text:
CASSIOPE

Cascade, Smallsat and Ionospheric Polar Explorer (CASSIOPE), is a Canadian Space Agency (CSA) multi-mission satellite operated by the University of Calgary. The mission development and operations from launch to February 2018 was funded through CSA and the Technology Partnerships Canada program. In February 2018 CASSIOPE became part of the European Space Agency's Swarm constellation through the Third Party Mission Program, known as Swarm Echo, or Swarm-E. It was launched September 29, 2013, on the first flight of the SpaceX Falcon 9 v1.1 launch vehicle. CASSIOPE is the first Canadian hybrid satellite to carry a dual mission in the fields of telecommunications and scientific research. The main objectives are to gather information to better understand the science of space weather, while verifying high-speed communications concepts through the use of advanced space technologies.

The satellite was deployed in an elliptical polar orbit and carries a commercial communications system called Cascade as well as a scientific experiment package called e-POP (enhanced Polar Outflow Probe).

Following staging, the Falcon 9's first stage was used by SpaceX for a controlled descent and landing test. While the first stage was destroyed on impact with the ocean, significant data was acquired and the test was considered a success.

Spacecraft
CASSIOPE is a 500 kg small satellite that is 180 cm long and 125 cm high. It combines the function of two distinct missions in order to be more cost-effective and reduce risk.

The spacecraft carries a primary payload of two instrument suites: the Cascade commercial communications system and a scientific payload named e-POP.

Cascade
The commercial payload, named Cascade, is a technology demonstrator courier in the sky, aimed at providing a proof of concept for a digital broadband courier service for commercial use. Built by MDA, the operational concept is to receive very large data files as the satellite orbits the globe, store them onboard temporarily, then deliver them at a later time to nearly any destination worldwide.

The demonstrator will provide a secure digital store-and-forward file delivery service, exploiting the fact that CASSIOPE passes over much of the globe 15 times per day. It has been described as a courier service, with the customers using a small parabolic antenna of one or two meters (three or six feet) to upload or download files at a rate of 1.2 gigabits per second. The storage capacity will be between 50 and 500 gigabytes and the data delivery time will be about 90 minutes, depending on the pickup and deposit points on the globe.

e-POP
The e-POP portion of CASSIOPE is a suite of eight scientific instruments. The University of Calgary's Institute for Space Research leads the science project, while MDA is the prime contractor for the mission including launch and operation of the spacecraft. The orbital science mission is scheduled for a 21-month duration.

e-POP will gather data on Solar storms in the upper atmosphere. These storms give rise to the polar aurora or northern lights seen in the skies in northern latitudes. While these atmospheric glows may offer a thrilling night time spectacle, the inducing radiation can interfere with radio communications, GPS navigation, and other space-based systems. The eight scientific instruments aboard CASSIOPE will help scientists understand solar weather and eventually plan for measures to mitigate its deleterious effects.

The e-POP payload contains eight scientific instruments:
 * Coherent EM Radio Tomography (CER), measuring radio propagation and ionospheric scintillation
 * Fast Auroral Imager (FAI), measuring large-scale auroral emissions
 * GPS Altitude and Profiling Experiment (GAP), high-precision position and attitude determination
 * Imaging and Rapid Scanning Ion Mass Spectrometer (IRM), measuring the three-dimensional distribution of ions
 * Fluxgate Magnetometer (MGF), high-precision magnetic field perturbation measurement
 * Neutral Mass Spectrometer (NMS), measuring the mass, composition and velocity of neutral particles
 * Radio Receiver Instrument (RRI), measuring radio wave propagation
 * Suprathermal Electron Imager (SEI), measuring low-energy electron distribution

Operations
After a successful launch on September 29, 2013, CASSIOPE entered into a commissioning phase that lasted to January 1, 2014, with no faults detected on the spacecraft bus or payloads. Three ground stations were utilized, including Kiruna (Sweden), Inuvik (Canada), and the German Antarctic Receiving Station at the General Bernardo O'Higgins Base in Antarctica. Routine operations were scheduled to run to March, 2015. The mission was extended via funding from the Technology Partnerships Canada program through the Industrial Technologies Office that was part of the Canadian government at the time. In February 2018, the European Space Agency, through the Third Party Mission Program, integrated the mission into the Swarm constellation of satellites, dubbing CASSIOPE "Swarm-Echo", recognizing the synergy between the two missions in collecting space weather data in low Earth orbit. The partnership allowed for four ground station contacts per day, rather than one, greatly increasing the amount of data that could be downloaded from the e-POP suite of instruments.

On August 11, 2016, one of the four reaction wheels used for spacecraft attitude control failed. This did not affect spacecraft operations in a significant way since only three wheels are required for 3-axis stabilized pointing. A second reaction wheel failed on February 27, 2021, forcing the spacecraft into a slowly spinning, safe-hold attitude configuration. Three-axis stabilized control was restored in September 2021 by implementing a bias momentum configuration on the two remaining wheels (spinning the wheels in opposite directions), and using the magnetic torque rods for attitude control. Three months later, on December 17, 2021, a third reaction wheel failed, leaving the spacecraft with no viable methods for fixed attitude pointing. Although most of the e-POP instruments were fully operational, without stabilized pointing much of the science objectives could not be met, resulting in a conclusion of the operational portion of the mission on December 31, 2021.

History
The satellite that became CASSIOPE began with a 1996 concept for a small (70 kg), inexpensive microsatellite called Polar Outflow Probe, or POP. The Canadian Space Agency funded a 1997 feasibility study that led to a modified mission concept that was designed during 2000-2005. The revised concept was to combine an enhanced version of POP, called e-POP, with an MDA Corporation commercial satellite called Cascade, into a single satellite, and to design and build a generic, low-cost small satellite bus that would be useful for other Canadian satellite missions in the future.

The eight e-POP scientific instruments were built, calibrated, and tested in 2005-2007, with integration onto the satellite bus for spacecraft-level testing in 2008-2009.

Launch

The satellite was launched on September 29, 2013, aboard a SpaceX Falcon 9 v1.1 rocket.

At the time the launch was contracted in 2005, a SpaceX Falcon 1 was the planned launch vehicle. The launch was originally scheduled for 2008 from Omelek Island. The launch date slipped several times, and after SpaceX discontinued the Falcon 1, the launch was shifted to the much larger Falcon 9 in June 2010.

MDA contracted with SpaceX to put the CASSIOPE payload on the first flight of an essentially new launch vehicle—a non-operational demonstration launch. The Falcon 9 v1.1, upgraded from the original Falcon 9, is a 60 percent heavier rocket with 60% more thrust. The flight was contracted with a payload mass that is very small relative to the rocket's capability, at a discounted rate because it was a technology demonstration mission for SpaceX, approximately 20% of the normal published price for SpaceX Falcon 9 LEO missions.

Since this was the first flight of a new launch vehicle, the US Air Force had estimated the overall probability of failure on the mission was nearly fifty percent. In the event, the mission was successful, as was each of the next 13 Falcon 9 v1.1 missions before a launch vehicle failure and loss of mission occurred on Falcon 9 Flight 19 in June 2015.

The Falcon 9 upper stage used to launch CASSIOPE was left derelict in a decaying elliptical low Earth orbit that,, had a perigee of 317 km and an apogee of 1283 km.

Post-mission launch vehicle testing
After the second stage separated from the booster stage, SpaceX conducted a novel flight test where the booster conducted a test to attempt to reenter the lower atmosphere in a controlled manner and decelerate to a simulated over-water landing. The test was successful, but the booster stage was not recovered.

After the three-minute boost phase of September 29, 2013 launch, the booster stage attitude was reversed, and three of the nine engines refired at high altitude, as planned, to initiate the deceleration and controlled descent trajectory to the surface of the ocean. The first phase of the test worked well and the first stage re-entered safely.

However, the first stage began to roll due to aerodynamic forces during the descent through the atmosphere, and the roll rate exceeded the capabilities of the booster attitude control system (ACS) to null it out. The fuel in the tanks centrifuged to the outside of the tank and the single engine involved in the low-altitude deceleration maneuver shut down. Debris from the first stage was subsequently retrieved from the ocean.

SpaceX also ran a post-mission test on the second stage. While a number of the new capabilities were successfully tested on the September 29, 2013, CASSIOPE flight, there was an issue with the second stage restart test. The test to reignite the second stage Merlin 1D vacuum engine once the rocket had deployed its primary payload (CASSIOPE) and all of its nanosat secondary payloads was unsuccessful. The engine failed to restart while the second stage was coasting in low Earth orbit.

Secondary payloads
Five nanosatellite spacecraft that were also carried to orbit on the same launch vehicle that carried the CASSIOPE primary payload:
 * CUSat, Cornell University
 * Drag and Atmospheric Neutral Density Explorer (DANDE), University of Colorado Boulder
 * three Polar Orbiting Passive Atmospheric Calibration Spheres (POPACS), each a 10 cm white aluminum sphere, joint project of Morehead State University, University of Arkansas, Montana State University, Drexel University, and Planetary Systems Corporation.

title: CASSIOPE


text:
List of fjords of Iceland

The fjords of Iceland, listed in a clockwise direction round the island from the SW to the east. There are no important fjords along the south coast: most of the inlets there are lagoons.

Western fjords

 * Faxaflói
 * Stakksfjörður
 * Hafnarfjörður
 * Skerjafjörður
 * Kollafjörður
 * Hvalfjörður
 * Borgarfjörður
 * Haffjörður
 * Breiðafjörður
 * Fjords on northern Snæfellsnes and in Dalasýsla ("Dalir"):
 * Grundarfjörður
 * Kolgrafafjörður
 * Hraunsfjörður
 * Vigrafjörður
 * Álftafjörður
 * Hvammsfjörður
 * Fjords in Barðaströnd:
 * Gilsfjörður
 * Króksfjörður
 * Berufjörður
 * Þorskafjörður
 * Djúpifjörður
 * Gufufjörður
 * Kollafjörður
 * Kvígindisfjörður
 * Skálmarfjörður
 * Vattarfjörður
 * Kerlingarfjörður
 * Mjóifjörður
 * Kjálkafjörður
 * Vatnsfjörður

Westfjords

 * Patreksfjörður
 * Tálknafjörður
 * Arnarfjörður
 * Suðurfirðir
 * Fossfjörður
 * Reykjarfjörður
 * Trostansfjörður
 * Geirþjófsfjörður
 * Borgarfjörður
 * Dýrafjörður
 * Önundarfjörður
 * Súgandafjörður
 * Ísafjarðardjúp
 * Skutulsfjörður
 * Álftafjörður
 * Seyðisfjörður
 * Hestfjörður
 * Skötufjörður
 * Mjóifjörður
 * Vatnsfjörður
 * Reykjarfjörður
 * Ísafjörður
 * Kaldalón
 * Jökulfirðir
 * Leirufjörður
 * Hrafnsfjörður
 * Lónafjörður
 * Veiðileysufjörður
 * Hesteyrarfjörður
 * Furufjörður
 * Þaralátursfjörður
 * Reykjarfjörður nyrðri
 * Bjarnarfjörður nyrðri
 * Eyvindarfjörður
 * Ófeigsfjörður
 * Ingólfsfjörður
 * Norðurfjörður
 * Reykjarfjörður (Ströndum)
 * Veiðileysufjörður (Ströndum)

Northwestern region

 * Bjarnarfjörður
 * Steingrímsfjörður
 * Kollafjörður
 * Bitrufjörður
 * Hrútafjörður
 * Miðfjörður
 * Húnafjörður
 * Skagafjörður
 * Siglufjörður
 * Héðinsfjörður
 * Ólafsfjörður

Northeastern region

 * Eyjafjörður
 * Þorgeirsfjörður
 * Hvalvatnsfjörður
 * Skjálfandi
 * Öxarfjörður
 * Þistilfjörður
 * Lónafjörður
 * Bakkaflói
 * Finnafjörður
 * Miðfjörður
 * Bakkafjörður
 * Vopnafjörður
 * Nýpsfjörður
 * Héraðsflói

Eastern fjords

 * Borgarfjörður Eystri
 * Loðmundarfjörður
 * Seyðisfjörður
 * Mjóifjörður
 * Norðfjarðarflói
 * Norðfjörður
 * Hellisfjörður
 * Viðfjörður
 * Reyðarfjörður
 * Eskifjörður
 * Fáskrúðsfjörður
 * Stöðvarfjörður
 * Berufjörður
 * Hamarsfjörður
 * Álftafjörður
 * Lónsfjörður
 * Papafjörður
 * Skarðsfjörður
 * Hornafjörður

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

title: List of fjords of Iceland


text:
Charles L. Veach

Charles Lacy Veach (September 18, 1944 – October 3, 1995) was a United States Air Force (USAF) fighter pilot and NASA astronaut.

Personal data
Veach was born September 18, 1944, in Chicago, Illinois, but considered Honolulu, Hawaii, to be his hometown. He was married to Alice Meigs Scott of Waycross, Georgia, they had two children. He enjoyed surfing, bicycling, reading and activities with his family. His parents reside in Honolulu, Hawaii. He was also known as Lacy Veach.

Education

 * 1962: Graduated from Punahou School, Honolulu, Hawaii
 * 1966: Received a Bachelor of Science degree in Engineering Management from the United States Air Force Academy

Special honors
Distinguished Flying Cross with 2 Oak Leaf Clusters, Air Medal with 13 Oak Leaf Clusters, Air Force Commendation Medal with 1 Oak Leaf Cluster, and Purple Heart.

Experience
Veach was commissioned in the United States Air Force upon graduation from the United States Air Force Academy. He received his pilot wings at Moody Air Force Base, Georgia, in 1967, and then attended fighter gunnery school at Luke Air Force Base, Arizona. Over the next 14 years, he served as a USAF fighter pilot, flying the F-100 Super Sabre, the F-111 Aardvark, and the F-105 Thunderchief, on assignments in the United States, Europe, and the Far East, including a 275-mission combat tour in South Vietnam during the Vietnam War. In 1976 and 1977, he was a member of the USAF Air Demonstration Squadron, the Thunderbirds, flying the T-38 Talon. Veach left active duty in 1981 but continued to fly fighters as an F-4 Phantom and F-16 Fighting Falcon pilot with the 147th Fighter Group, later 147th Fighter Wing, of the Texas Air National Guard. His name still adorns the museum display F-16 just inside the front gate of the Ellington Field Joint Reserve Base in Houston, Texas.

He had logged over 5,000 flying hours.

NASA experience
Veach came to work for NASA in January 1982 as an engineer and research pilot at the Johnson Space Center in Houston, Texas. His primary duty was as an instructor pilot in the Shuttle Training Aircraft, the highly modified Gulfstream II used to train astronaut pilots to land the Space Shuttle.

Veach was selected as an astronaut candidate in May 1984 and became an astronaut in June 1985. He held a variety of technical assignments, and had flown as a mission specialist on two Space Shuttle missions, STS-39 in 1991 and STS-52 in 1992. He had logged 436.3 hours in space. Most recently, Lacy had worked as the lead astronaut for the development and operation of robotics for the International Space Station.

On STS-39, Veach was responsible for operating a group of instruments which included an ultraviolet astronomical camera, an x-ray telescope, and a liquid helium-cooled infrared telescope which performed landmark observations of the Earth's atmosphere and the Aurora Australis (the Southern Lights). The 8-day unclassified Department of Defense mission aboard the Orbiter Discovery launched from the Kennedy Space Center in Florida on April 28, 1991, and landed at Kennedy on May 6, 1991.

STS-52 was a 10-day mission aboard the Orbiter Columbia during which the crew successfully deployed the Laser Geodynamic Satellite (LAGEOS), a joint Italian-American project. They also operated the first U.S. Microgravity Payload (USMP) with French and American experiments. Veach was the primary Remote Manipulator System (RMS) operator on the mission, supporting the initial flight tests of the Canadian-built Space Vision System (SVS). STS-52 launched from the Kennedy Space Center in Florida on October 22, 1992, and landed at Kennedy on November 1, 1992. Lacy Veach died in Houston, Texas, on October 3, 1995, of cancer. He is interred at the National Memorial Cemetery of the Pacific in Honolulu, Hawaii.

title: Charles L. Veach


text:
Desuetude

In law, desuetude is a doctrine that causes statutes, similar legislation, or legal principles to lapse and become unenforceable by a long habit of non-enforcement or lapse of time. It is what happens to laws that are not repealed when they become obsolete. It is the legal doctrine that long and continued non-use of a law renders it invalid, at least in the sense that courts will no longer tolerate punishing its transgressors.

The policy of inserting sunset clauses into a constitution or charter of rights (as in Canada since 1982) or into regulations and other delegated/subordinate legislation made under an act (as in Australia since the early 1990s) can be regarded as a statutory codification of this jus commune doctrine.

English law
The doctrine of desuetude has been diluted in the common law tradition. The doctrine went into decline from the Middle Ages, when the counter-notion became prevalent that enrolled bill rule existed: the king's assent was required to nullify a clear or settled law; its second limb is similar, stating later Acts and other legislation are to be preferred when conflicting. The non-preparatory, constitutional Bill of Rights 1689 clarified the fact of Parliamentary supremacy over the executive and any directly conflicting case law. In 1818, the English court of King's Bench held in the case of Ashford v Thornton that trial by combat remained available at a defendant's option in a case where it was available under the common law. Parliament hastily enacted that such mortal combat was illegal; promotors and commentators cited morality including promoting the public good. Similarly the law of residential property distress and of attainder of estates had been little weakened despite widespread judicial displeasure before substantial, required reform via legislation.

Scots law
The doctrine exists in Scotland, being of the civil law tradition, where it can operate as a rare form of repeal. In Scotland, non-use is not the same as desuetude. Disuse must be accompanied by other identifiable provisions that would make the enforcement of the statute inconsistent: neglect over such a period of time that it would appear that a contrary custom had developed; and that a contrary practice had developed which is inconsistent with the law. Regarding the Scottish application, Lord McKay stated in Brown vs. Magistrates of Edinburgh: "Desuetude requires for its operation a very considerable period, not merely of neglect, but a contrary usage of such a character as practically to infer such completely established habit of the community as to set up a counter law or establish a quasi repeal."

United States law
Desuetude does not apply to requirements of the United States Constitution. In Walz v. Tax Commission of the City of New York, 397 U.S. 664, 678 (1970), the United States Supreme Court asserted that: "It is obviously correct that no one acquires a vested or protected right in violation of the Constitution by long use, even when that span of time covers our entire national existence and indeed predates it."

It may, however, have validity as a doctrine in defense of penal prosecution. In 1825, the Pennsylvania Supreme Court declined to enforce the traditional punishment of ducking for women convicted as common scolds, stating that "total disuse of any civil institution for ages past, may afford just and rational objections against disrespected and superannuated ordinances." Wright v. Crane, 13 Serg. & Rawle 220, 228 (Pa. 1825).

The seminal modern case under U.S. state law is a West Virginia opinion regarding desuetude, Committee on Legal Ethics v. Printz, 187 W.Va. 182, 416 S.E.2d 720 (1992). In that case, the West Virginia Supreme Court of Appeals held that penal statutes may become void under the doctrine of desuetude if:

 * 1) The statute proscribes only acts that are malum prohibitum (wrong because prohibited by statute) and not malum in se (intrinsically wrong);
 * 2) There has been open, notorious and pervasive violation of the statute for a long period; and
 * 3) There has been a conspicuous policy of nonenforcement of the statute.

This holding was reaffirmed in 2003 in ''State ex rel. Canterbury v. Blake'', 584 S.E.2d 512 (W. Va. 2003).

While it may not be a violation of due process to enforce a desuetudinal law, the fact that a law has long gone unenforced may present a bar to standing in a suit to prevent its future enforcement. In Poe v. Ullman, the Supreme Court refused to hear a challenge to Connecticut's ban on birth control, writing:

"The undeviating policy of nullification by Connecticut of its anti-contraceptive laws throughout all the long years that they have been on the statute books bespeaks more than prosecutorial paralysis ... 'Deeply embedded traditional ways of carrying out state policy ...' – or not carrying it out – 'are often tougher and truer law than the dead words of the written text.'"

Shortly thereafter, Connecticut's birth control law was enforced, and struck down, in Griswold v. Connecticut.

title: Desuetude


text:
Talk:A Course in Miracles

Could use a content section
This article gives some background and a very basic explanation of what it is, but it lacks even a fundamental description of its content. 166.182.250.207 (talk) 20:43, 23 August 2022 (UTC)

What if the reason the article only gives the most basic outline of the Course is because no one really knows what it is talking about? For what if there is no reason or light in this darkness? — Preceding unsigned comment added by 95.149.166.189 (talk) 09:12, 21 October 2023 (UTC)

A Commons file used on this page or its Wikidata item has been nominated for speedy deletion
The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for speedy deletion: You can see the reason for deletion at the file description page linked above. —Community Tech bot (talk) 08:38, 7 March 2023 (UTC)
 * ACIM3COVER.jpg

A Commons file used on this page or its Wikidata item has been nominated for deletion
The following Wikimedia Commons file used on this page or its Wikidata item has been nominated for deletion: Participate in the deletion discussion at the. —Community Tech bot (talk) 11:08, 7 March 2023 (UTC)
 * ACIM3COVER.jpg

Journalist
Matthew Remski passes WP:N. If you think he doesn't, this is not the place to argue that, instead you should submit his article for deletion. Do I like yoga? No, but it's a free country. People don't have to ask for my permission in order to practice yoga. tgeorgescu (talk) 14:25, 26 March 2023 (UTC)

 * What if, seeming to tell the truth, ACiM is a book of lies?

 * What if, appearing to heal, the book contains many harmful ideas?

 * What if, having promised to show the/a way - the Course sets out to mislead? — Preceding unsigned comment added by 95.147.153.122 (talk) 21:10, 11 November 2023 (UTC)

 * Wikipedia isn't about WP:THETRUTH, but about WP:Verifiable information form reliable sources. tgeorgescu (talk) 21:30, 11 December 2023 (UTC)

A Course In Miracles
it is misleading to claim that this teaching " borrows from New Age ideas " There is no evidence of this at all. It is highly original in content. Of course those indoctrinated with familiar Christian dogma, are going to dismiss it, on entirely spurious grounds 80.189.60.71 (talk) 22:49, 28 November 2023 (UTC)
 * The statement is sourced. --Hob Gadling (talk) 06:59, 10 July 2024 (UTC)

title: Talk:A Course in Miracles


text:
Roberto Vittori

Brigadier Roberto Vittori, OMRI (born 15 October 1964, in Viterbo) is an Italian Air Force officer and an ESA astronaut. After graduating from the Italian Accademia Aeronautica in 1989, Vittori flew in the Italian Air Force. He then trained as a test pilot in the United States.

In 1998, Vittori was selected by the ESA to join the European Astronaut Corps. Since then, he has participated in three spaceflights: the Soyuz TM-34/33 and Soyuz TMA-6/5 taxi flights to the ISS, as well as STS-134, the penultimate mission of the American Space Shuttle Program in 2011. He was the last non-American to fly aboard the Shuttle.

Career
Vittori graduated from the Italian Air Force Academy in 1989 and trained in the United States. He flew the Tornado in the Italian Air Force before graduating in 1995 from the U.S. Naval Test Pilot School at Patuxent River, Maryland where he was the first in his class. He served at the Italian Test Center as a project pilot for the development of the new European aircraft, the EF2000. Vittori flew Tornado GR1 aircraft with the 155º Gruppo, 50° Stormo, in Piacenza, Italy from 1991 to 1994. During that time, he qualified for day/night air-to-air refuelling as well as a formation leader. He has logged over 1700 hours in over 40 different aircraft including F-104, F-18, AMX, M-2000, G-222 and P-180.

In August 1998, after selection by ESA to join the European Astronaut Corps, he reported to the Johnson Space Center in Houston, Texas. Following a period of training and evaluation, Vittori served in various technical assignments within the NASA Astronaut Office.

Soyuz TM-34
From April 25 to May 5, 2002, Vittori participated in the Soyuz TM-34 taxi-flight to the International Space Station (ISS), under an agreement between the Russian Rosaviakosmos, the Italian Space Agency (ASI), and the ESA. During his stay aboard ISS he worked alongside the resident crew overseeing four European scientific experiments. The mission successfully delivered a new "lifeboat" to the Station for use by resident crews in the event of an on-board emergency. Vittori returned to Earth aboard Soyuz TM-33.

Soyuz TMA-6
On 15 April 2005 Vittori participated in a second taxi-flight to the International Space Station (ISS), Soyuz TMA-6, returning to Earth on 24 April in the Soyuz TMA-5 capsule. He became the first European astronaut to visit the ISS twice and conducted experiments in upper limb fatigue in astronauts and germination of herbaceous plant seeds for possible space nutrition.

The astronaut also had a painting of the artist George Pusenkoff titled Single Mona Lisa (1:1) with him and took photos with it on the International Space Station. It is the ultimate continuation of the project "Mona Lisa Travels" developed by Pusenkoff and could only be realized under difficult conditions. The authorities found the idea good in theory, but constantly put forward new reasons why the project was unrealizable. Only when George Pusenkoff wrote to the then Italian ambassador in Russia, Gianfranco Facco Bonetti, the possibility of realizing the idea arose. The connection between science and art, which was also important in Leonardo da Vinci's life, found here an "actualization" in the form of this journey of an image of Mona Lisa into space. For the action, Pusenkoff's painting was removed from the frame so that it could be rolled. On April 25, 2005, Vittori took the painting back to the Earth with him.

STS-134
Vittori was a mission specialist for NASA Space Shuttle mission STS-134 in 2011. He is the last non-US astronaut to have flown on the Shuttle.

Personal life
Vittori has 3 sons.

While living in Washington, DC in 2015, Vittori was nearly single-handedly responsible for the rerouting of flight paths from Reagan National Airport over DC's Ward 3 to other routes. As reported by WAMU, of the 8,760 complaints about Reagan National filed with the airports authority in 2015, 6,852 came from one household in DC's Foxhall neighborhood (Vittori's).

title: Roberto Vittori


text:
Rex J. Walheim

Rex Joseph Walheim (born October 10, 1962) is a retired United States Air Force officer, engineer and NASA astronaut. He flew three Space Shuttle missions, STS-110, STS-122, and STS-135. Walheim logged over 566 hours in space, including 36 hours and 23 minutes of spacewalk (EVA) time. He was assigned as mission specialist and flight engineer on STS-135, the final Space Shuttle mission.

Biography
Walheim was born in Redwood City, California, but considers San Carlos, California, his hometown.

Education
Walheim graduated from San Carlos High School in 1980 and received a Bachelor of Science degree in mechanical engineering from the University of California, Berkeley in 1984. He then received a Master of Science degree in industrial engineering from the University of Houston in 1989.

Military career
Walheim was commissioned as a second lieutenant in the Air Force in May 1984. In April 1985 he was assigned to Cavalier Air Force Station in Cavalier, North Dakota, where he worked as a missile warning operations crew commander. In October 1986, he was reassigned to the Johnson Space Center, in Houston, Texas, where he worked as a mechanical systems flight controller and was the lead operations engineer for the Space Shuttle landing gear, brakes, and emergency runway barrier.

Walheim was transferred to Headquarters Air Force Space Command in Colorado Springs, Colorado, in August 1989, where he was manager of a program upgrading missile warning radars. He was selected for USAF Test Pilot School in 1991, and attended the course at Edwards AFB in California in 1992. Following graduation, he was assigned to the F-16 Combined Test Force at Edwards where he was a project manager, and then commander of the avionics and armament flight. In January 1996, Walheim became an instructor at USAF Test Pilot School, where he served until he began astronaut training.

NASA career
Walheim served as a flight controller and operations engineer at the Johnson Space Center from October 1986 to January 1989. He was selected by NASA as an astronaut candidate in March 1996 and reported to the Johnson Space Center in August 1996. Having completed two years of training and evaluation, he was qualified for flight assignment as a mission specialist. Initially, Walheim was assigned technical duties in the Astronaut Office Space Station Operations Branch. Walheim flew three flights, STS-110, STS-122 and STS-135, the final flight of the shuttle, logging over 566 hours in space, including over 36 hours and 23 minutes of EVA time. After his first flight, he was assigned to the EVA branch, where he served as the astronaut office representative for the Extra Vehicular Mobility Unit (the EVA spacesuit).

In September 2002, Walheim served as an aquanaut on the joint NASA-NOAA NEEMO 4 expedition (NASA Extreme Environment Mission Operations), an exploration research mission held in Aquarius, the world's only undersea research laboratory, four miles off shore from Key Largo. Walheim and his crewmates spent five days saturation diving from the Aquarius habitat as a space analogue for working and training under extreme environmental conditions. The mission was delayed due to Hurricane Isadore, forcing National Undersea Research Center managers to shorten it to an underwater duration of five days. Then, three days into their underwater mission, the crew members were told that Tropical Storm Lili was headed in their direction and to prepare for an early departure from Aquarius. However, Lili degenerated to the point where it was no longer a threat, so the crew was able to remain the full five days.

During the inauguration of Barack Obama on January 20, 2009, in Washington, D.C., Walheim marched in the parade carrying an American flag and wearing a prototype of NASA's next generation spacesuit.

STS-110
Walheim served as mission specialist 1 on STS-110. STS-110 delivered the S0 truss segment to the International Space Station (ISS). Walheim conducted two spacewalks to install the S0 truss and reconfigure Canadarm2 for use on S0, spending 14 hours and 15 minutes outside the ISS. STS-110 lasted 10 days, 19 hours, 43 minutes and 38 seconds.

STS-122
Walheim served as mission specialist 2 and was the flight engineer for STS-122. STS-122, which was a 12-day, 18-hour flight, delivered the European-built Columbus module to the ISS the European Space Agency (ESA). Walheim conducted three spacewalks, totaling 22 hours and 8 minutes.

STS-135
Walheim served as mission specialist 2 on the final flight of the Space Shuttle, STS-135, a thirteen-day mission to the International Space Station. The mission launched on July 8, 2011, and landed on July 21.

Rex Walheim retired from NASA August 2020.

Personal
Walheim is married to Margie Dotson, formerly of Villa Park, California. They have two children. He enjoys snow skiing, hiking, softball and football. His father, Lawrence M. Walheim, Jr., resides in Visalia, California. His mother, Avis L. Walheim, is deceased.

Awards and honors

 * Distinguished Graduate, Reserve Officers Training Corps, University of California, Berkeley
 * Distinguished Graduate and top flight test engineer in USAF Test Pilot School Class 92A
 * Meritorious Service Medal
 * Air Force Commendation Medals (2)
 * Aerial Achievement Medal
 * 20th member of the "Rex Streak" on the Jim Rome radio show. Rome dubbed him "King of the Rexes"

title: Rex J. Walheim


text:
N. M. Perera

Nanayakkarapathirage Martin Perera, commonly known as Dr. N. M. Perera (Sinhala එන්.එම්.පෙරේරා ; 6 June 1904 – 14 August 1979), was one of the leaders of the Sri Lankan Trotskyist Lanka Sama Samaja Party (LSSP). He was the first Trotskyist to become a cabinet minister. He served two terms as Minister of Finance and Leader of the Opposition, as well as one term as the Mayor of Colombo.

Early life and education
Born to Nanayakkarapathirage Abraham Perera who was a rent collector at 36 St Joseph 's Street, in Grandpass, Colombo and Johana Perera. He was the fifth of nine siblings that was made up of five boys and four girls.

Perera started his schooling in the vernacular section of St. Joseph's School, Grandpass and was later admitted to the English section. From there he spent a year at the Cathedral Boys' School, Mutwal a branch school of S. Thomas' College, Mutwal,  then known as Cathedral Boys School, Mutwal. In 1919, he entered S. Thomas' College, Mount Lavinia and left in 1922 to join Ananda College. At Ananda he played cricket for the college team.

From 1922 to 1927, he studied at the University College, Colombo where he was a contemporary of J. R. Jayewardene. Perera graduated with a BSc degree from the University of London External System. Thereafter he left to the United Kingdom, to enter the London School of Economics in 1927. He was in London from 1927 to 1933, where he studied under Professor Harold Laski, gaining his PhD with the thesis on the Constitution of the German Weimar Republic. This was followed by a further comparative study, of the Constitutions of the UK, United States, France and Germany; which gained him a DSc from the University of London. Perera was the first Ceylonese to gain a degree of Doctor of Science from the University of London.

Formation of the Lanka Sama Samaja Party
Perera returned to Ceylon in 1933. The work done by Perera (as a member of the Suriya-Mal Movement) in the Kegalle district during the malaria epidemic of 1934 and during the subsequent floods gained for him the support of the poor and caste-oppressed people of the area, who called him Parippu Mahathmaya after the dhal (or parippu) he distributed as relief supplies. In 1935 Perera was one of the founder members of the LSSP and played a leading role in the party's Trotskyist activities between 1936 and 1940.

State Council of Ceylon
In 1936 he contested the Ruwanwella constituency, which at the time was the Thun Korale areas of Yatiyantota, Ruwanwella and Dereniyagala and parts of the present Galigamuwa electoral division, from the LSSP. His opponent was the incumbent Molamure Kumarihamy of the Meedeniya Walauwa, the feudal manor which had tremendous power over the poor people of the Sabaragamuwa area at the time. He was to hold this seat, or its Yatiyantota portion on division, continuously until 1977. Following his election, he and Philip Gunawardena, the other LSSP member of the State Council, used it as a platform voice the party's policy and objectives for complete independence from Britten, where as the Ceylon National Congress was advocating self-rule. In 1937, he formed the Ratmalana Railway Workers' Union and was the LSSP delegate to the Indian National Congress session.

Anti-war activity and imprisonment
With the outbreak of World War II, the Board of Ministers declared its support to the British government. The LSSP opposed the move, claiming that it was an imperialist war and organized protest. In 1939, Perera formed the All-Ceylon Estate Workers' Union and lead a militant strike at Mooloya Plantation in January 1940. Perera and Gunawardana voted against the war budget in the State Council, On protests of the planters, the Governor of Ceylon declared LSSP activity against war effort as subversive and order the police to arrest the leaders of the LSSP. On 18 June 1940, N.M. Perera, Philip Gunawardena, and Colvin R de Silva were arrested by the police with Edmund Samarakkody being arrested the following day, but Leslie Goonewardene evaded arrest. The LSSP called for a gathering to protest the arrest and carried out a protest march which was dispersed by the police with a baton charge and followed by arrests. LSSP leaders were detained at the Welikada Prison but was later transferred to the Bogambara Prison after it was suspected that they were planning a hunger strike. On 5 April 1942 during the Easter Sunday Raid, Perera along with several other imprisoned LSSP members escaped from prison. He was smuggled into Bombay in July 1942 and worked with the Bolshevik-Leninist Party of India, Ceylon and Burma (BLPI) in that country's independence struggle. He was arrested in Bombay in July 1943 and was deported to Ceylon where he was sentenced to six months' rigorous imprisonment by the Magistrates Court of Kandy for prison escape and was imprisoned in Badulla for the duration of the war. He was released in 1945.

Leader of the LSSP
During the war the LSSP had several divisions. With the first taking place in 1940, with the split of the ro-Moscow fraction led by S. A. Wickremasinghe, M. G. Mendis, Pieter Keuneman and A. Vaidialingam. This was followed by a second slit over N. M. Perera and Philip Gunawardena opposition to merger into the Bolshevik-Leninist Party of India, Ceylon and Burma, resulting in the formation the Workers' Opposition. After the war this faction, reconstructed the LSSP as an independent political party with N. M. Perera becoming its leader.

Trade union activities
Perera was the president of the All Ceylon United Motor Workers' Union, and the United Corporations and Mercantile Union the Ceylon Federation of Labour (CFL). He was appointed their chief negotiator by the striking workers during the 1946 general strike.

Leader of the opposition (1947-1952)
Having lost their seats in the State Council due to their imprisonment, the LSSP contested the 1947 general elections under the new constitution. N. M. Perera was elected from Ruwanwella and the LSSP gained the 28 seats in parliament, becoming the second largest representation, making Perera the Leader of the Opposition. He opposed the Ceylon Citizenship Act. On reunification with the Bolshevik Samasamaja Party (BSSP), he remained with the LSSP when the Viplavakari Lanka Sama Samaja Party (VLSSP) split off under Philip Gunawardena. He served as opposition leader until fresh elections were called in 1952. In the 1952 general elections, he was re-elected, but the LSSP became the second largest party in the opposition and S. W. R. D. Bandaranaike became the opposition leader.

Mayor of Colombo
In 1954, the LSSP won a string of local government elections which included nine Village Councils and three Urban Councils and the Colombo Municipal Council, where N. M. Perera was elected Mayor of Colombo, only non-United National Party-politician to win that office after 1945. He was Mayor for two years, before he was voted out of office on 28 February 1956 by the United National Party.

Leader of the opposition (1956-1959)
N. M. Perera contested the 1956 general elections, where the Sri Lanka Freedom Party of the Bandaranaike gained landslide victory over the United National Party which was reduced to eight seats in parliament. Once again N. M. Perera was elected leader of the opposition in parliament, a post he held until 1959. He was a strong opponent of the Official Language Act, and narrowly escaped death then a bomb was thrown on stage when he was addressing a crowd at the Old Town Hall.

Split in the party
He was re-elected in the 1960 March general election and the 1960 July general election from Yatiyantota and sat in the opposition. When LSSP was divided over possible government participation in the early 1960s, Perera was the principal leader of the wing that wanted to enter into government with the Sri Lanka Freedom Party, which led to LSSP's expulsion from the Fourth International in 1964.

Minister of Finance (1964)
A short lived Coalition government was formed in 1964 known as the United Front and Perera was appointed Minister of Finance in it. He had to step down as minister when the United Front was defeated in the 1965 general elections and sat in the opposition having retained his seat in parliament.

Minister of Finance
He was reappointed as Minister of Finance in 1970, when the United Front won the 1970 general elections. He served as Minister of Finance from 10 May 1970 to 2 September 1975. Perera faced a budget deficit and first attempted to increase government tax revenue. In October 1970, he demonetized with the denominations of Rupees 50 and 100 to flush out black money. This failed to increase government tax revenue at the significant operational cost to the Central Bank. The 1971 Janatha Vimukthi Peramuna Insurrection of left-wing youths to the leftist government by surprise and was almost toppled. He initiated a program of nationalization of private property and industries. It stunted both domestic and foreign investment in industry and development, unemployment and inflation remained unchecked. By 1974, the budget deficits of $195 million and Ceylon was facing a foreign exchange crisis. This was party due to global macro economic conditions of the such as the 1973 oil crisis as well as the results of government policies such as the Bandaranaike government's attempts to centralise the economy and implement price controls which resulted in declining revenue from coconut, rubber and tea exports and increased food-importation costs. In September 1975, N. M. Perera and other LSSP ministers were removed by Prime Minister Sirima Bandaranaike. In the 1977 general elections, which the United National Party won with a total landslide of 5/6 of the seats, the LSSP like other leftist parties suffered a complete defeat and lost all of its seats. Perera lost his parliamentary seat in Yatiyantota.

Later years
From 1977 to 1978, he served as Chairman of the Board of Control of Cricket in Sri Lanka, and worked hard to obtain test status for Sri Lanka. In 1978, he represented Sri Lanka at the United Nations Conference on Trade and Development as an adviser. He died on 14 August 1979 at the Colombo National Hospital following gall-bladder complication, aged 75 and his funeral gathered large crowds.

Personal life
He married fellow LSSP founding member and later party secretary, Selina Margaret Peiris on 6 March 1936. N. M. Perera was an avid cricket fan and a keen tennis player.

Publications

 * Parliamentary Democracy (1931)
 * The Case for Free Education (1944)
 * External Economic Assistance (1964)
 * The Economy of Ceylon: Trends and Prospects (1971)
 * Critical Analysis of the New Constitution of the Sri Lanka Government (1979)

title: N. M. Perera


text:
Differential

Differential may refer to:

Mathematics

 * Differential (mathematics) comprises multiple related meanings of the word, both in calculus and differential geometry, such as an infinitesimal change in the value of a function
 * Differential algebra
 * Differential calculus
 * Differential of a function, represents a change in the linearization of a function
 * Total differential is its generalization for functions of multiple variables
 * Differential (infinitesimal) (e.g. dx, dy, dt etc.) are interpreted as infinitesimals
 * Differential topology
 * Differential (pushforward) The total derivative of a map between manifolds.
 * Differential exponent, an exponent in the factorisation of the different ideal
 * Differential geometry, exterior differential, or exterior derivative, is a generalization to differential forms of the notion of differential of a function on a differentiable manifold
 * Differential (coboundary), in homological algebra and algebraic topology, one of the maps of a cochain complex
 * Differential cryptanalysis, a pair consisting of the difference, usually computed by XOR, between two plaintexts, and the difference of the corresponding ciphertexts

Science and technology

 * Differential (mechanical device), as part of a motor vehicle drivetrain, the device that allows driving wheels or axles on opposite sides to rotate at different speeds
 * Limited-slip differential
 * Differential steering, the steering method used by tanks and similar tracked vehicles
 * Electronic differential, an electric motor controller which substitutes its mechanical counterpart with significant advantages in electric vehicle application
 * Differential signaling, in electronics, applies to a method of transmitting electronic signals over a pair of wires to reduce interference
 * Differential amplifier an electronic amplifier that amplifies signals.

Social sciences

 * Semantic and structural differentials in psychology
 * Quality spread differential, in finance
 * Compensating differential, in labor economics

Medicine

 * Differential diagnosis, the characterization of the underlying cause of pathological states based on specific tests
 * White blood cell differential, the enumeration of each type of white blood cell either manually or using automated analyzers

Other

 * Differential hardening, in metallurgy
 * Differential rotation, in astronomy
 * Differential centrifugation, in cell biology
 * Differential scanning calorimetry, in materials science
 * Differential signalling, in communications
 * Differential GPS, in satellite navigation technology
 * Differential interferometry in radar
 * Differential, an extended play by The Sixth Lie
 * Handicap differential, part of the calculation used in producing golf handicaps

title: Differential


text:
Talk:Sonoluminescence

Parts of this looks just like this:

http://www-phys.llnl.gov/N_Div/sonolum/

Copyright violation? - Omegatron 18:46, May 24, 2004 (UTC)

 * I scrambled it up a bit. With some more editing it should lose most resemblance to the original. - Omegatron 21:39, May 24, 2004 (UTC)

 * But... "scrambled up" plagiarism is still plagiarism. I appreciate what you're trying to do, but if that article is a source, it should be credited, "scrambled up" or not. --Rodii 22:32, 20 Jan 2005 (UTC)

 * Well, isn't it in the public domain, seeing that it's on a U.S. govt website? - Ta bu shi da yu 13:41, 29 Jan 2005 (UTC)

 * "Copyright Status LLNL-authored documents are sponsored by the U.S. Department of Energy under Contract W-7405-Eng-48. Accordingly, the U.S. Government retains a nonexclusive, royalty-free license to publish or reproduce these documents, or allow others to do so, for U.S. Government purposes. All documents available from this server may be protected under the U.S. and Foreign Copyright Laws. Permission to reproduce may be required." http://www.llnl.gov/disclaimer.html 64.168.30.4 02:50, 2 Feb 2005 (UTC)

I dont know when this was last edited but according to this article:http://www.sciencedaily.com/releases/2005/03/050307215613.htm the light is created from compression of the gas in the bubble.

hey! i added that.
mayer nest pas daccord "removing entire nonsensical pseudoscience theory section since no one has improved it."

 * :-( you make me sad.  what needs improving? - Omegatron 06:21, Mar 13, 2005 (UTC)

 * Moving section here:

Theories
The mystery of how a low-energy-density sound wave can concentrate enough energy in a small enough volume to cause the emission of light is still unsolved. It requires a concentration of energy by about a factor of 1012 (one trillion).

There are two prominent theories to account for the light generated by the collapsing bubble:

 * 1) Dr. Claudia Eberlein, a physicist at the University of Sussex, suggests that the light is generated by the vacuum around the bubble in a process similar to Hawking radiation, the radiation generated by the edges of black holes.  Quantum theory holds that a vacuum is filled with virtual particles, and the rapidly moving interface between water and air converts virtual photons into real photons.  This is related to the Unruh effect or the Casimir effect.  If true, sonoluminescence may be the first observable example of quantum vacuum radiation.  The fact that addition of inert gases changes the properties of light emission, when emission should only depend on the properties of the vacuum and interface movement, is evidence against this theory.
 * 2) Andrea Prosperetti believes that the light is generated as a jet of liquid shoots from one side of the bubble to the other at very high speed (around 6000 km/h).  Water ice and Wint-O-Green Lifesavers can give off light when they crack (called triboluminescence), and it is thought that the high pressures inside the bubble cause the water to form ice-like structures.  As the jet hits the other side, the water "fractures" in the same way that silly putty and other non-Newtonian fluids behave like solids when subjected to sudden stresses.  The fracture causes a release of photons.  Prosperetti believes that an introduction of noble gases changes the way the water molecules align themselves, creating flaws in the crystal-like structure that enhance the fracturing effect.  This theory may be tested by firing hyper-fast jets of water to see if it produces light without the acoustic cavitation.

 * Hi Omegatron, I probably should have put the text here with a more thorough explanation. Sorry. The reason I removed this section is the following: I put the article up for request for cleanup and got no reactions, I put it up for peer review twice I think and got no response. So I removed what I saw as inappropriate sections. The theory of "fracturing liquid" put forth by Prosperetti along with the Eberlein casimir\hawking\virtual particle theory, is now resoundingly rejected by mainstream science today and the actual mechanism, while not completely known is thought to be a far more prosaic adiabatic compression model. Beyond that, shock convergence, plasma ionisation and photo-recombination, Bremsstrahlung radiation, and even fusion are all still intensely debated possible explanations, but no hawking radiation or other very far fetched theories are needed and are practially never invoked anymore. I don't personally know the intricate detail of the sbsl mechanism which is why I have not yet added it to the article. Perhaps the section I removed shoud stay as "rejected theories"? I wouldn't mind that.--Deglr6328 17:35, 15 Mar 2005 (UTC)

 * Certainly leave it in and show that it is now considered obsolete. If you don't, people like me will never find out and think it is current and put it back in.  :-)  Updating and fixing things is always better than deleting.
 * What are the latest theories, then? - Omegatron 00:12, Mar 16, 2005 (UTC)

 * I'm afraid I really don't know the detail of the current adiabatic compression theory. I will re-insert your additions in a little while when I have time to complete the section. promise.--Deglr6328 04:48, 16 Mar 2005 (UTC)

why does it still have a cleanup tag?
? - Omegatron 21:53, Mar 27, 2005 (UTC)

Eh, I just dont think its in good shape really....It really really needs a scientist to look at it and make changes. --Deglr6328 05:27, 28 Mar 2005 (UTC)

Hey I didn't know you were a skeptic too...cool.--Deglr6328 05:31, 28 Mar 2005 (UTC)

 * *Suspicious gaze* That's what you'd like me to believe...

 * :-) I didn't post that stuff because I am a crackpot.  I looked online for an explanation and that is what I found.  If it's wrong then of course it should be fixed.  Truth is paramount.  (All Truth is subject to change.  Void where prohibited by law.) - Omegatron 13:55, Mar 28, 2005 (UTC)

 * This has several different theories, including those two: http://www.dawnlink.ltd.uk/sl/report.html - Omegatron 14:17, Mar 28, 2005 (UTC)

 * This is probably where I got the info originally: http://members.aol.com/cpeter2001/science2/ - Omegatron 15:50, Mar 28, 2005 (UTC)

 * Oh no! Someone quoted it!  :-) http://www.physicsforums.com/archive/topic/t-61894_Re_Sonoluminescence_&_Bose-Einstein_Condensates.html - Omegatron 19:39, Mar 28, 2005 (UTC)

 * Who would quote wikipedia authoritatively?! I mean it's fun to read an all but... duh!--Deglr6328 00:55, 29 Mar 2005 (UTC)
 * I hope my edits to this section are approved of. I cleaned style and grammar elements, and hopefully made it clearer that this was a simplification of rough, but technical theories on the phenomenon.  I don't believe the cleanup tag is necessary, so I went ahead and removed it. If anything, I say it needs more citations and/or expert help.Alexnye 07:29, 7 October 2007 (UTC)

Light Pulse Temporal Shape
Just a heads up: the llnl.gov page on SBSL is not authoratative. I only say that because it hasn't changed since 1996. There has been a lot of work in this field since then. Most notably, in 1996, we hadn't even started time-correlated photon counting. In other words, the statistics on that page have been shown incorrect.

Moran (the main author of the paper cited) even updated his temporal shape calculations in Phys. Rev. Lett. 80, 4987–4990 (1998). From his conclusion:
 * The data above show SBSL pulse durations that vary from about 150 to 300 ps, depending on experimental conditions. We have confirmed SBSL pulse lengths in this range with single-pulse measurements using a fast MCP and transient digitizer [7]. This pulse-width range is consistent with the results of Gompf [3] and Hiller [4]. Furthermore, recent streak-camera measurements of SBSL duration also find that SBSL duration is of the order of 200 ps [8]. The recent streak data also confirm our observation of slightly prolonged pulse tails. These pulse widths are consistent with previous reports of 50-ps widths [9], and longer than our own report of a 15-ps width [10]. (emphasis added)

A good source of (relatively) current information can be found in Rev. Mod. Phys. 74, 425 (2002).

S.N. Hillbrand 14:14, 20 July 2005 (UTC)

 * I bow to your obviously superior knowledge. What do you think of the "mechanism of production" section? I think it rather sucks but I don't know enough about the current (quasi)consensus about the mechanism to usefully add here....you however, sound like you can add to this greatly. Also, what do you mean by "The light flashes from the bubbles are extremely short—between 35 and a few hundred picoseconds long at visible wavelengths." have we measured radio or X emission from them? Does the UV emission differ in pulsewidth?--Deglr6328 16:54, 20 July 2005 (UTC)

 * I am curious as to how these two theories ended up being the ones highlighted. I think that Eberlein's was never seriously considered on the basis of the principle of parsimony.  Prosperetti did receive consideration but discarded in the face of Putterman's evidence for Blackbody radiation.
 * Currently, it is well accepted that SBSL is the result of a hot-plasma core producing bremsstrahlung radiation. The study showing this effect is noted just above the Mechanism section.  I think that we should probably remove the two guesses and replace it with a good description of the plasma formation/blackbody radiation.
 * I worded the phrase "at visible wavelengths" poorly. I definitely did not want to imply that there is a difference in the pulse width between wavelengths.  I've removed the ending.  To my knowledge, there has been no evidence for X-ray or radio wave emissions in SBSL. S.N. Hillbrand 19:31, 20 July 2005 (UTC)

 * They are highlighted because they were the only descriptions I could find when I wrote that section. See .  Please add other explanations.  Leave these in though, as debunked models. - Omegatron 20:31, July 20, 2005 (UTC)

 * Understood. Do you think that we should include all of the debunked mechanisms? S.N. Hillbrand 11:47, 21 July 2005 (UTC)

 * Heh. No.  Which invalidates what I said before.  If there are popular debunked mechanisms they should probably be included, though.  Or if there are only a few of them it's fine.  We don't want to turn the article into a huge archive of all the possible theories that we now know are false.  I added these originally because they were all I could find, and listed in news articles and such.  Someone who knows more about it debunked them. - Omegatron 14:02, July 21, 2005 (UTC)

Size of the bubbles
How big are the bubbles before they're compressed? What magnitude of change in both volume and pressure is the compression that causes light to be emitted? - G3, 01:01, 25 April 2006 (UTC)

Exotic proposals
Uhm, someone should try to clean this section up a bit. This sentence "yet remains widely discredited within the scientific community at large," is ridiculiusly biased, and not true as far as I can tell. I mean, yes, there is debate, and there are those who remain unconvinced, as Eberlein's theory lacks enough detail to make it verifiable. But, I mean, how does this work "The fact that addition of inert gases changes the properties of light emission, when emission should only depend on the properties of the vacuum and interface movement, is evidence against this theory."? This is very poor logic. Quantum field theory, which is what Eberlain dips into in her theory, is going to amplify the effects of atomic composition by a lot. The fact that this hasn't been addressed in the theory as of yet, is what makes the theory incomplete, but does not comprise evidence against it. It's not evidence at all really. It's common knowledge in the field, and is only evidence that the mechanism of sonoluminescence is complex and very interdisciplinary. The statement is that the Casimir effect plays a role in sonoluminescence, not that it is the solitary mechanism explaining the phenomenon. If we can't get a NPOV presenting the ideas without the smear campaign, then we need to omit the entire discussion. Eberlain caused a significant splash in the field when she proposed her model, and so mentioning it under exotic theories seems appropriate. I think we should mention what it is, and that there is debate in the field; if there is no consensus on that, then we need to erase the section entirely, as she does not deserve the ignorant vitriol. 128.62.99.17 01:51, 14 June 2006 (UTC)

 * The reason Eberlein's quantum vacuum sonolum. explanation caused "a significant splash" was mostly becase it was so wacky! It is hard to think of another supposedly serious recent theory failing occam's razor so spectacularly. Her theory is the definition of EXOTIC, (fringe I would say even) and belongs in the section that its in, it is by no means considered in the mainstream. There is no "smear campaign", hydrodynamic simulations of slbs are in good agreement with experiment, there is no need for QED vacuum effects to be invoked.--Deglr6328 06:39, 14 June 2006 (UTC)

 * The suggestion was actually first due to Schwinger in 1993 8 (Proc. Natl. Acad. Sci. USA vol.90 (1993) p. 958, also p.2105, 4505 and 7285, and vol. 91 (1994) p.6476. I think it is conclusively rebuffed by Brevik, Marachevsky and Milton in 1999 (Phys.Rev.Lett. v.82 p.3948). [S. Ellingsen Nov. 2007]

The hydrodynamic models apply to the motion of the bubble. The modified hydrodynamic models give some approximate results on the temperatures inside the bubble. The models of light emission are not hydrodynamic at this point, and would have to be, at the very least, magnetohydrodynamic in order to address the light emission mechanism; by the very nature of the phenomenon. The models which do describe the emission of light are not hydrodynamic, and most of them invoke some quantum interpretation (for example, see the excimer model, or the Bremsstrahlung model, or the proton tunneling model). It is true that there are big names in the field (eg. Brenner, Lohse, Prosperetti) who seem to feel that Eberlein's work is unrealistic, but it is not unrealistic because it fails Occam's razor, since many of the mechanisms rely heavily on quantum effects. The general argument is that the speeds required for the casimir effect to be of primary importance are not of the same order of magnitude as the speed of sound, and so this cannot be the primary mechanism of light emission. The general statement is that "thermal models" are bet fitted to describe the standard SBSL mechanism (see Brenner et. al. "Single-bubble Sonoluminescence" review). However, this all assumes (relatively) laminar flow models, which it is fairly clear is unrealistic to apply to a transonic flow model. The sentence ["The fact that addition of inert gases changes the properties of light emission, when emission should only depend on the properties of the vacuum and interface movement, is evidence against this theory."] makes no sense, and is not in keeping with the science, with Eberlein's work, with a basic understanding of QFT, or with the understanding of SBSL, so needs to be clarified or omitted. It is also not clear what makes her theory so much more suited to public criticism, as other QFT models. It seems inappropriate to discredit her hypothesis without a much closer look at the science. Cypa 16:09, 14 June 2006 (UTC)

Not just liquids?
This paper talks about sonoluminesence of gas and I think in solid crystals, too. — Omegatron 23:00, 27 April 2007 (UTC)

Does this mean Dragonball Z is plausible then? I mean, the Pistol Shrimp can do it, why can't we? I used to think DBZ was just inertial effects, with color added for drama, like Hubble photos. That you couldn't actually fire kung fu lasers... — Preceding unsigned comment added by 142.167.231.0 (talk) 19:02, 6 April 2012 (UTC)

Argon flash
Is sonoluminescence somehow related to argon flash?  J kasd    05:59, 30 March 2008 (UTC)

who said Sonoluminescence??? it is water braking apart. or whatever it has its own frequency.
(i hope i am correct) when you shock water with sound in special frequencies it disassociates hydrogen from oxygen by resonance. and bubbles appear and also the surrounding pressure on bubbles create in it little explosions and because of it the light. for more see Stenly Mayers he has some patents of H2O disassociates and he is researched it a lot. —Preceding unsigned comment added by 84.109.113.41 (talk) 10:06, 5 May 2008 (UTC)

Indeed, every discussion I have ever read about Sonoluminescence mentions the fact that it disassociates water into hydrogen and oxygen. Very strange that this is not mentioned on the wikipedia page. — Preceding unsigned comment added by 24.9.66.63 (talk) 19:47, 20 June 2021 (UTC)

Early nazi work?
In a radio interview with Dr Michio Kaku, he said that the earliest serious work on sonoluminescence was by the nazi military when they saw the effect around submarine blades, perhaps he's confused on that, but what I understand is that Kaku was groomed for military work (ie they payed for some of his education, and tried to get him at los alamos and other places like that), and knew a large number of the people who would have been working with the paperclip scientists, maybe he knows something about the history that hasn't become widely public yet?

Has anyone read enough of Kakus work to have seen this in print? Is there anything behind this claim by Kaku? Hulahulahulahula (talk) 14:37, 8 May 2008 (UTC)

Boat propellers get eroded/eaten by cavitation bubbles if they're not properly shaped. — Preceding unsigned comment added by 142.167.231.0 (talk) 19:05, 6 April 2012 (UTC)

Picture of SBSL
Hi, I'm participating in experimental study of SBSL and have some pictures of it. I'd like to insert one of them to english wiki-page also (in slovak page ther's no problem), but unfortunately I named this picture with name already existed: Sonoluminescence.jpg. Can anyone help me with renaming this picture? Thanks a lot for advice ;) --WackerSK (talk) 19:02, 20 July 2008 (UTC)

Derivation of Rayleigh Plesset
Isn't the R-P equation derived from the incompressible NS equations? —Preceding unsigned comment added by 138.38.149.121 (talk) 10:55, 21 September 2008 (UTC)

References need cleaning up
I changed the names of the reference sections and switched them around to be more standard. I also put in a journal citations using ASDABS for one of the inline citations (the suslick one, replacing the link to the PDF) as an example. The ASDABs URL allows the user to find the PDF or choose to look at a postscript, etc. But several of the other inline references need to be put in a more standard form. Also, it would make sense to have some of the general refs relocated to the inline refs, prehaps being cited more than once, if they are being used for the article. I suggest looking at an article like stellar structure or triple-alpha process for a suitable reference form that is more standard. The external links ought to all be in the External links section.

It's not about how authoritative the refs are supposed to be, just that they are clearly organised and reflect standard practice in the rest of the Wikipedia physics articles. Puzl bustr (talk) 12:59, 3 November 2009 (UTC)

Just to be clear, there are good reasons for the standard form. External links are the most accessible for a general reader, but web links can get broken, the external page could get moved or taken down, etc. So inline references to books and journals should include the name and title info, referring to a more permanent paper copy. Perhaps look at WikiProject Physics and Wikipedia:Manual of Style. Puzl bustr (talk) 13:19, 3 November 2009 (UTC)

As a simple college student trying to learn about Sonoluminescence(SL) and not a Wikipedia editor, so I am going to be very candid and starkly blunt with you guys. Regardless of any standards of the citation used on Wikipedia or by other articles, They way the are referenced now and referenced really doesn't matter as long as their is a date, the name of publisher when it was written, name journal for articles), Volume and Issue, and especially the ISBN number is kept.  I may be preaching to the choir, but this is primary b/c most of the detailed in depth information SL is actually hard to find or hard to get access to.  In fact, I never seen someone cite the book Sonoluminescence by F. Ronald Young even simply for historical reasons.  However this book is very hard to find just like link "doi:10.1146/annurev.fluid.32.1.445", the better article by Seth Putterman than the on you have cited from Scientific American in 1995 because he addresses the primary problems, specifically those involving the Rayleigh–Plesset. The way I found out about both those article was through citations of the references you included. However, I could only find those articles not on their author or there title alone but more their publisher, date, volume/issue #, and the journal name when combined with its ISBN number. I really don't think you can successfully serve the general public in finding out more information about SL if you change the references in such a way that you remove these things143.215.106.208 (talk) 19:14, 5 December 2009 (UTC)

Doppler effect
Couldn't the Doppler effect shift up the frequency of infrared light as it bounces by total internal reflection around the edges of a collapsing bubble? Wnt (talk) 22:13, 7 January 2010 (UTC)
 * No. —Preceding unsigned comment added by 203.166.231.131 (talk) 20:09, 6 February 2010 (UTC)

Assessment comment
Substituted at 06:23, 7 May 2016 (UTC)

title: Talk:Sonoluminescence


text:
Carl E. Walz

Carl Erwin Walz (born 6 September 1955) is a retired NASA astronaut currently working for Orbital Sciences Corporation's Advanced Programs Group as vice president for Human Space Flight Operations. Walz was formerly assigned to the Exploration Systems Mission Directorate at NASA Headquarters in Washington, D.C. He was the Acting Director for the Advanced Capabilities Division in the Exploration Systems Mission Directorate, and was responsible for a broad range of activities to include Human Research, Technology Development, Nuclear Power and Propulsion and the Lunar Robotic Exploration Programs to support the Vision for Space Exploration.

Personal life
Walz was born on September 6, 1955, in Cleveland, Ohio, and is married to the former Pamela J. Glady of Lyndhurst, Ohio. They have two children. He enjoys piano and vocal music, sports, and was notably the lead singer for Max Q, a rock-and-roll band composed of astronauts.

Education
Graduated from Charles F. Brush High School, Lyndhurst, Ohio, in 1973; received a Bachelor of Science degree in physics from Kent State University, Ohio, in 1977, and a Master of Science in solid state physics from John Carroll University, Ohio, in 1979.

Organizations
American Legion, Kent State University Alumni Association, John Carroll University Alumni Association, and the Association of Space Explorers.

Honors
Graduated summa cum laude from Kent State University. Awarded the Defense Superior Service Medal, the USAF Meritorious Service Medal with one Oak Leaf Cluster, the Defense Meritorious Service Medal with one Oak Leaf, the USAF Commendation Medal, and the USAF Achievement Medal with one Oak Leaf Cluster. Distinguished Graduate from the USAF Test Pilot School, Class 83A. Inducted into the Ohio Veterans Hall of Fame. Awarded three NASA Space Flight Medals, NASA Exceptional Service Medal. Distinguished Alumnus Award, Kent State University, 1997.

Experience
From 1979 to 1982, Walz was responsible for analysis of radioactive samples from the United States Atomic Energy Detection System at the 1155th Technical Operations Squadron, McClellan Air Force Base, California. The subsequent year was spent in study as a flight test engineer at the U.S. Air Force Test Pilot School, Edwards Air Force Base, California. From January 1984 to June 1987, Walz served as a Flight Test Engineer to the F-16 Combined Test Force at Edwards Air Force Base, where he worked on a variety of F-16C airframe avionics and armament development programs. From July 1987 to June 1990, he served as a Flight Test Manager at Detachment 3, Air Force Flight Test Center.

NASA experience
Selected by NASA in January 1990, Walz is a veteran of four space flights, and has logged 231 days in space. He was a mission specialist on STS-51 (1993), was the Orbiter flight engineer (MS-2) on STS-65 (1994), was a mission specialist on STS-79 (1996), and served as flight engineer on ISS Expedition 4 (2001–2002).

In 2008, Walz left NASA for private industry. Walz was the Vice President for Human Spaceflight Operations at Orbital Sciences Corporation in Dulles, Virginia, responsible for cargo and mission operations for Orbital's Commercial Resupply Services program from 2008 to 2015. He then joined Oceaneering as Director Business Development.

Space flight experience
STS-51 Discovery (12–22 September 1993). During the mission, the five-member crew deployed the U.S. Advanced Communications Technology Satellite (ACTS), and the Shuttle Pallet Satellite (SPAS) with NASA and German scientific experiments aboard. Walz also participated in a 7-hour spacewalk (EVA) to evaluate tools for the Hubble Space Telescope servicing mission. The mission was accomplished in 9 days, 22 hours, and 12 minutes.

STS-65 Columbia (8–23 July 1994). STS-65 flew the second International Microgravity Laboratory (IML-2) Spacelab module and carried a crew of seven. During the 15-day flight, the crew conducted more than 80 experiments focusing on materials and life sciences research in microgravity. The mission completed 236 orbits of the Earth, traveling 6.1 million miles, setting a new flight duration record for the Shuttle program.

STS-79 Atlantis (16–26 September 1996). On STS-79 the six-member crew aboard Atlantis docked with the Russian Mir station, delivered food, water, U.S. scientific experiments and Russian equipment, and exchanged NASA long duration crewmembers. During the mission, the Atlantis/Mir complex set a record for docked mass in space. STS-79 was the first flight of the double Spacehab module and landed at KSC after 10 days 3 hours and 13 minutes.

The Expedition 4 crew launched on 5 December 2001, aboard STS-108 and docked with the International Space Station on 7 December 2001. During a 6½ month stay aboard the Space Station, the crew of three (two American astronauts and one Russian cosmonaut) performed flight tests of the station hardware, conducted internal and external maintenance tasks, and developed the capability of the station to support the addition of science experiments. Wearing the Russian Orlan space suit, Walz logged 11 hours and 52 minutes of EVA time in two separate spacewalks. The Expedition 4 crew returned to Earth aboard STS-111, with Endeavour landing at Edwards Air Force Base, California, on 19 June 2002.

With the Expedition 4 mission, Astronauts Bursch and Walz set a new U.S. space endurance record of 195 days 16 hours 33 minutes when they beat the old mark of 188 days set by astronaut Shannon Lucid aboard the Russian Mir space station in 1996.

title: Carl E. Walz


text:
Philadelphi Corridor

The Philadelphi Corridor, also called Philadelphi Route, is the Israeli code name for a narrow strip of land, 14 km (8.7 miles) in length, situated along the entirety of the border between Gaza Strip and Egypt.

Following Israel's unilateral disengagement from the Gaza Strip in 2005, the Philadelphi Accord with Egypt was concluded, which authorized Egypt to deploy 750 border guards along the route to patrol the border on Egypt's side. The Palestinian side of the border was controlled by the Palestinian Authority, until the 2007 takeover by Hamas. The joint authority for the Rafah Border Crossing was transferred to the Palestinian Authority and Egypt for restricted passage by Palestinian ID card holders, and by others by exception.

One purpose of the Philadelphi Route was to prevent the movement of illegal materials (including weapons and ammunition) and people between Egypt and the Gaza Strip.

Name
The name Philadelphi was "randomly chosen by the Israeli army as a code name for the border zone". It was defined in the 18 April 2004 draft Disengagement Plan as "The border area between the Gaza Strip and Egypt".

Background
The 1979 Egypt–Israel peace treaty, in which Israel agreed to withdraw from the Sinai in exchange for peace with Egypt, stipulated that the border with Egypt would follow the border of Mandatory Palestine. The new border cut across Rafah, dividing the town and leaving families separated on both sides of the border. Rafah would be the main border crossing in Gaza. It was agreed that the area near the border (known as Area C) would be demilitarized, with Egypt only permitted to maintain police forces there.

Philadelphi Accord

In 2004, the Knesset passed a resolution to unilaterally withdraw all Israeli citizens and forces from the Gaza Strip, which went into force in August 2005. To enable Israel's evacuation from the Philadelphi Corridor, while preventing smuggling of weapons from Egypt into the Gaza Strip and infiltration and other criminal activity, Israel signed with Egypt the "Agreed Arrangements Regarding the Deployment of a Designated Force of Border Guards Along the Border in the Rafah Area" (Philadelphi Accord) on 1 September 2005. Under the Philadelphi Accord, Egypt was authorized to deploy border guards along the Philadelphi route to patrol the border on Egypt's side. Part of the agreement was a continuous coordination between Israel and Egypt regarding operations and intelligence.

Much opposition arose within the Israeli defense establishment to vacating the Philadelphi route for strategic reasons. The primary concern was the militarization of Gaza and the threat to Israeli security that its militarization would pose. However, it was decided to vacate the corridor in order to prevent Israeli-Palestinian friction which could destabilize the region further.

Israel's decision to withdraw from the Philadelphi Route also posed a threat to the neighboring Egyptians through the potential militarization of Gaza. It was feared that Israel's departure would create a power vacuum that the weak Palestinian leadership would not be able to fill, thus creating a void to be filled by radical Islamists.

The Accord itself contains 83 clauses and specifically describes the mission and obligations of the parties, including the specific types of machinery, weaponry and infrastructure permitted.

Egyptian Border Guard Force
Under the Philadelphi Accord, Egypt was authorized to deploy 750 border guards along the route to patrol the border on Egypt's side. The agreement specified that the Egyptian force is "a designated force for the combating of terrorism and infiltration across the border" and not intended for any military purposes.

The Accord specifically indicated that the new agreement did not modify or amend the 1979 Egypt–Israel peace treaty, and maintained the status of the Philadelphi route and Sinai desert as a demilitarized zone.

"The parties acknowledge that the BGF [Border Guard Force] deployment and these Agreed Arrangements, in no way constitute an amendment to or a revision or modification of Annex I to the Peace Treaty. Rather they constitute additional mission-oriented security measures agreed upon by the parties."

Instead, it "enhance[ed] Egypt's capability to fight smuggling along the border," while ensuring that the forces would not serve any military purposes. Israel insisted on the inclusion in the agreement of provisions indicating that it was not an amendment to the 1979 Peace Treaty because during negotiations Egypt attempted to frame the agreement toward the re-militarization of the Sinai and its borders with Israel and Gaza.

The Philadelphi Accord created the Egyptian Border Guard Force (BGF) composed of 750 ground personnel divided between headquarters and four companies. The agreement specified that the BGF be equipped with the following:
 * 500 assault rifles
 * 67 light machine guns
 * 27 light anti-personnel launchers
 * ground radar
 * 31 police-style vehicles
 * 44 logistical and auxiliary vehicles

Sentry posts, watchtowers and logistical facilities were permitted. Heavy armored vehicles, fortification, military-style intelligence-gathering equipment, and weaponry and equipment beyond the above numbers were prohibited.

Controversy in the Knesset
A number of scholars have looked into the legal issue of whether or not the Philadelphi Accord needed to be passed by the Knesset. Generally, the Knesset approves of major treaties either before or after their passage. The issue arose because the Philadelphi Accord would partially militarize Area C of the Egypt–Israel Peace Treaty, changing the treaty and hence needing Knesset approval. This position was advocated by the Knesset's Foreign Affairs and Defense Committee Chairperson, Yuval Steinitz; he was supported by MK Danny Yatom and they jointly filed a petition to the Supreme Court against the Government. Prime Minister Ariel Sharon on the other hand, argued that the treaty did not change the "demilitarized" status of Area C, and therefore was not a significant enough treaty that it needed to be ratified. On July 6, 2005, the Attorney General ruled that the government was not bound to seek Knesset approval for the treaty, but convention stipulated that it should.

Rafah border crossing
Following the disengagement from Gaza, Israel signed with the Palestinian Authority the Agreement on Movement and Access (AMA) on 15 November 2005. The Agreement allowed the opening of the Gaza-Egypt border for restricted passage of Palestinian residents, and the export of agricultural products from Gaza. The AMA also promised a link between Gaza and West Bank for buses and trucks, construction of a Gaza Seaport, discussion regarding a Gaza airport, and more freedom of movement within the West Bank. None of the promises were kept.

The Rafah Border Crossing was opened near Rafah on 25 November 2005, operated by the Palestinian Authority and US-sponsored Egypt, under supervision of EU observers. During the first six months of 2006, the crossing was opened nine and a half hours a day with an average of 650 people crossing daily each way, which was almost double the average prior to the AMA. After the capture of an Israeli soldier, the Rafah border was closed on 25 June 2006, although the incident did not happen in Rafah. Since then, the crossing was only irregularly opened for very limited cases. Israel denied the EU observers access to the border crossing. The border was never opened for the passage of goods. When Hamas took over the Gaza Strip in 2007, Egypt and Israel closed the borders with Gaza.

Hamas control of Gaza
In January 2008, Palestinian militants breached several parts of the wall bordering the town of Rafah. Thousands of Gazans flowed into Egypt in search of food and supplies. the Egyptian Army continued to destroy tunnels linking Egypt and Gaza and their security source said their demolition will continue "in order to fight any element of terrorism."

After the fall of the Mubarak regime in 2011, Egypt relaxed restrictions at its border with the Gaza Strip, allowing more Palestinians to cross freely for the first time in four years. The Egyptian army continued to destroy Gaza Strip smuggling tunnels, according to the Egyptian army "in order to fight any element of terrorism".

As of April 2013, Egypt reinforced its troops on the border with the Gaza Strip. The Egyptian Army has been destroying tunnels by flooding them.

In October 2014, Egypt announced that they planned to expand the buffer zone between Gaza and Egypt, following a terrorist attack from Gaza that killed 31 Egyptian soldiers. Between July 2013 and August 2015, Egyptian Govt demolished 3,255 private houses on their side of the Egypt-Gaza border in order to create a buffer zone.

Hamas-Israel war
The Rafah area was the site of active conflict in the Israel–Hamas war, including the border crossing which was at least partially closed due to military action.

On 11 December 2023, Israeli Prime Minister Benjamin Netanyahu told a Knesset Foreign Affairs and Security Committee that Israel will control the Philadelphi Corridor (border between Gaza and Egypt) and that Israel would impose a buffer zone inside the Gaza Strip. On 7 May 2024, Israel took control of the Rafah crossing and stationed its forces within the Philadelphi Corridor, the control of which is supposed to remain with Egypt according to the Camp David Accords.

title: Philadelphi Corridor