had more clubs. The England Union also refused to accept the IRFB as the recognised lawmaker of the game. This led to the IRFB taking the stance of member countries not playing England until they joined, and no games were played against England in 1888 and 1889. In 1890 England joined the IRFB, gaining six seats while the other unions had two each. The same year, the IRFB wrote the first international laws of rugby union.

In 1893, the IRFB was faced with the divide between amateurism and professionalism, which was nicknamed the "Great Schism". Following the introduction of working-class men to the game in Northern England, clubs began paying "broken time" payments to players, due to the loss of earnings from playing on a Saturday. Cumberland County Union also complained of another club using monetary incentives to lure players, leading to the IRFB conducting an enquiry. The IRFB was warned by all the chief clubs in Lancashire and Yorkshire that any punishment would lead to the clubs seceding from the union. The debate over broken time payments ultimately caused the 22 leading clubs in Yorkshire and Lancashire to form the Northern Rugby Football Union. The competing unions' laws of the game diverged almost immediately; the northern body's code eventually became known as rugby league football.

England's seats on the IRFB were reduced from six to four in 1911. The Australian Rugby Union, New Zealand Rugby Football Union and South African Rugby Board joined the board with one seat each in 1948, with England's seats being reduced to two, the same as the other home nations. The three Southern Hemisphere unions were given a second seat each in 1958. The French Rugby Federation was admitted in 1978, the Argentine Rugby Union, Italian Rugby Federation and USA Rugby Football Union in 1987, and the Canadian Rugby Union, and Japan Rugby Football Union were admitted in 1991. In 2016, the Georgia Rugby Union, Romanian Rugby Federation, and the USA were added to the voting Council with one vote each. Additionally, current Council members Argentina, Canada and Italy were granted a second representative and vote. The six regional associations represented on the council also received an additional vote.

After the 2022 Russian invasion of Ukraine, World Rugby suspended Russia from international and European continental rugby union competition. In addition, the Rugby Union of Russia was suspended from World Rugby.

Rugby World Cup
In the 1960s Australians Harold Tolhurst and Jock Kellaher suggested a World Rugby Championship be held in Australia but the IRFB refused. In 1983 and 1984 respectively, the Australian and New Zealand Rugby Football Unions each proposed hosting such a tournament. The following year the board committed to conduct a feasibility study. A year later another meeting took place in Paris, and the Union subsequently voted on the idea. The South African Rugby Board's vote that proved crucial in setting up a tied vote, as they voted in favour, even though they knew they would be excluded due to the sporting boycott because of their apartheid policies. English and Welsh votes then changed, and the vote was won 10 to 6.

Member unions
As at June 2024, World Rugby has 113 member unions and 17 associate member unions.

Membership of World Rugby is a four-step process:

 * 1) A Union must apply to become an associate member of its Regional Union
 * 2) After all membership criteria are met, including one year as an associate member, the Union is admitted to the Regional Union as a full member
 * 3) After completion of stages 1 and 2, and two years as a full member of a Regional Union, the Union may then apply to become an Associate member of World Rugby. As an associate member, the union can participate in World Rugby funded tournaments but not the Rugby World Cup
 * 4) Following two years of associate membership of World Rugby, the union may then apply to become a Full Member

Regional Unions

Six regional associations, which represent each continent, are affiliated with World Rugby and help to develop the fifteen-a-side game as well as Rugby sevens across the world. Not all members of the regional associations are members of World Rugby. Below is a list of member and associate unions and their regional associations with the year that they joined World Rugby. Associate unions are in italics.

Africa
There are 21 World Rugby members and 6 World Rugby associates:

• (2021)

•  (1994)

•  (2020)

•  (2021)

•  (1999)

•  (2022*)

•  (2022*)

•  (1998)

•  (2017)

•  (1988)

•  (1990)

•  (2022*)

•  (1998)

•  (2004*)

•  (2009)

•  (1998)

•  (1990)

•  (2001)

•  (2015)

•  (1999)

•  (1949)

•  (2004*)

•  (2004*)

•  (1988)

•  (1997)

•  (1995)

•  (1987)

Suspended unions:

Notes:

* Denotes associate membership date.

Asia
There are 22 World Rugby members, and 6 World Rugby associates:

•  (2004*)

•  (2013*)

• (1997)

•  (1998)

•  (1998)

•  (1988)

•  (1999)

•  (2013)

•  (2010)

•  (1987)

•  (2020*)

•  (1997)

•  (1988)

•  (2004*)

•  (2004)

•  (2018*)

•  (1988)

•  (2021)

•  (2023)

•  (2008)

•  (2008)

•  (2023)

•  (1989)

•  (2022*)

•  (1988)

•  (1989)

• (2012)

•  (2014)

Notes: * Denotes associate membership date.

Europe
There are 38 World Rugby members, and 2 World Rugby associates:

• (1991)

•  (1992)

•  (1988)

• (1996)

•  (1992)

•  (1992)

•  (2014*)

• (1988)

•  (1988)

•  (1890)

•  (2001)

•  (1978)

•  (1992)

•  (1988)

•  (1991)

•  (1886)

•  (1988)

•  (1987)

•  (1991)

•  (1992)

•  (1991)

•  (2000)

•  (1994)

•  (1996)

•  (1988)

•  (1993)

•  (1988)

•  (1988)

•  (1987)

•  (1886)

•  (1988)

• (2016*)

•  (1996)

•  (1988)

•  (1988)

•  (1988)

•  (2023)

•  (1992)

•  (1886)

Suspended unions:

Notes: * Denotes associate membership date.

North America
There are 12 World Rugby members, and 1 World Rugby associate:

• (1994)

•  (1995)

•  (1992)

•  (2001*)

•  (1987)

•  (1997)

•  (1995)

•  (1996)

•  (2006)

•  (2022)

• (2001)

• (1992)

•  (1987)

Notes: * Denotes associate membership date.

South America
There are 9 World Rugby members, and 2 World Rugby associates:

• (1987)

•  (1995)

•  (1991)

•  (1999)

•  (2017)

•  (2016*)

•  (2020*)

•  (1989)

•  (1999)

•  (1989)

•  (1998)

Notes: * Denotes associate membership date.

Oceania
There are 11 World Rugby members:

• (2012)

•  (1949)

•  (1995)

•  (1987)

•  (1949)

•  (1999)

•  (1993)

•  (1988)

•  (1999)

•  (1987)

•  (1999)

Participation figures
World Rugby's largest members, ranked by number of participants in 2019, are: • # (2.11 million)

• # (1.48 million)

• # (692,000)

• # (533,000)

• # (477,000)

• # (296,000)

• # (266,000)

• # (225,000)

• # (217,000)

• # (215,000)

• # (210,000)

• # (182,000)

• # (174,000)

• # (161,000)

• # (156,000)

• # (123,000)

• # (114,000)

• # (109,000)

• # (108,000)

• # (96,000)

Council
The World Rugby Council meets twice a year and manages and controls the affairs of World Rugby. The Council formulates and oversees the implementation of World Rugby's strategic plan and application of policy decisions, and selects the host nation(s) for the Rugby World Cup. The Council considers recommendations of the General Assembly. The Council may admit or expel member nations. The council is also the supreme legislative authority of World Rugby. Most Council decisions require approval of simple majority, but to amend the World Rugby's by-laws, regulations, or the Laws of the Game requires approval of three quarters of the council.

Prior to 2016, the council had 28 voting members from 12 national unions. In November 2015, World Rugby announced that they would add more unions to the voting council and give the six regional associations two votes each on the council.

, the council had 52 members including the non-voting chairman, so there were 51 voting members from 17 national unions and 6 regional associations, allocated as follows:

 * (33) Eleven unions with three votes each:, , , , , , , , , , and.
 * (6) Six unions with one vote each:, , , , and.
 * (12) The six regional associations representing Africa, Asia, Europe, North America, South America and Oceania with two votes each.

In total, Europe has 22 votes; Oceania 9 votes; South America 6 votes; Africa 5 votes; Asia 5 votes and North America 4 votes.

A Chairman and Vice Chairman are elected from among the council members. These positions are held by Bill Beaumont of England and Bernard Laporte of France, respectively, elected.

Executive committee
The executive committee, in accordance with bye-laws 9.14–9.16, ensures the effective management and operation of the World Rugby. The Committee formulates and monitors the implementation of the World Rugby's strategic plan, business plan, operational plan and budget. In 2016, as part of the reforms to the World Rugby Council, the executive committee was increased to 12 members. The Chairman, Vice-chairman, nine elected officials, including two independent members, and the Chief Executive sit on the World Rugby Executive Committee.

General Assembly
A General Assembly of the full membership is convened every two years. The General Assembly may make recommendations to the council, and may consider business that the council has referred to it, but the General Assembly has no legislative powers.

Leadership
The Chairman and vice-chairman of the World Rugby are elected by the council. The current chairman is Bill Beaumont, previously president of the Rugby Football Union (RFU). He was elected chairman effective on 1 July 2016 following the Executive Council vote on 11 May 2016. Previous chairmen include Bernard Lapasset (2008 to 2016), Syd Millar (2002 to 2007) and Vernon Pugh, QC (1994 to 2002).

In July 2012, Brett Gosper was appointed as the new Chief Executive of what was then the IRB. He will leave this role at the end of 2020 to become head of the National Football League's operations in Europe.

Funding
In 2013 World Rugby released £18.6 million of funding over three years for developing rugby in Canada, the United States, Japan, Romania, Fiji, Samoa, and Tonga. Argentina also received additional support to enable it to retain its tier one status. The money, built up from successful World Cups, was released following a report commissioned by World Rugby highlighting the growing disparity between tier one and tier two nations. This is in addition to the £10–12 million it normally gives out grants and tournament costs. The emphasis is on three areas infrastructure, high performance units and cross border competitions. In April 2006, tier-3 rugby nations Georgia, Portugal, Tunisia and Russia were identified as key investment nations over the next three years. The program was designed to increase the competitiveness of international rugby union.

Rugby World Cups
World Rugby organises the Rugby World Cup, the sport's most recognised and most profitable competition, which has been held every four years since 1987. Despite the profitability of the World Cup, the majority of its revenues and viewers come from a small number of countries. For the 2007 Rugby World Cup final, 87% of viewers came from England, France, Wales, Ireland, and Scotland, 15% came from the South Africa, Australia, and New Zealand, with just 2% of viewers coming from all other countries.

The most recent Rugby World Cup was held in France in 2023. South Africa defeated New Zealand 12–11 in the Rugby World Cup final, winning a record fourth title.

World Rugby also organises the women's Rugby World Cup, also held every four years. It was first held by the IRB in 1998, though tournaments in 1991 and 1994 were retrospectively recognised in 2009. The women's World Cup is contested by fewer teams than the men's Cup, with only the 1998 and 2002 editions featuring more than 12 teams (these competitions both had 16 teams, compared to the 20 teams in the men's Rugby World Cup).

On 21 August 2019, World Rugby announced that all future men's and women's World Cups would officially be known as "Rugby World Cup", with no sex or gender designations. The first tournament to be affected by this policy was the 2021 Rugby World Cup, for women's team in New Zealand.

Sevens
World Rugby organised three international sevens tournaments - two annual Sevens Series (one for men and one for women) which are now defunct. The quadrennial Rugby World Cup Sevens is still active.

The men's season-long annual Sevens Series took place over 10 legs, each held in a different country. The women's Sevens Series is held over five- or six-legs. Both tournaments followed the same principle—points are awarded based on a teams position in each round of the series, and the team with the most points at the end of the Series is crowned champions. Following the inclusion of rugby sevens into the Olympics, beginning with the 2014–15 series, the series prior to an Olympic event (i.e. the series which ends in the year before the Olympics takes place) forms the first phase of Olympic qualification. When Olympic Qualification was included, the top four teams from both the men's and women's series qualified for the Olympic Games, and remaining teams competed in regional competitions for one of the remaining places.

The quadrennial Rugby World Cup Sevens includes both the men's and women's world cup tournaments. It was originally due to be discontinued after the inclusion of rugby sevens into the Olympic Programme. However, it was later decided to retain the tournament, as it involved a significantly larger number of teams than the Olympics would, and to move the tournament so as to create a more even sevens calendar (with the major sevens events alternating every two years). As a result, the most recent tournament was the 2018 Rugby World Cup Sevens in San Francisco, US. The men's and women's competitions at this event were both won by New Zealand.

SVNS
In 2023 World Rugby re-branded the Sevens series to a new World Rugby SVNS Series known as the HSBC SVNS. The new format will showcase the twelve best men’s and women’s teams, which will conclude in a Grand Final weekend where the top eight teams will compete to be crowned Series champions. The teams ranked ninth to twelfth will compete against the top four teams from a new Challenger Series in a relegation play-off to see who secures their place in the 2024-2025 season. Both men and women’s teams will earn the same with equal participation fees. Both men and women will play in joint tournaments in eight cities around the world. Starting in December 2023 in Dubai, Cape Town, Perth, Vancouver, Los Angeles, Hong Kong, Singapore and will conclude in Madrid in June 2024. The tournament is set to bring about a festival type atmosphere and serve as a build up to the Paris 2024 Olympic Games.

Developmental competitions
World Rugby organizes annual international competitions involving Tier 2 nations.

 * Pacific Nations Cup, which has been played annually since 2006. The national teams of Fiji, Samoa, Japan, Tonga, Canada and the United States currently compete for the cup. At various times in the past, the national teams of Japan, Georgia, Canada, and the United States, plus second-tier representative sides from Australia and New Zealand, have also been involved.
 * Pacific Challenge, which is a competition involving the national "A" sides from Fiji, Samoa, and Tonga (and more recently Junior Japan, Canada A, and Argentina's Pampas XV).
 * Americas Rugby Championship, whose current incarnation involves Argentina's "A" side, currently branded as Argentina XV, and the full national teams of Brazil, Canada, Chile, Uruguay, and the USA.

Junior competitions
World Rugby organizes two competitions for under-20 national teams, the World Rugby Under 20 Championship and the World Rugby Under 20 Trophy. These competitions were created following the merger of under-19 and under-21 representative teams, into an under-20 age group

Olympics
The sport of rugby union has been played at the Summer Olympics on four occasions, with the last being in 1924. The winners, and thus the reigning champions, were the U.S. team. Rugby union made one more appearance as a demonstration event but was then removed from the Games. World Rugby has most recently been very keen to see it return to the Games and is adamant that the sport (specifically referring to rugby sevens) satisfies every respect of the criteria set out in the Olympic Charter.

The main problem for reintroducing the 15-man game to the Olympics is the 7-day turnaround required by World Rugby regulations for players to rest between games. Since the Olympics only officially run for 16 days, with only slight expansions allowed to accommodate sports such as football, this effectively makes it impossible to conduct a 15s tournament within the current Olympic schedule. This limitation does not apply to sevens, as games last only 14 minutes instead of the 80 minutes in the 15s game. All of the events in the current men's and women's Sevens Series, which feature a minimum of 16 national teams for men and 12 for women, are conducted within a single weekend.

But in furthering the World Rugby cause, the organisation became an International Olympic Committee Recognised International Federation in 1995, marked by a ceremonial signing by President Juan Antonio Samaranch prior to a match between Wales and South Africa in Cardiff.

World Rugby cites rugby union's global participation, with men playing the game in well over 100 countries and women playing in over 50 as well; the organisation's compliance with the World Anti-Doping Code; and that a rugby sev3ns tournament could be (and generally is) accommodated in one stadium and is relatively inexpensive to play. Not only is the sevens game successful in the context of the Sevens World Series and World Cup Sevens, it is also very successfully played in the Commonwealth Games; the sevens tournament at the 2006 Games in Melbourne set all-time attendance records for a sevens tournament.

As a result of this, World Rugby applied to the International Olympic Committee for a Sevens tournament to form part of the Olympics. Subsequently, Sevens was accepted into the Summer Olympic Games and was first played in 2016 in Rio de Janeiro which was won by Fiji in the men's competition (defeating Great Britain) and by Australia in the women's competition (defeating New Zealand). In the Tokyo Olympics 2020 edition, the Fiji 7s men's team and the New Zealand 7s women's team claimed the gold medals in their respective competitions.

Laws and regulations
The laws of rugby union are controlled by a standing Laws Committee, which is established by the World Rugby Council. The current chairman of the committee is Bill Beaumont. The Laws of the Game are formulated by World Rugby, and are then circulated by the national Unions. The official laws of the game are written in English, French, Russian and Spanish. There are variations for under-19 and Sevens rugby. There are 21 regulations in total, these regulations range from definitions, eligibility, advertising, disciplinary, anti-doping and a number of other areas. World Rugby also approves equipment, which are tested at an Approved Testing House.

Experimental law variations
In 2006, the IRB initiated proposals for variations to the laws, which were formulated and trialled initially at Stellenbosch University in South Africa. Further trials were set down for 2007 and 2008. The law variations aimed to push the balance between defensive and attacking play more in favour of attacking play, and to reduce stoppages for penalties and infringements.

Anti-doping
World Rugby is compliant with the WADA code. The World Rugby anti doping programme includes testing at the under 19 and under 21 level, sevens and senior 15 a side. Testing is a mix of in-competition at World Rugby organised events, as well as out-of-competition testing, which can occur during a specified one-hour time slot designated by a player. In 2003, World Cup year, the World Rugby member unions undertook approximately 3,000 tests. "Keep Rugby Clean" is a campaign message run by the World Rugby Anti-Doping Manager Tim Ricketts. The programme is supported by stars such as Brian O'Driscoll.

Men's
The following table has the Top 20 ranked men's rugby union countries in the world.

Women's
The following table has the Top 20 ranked women's rugby union countries in the world.

Background
World Rugby publishes and maintains the World Rugby Rankings of the men's national rugby union teams (and more recently also for women's teams ). The concept was launched in October 2003, at the start of that year's world cup in Australia. The rankings are calculated using a Points Exchange system, whereby nations take points off each other based on a match result. Several years of research went into developing the rankings system, using an extensive database of international matches that date back to 1871.

The system's reliability is assessed in a number of objective ways, which includes predictions of current strength and responds to changes in form. The system takes into account home advantage, in that the home nation is treated as though it has an extra three rating points, effectively handicapping them, as they will gain fewer ranking points for a win, and lose more should they lose. In the case of a freak result, there is a maximum number of movements on the ranking that any nation can gain from one match.

If a nation does not play for a number of years they are considered dormant, and excluded from the rankings, upon returning, picking up from where they were excluded. If a nation is to merge or split, the highest rating of any of the rankings is inherited.

Currently all capped international matches are equally weighted, whether or not they take place within a competition or are played as tests; the sole exception to this is the World Cup final tournament.

Recognitions and awards
The World Rugby Awards were introduced in 2001, to honour outstanding achievements in rugby union. Prior to 2009, all of the awards were announced at an annual ceremony; the most recent such ceremony was held in London on 23 November 2008.

However, as a response to the Great Recession, the annual ceremony only saw the International Player, Team, and Coach of the Year Awards presented in 2009 and 2010; all other awards were presented at different times throughout the year. The IRB reinstated a single year-end ceremony in 2011 after the 2011 Rugby World Cup. Since then, it has chosen to present some awards at times relevant to those specific prizes—such as Sevens awards after the London Sevens, the final event of the Sevens World Series, and the Junior Player award after the final of the Junior World Championship. The bulk of awards will be presented at the year-end Awards ceremony.

The current awards are:
 * World Rugby Men's 15s Player of the Year
 * World Rugby Women’s 15s Player of the Year
 * World Rugby Men’s Sevens Player of the Year
 * World Rugby Women's Sevens Player of the Year
 * World Rugby Junior Player of the Year
 * Vernon Pugh Award for Distinguished Service
 * World Rugby Coach of the Year
 * World Rugby Men’s 15s Breakthrough Player of the Year
 * World Rugby Women’s 15s Breakthrough Player of the Year
 * World Rugby Referee Award
 * World Rugby Women's 15s Dream Team of the Year
 * World Rugby Men's 15s Dream Team of the Year
 * World Rugby Team of the Year

At the year-end ceremony, the International Rugby Players' Association also hands out the following awards:
 * IRP Men's Try of the Year
 * IRP Women's Try of the Year
 * IRP Special Merit Award

In the past, the following awards have also been awarded:
 * IRB International U21 Player of the Year
 * IRB Under 19 Player of the Year
 * IRB Chairman's Award
 * IRB Development Award
 * IRB Spirit of Rugby Award

The awards that recognise achievements in the preceding 12 months tend to be won by that season's most successful nation(s): France in 2002, England in 2003, South Africa in 2004, New Zealand in 2005, South Africa again in 2007. For those award categories that have nominees, a shortlist is drawn up by an independent panel of judges, who are all former internationals. The panel then reconvenes to choose a winner. The current judges are Jonathan Davies, Will Greenwood, Gavin Hastings, Michael Jones, Dan Lyle, Federico Méndez, Francois Pienaar and past Player of the Year winners Fabien Galthié and Keith Wood, with John Eales as convenor. The judges have a total of over 500 caps between them.

In 2006 a Hall of Fame was established to chronicle the achievements and special contribution of the sport's players, coaches, administrators, match officials, institutions and other individuals. The Hall of Fame was inaugurated at the 2006 IRB Awards, when William Webb Ellis and Rugby School were named as the first two inductees. Hall of Fame inductees in 2007 were Pierre de Coubertin, Danie Craven, John Eales, Gareth Edwards and Wilson Whineray. The 2008 inductees were the 1888–89 New Zealand Native football team and its organiser Joe Warbrick, Jack Kyle, Melrose RFC and Ned Haig (for their roles in the invention of rugby sevens), Hugo Porta, and Philippe Sella. Since then, induction ceremonies have been held annually, except in 2010.

The last year for a single induction ceremony was 2009. Starting in 2011, ceremonies have been held at multiple locations around the world. Also, some or all of the inductions have had an overriding theme since 2009:
 * 2009 – Lions tours to South Africa; all candidates for induction were either Lions or Springboks.
 * 2011 – The year's final set of inductions, held at the IRB Awards in Auckland on the night after the 2011 Rugby World Cup final, was, according to the IRB, "under the theme of Rugby World Cup founders, visionaries and iconic figures".
 * 2012 – The IRB's theme for this year's inductions was Rugby - a global Game, "celebrat[ing] Rugby's expansion to become a global sport played by millions of men and women worldwide."

title: World Rugby


text:
Reflecting telescope

A reflecting telescope (also called a reflector) is a telescope that uses a single or a combination of curved mirrors that reflect light and form an image. The reflecting telescope was invented in the 17th century by Isaac Newton as an alternative to the refracting telescope which, at that time, was a design that suffered from severe chromatic aberration. Although reflecting telescopes produce other types of optical aberrations, it is a design that allows for very large diameter objectives. Almost all of the major telescopes used in astronomy research are reflectors. Many variant forms are in use and some employ extra optical elements to improve image quality or place the image in a mechanically advantageous position. Since reflecting telescopes use mirrors, the design is sometimes referred to as a catoptric telescope.

From the time of Newton to the 1800s, the mirror itself was made of metal – usually speculum metal. This type included Newton's first designs and the largest telescope of the 19th century, the Leviathan of Parsonstown with a 6 ft wide metal mirror. In the 19th century a new method using a block of glass coated with very thin layer of silver began to become more popular by the turn of the century. Common telescopes which led to the Crossley and Harvard reflecting telescopes, which helped establish a better reputation for reflecting telescopes as the metal mirror designs were noted for their drawbacks. Chiefly the metal mirrors only reflected about of the light and the metal would tarnish. After multiple polishings and tarnishings, the mirror could lose its precise figuring needed.

Reflecting telescopes became extraordinarily popular for astronomy and many famous telescopes, such as the Hubble Space Telescope, and popular amateur models use this design. In addition, the reflection telescope principle was applied to other electromagnetic wavelengths, and for example, X-ray telescopes also use the reflection principle to make image-forming optics.

History

The idea that curved mirrors behave like lenses dates back at least to Alhazen's 11th century treatise on optics, works that had been widely disseminated in Latin translations in early modern Europe. Soon after the invention of the refracting telescope, Galileo, Giovanni Francesco Sagredo, and others, spurred on by their knowledge of the principles of curved mirrors, discussed the idea of building a telescope using a mirror as the image forming objective. There were reports that the Bolognese Cesare Caravaggi had constructed one around 1626 and the Italian professor Niccolò Zucchi, in a later work, wrote that he had experimented with a concave bronze mirror in 1616, but said it did not produce a satisfactory image. The potential advantages of using parabolic mirrors, primarily reduction of spherical aberration with no chromatic aberration, led to many proposed designs for reflecting telescopes. The most notable being James Gregory, who published an innovative design for a ‘reflecting’ telescope in 1663. It would be ten years (1673), before the experimental scientist Robert Hooke was able to build this type of telescope, which became known as the Gregorian telescope.

Five years after Gregory designed his telescope and five years before Hooke built the first such Gregorian telescope, Isaac Newton in 1668 built his own reflecting telescope, which is generally acknowledged as the first reflecting telescope. It used a spherically ground metal primary mirror and a small diagonal mirror in an optical configuration that has come to be known as the Newtonian telescope.

Despite the theoretical advantages of the reflector design, the difficulty of construction and the poor performance of the speculum metal mirrors being used at the time meant it took over 100 years for them to become popular. Many of the advances in reflecting telescopes included the perfection of parabolic mirror fabrication in the 18th century, silver coated glass mirrors in the 19th century (built by Léon Foucault in 1858), long-lasting aluminum coatings in the 20th century, segmented mirrors to allow larger diameters, and active optics to compensate for gravitational deformation. A mid-20th century innovation was catadioptric telescopes such as the Schmidt camera, which use both a spherical mirror and a lens (called a corrector plate) as primary optical elements, mainly used for wide-field imaging without spherical aberration.

The late 20th century has seen the development of adaptive optics and lucky imaging to overcome the problems of seeing, and reflecting telescopes are ubiquitous on space telescopes and many types of spacecraft imaging devices.

Technical considerations

A curved primary mirror is the reflector telescope's basic optical element that creates an image at the focal plane. The distance from the mirror to the focal plane is called the focal length. Film or a digital sensor may be located here to record the image, or a secondary mirror may be added to modify the optical characteristics and/or redirect the light to film, digital sensors, or an eyepiece for visual observation.

The primary mirror in most modern telescopes is composed of a solid glass cylinder whose front surface has been ground to a spherical or parabolic shape. A thin layer of aluminum is vacuum deposited onto the mirror, forming a highly reflective first surface mirror.

Some telescopes use primary mirrors which are made differently. Molten glass is rotated to make its surface paraboloidal, and is kept rotating while it cools and solidifies. (See Rotating furnace.) The resulting mirror shape approximates a desired paraboloid shape that requires minimal grinding and polishing to reach the exact figure needed.

Optical errors
Reflecting telescopes, just like any other optical system, do not produce "perfect" images. The need to image objects at distances up to infinity, view them at different wavelengths of light, along with the requirement to have some way to view the image the primary mirror produces, means there is always some compromise in a reflecting telescope's optical design.

Because the primary mirror focuses light to a common point in front of its own reflecting surface almost all reflecting telescope designs have a secondary mirror, film holder, or detector near that focal point partially obstructing the light from reaching the primary mirror. Not only does this cause some reduction in the amount of light the system collects, it also causes a loss in contrast in the image due to diffraction effects of the obstruction as well as diffraction spikes caused by most secondary support structures.

The use of mirrors avoids chromatic aberration but they produce other types of aberrations. A simple spherical mirror cannot bring light from a distant object to a common focus since the reflection of light rays striking the mirror near its edge do not converge with those that reflect from nearer the center of the mirror, a defect called spherical aberration. To avoid this problem most reflecting telescopes use parabolic shaped mirrors, a shape that can focus all the light to a common focus. Parabolic mirrors work well with objects near the center of the image they produce, (light traveling parallel to the mirror's optical axis), but towards the edge of that same field of view they suffer from off axis aberrations:

 * Coma – an aberration where point sources (stars) at the center of the image are focused to a point but typically appears as "comet-like" radial smudges that get worse towards the edges of the image.
 * Field curvature – The best image plane is in general curved, which may not correspond to the detector's shape and leads to a focus error across the field. It is sometimes corrected by a field flattening lens.
 * Astigmatism – an azimuthal variation of focus around the aperture causing point source images off-axis to appear elliptical. Astigmatism is not usually a problem in a narrow field of view, but in a wide field image it gets rapidly worse and varies quadratically with field angle.
 * Distortion – Distortion does not affect image quality (sharpness) but does affect object shapes. It is sometimes corrected by image processing.

There are reflecting telescope designs that use modified mirror surfaces (such as the Ritchey–Chrétien telescope) or some form of correcting lens (such as catadioptric telescopes) that correct some of these aberrations.

Use in astronomical research
Nearly all large research-grade astronomical telescopes are reflectors. There are several reasons for this:
 * Reflectors work in a wider spectrum of light since certain wavelengths are absorbed when passing through glass elements like those found in a refractor or in a catadioptric telescope.
 * In a lens the entire volume of material has to be free of imperfection and inhomogeneities, whereas in a mirror, only one surface has to be perfectly polished.
 * Light of different wavelengths travels through a medium other than vacuum at different speeds. This causes chromatic aberration. Reducing this to acceptable levels usually involves a combination of two or three aperture sized lenses (see achromat and apochromat for more details). The cost of such systems therefore scales significantly with aperture size. An image obtained from a mirror does not suffer from chromatic aberration to begin with, and the cost of the mirror scales much more modestly with its size.
 * There are structural problems involved in manufacturing and manipulating large-aperture lenses. Since a lens can only be held in place by its edge, the center of a large lens will sag due to gravity, distorting the image it produces. The largest practical lens size in a refracting telescope is around 1 meter. In contrast, a mirror can be supported by the whole side opposite its reflecting face, allowing for reflecting telescope designs that can overcome gravitational sag. The largest reflector designs currently exceed 10 meters in diameter.

Gregorian

The Gregorian telescope, described by Scottish astronomer and mathematician James Gregory in his 1663 book Optica Promota, employs a concave secondary mirror that reflects the image back through a hole in the primary mirror. This produces an upright image, useful for terrestrial observations. Some small spotting scopes are still built this way. There are several large modern telescopes that use a Gregorian configuration such as the Vatican Advanced Technology Telescope, the Magellan telescopes, the Large Binocular Telescope, and the Giant Magellan Telescope.

Newtonian

The Newtonian telescope was the first successful reflecting telescope, completed by Isaac Newton in 1668. It usually has a paraboloid primary mirror but at focal ratios of about f/10 or longer a spherical primary mirror can be sufficient for high visual resolution. A flat secondary mirror reflects the light to a focal plane at the side of the top of the telescope tube. It is one of the simplest and least expensive designs for a given size of primary, and is popular with amateur telescope makers as a home-build project.

The Cassegrain design and its variations

The Cassegrain telescope (sometimes called the "Classic Cassegrain") was first published in a 1672 design attributed to Laurent Cassegrain. It has a parabolic primary mirror, and a hyperbolic secondary mirror that reflects the light back down through a hole in the primary. The folding and diverging effect of the secondary mirror creates a telescope with a long focal length while having a short tube length.

Ritchey–Chrétien
The Ritchey–Chrétien telescope, invented by George Willis Ritchey and Henri Chrétien in the early 1910s, is a specialized Cassegrain reflector which has two hyperbolic mirrors (instead of a parabolic primary). It is free of coma and spherical aberration at a nearly flat focal plane if the primary and secondary curvature are properly figured, making it well suited for wide field and photographic observations. Almost every professional reflector telescope in the world is of the Ritchey–Chrétien design.

Three-mirror anastigmat
Including a third curved mirror allows correction of the remaining distortion, astigmatism, from the Ritchey–Chrétien design. This allows much larger fields of view.

Dall–Kirkham
The Dall–Kirkham Cassegrain telescope's design was created by Horace Dall in 1928 and took on the name in an article published in Scientific American in 1930 following discussion between amateur astronomer Allan Kirkham and Albert G. Ingalls, the magazine editor at the time. It uses a concave elliptical primary mirror and a convex spherical secondary. While this system is easier to grind than a classic Cassegrain or Ritchey–Chrétien system, it does not correct for off-axis coma. Field curvature is actually less than a classical Cassegrain. Because this is less noticeable at longer focal ratios, Dall–Kirkhams are seldom faster than f/15.

Off-axis designs
There are several designs that try to avoid obstructing the incoming light by eliminating the secondary or moving any secondary element off the primary mirror's optical axis, commonly called off-axis optical systems.

Herschelian
The Herschelian reflector is named after William Herschel, who used this design to build very large telescopes including the 40-foot telescope in 1789. In the Herschelian reflector the primary mirror is tilted so the observer's head does not block the incoming light. Although this introduces geometrical aberrations, Herschel employed this design to avoid the use of a Newtonian secondary mirror since the speculum metal mirrors of that time tarnished quickly and could only achieve 60% reflectivity.

Schiefspiegler
A variant of the Cassegrain, the Schiefspiegler telescope ("skewed" or "oblique reflector") uses tilted mirrors to avoid the secondary mirror casting a shadow on the primary. However, while eliminating diffraction patterns this leads to an increase in coma and astigmatism. These defects become manageable at large focal ratios — most Schiefspieglers use f/15 or longer, which tends to restrict useful observations to objects which fit in a moderate field of view. A 6" (150mm) f/15 telescope offers a maximum 0.75 degree field of view using 1.25" eyepieces. A number of variations are common, with varying numbers of mirrors of different types. The Kutter (named after its inventor Anton Kutter) style uses a single concave primary, a convex secondary and a plano-convex lens between the secondary mirror and the focal plane, when needed (this is the case of the catadioptric Schiefspiegler). One variation of a multi-schiefspiegler uses a concave primary, convex secondary and a parabolic tertiary. One of the interesting aspects of some Schiefspieglers is that one of the mirrors can be involved in the light path twice — each light path reflects along a different meridional path.

Stevick-Paul
Stevick-Paul telescopes are off-axis versions of Paul 3-mirror systems with an added flat diagonal mirror. A convex secondary mirror is placed just to the side of the light entering the telescope, and positioned afocally so as to send parallel light on to the tertiary. The concave tertiary mirror is positioned exactly twice as far to the side of the entering beam as was the convex secondary, and its own radius of curvature distant from the secondary. Because the tertiary mirror receives parallel light from the secondary, it forms an image at its focus. The focal plane lies within the system of mirrors, but is accessible to the eye with the inclusion of a flat diagonal. The Stevick-Paul configuration results in all optical aberrations totaling zero to the third-order, except for the Petzval surface which is gently curved.

Yolo
The Yolo was developed by Arthur S. Leonard in the mid-1960s. Like the Schiefspiegler, it is an unobstructed, tilted reflector telescope. The original Yolo consists of a primary and secondary concave mirror, with the same curvature, and the same tilt to the main axis. Most Yolos use toroidal reflectors. The Yolo design eliminates coma, but leaves significant astigmatism, which is reduced by deformation of the secondary mirror by some form of warping harness, or alternatively, polishing a toroidal figure into the secondary. Like Schiefspieglers, many Yolo variations have been pursued. The needed amount of toroidal shape can be transferred entirely or partially to the primary mirror. In large focal ratios optical assemblies, both primary and secondary mirror can be left spherical and a spectacle correcting lens is added between the secondary mirror and the focal plane (catadioptric Yolo). The addition of a convex, long focus tertiary mirror leads to Leonard's Solano configuration. The Solano telescope doesn't contain any toric surfaces.

Liquid-mirror telescopes
One design of telescope uses a rotating mirror consisting of a liquid metal in a tray that is spun at constant speed. As the tray spins, the liquid forms a paraboloidal surface of essentially unlimited size. This allows making very big telescope mirrors (over 6 metres), but they are limited to use by zenith telescopes.

Prime focus

In a prime focus design no secondary optics are used, the image is accessed at the focal point of the primary mirror. At the focal point is some type of structure for holding a film plate or electronic detector. In the past, in very large telescopes, an observer would sit inside the telescope in an "observing cage" to directly view the image or operate a camera. Nowadays CCD cameras allow for remote operation of the telescope from almost anywhere in the world. The space available at prime focus is severely limited by the need to avoid obstructing the incoming light.

Radio telescopes often have a prime focus design. The mirror is replaced by a metal surface for reflecting radio waves, and the observer is an antenna.

Cassegrain focus
For telescopes built to the Cassegrain design or other related designs, the image is formed behind the primary mirror, at the focal point of the secondary mirror. An observer views through the rear of the telescope, or a camera or other instrument is mounted on the rear. Cassegrain focus is commonly used for amateur telescopes or smaller research telescopes. However, for large telescopes with correspondingly large instruments, an instrument at Cassegrain focus must move with the telescope as it slews; this places additional requirements on the strength of the instrument support structure, and potentially limits the movement of the telescope in order to avoid collision with obstacles such as walls or equipment inside the observatory.

Nasmyth
The Nasmyth design is similar to the Cassegrain except the light is not directed through a hole in the primary mirror; instead, a third mirror reflects the light to the side of the telescope to allow for the mounting of heavy instruments. This is a very common design in large research telescopes.

Coudé
Adding further optics to a Nasmyth-style telescope to deliver the light (usually through the declination axis) to a fixed focus point that does not move as the telescope is reoriented gives a coudé focus (from the French word for elbow). The coudé focus gives a narrower field of view than a Nasmyth focus and is used with very heavy instruments that do not need a wide field of view. One such application is high-resolution spectrographs that have large collimating mirrors (ideally with the same diameter as the telescope's primary mirror) and very long focal lengths. Such instruments could not withstand being moved, and adding mirrors to the light path to form a coudé train, diverting the light to a fixed position to such an instrument housed on or below the observing floor (and usually built as an unmoving integral part of the observatory building) was the only option. The 60-inch Hale telescope (1.5 m), Hooker Telescope, 200-inch Hale Telescope, Shane Telescope, and Harlan J. Smith Telescope all were built with coudé foci instrumentation. The development of echelle spectrometers allowed high-resolution spectroscopy with a much more compact instrument, one which can sometimes be successfully mounted on the Cassegrain focus. Since inexpensive and adequately stable computer-controlled alt-az telescope mounts were developed in the 1980s, the Nasmyth design has generally supplanted the coudé focus for large telescopes.

Fibre-fed spectrographs
For instruments requiring very high stability, or that are very large and cumbersome, it is desirable to mount the instrument on a rigid structure, rather than moving it with the telescope. Whilst transmission of the full field of view would require a standard coudé focus, spectroscopy typically involves the measurement of only a few discrete objects, such as stars or galaxies. It is therefore feasible to collect light from these objects with optical fibers at the telescope, placing the instrument at an arbitrary distance from the telescope. Examples of fiber-fed spectrographs include the planet-hunting spectrographs HARPS or ESPRESSO.

Additionally, the flexibility of optical fibers allow light to be collected from any focal plane; for example, the HARPS spectrograph utilises the Cassegrain focus of the ESO 3.6 m Telescope, whilst the Prime Focus Spectrograph is connected to the prime focus of the Subaru telescope.

title: Reflecting telescope


text:
User:Barrye

User Page for Barry Ethridge

Proud to be a contributor to the Wikipedia. One of the Internet's most intersting living, breathing sites.

title: User:Barrye