title: United States in the Vietnam War

text: On March 16, 1968, three companies of Task Force Barker, part of the Americal Division, took part in a search and destroy operation near the village of My Lai, in Quang Ngai Province. Although not all of the members of the company participated, a significant number of them, led by Calley, did. He personally ordered the executions of hundreds of villagers in large groups. The killings ended only when an American helicopter crew, headed by Warrant Officer Hugh Thompson, Jr., discovered Calley's unit in the act and threatened to attack them with his aircraft's weapons unless they stopped. One of the soldiers on the scene was Ron Haeberle, a photographer for the newspaper "Stars and Stripes", who took unobtrusive official black-and-white photos of the operation through the lens of his military-issued camera and color shots of the massacre with his personal camera. Although the operation appeared suspicious to Calley's superiors, it was forgotten.


title: United States in the Vietnam War

text: In 1969, investigative journalist Seymour Hersh exposed the My Lai massacre in print, and the Haeberle photos were released to the world media. The Pentagon launched an investigation headed by General William R. Peers to look into the allegations. After a flurry of activity, the Peers Commission issued its report. It declared that "an atmosphere of atrocity" surrounded the event, concluding that a massacre had taken place and the crime had been covered up by the commander of the Americal Division and his executive officer. Perhaps 400 Vietnamese civilians, mostly old men, women, and children had been killed by Charlie company. Several men were charged in the killings, but only Calley was convicted. He was given a life sentence by a court-martial in 1970, but after numerous appeals, he was finally set free; he had served just over three years of house arrest.


title: United States in the Vietnam War

text: Although My Lai generated a lot of civilian recriminations and bad publicity for the military, it was not the only massacre. The Vietnam War Crimes Working Group Files made public in 1994 by the "Freedom of Information Act" reveals seven, albeit much smaller, massacres previously unacknowledged by the Pentagon, in which at least 137 civilians had died.Civilian Killings Went Unpunished


title: United States in the Vietnam War

text: Cover-ups may have occurred in other cases, as detailed in the Pulitzer Prize-winning series of articles concerning the Tiger Force of the 101st Airborne Division by the "Toledo Blade" in 2003.


title: United States in the Vietnam War

text: Richard Nixon had campaigned in the 1968 presidential election under the slogan that he would end the war in Vietnam and bring "peace with honor". However, there was no plan to do this, and the American commitment continued for another five years. The goal of the American military effort was to buy time, gradually building up the strength of the South Vietnamese armed forces, and re-equipping it with modern weapons so that they could defend their nation on their own. This policy became the cornerstone of the so-called Nixon Doctrine. As applied to Vietnam, it was labeled Vietnamization.


title: United States in the Vietnam War

text: Nixon's papers show that in 1968, as a presidential candidate, he ordered Anna Chennault, his liaison to the South Vietnam government, to persuade them to refuse a cease-fire being brokered by President Lyndon Johnson.


title: United States in the Vietnam War

text: Soon after Tet, General Westmoreland was promoted to Army Chief of Staff and he was replaced by his deputy, General Creighton W. Abrams. Because of the change in American strategy posed by Vietnamization, Abrams pursued a very different approach. The U.S. was gradually withdrawing from the conflict, and Abrams favored smaller-scale operations aimed at PAVN/NLF logistics, more openness with the media, less indiscriminate use of American firepower, elimination of the body count as the key indicator of battlefield success, and more meaningful cooperation with South Vietnamese forces.


title: United States in the Vietnam War

text: Vietnamization of the war, however, created a dilemma for U.S. forces: the strategy required that U.S. troops fight long enough for the ARVN to improve enough to hold its own against Communist forces. Morale in the U.S. ranks rapidly declined during 1969–1972, as evidenced by declining discipline, worsening drug use among soldiers, and increased "fraggings" of U.S. officers by disgruntled troops.


title: United States in the Vietnam War

text: One of Nixon's main foreign policy goals had been the achievement of a breakthrough in U.S. relations with the People's Republic of China and the Soviet Union. An avowed anti-communist since early in his political career, Nixon could make diplomatic overtures to the communists without being accused of being "soft on communism". The result of his overtures was an era of détente that led to nuclear arms reductions by the U.S. and Soviet Union and the beginning of a dialogue with China. In this context, Nixon viewed Vietnam as simply another limited conflict forming part of the larger tapestry of superpower relations; however, he was still determined to preserve South Vietnam until such time as he could not be blamed for what he saw as its inevitable collapse (or a "decent interval", as it was known). To this end he and National Security Advisor Henry Kissinger employed Chinese and Soviet foreign policy gambits to successfully defuse some of the anti-war opposition at home and secured movement at the negotiations that had begun in Paris.


title: United States in the Vietnam War

text: China and the Soviet Union had been the principal backers of North Vietnam's effort through large-scale military and financial aid. The two communist superpowers had competed with one another to prove their "fraternal socialist links" with the regime in Hanoi. The North Vietnamese had become adept at playing the two nations off against one another. Even with Nixon's rapprochement, their support of North Vietnam increased significantly in the years leading up to the U.S. departure in 1973, enabling the North Vietnamese to mount full-scale conventional offensives against the South, complete with tanks, heavy artillery, and the most modern surface-to-air missiles.


title: United States in the Vietnam War

text: The credibility of the U.S. government again suffered in 1971 when "The New York Times", "The Washington Post" and other newspapers serially published "The Pentagon Papers" (actually "U.S.-Vietnam Relations, 1945–1967"). This top-secret historical study of the American commitment in Vietnam, from the Franklin Roosevelt administration until 1967, had been contracted to the RAND Corporation by Secretary of Defense McNamara. The documents were leaked to the press by Daniel Ellsberg, a former State Department official who had worked on the study.


title: United States in the Vietnam War

text: The "Pentagon Papers" laid out the missteps taken by four administrations in their Vietnam policies. For example, they revealed the Johnson administration's obfuscations to Congress concerning the Gulf of Tonkin incidents that had led to direct U.S. intervention; they exposed the clandestine bombing of Laos that had begun in 1964; and they detailed the American government's complicity in the death of Ngô Đình Diệm. The study presented a continuously pessimistic view of the likelihood of victory and generated fierce criticism of U.S. policies.


title: United States in the Vietnam War

text: The importance of the actual content of the papers to U.S. policy-making was disputed, but the window that they provided into the flawed decision-making process at the highest levels of the U.S. government opened the issue for other questions. Their publication was a news event and the government's legal (Nixon lost to the Supreme Court) and extra-legal efforts (the "Plumbers" break-in at the office of Ellsberg's psychiatrist committed to gain material to discredit him, was one of the first steps on the road to Watergate) carried out to prevent their publication—mainly on national security grounds—then went on to generate yet more criticism and suspicion of the government by the American public.


title: United States in the Vietnam War

text: By 1969 the policy of non-alignment and neutrality had worn thin for Prince Sihanouk, ruler of Cambodia. Pressures from the right in Cambodia caused the prince to begin a shift away from the pro-left position he had assumed in 1965–1966. He began to make overtures for normalized relations with the U.S. and created a Government of National Salvation with the assistance of the pro-American General Lon Nol. Seeing a shift in the prince's position, President Nixon ordered the launching of a top-secret bombing campaign, targeted at the PAVN/NLF Base Areas and sanctuaries along Cambodia's eastern border.


title: United States in the Vietnam War

text: On March 18, 1970, Sihanouk, who was out of the country on a state visit, was deposed by a vote of the National Assembly and replaced by General Lon Nol. Cambodia's ports were immediately closed to North Vietnamese military supplies, and the government demanded that PAVN/NLF forces be removed from the border areas within 72 hours. On March 29, 1970, the Vietnamese had taken matters into their own hands and launched an offensive against the Cambodian army. A force of North Vietnamese quickly overran large parts of eastern Cambodia reaching to within of Phnom Penh allowing their allies, the Chinese-supported Khmer Rouge to extend their power. Nixon ordered a military incursion into Cambodia by U.S. and ARVN troops in order to both destroy PAVN/NLF sanctuaries bordering South Vietnam and to buy time for the U.S. withdrawal. During the Cambodian Campaign, U.S. and ARVN forces discovered and removed or destroyed a huge logistical and intelligence haul in Cambodia.


title: United States in the Vietnam War

text: The incursion also sparked large-scale demonstrations on and closures of American college campuses. The expansion of the conflict into Cambodia was seen as an expansion of the conflict into yet another country, nullifying Nixon's promises of de-escalating the war. During the ensuing protests, four students were killed and a score were wounded by Ohio National Guardsmen during a demonstration at Kent State University. Two other students were killed at Jackson State University in Mississippi. In an effort to lessen opposition to the U.S. commitment, Nixon announced on October 12 that the U.S. would withdraw 40,000 more troops from Vietnam before Christmas.


title: United States in the Vietnam War

text: Following the coup, Sihanouk arrived in Beijing, where he established and headed a government in exile, throwing his substantial personal support behind the Khmer Rouge, the North Vietnamese, and the Laotian Pathet Lao.


title: United States in the Vietnam War

text: In 1971 the U.S. authorized the ARVN to carry out an offensive operation aimed at cutting the Ho Chi Minh Trail in southeastern Laos. Besides attacking the PAVN logistical system (which would buy time for the U.S. withdrawal) the incursion would be a significant test of Vietnamization. Backed by U.S. air and artillery support (American troops were forbidden to enter Laos), the ARVN moved across the border along Route 9, utilizing the abandoned Marine outpost of Khe Sanh as a jumping-off point. At first, the incursion went well, but unlike the Cambodian operation of 1970, the PAVN decided to stand and fight, finally mustering around 60,000 men on the battlefield.


title: United States in the Vietnam War

text: The North Vietnamese first struck the flanks of the ARVN column, smashed its outposts, and then moved in on the main ARVN force. Unlike previous encounters during the conflict, the PAVN fielded armored formations, heavy artillery, and large amounts of the latest anti-aircraft artillery. After two months of savage fighting, the ARVN retreated back across the border, closely pursued by the North Vietnamese. One half of the invasion force was killed or captured during the operation, and Vietnamization was seen as a failure.


title: United States in the Vietnam War

text: On August 18, Australia and New Zealand decided to withdraw their troops from the conflict. The total number of U.S. forces in South Vietnam dropped to 196,700 on October 29, 1971, the lowest level since January 1966. On November 12, 1971, Nixon set a February 1, 1972 deadline for the removal of another 45,000 troops.


title: United States in the Vietnam War

text: Vietnamization received another severe test in the spring of 1972 when the North Vietnamese launched a massive conventional offensive across the Demilitarized Zone. Beginning on March 30, the Easter Offensive (known as the "Nguyễn Huệ Offensive" to the North Vietnamese) quickly overran the three northernmost provinces of South Vietnam, including the provincial capital of Quảng Trị City. PAVN forces then drove south toward Huế.


title: United States in the Vietnam War

text: Early in April, PAVN opened two additional operations. The first, a three-division thrust supported by tanks and heavy artillery, advanced out of Cambodia on April 5. The North Vietnamese seized the town of Loc Ninh and advanced toward the provincial capital of An Lộc in Bình Long Province. The second new offensive, launched from the tri-border region into the Central Highlands, seized a complex of ARVN outposts near Dak To and then advanced toward Kon Tum, threatening to split South Vietnam in two.


title: United States in the Vietnam War

text: The U.S. countered with a buildup of American airpower to support ARVN defensive operations and to conduct Operation Linebacker, the first offensive bombing of North Vietnam since "Rolling Thunder" had been terminated in 1968. The PAVN attacks against Huế, An Lộc, and Kon Tum were contained and the ARVN launched a counteroffensive in May to retake the lost northern provinces. On September 10, the South Vietnamese flag once again flew over the ruins of the Citadel of Quảng Trị City, but the ARVN offensive then ran out of steam, conceding the rest of the occupied territory to the North Vietnamese. South Vietnam had countered the heaviest attack since Tet, but it was very evident that it was totally dependent on U.S. airpower for its survival. Meanwhile, the withdrawal of American troops, who numbered less than 100,000 at the beginning of the year, was continued as scheduled. By June only six infantry battalions remained. On August 12, the last American ground combat division left the country. However, the U.S. continued to operate the base at Long Binh. Combat patrols continued there until November 11 when the U.S. handed over the base to the South Vietnamese. After this, only 24,000 American troops remained in Vietnam and President Nixon announced that they would stay there until all U.S. POW's were freed.


title: United States in the Vietnam War

text: At the beginning of the North Vietnamese invasion, the media, including conservative commentator William F. Buckley, predicted the downfall of the Republic of Vietnam; Buckley even called for the firing of General Creighton Abrams as an incompetent military leader. But the ARVN succeeded in defeating General Giap and his huge invading army. His forces were shattered at the Battle of An Lộc, where he threw several divisions at the entrenched South Vietnamese forces, ultimately losing over half of his army as casualties. General Giap's loss and subsequent retreat was viewed as so great a failure by the North Vietnamese Communist Party that Giap was relieved of his command. Although ARVN troops withstood and repelled the massive PAVN attack at An Lộc, American air power seems to have been a key to the ARVN success, just as it had been a key factor in supporting U.S. ground forces when they operated in South Vietnam prior to 1972. Thus, the 1973 withdrawal of U.S. military support and passage of Congressional resolutions cutting off U.S. funding for combat activities in Indochina (H.R. 9055 and H.J.Res. 636) opened the way for the 1975 defeat of the Republic of Vietnam.


title: United States in the Vietnam War

text: During the run-up to the 1972 presidential election, the war was once again a major issue. An antiwar Democrat, George McGovern, ran against President Nixon. The president ended Operation "Linebacker" on October 22 after the negotiating deadlock was broken and a tentative agreement had been hammered out by U.S. and North Vietnamese representatives at the peace negotiations in Paris. The head of the U.S. negotiating team, Henry Kissinger, declared that "peace is at hand" shortly before election day, dealing a death blow to McGovern's already doomed campaign. Kissinger had not, however, counted on the intransigence of South Vietnamese President Thieu, who refused to accept the agreement and demanded some 90 changes in its text. These the North Vietnamese refused to accept, and Nixon was not inclined to put too much pressure on Thieu just before the election, even though his victory was all but assured. The mood between the U.S. and North further turned sour when Hanoi went public with the details of the agreement. The Nixon Administration claimed that North Vietnamese negotiators had used the pronouncement as an opportunity to embarrass the President and to weaken the United States. White House Press Secretary Ron Ziegler told the press on November 30 that there would be no more public announcements concerning U.S. troop withdrawals from Vietnam since force levels were down to 27,000.


title: United States in the Vietnam War

text: Because of Thieu's unhappiness with the agreement, primarily the stipulation that North Vietnamese troops could remain "in place" on South Vietnamese soil, the negotiations in Paris stalled as Hanoi refused to accept Thieu's changes and retaliated with amendments of its own. To reassure Thieu of American resolve, Nixon ordered a massive bombing campaign against North Vietnam utilizing B-52s and tactical aircraft in Operation Linebacker II, which began on December 18 with large raids against both Hanoi and the port of Haiphong. Nixon justified his actions by blaming the impasse in negotiations on the North Vietnamese. Although this heavy bombing campaign caused protests, both domestically and internationally, and despite significant aircraft losses over North Vietnam, Nixon continued the operation until December 29. He also exerted pressure on Thieu to accept the terms of the agreement reached in October.


title: United States in the Vietnam War

text: On January 15, 1973, citing progress in peace negotiations, Nixon announced the suspension of all offensive actions against North Vietnam, to be followed by a unilateral withdrawal of all U.S. troops. The Paris Peace Accords on "Ending the War and Restoring Peace in Vietnam" were signed on January 27, officially ending direct U.S. involvement in the Vietnam War.


title: United States in the Vietnam War

text: The agreement called for the withdrawal of all U.S. personnel and an exchange of prisoners of war. Within South Vietnam, a cease-fire was declared (to be overseen by a multi-national, 1,160-man International Commission of Control and Supervision force) and both ARVN and PAVN/NLF forces would remain in control of the areas they then occupied, effectively partitioning South Vietnam. Both sides pledged to work toward a compromise political solution, possibly resulting in a coalition government. To maximize the area under their control, both sides in South Vietnam almost immediately engaged in land-grabbing military operations, which turned into flashpoints. The signing of the Accords was the main motivation for the awarding of the 1973 Nobel Peace Prize to Henry Kissinger and to leading North Vietnamese negotiator Le Duc Tho. A separate cease-fire had been installed in Laos in February. Five days before the signing of the agreement in Paris, President Lyndon Johnson, whose presidency had been tainted with the Vietnam issue, died.


title: United States in the Vietnam War

text: The first U.S. prisoners of war were released by North Vietnam on February 11, and all U.S. military personnel were to leave South Vietnam by March 29. As an inducement for Thieu's government to sign the agreement, Nixon had promised that the U.S. would provide financial and limited military support (in the form of air strikes) so that the South would not be overrun. But Nixon was fighting for his political life in the growing Watergate scandal and facing an increasingly hostile Congress that withheld funding. The President was able to exert little influence on a hostile public long sick of the Vietnam War.


title: United States in the Vietnam War

text: Thus, Nixon (or his successor Gerald Ford) was unable to fulfill his promises to Thieu. At the same time, aid to North Vietnam from the Soviet Union increased. With the U.S. no longer heavily involved, both the U.S. and the Soviet Union no longer saw the war as significant to their relations. The balance of power shifted decisively in North Vietnam's favor, and the North subsequently launched a major military offensive, the Ho Chi Minh Campaign, against the South that culminated in the surrender of the Republic of Vietnam to PAVN forces on April 30, 1975.


title: United States in the Vietnam War

text: In the post-war era, Americans struggled to absorb the lessons of the military intervention. General Maxwell Taylor, one of the principal architects of the war, noted:


title: United States in the Vietnam War

text: President Ronald Reagan coined the term "Vietnam Syndrome" to describe the reluctance of the American public and politicians to support further military interventions abroad after Vietnam. According to a 2004 Gallup poll, 62 percent of Americans believed it was an unjust war. US public polling in 1978 revealed that nearly 72% of Americans believed the war was "fundamentally wrong and immoral." Nearly a decade later, the number fell to 66%. In the past three decades, surveys have consistently shown that only around 35% of Americans believe that the war was fundamentally wrong and immoral. When surveyed in 2000, one third of Americans believed that the war was a noble cause.


title: United States in the Vietnam War

text: Failure of the war is often placed at different institutions and levels. Some have suggested that the failure of the war was due to political failures of U.S. leadership. The official history of the United States Army noted that "tactics have often seemed to exist apart from larger issues, strategies, and objectives. Yet in Vietnam the Army experienced tactical success and strategic failure... success rests not only on military progress but on correctly analysing the nature of the particular conflict, understanding the enemy's strategy, and assessing the strengths and weaknesses of allies. A new humility and a new sophistication may form the best parts of a complex heritage left to the Army by the long, bitter war in Vietnam."


title: United States in the Vietnam War

text: Others point to a failure of U.S. military doctrine. Secretary of Defense Robert McNamara stated that "the achievement of a military victory by U.S. forces in Vietnam was indeed a dangerous illusion." The inability to bring Hanoi to the bargaining table by bombing also illustrated another U.S. miscalculation, and demonstrated the limitations of U.S. military abilities in achieving political goals. As Army Chief of Staff Harold Keith Johnson noted, "if anything came out of Vietnam, it was that air power couldn't do the job." Even General William Westmoreland admitted that the bombing had been ineffective. As he remarked, "I still doubt that the North Vietnamese would have relented." U.S. Secretary of State Henry Kissinger wrote in a secret memo to President Gerald Ford that "in terms of military tactics, we cannot help draw the conclusion that our armed forces are not suited to this kind of war. Even the Special Forces who had been designed for it could not prevail."


title: United States in the Vietnam War

text: Hanoi had persistently sought unification of the country since the Geneva Accords, and the effects of U.S. bombings had negligible impact on the goals of the North Vietnamese government. The effects of U.S. bombing campaigns had mobilised the people throughout North Vietnam and mobilised international support for North Vietnam due to the perception of a super-power attempting to bomb a significantly smaller, agrarian society into submission.


title: United States in the Vietnam War

text: The Vietnam War POW/MIA issue, concerning the fate of U.S. service personnel listed as missing in action, persisted for many years after the war's conclusion. The costs of the war loom large in American popular consciousness; a 1990 poll showed that the public incorrectly believed that more Americans lost their lives in Vietnam than in World War II.


title: United States in the Vietnam War

text: Between 1953 and 1975, the United States was estimated to have spent $168 billion on the war (equivalent to $ trillion in ). This resulted in a large federal budget deficit. Other figures point to $138.9 billion from 1965 to 1974 (not inflation-adjusted), 10 times all education spending in the US and 50 times more than housing and community development spending within that time period. General record-keeping was reported to have been sloppy for government spending during the war. It was stated that war-spending could have paid off every mortgage in the US at that time, with money leftover.


title: United States in the Vietnam War

text: More than 3 million Americans served in the Vietnam War, some 1.5 million of whom actually saw combat in Vietnam. James E. Westheider wrote that "At the height of American involvement in 1968, for example, 543,000 American military personnel were stationed in Vietnam, but only 80,000 were considered combat troops." Conscription in the United States had been controlled by the president since World War II, but ended in 1973.


title: United States in the Vietnam War

text: As of 2013, the U.S. government is paying Vietnam veterans and their families or survivors more than $22 billion a year in war-related claims.


title: United States in the Vietnam War

text: By the war's end, 58,220 American soldiers had been killed, more than 150,000 had been wounded, and at least 21,000 had been permanently disabled. The average age of the U.S. troops killed in Vietnam was 23.11 years. According to Dale Kueter, "Of those killed in combat, 86.3 percent were white, 12.5 percent were black and the remainder from other races." Approximately 830,000 Vietnam veterans suffered some degree of posttraumatic stress disorder (PTSD). Vietnam veterans suffered from PTSD in unprecedented numbers, as many as 15.2% of Vietnam veterans, because the U.S. military had routinely provided heavy psychoactive drugs, including amphetamines, to American servicemen, which left them unable to process adequately their traumas at the time. An estimated 125,000 Americans left for Canada to avoid the Vietnam draft, and approximately 50,000 American servicemen deserted. In 1977, United States president Jimmy Carter granted a full and unconditional pardon to all Vietnam-era draft dodgers with Proclamation 4483.


title: United States in the Vietnam War

text: As the Vietnam War continued inconclusively and became more unpopular with the American public, morale declined and disciplinary problems grew among American enlisted men and junior, non-career officers. Drug use, racial tensions, and the growing incidence of fragging—attempting to kill unpopular officers and non-commissioned officers with grenades or other weapons—created severe problems for the U.S. military and impacted its capability of undertaking combat operations. By 1971, a U.S. Army colonel writing in the Armed Forces Journal declared:


title: United States in the Vietnam War

text: Between 1969 and 1971 the U.S. Army recorded more than 900 attacks by troops on their own officers and NCOs with 99 killed.


title: United States in the Vietnam War

text: The Vietnam War called into question the U.S. Army doctrine. Marine Corps general Victor H. Krulak heavily criticised Westmoreland's attrition strategy, calling it "wasteful of American lives... with small likelihood of a successful outcome." In addition, doubts surfaced about the ability of the military to train foreign forces. Furthermore, throughout the war there was found to be considerable flaws and dishonesty by officers and commanders due to promotions being tied to the body count system touted by Westmoreland and McNamara. And behind the scenes Secretary of Defense McNamara wrote in a memo to President Johnson his doubts about the war: "The picture of the world's greatest superpower killing or seriously injuring 1,000 noncombatants a week, while trying to pound a tiny backward nation into submission on an issue whose merits are hotly disputed, is not a pretty one."


title: United States in the Vietnam War

text: Ron Milam has questioned the severity of the "breakdown" of the U.S. armed forces, especially among combat troops, as reflecting the opinions of "angry colonels" who deplored the erosion of traditional military values during the Vietnam War. Although acknowledging serious problems, he questions the alleged "near mutinous" conduct of junior officers and enlisted men in combat. Investigating one combat refusal incident, a journalist declared, "A certain sense of independence, a reluctance to behave according to the military's insistence on obedience, like pawns or puppets... The grunts [infantrymen] were determined to survive... they insisted of having something to say about the making of decisions that determined whether they might live or die." The morale and discipline problems and resistance to conscription were important factors leading to the creation of an all-volunteer military force by the United States and the termination of conscription. The last conscript was inducted into the army in 1973. The all-volunteer military moderated some of the coercive methods of discipline previously used to maintain order in military ranks.


title: United States in the Vietnam War

text: The earliest reported use of drugs among US troops in Vietnam was recorded in 1963. During this time the most commonly used drug was marijuana, which was sometimes used in the form of hashish. Soldiers mainly used the drug during downtime in rear areas and commanders expressed concern that it would hinder combat operations. On the topic, Major General Raymond G. Davis noted that the troops policed themselves while they were out in the field, where combat was possible, as they would need a clear head to survive. Heroin usage was also common among US troops and per historians, was a much larger problem. Opium and marijuana were widely available and sold for low prices by villagers and locals. Vietnamese heroin was more potent and was smoked instead of injected.


title: United States in the Vietnam War

text: Towards the end of US involvement in Vietnam, heroin use spiked. Morale dropped toward the end of US involvement due to lack of support at home, and a feeling that the war was purposeless. Troops used heroin and other drugs to pass time, deal with the mental stresses of combat, boredom, and feelings of hopelessness. Historians state that one third of the heroin abusers in the military became an addict during their first month in the country.


title: United States in the Vietnam War

text: The military had launched education programs to deal with the growing drug abuse problem among the troops. When it failed, the military began to court martial offenders in large numbers. When the number of court-martials became too high, the military began to discharge troops from the service. The Marines especially believed in punishment to curb drug use. The Marine Commandant at the time, General Wilson Jr., believed it was better to be reduced in strength than to allow heroin addicted Marines to continue to serve. This method was effective at preventing new troops from becoming users because new troops had become users due to existing troops introducing them to the drugs.


title: Op-ed

text: An op-ed, short for "opposite the editorial page", is a written prose piece, typically published by a North-American newspaper or magazine, which expresses the opinion of an author usually not affiliated with the publication's editorial board. Op-eds are different from both editorials (opinion pieces submitted by editorial board members) and letters to the editor (opinion pieces submitted by readers). In 2021, "The New York Times"—the paper credited with developing and naming the modern op-ed page—announced that it was retiring the label, and would instead call submitted opinion pieces "Guest Essays." The move was a result of the transition to online publishing, where there is no concept of physically opposing (adjacent) pages.


title: Op-ed

text: The direct ancestor of the modern op-ed page was created in 1921 by Herbert Bayard Swope of "The New York Evening World". When Swope took over as main editor in 1920, he realized that the page opposite the editorials was "a catchall for book reviews, society boilerplate, and obituaries". He wrote:


title: Op-ed

text: Swope included only opinions by employees of his newspaper, leaving the "modern" op-ed page to be developed in 1970 under the direction of "The New York Times" editor John B. Oakes. The first op-ed page of "The New York Times" appeared on 21 September 1970.


title: Op-ed

text: Writes media scholar Michael J. Socolow of Oakes' innovation: The Times' effort synthesized various antecedents and editorial visions. Journalistic innovation is usually complex, and typically involves multiple external factors. The Times' op-ed page appeared in an era of democratizing cultural and political discourse and of economic distress for the company itself. The newspaper's executives developed a place for outside contributors with space reserved for sale at a premium rate for additional commentaries and other purposes.


title: Op-ed

text: Beginning in the 1930s, radio began to threaten print journalism, a process that was later accelerated by the rise of television. To combat this, major newspapers such as "The New York Times" and "The Washington Post" began including more openly subjective and opinionated journalism, adding more columns and increasing the extent of their op-ed pages.


title: Op-ed

text: The various connections between op-eds, editors, and funding from interest groups have raised concern. In 2011, in an open letter to "The New York Times", a group of U.S. journalists and academics called for conflict of interest transparency in op-eds.


title: Chair of the Federal Reserve

text: The chair of the Board of Governors of the Federal Reserve System is the head of the Federal Reserve, and is the active executive officer of the Board of Governors of the Federal Reserve System. The chair shall preside at the meetings of the Board.


title: Chair of the Federal Reserve

text: The chair serves a four-year term after being nominated by the President of the United States and confirmed by the United States Senate; the officeholder serves concurrently as member of the Board of Governors. The chair may serve multiple terms, pending a new nomination and confirmation at the end of each term, with William McChesney Martin as the longest serving chair from 1951 to 1970 and Alan Greenspan as a close second. The chairs cannot be dismissed by the president before the end of their term.


title: Chair of the Federal Reserve

text: The current chair is Jerome Powell, who was sworn in on February 5, 2018. He was nominated to the position by President Donald Trump on November 2, 2017, and later confirmed by the Senate. He was subsequently nominated to a second term by President Joe Biden, later confirmed by the Senate and sworn in on May 23, 2022.


title: Chair of the Federal Reserve

text: As stipulated by the Banking Act of 1935, the president may designate to serve as Chairman of the Board for four-year terms with the advice and consent of the Senate, from among the sitting governors. The Senate Committee responsible for vetting a Federal Reserve chair nominee is the Senate Committee on Banking.


title: Chair of the Federal Reserve

text: By law, at meetings of the Board the chairman shall preside, and, in his absence, the vice chairman shall preside. In the absence of the chairman and the vice chairman, the Board shall elect a member to act as chairman pro tempore.


title: Chair of the Federal Reserve

text: Under the chair’s leadership, the Board’s responsibilities include analysis of domestic and international financial and economic developments. The board also supervises and regulates the Federal Reserve Banks, exercises responsibility in the nation’s payments system, and administers consumer credit protection laws.


title: Chair of the Federal Reserve

text: One of the chair's most important duties is to serve as the chair of the Federal Open Market Committee (FOMC), which is critical in setting short-term U.S. monetary policy.


title: Chair of the Federal Reserve

text: By law, the chair reports twice a year to Congress on the Federal Reserve's monetary policy objectives. He or she also testifies before Congress on numerous other financial issues and meets periodically with the treasury secretary, who is a member of the president's Cabinet.


title: Chair of the Federal Reserve

text: Chair of the Federal Reserve is a Level I position in the Executive Schedule and thus earns the salary prescribed for that level (US$226,300, as of January 2022).


title: Chair of the Federal Reserve

text: The following is a list of past and present chairs of the Board of Governors of the Federal Reserve System. A chair serves for a four-year term after appointment, but may be reappointed for several consecutive four-year terms. Since the Federal Reserve was established in 1914, the following people have served as chair.


title: Any Given Sunday

text: Any Given Sunday is a 1999 American sports drama film directed by Oliver Stone depicting a fictional professional American football team. The film features an ensemble cast, including Al Pacino, Cameron Diaz, Dennis Quaid, Jamie Foxx, James Woods, LL Cool J, Ann-Margret, Lauren Holly, Matthew Modine, John C. McGinley, Charlton Heston, Bill Bellamy, Lela Rochon, Aaron Eckhart, Elizabeth Berkley, and NFL players Jim Brown and Lawrence Taylor. It is partly based on the 1984 novel "On Any Given Sunday" by NFL defensive end Pat Toomay; the title is derived from a line in the book (also used in the film) that a team can win or lose on "any given Sunday", said by the fictitious coach Tony D'Amato.


title: Any Given Sunday

text: Cameo roles also featured many former American football players including Dick Butkus, Y. A. Tittle, Pat Toomay, Warren Moon, Johnny Unitas, Ricky Watters, Emmitt Smith and Terrell Owens, as well as coach Barry Switzer.


title: Any Given Sunday

text: The Miami Sharks, a once-great American football team, are struggling to make the 2001 Affiliated Football Franchises of America (AFFA) playoffs. They are coached by thirty-year veteran Tony D'Amato, who has fallen out of favor with young team owner Christina Pagniacci and offensive coordinator and D'Amato's expected successor Nick Crozier. In the thirteenth game of the season, both starting quarterback Jack "Cap" Rooney and second-string quarterback Tyler Cherubini are injured and forced to leave the field. The desperate Sharks call upon third-string quarterback Willie Beamen to replace them. While a nervous Beamen makes a number of errors and fails to win the game for the Sharks, he plays well and gains confidence. Rooney vows to make it back by the playoffs, with D'Amato promising to not give up on him.


title: Any Given Sunday

text: The next day, D'Amato and Pagniacci argue about the direction of the team. Pagniacci favors Crozier and wants to eventually cut Rooney. D'Amato argues that Pagniacci's father, the previous owner, would never meddle in his coaching plans. During the next game, to D'Amato's chagrin, Beamen disregards the team's conservative offense and changes plays in the huddle. As the media hails Beamen as the next model of quarterback, the newfound success feeds his growing narcissism and leads to tension with teammates and coaches. During a confrontation with Beamen, D'Amato demotes him back to the bench. After Beamen gives an interview taking sole credit for the Sharks' winning streak, the other players refuse to perform for Beamen and consequently lose a home game. After Beamen gets into a brawl with Julian "J-Man" Washington, an irate D'Amato expresses his embarrassment at his team before leaving. Beamen contemplates and amends his self-centered behavior.


title: Any Given Sunday

text: As the playoffs come around, Sharks middle linebacker Luther Lavay reminds Beamen how lucky he is to be in the league and to find a life outside of football; his words fall on deaf ears. D'Amato worsens his relationship with Pagniacci and berates Rooney for second-guessing his availability. Before the game, D'Amato gives a speech urging team unity that Beamen takes to heart and energizes the rest of the team. Rooney returns as starting quarterback, but is injured with a concussion after scoring a touchdown. Rooney urges D'Amato to let Beamen finish the game; after an argument, D'Amato relents. Subsequently, Pagniacci enters the locker room to demand that D'Amato play Beamen. After she and D'Amato argue, Beamen informs her that he had already been told he would start the second half. Beamen apologizes to his teammates for his actions and leads the team to win. In a post-game talk with D'Amato, Beamen dedicates the next game to Rooney, but admits that he is worried about his ongoing health.


title: Any Given Sunday

text: An epilogue voiceover says that the Sharks eventually lost the championship final (the Pantheon Cup) to San Francisco. At D'Amato's final press conference as head coach, he is thanked by Pagniacci. D'Amato is expected to announce his retirement, but he instead drops two bombshells and announces that he has been hired as head coach and general manager of an expansion team in New Mexico, the Albuquerque Aztecs, and that he has signed Willie Beamen to be his starting quarterback and franchise player.


title: Any Given Sunday

text: Oliver Stone developed a script called "Monday Night" written by Jamie Williams, a former tight end for the Nebraska Cornhuskers and later the San Francisco 49ers, and Richard Weiner, a sports journalist. Stone separately acquired the spec script "On Any Given Sunday", by John Logan. Stone later amalgamated a third screenplay, "Playing Hurt" by Daniel Pyne, into the project.


title: Any Given Sunday

text: As of May 1, 1999, the screenplay's cover page listed the following writers: original draft by Jamie Williams & Richard Weiner, John Logan, Daniel Pyne; subsequent revisions by Gary Ross; revisions by Raynold Gideon & Bruce A. Evans; revisions by John Logan; revisions by Lisa Amsterdam & Robert Huizenga; latest revisions by Oliver Stone.


title: Any Given Sunday

text: The Writers Guild of America ultimately awarded screenplay credit to Logan and Stone, with "story" credit to Pyne and Logan. Williams and Weiner went uncredited for their original screenplay, but were credited for their work on the film as technical consultants.


title: Any Given Sunday

text: The screenplay was also based in part on the 1994 book "You're Okay, It's Just a Bruise: A Doctor's Sideline Secrets" by Robert Huizenga. Huizenga was the intern doctor for the Los Angeles Raiders in their 1980s heyday, working under Dr. Robert T. Rosenfeld, who dismissed many players' injuries with the phrase, "You're okay, it's just a bruise." James Woods' character was based on Rosenfeld, and his first diagnosis of "Cap" Rooney's career-threatening injury at the beginning of the film is "you're okay, it's just a bruise." Huizenga left the Raiders in the early 1990s, disgusted at the way the medical advice was kept from players and Rosenfeld being allowed to continue treating them after several mishaps, one of which is closely mirrored in the film—Shark's neck injury and risk of sudden death, based on the real-life Mike Harden case.


title: Any Given Sunday

text: Director Oliver Stone's first two choices to play Tony D'Amato were Al Pacino and Robert De Niro. Henry Rollins was offered a role as a football player but turned it down as he felt he did not have the size to make the portrayal believable. Sean "P. Diddy" Combs was cast as Willie Beamen, but dropped out amidst rumors he could not throw a football convincingly. Publicly Combs dropped off the project because of scheduling conflicts with his recording career. According to Cuba Gooding Jr., he met with Oliver Stone about playing the role of Willie Beamen but Stone turned Gooding down because he had already played a football player in "Jerry Maguire" (1996). Chris Tucker turned down the role of Willie Beamen. George Clooney was offered the role of Jack Rooney but turned it down.


title: Any Given Sunday

text: Five Pro Football Hall of Fame Players made cameo appearances as opposing head coaches. Bob St. Clair appears as the coach for Minnesota in the first game. Y. A. Tittle, for Chicago, the second game. Dick Butkus, with California, the road game. Warren Moon, with New York in the rain soaked game. For the final game in Dallas, Johnny Unitas appears as the coach.


title: Any Given Sunday

text: Jim Caviezel played Tony D'Amato's estranged son, but his scenes were cut. They can be seen in the extras of the Oliver Stone Collection DVD. Tom Sizemore also had a role in the film, but it too was cut.


title: Any Given Sunday

text: The film was shot in Miami, Florida and Irving, Texas. Miami's Orange Bowl stadium represents the home of the fictitious American football team, the Miami Sharks. When the team traveled to California, the stadium used was Pro Player Stadium, which is located in Miami Gardens. Texas Stadium is used for the home of the fictitious Dallas Knights.


title: Any Given Sunday

text: Director Oliver Stone requested, but did not receive, the National Football League's permission to use real NFL team logos and stadiums for the film. As a result, the fictional Affiliated Football Franchises of America (AFFA) was created (not to be confused with the real AFA). The AFFA apparently exists alongside the NFL, since the Miami Dolphins are mentioned.


title: Any Given Sunday

text: For the scenes during a football game, production asked local schools to participate as extras for the film, including Lake Stevens Middle School in Miami, Florida. For each shot the crowd was asked to move around so that each section looked filled. In empty seats cardboard cutouts were placed in seats with balloons attached to them so that they would seem in motion.


title: Any Given Sunday

text: The film also used Arena Football League players such Pat O'Hara, who played for the Tampa Bay Storm, later coached the Orlando Predators and is now an assistant coach with the Tennessee Titans, and Connell Maynor, who also played for the Orlando Predators and spent time as both a player and coach for the Philadelphia Soul. Bjorn Nittmo, then with the AFL's Buffalo Destroyers, was the Sharks' placekicker. Matt Martinez, a former Gurkha & ex-husband of Niki Taylor and linebacker for the AFL's Miami Hooters, played himself, #31 for the Sharks.


title: Any Given Sunday

text: A soundtrack containing hip hop, rock and R&B music was released on January 4, 2000, by Atlantic Records. It peaked at #28 on the "Billboard" 200 and #11 on the Top R&B/Hip-Hop Albums.


title: Any Given Sunday

text: Oliver Stone wanted to use the music of the Canadian band Godspeed You! Black Emperor and actually filmed a scene using their music; when he later asked for permission the band said no, and Stone was forced to redo the scene without the music.


title: Any Given Sunday

text: Film composer Richard Horowitz, who supplied the original score, published his complete music for the film on a promotional CD.


title: Any Given Sunday

text: "Any Given Sunday" was a financial success; made on a budget of $55 million, it went on to earn $100.2 million worldwide.


title: Any Given Sunday

text: "Time Out New York"s Andrew Johnston wrote: "It's often been said of films about sports that smaller balls equal better movies. "Any Given Sunday" explodes that theory, and not just because of the incredible intensity of its gridiron action. Oliver Stone's best movie in many years—and one of his finest ever—looks at the world of professional football from almost every conceivable angle, but it never tries to be the definitive statement on the subject. A surprisingly balanced film that merges Stone's hyperkinetic style with a character-centric narrative approach reminiscent of John Sayles and Robert Altman at their best, "Sunday" proves that powerful human drama and MTV visual pyrotechnics actually can coexist after all."


title: Any Given Sunday

text: Roger Ebert of the "Chicago Sun-Times" also gave the film a mostly positive review, awarding it 3 out of 4 stars, but criticized its length: "I guess I recommend the movie because the dramatic scenes are worth it. Pacino has some nice heart-to-hearts with Quaid and Foxx, and the psychology of the veteran coach is well-captured in the screenplay by Stone and John Logan. But if some studio executive came along and made Stone cut his movie down to two hours, I have the strangest feeling it wouldn't lose much of substance and might even play better."


title: Any Given Sunday

text: Conversely, Richard Schickel of "Time" criticized the story as being "standard" and stated "(a)lmost three hours of this jitter deteriorates from bravura filmmaking to annoying mannerism, and Any Given Sunday ends up less than the sum of its many, often interesting parts." Rick Groen of "The Globe and Mail" wrote that the story was "(c)hoc-a-bloc with manly blather about sacrifice and honour and rugged individuals pulling together for the greater glory of the team." And, elaborating on many critics' shared observations that the movie was "hyperkinetic", Jack Matthews of the "New York Daily News" states that "the sensation we get from the blizzard of images and teeth-jarring sound effects is of having our head used as the football."


title: Any Given Sunday

text: The film received an aggregated score of 52% from 127 reviews on Rotten Tomatoes, with an average rating of 5.5/10. The site's consensus states: "Sometimes entertaining, but overall "Any Given Sunday" is a disappointment coming from Oliver Stone." On Metacritic, "Any Given Sunday" has an aggregated score of 52% based on reviews from 33 critics, indicating "mixed or average reviews". Audiences polled by CinemaScore gave the film an average grade of "B−" on an A+ to F scale.


title: Any Given Sunday

text: When released to home video on VHS and DVD, a new director's cut by Oliver Stone was used. Due to the packaging listing "6 minutes of previously unseen footage" and a running time of 156 minutes, many assumed that the theatrical cut was 150 minutes, and that Stone had added six minutes of footage. In actuality, the theatrical cut ran 162 minutes; 12 minutes were deleted for the director's cut, and six minutes of new footage were added. Stone said these changes were made to help with the film's pacing.


title: Sex offender

text: A sex offender (sexual offender, sex abuser, or sexual abuser) is a person who has committed a sex crime. What constitutes a sex crime differs by culture and legal jurisdiction. The majority of convicted sex offenders have convictions for crimes of a sexual nature; however, some sex offenders have simply violated a law contained in a sexual category. Some of the serious crimes which usually result in a mandatory sex-offender classification are sexual assault, statutory rape, bestiality, child sexual abuse, incest, rape, and sexual imposition.


title: Sex offender

text: Sex offender registration laws in the United States may also classify less serious offenses as sexual offenses requiring sex offender registration. In some states public urination, having sex on a beach, or unlawful imprisonment of a minor also constitute sexual offenses requiring registration.


title: Sex offender

text: In looking at various types of offenses, an example of a digital obscenity offense is child pornography. In the modern world of technology, many jurisdictions are reforming their laws to prevent the over-prosecution of sex offenders and focusing on crimes involving a victim. The term "sexual predator" is often used to describe a sex offender or any of the "tier offenders"; however, only the category just below sexually-violent sexual predator is reserved for a severe or repeated sex offender: sexual predator.


title: Sex offender

text: In the United States, the Adam Walsh Act (AWA) proposed to provide funding to each jurisdiction which would agree to incorporate its Act into their law. In the few jurisdictions accepting the agreement, there are Tier I, Tier II, or Tier III sex offenders. Individuals convicted of petty crimes not covered by the AWA are still liable to abide by the previous regulations denoting them as a sex offender (or habitual sex offender, sexual predator, sexually violent sexual predator, or child-victim offender).


title: Sex offender

text: In the United States, the United Kingdom, and other countries, a convicted sex offender is often required to register with the respective jurisdiction's sex offender registry. In the U.S., registry databases are often open to the public. Sexual offenders are sometimes classified by level. The highest-level offenders generally must register for their entire lives; low-level offenders may only need to register for a period of time.


title: Sex offender

text: The level of recidivism in sexual offenders varies by surveys and by the types of sex offense. Some surveys reported it is lower than is commonly believed. However, according to the Office of Justice Programs (OJP) of the United States Department of Justice, observed recidivism rates of sex offenders are underestimated of actual reoffending. This is due to reasons such as the frequency with which sex crimes are not reported to police, the disparity between the number of sex offenses reported and those solved by arrest, and the disproportionate attrition of certain sex offenses and sex offenders within the criminal justice system. For example, Grotpeter and Elliot (2002) found that only 2.5 % of sexual assaults and 10 % of serious sexual assaults resulted in an arrest.


title: Sex offender

text: A 2002 study by the Office of Justice Programs (OJP) following 9,691 male sex offenders released from prisons in 15 US states in 1994 indicated that within the first 3 years following their release, rearrest and reconviction rates for new sex offenses were 5.3 and 3.5 percent, respectively; that is, about 1 in 19 of released sex offenders were arrested within three years for another sex crime. The same study found that during the same 3 years from release, 68 percent of released non-sex offenders were re-arrested for any crime (and 47.8 percent reconvicted), while 43 percent of the released sex offenders were rearrested for any crime (and 24 percent reconvicted).


title: Sex offender

text: According to the Office of Justice Programs (OJP), in New York state, the recidivism rate for sex offenders has been shown to be lower than any other crime except murder. Another report from the OJP which studied the recidivism of prisoners released in 1994 in 15 states (accounting for two-thirds of all prisoners released in the United States that year) reached the same conclusion.


title: Sex offender

text: Of released sex offenders who allegedly committed another sex crime, 40 percent perpetrated the new offense within a year or less from their prison discharge. Within three years of release, 2.5 percent of released rapists were rearrested for another rape, and 1.2 percent of those who had served time for homicide were arrested for a new homicide. Sex offenders were about four times more likely than non-sex offenders to be arrested for another sex crime after their discharge from prison (5.3 percent of sex offenders, versus 1.3 percent of non-sex offenders). In 1991, an estimated 24 percent of those serving time for rape and 19 percent of those serving time for sexual assault had been on probation (or parole) at the time of the offense for which they were in state prison.


title: Sex offender

text: Approximately 4,300 child molesters were released from prisons in 15 U.S. states in 1994. An estimated 3.3 percent of these 4,300 were rearrested for another sex crime against a child within 3 years of release from prison. Among child molesters released from prison in 1994, 60 percent had been in prison for molesting a child 13 years old or younger. The median age of victims of those imprisoned for sexual assault was less than 13 years old; the median age of rape victims was about 22 years. Child molesters were, on average, five years older than violent offenders who committed their crimes against adults. Nearly 25 percent of child molesters were age 40 or older, but about 10 percent of inmates with adult victims were in that age group.


title: Sex offender

text: The recidivism rate for chikans and voyeurs is considerably higher than for other sex offenses, according to the Crime White Paper 2015 published by the Ministry of Justice of Japan. The survey reported 85.0% of the molesters and 64.9% of the voyeurs had a prior conviction for a sex offense.


title: Sex offender

text: Various methods can be used to assess individual sex offenders' recidivism risk. Some risk assessment tools consider factors that have been empirically linked by research to sexual recidivism risk. These factors include biological and demographic markers, criminogenic correlates, behavioral and developmental indicators, and clinical markers that have been shown to be associated with reoffending. However, the quality of the studies that link various factors to sexual recidivism risk vary widely in terms of methodological rigor. For example, some studies link certain factors to sexual recidivism risk through clinical anecdotal evidence, which are sometimes criticized as less methodologically rigorous than other studies have used empirical approaches, including experimental methods.


title: Sex offender

text: There are at least four classifications of structured sexual recidivism risk assessment tools: empirical actuarial, mechanical, adjusted actuarial, and structured professional judgement. Of these classifications, empirical actuarial tools are the most methodologically rigorous because they contain explicit empirical risk factors, defined in advance, that are combined mechanically using explicitly defined guidelines into a score or risk category, and then linked to a recidivism probability estimate. Structured professional judgement (SPJ) tools are among the least methodologically rigorous risk assessment tools, because these tools specify items to be considered, and ultimately the clinician subjectively integrates the factors to reach assessment conclusions like “low,” “moderate,” or “high” risk. Furthermore, clinicians may also use unstructured sexual recidivism risk assessments, where they do not use any structured guidelines to aid in their risk assessment.


title: Sex offender

text: Researchers and practitioners consider some factors as "static", in that they do not change with time, such as number of prior sex offenses, victim gender, and deviant sexual arousal, and some other factors as "dynamic", such as an offender's compliance with supervision and treatment. By examining both types of factors, a more complete picture of the offender's risk can emerge, compared with static or dynamic factors used alone.


title: Sex offender

text: There is no single assessment tool that clinicians must use for assessing sexual recidivism risk, but there are tools that are widely used, such as the Static-99R. The Static-99R is the most popular actuarial scale in the United States. The Static-99R is a 10-item scale for ranking a sex offender’s relative risk of sexual recidivism compared other offenders. This scale is based on demographic and criminal history data, for example, age at release and number of prior sex offenses. Researchers have shown that the Static-99R is valid across a wide range of individuals (in terms of demographics, such as race/ethnicity). However, the Static-99R has only a modest ability to discriminate correctly between sex offenders and non sex offenders. This means that a randomly selected sex offender would be correctly classified as higher risk than a randomly selected non sex offender with "modest" accuracy. In addition, the Static-99R does not account for every factor that makes a sex offender more likely to reoffend. Despite these shortcomings, the Static-99R is arguably the highest quality tool, in terms of methodological rigor, that is widely available to clinicians to assess sex offender risk of recidivism.


title: Sex offender

text: A sex offender registry is a system in place in a number of jurisdictions designed to allow authorities to keep track of the residence and activity of sex offenders (including those released from prison). In some jurisdictions (especially in the United States), information in the registry is made available to the public via a website or other means. In many jurisdictions, registered sex offenders are subject to additional restrictions (including housing). Those on parole (or probation) may be subject to restrictions not applicable to other parolees or probationers. These include restrictions on being in the presence of minors, living in proximity to a school or daycare center, or owning toys (or other items of interest to minors). Israel's sex offender registry is accessible only to security officials, rather than to the general public.


title: Sex offender

text: Megan's Law, in the U.S., is designed to sanction sex offenders and reduce their recidivism rate. The law is enacted and enforced on a state-by-state basis. Most states also restrict where convicted sex offenders can live after their release, prohibiting residency within a designated distance of schools and daycare centers (usually ). Guided by the 2007 Adam Walsh Child Protection and Safety Act, sex offenders must avoid such areas as schools, bus stops, gyms, recreation centers, playgrounds, parks, swimming pools, libraries, nursing homes, and places of worship by . However, residence stipulations vary from state to state. Some states (such as Arkansas, Illinois, Washington and Idaho) do not require sex offenders to move from their residences if a forbidden facility is built or a law is enacted after the offender takes up residency. Many aspects of the laws are criticised by reformists and civil right groups like National RSOL and Human Rights Watch, and treatment professionals as Atsa.


title: Sex offender

text: Committing to a residence requires a convicted sex offender to be notified of registration regulations by local law enforcement if convicted after January 1, 2005. The offender must act upon the notification within five business days of receipt. If and when an offender is released from incarceration, they must confirm their registration status within five business days. Registration data includes the offender's sex, height, weight, date of birth, identifying characteristics (if any), statutes violated, fingerprints and a current photograph. An offender's email addresses, chat room IDs and instant-messaging aliases must be surrendered to authorities. In Colorado, an offender must re-register when moving to a new address, changing their legal name, employment, volunteer activity, identifying information used online or enrollment status at a post-secondary educational institution. A web-based registration list may be found on county websites, which identifies adult convicted sex offenders who are sexually-violent predators convicted of felony sexual acts, crimes of violence or failure to register as required. Legally, "any person who is a sexually violent predator and any person who is convicted as an adult...has a duty to register for the remainder of his or her natural life". Exceptions to this include deferred sentencing for the offense or petition of the court for termination of registration.


title: Sex offender

text: Some sex offenders are deemed too dangerous to society to be released, and are subjected to civil confinement — indefinite continuing incarceration, which is supposed to, but does not always, provide meaningful treatment to the offender.


title: Sex offender

text: Behavior modification programs have been shown to reduce recidivism in sex offenders. Often, such programs use principles of applied behavior analysis. Two such approaches from this line of research have promise. The first uses operant conditioning approaches (which use reward and punishment to train new behavior, such as problem-solving) and the second uses respondent conditioning procedures, such as aversion therapy. Many of the behaviorism programs use covert sensitization and/or odor aversion: both are forms of aversion therapy, which have had ethical challenges. Such programs are effective in lowering recidivism by 15–18 percent. The use of aversion therapy remains controversial, and is an ethical issue related to the professional practice of behavior analysis.


title: Sex offender

text: In 2007, the Texas State Auditor released a report showing that sex offenders who completed the Texas Sex Offender Treatment Program (SOTP) were 61 percent less likely to commit a new crime.


title: Sex offender

text: Chemical castration is used in some countries and U. S. states to treat male sex offenders. Unlike physical castration, it is reversible by stopping the medication. For male sex offenders with severe or extreme paraphilias, physical castration appears to be effective. It results in a 20-year re-offense rate of less than 2.3 percent (versus 80 percent in the untreated control group), according to a large 1963 study involving a total of 1036 sex offenders by the German researcher A. Langelüddeke. This was much lower than otherwise expected, compared with overall sex offender recidivism rates. Although considered cruel and unusual punishment by many, physical castration does not otherwise affect the lifespan of men (compared with uncastrated men).


title: Sex offender

text: It is argued that in the U.S., sex offenders have been selected as the new realization of moral panics about sex, stranger danger, and national paranoia, the new folk devils or boogeymen. People convicted of any sex crime are "transformed into a concept of evil, which is then personified as a group of faceless, terrifying, and predatory devils", who are, contrary to scientific evidence, perceived as a constant threat, habitually waiting for an opportunity to attack. Consequently, sex offenders are brought up by media on Halloween, despite the fact that there has never been a recorded case of abduction or abuse by a registered sex offender on Halloween.


title: Sex offender

text: Academics, treatment professionals, and law reform groups such as National Association for Rational Sexual Offense Laws and Women Against Registry criticize current sex offender laws as based on media-driven moral panic and "public emotion", rather than a real attempt to protect society. This can motivate legislators to pass knee-jerk laws to address public hysteria, echoing a "populist punitiveness" perspective. Many lawmakers feel that they will attract votes by appearing to be "tough on sex offenders". One discrepancy pointed out by critics is that John Walsh, father of Adam Walsh and supporter of the Adam Walsh Act, has admitted having a relationship with a 16-year-old girl while being in his early 20s and aware of age of consent being 17 in New York, meaning that, had he been convicted, John Walsh himself could be required to register as a sex offender. Since passage of the Adam Walsh Act, Walsh himself has criticized the law, stating "You can't paint sex offenders with a broad brush."


title: Sex offender

text: Critics point out that contrary to media depictions, abductions by predatory offenders are very rare and 93% of child sexual abuse is committed by someone the child knows: a family member, a family friend or someone in a position of authority. According to the U.S. Department of Justice, sex offender recidivism is 5.3%, the lowest for any type of crime except homicide.


title: Sex offender

text: Critics say that, while originally aimed at the worst offenders, as a result of moral panic the laws have gone through series of amendments, many named after the victim of a highly publicized predatory offense, expanding the scope of the laws to low-level offenders, and treating them the same as predatory offenders, leading to the disproportionate punishment of being placed on a public sex offender registry, with the consequent restrictions on movement, employment, and housing. As a result of this persistent media narrative of sex offenders, this panic is being preserved, leading legislators to make registration mandatory for all sex offences, without the possibility of judicial discretion for less dangerous offenders.


title: Faster-than-light

text: Faster-than-light (also FTL, superluminal or supercausal) travel and communication are the conjectural propagation of matter or information faster than the speed of light (). The special theory of relativity implies that only particles with zero rest mass (i.e., photons) may travel "at" the speed of light, and that nothing may travel faster.


title: Faster-than-light

text: Particles whose speed exceeds that of light (tachyons) have been hypothesized, but their existence would violate causality and would imply time travel. The scientific consensus is that they do not exist. "Apparent" or "effective" FTL, on the other hand, depends on the hypothesis that unusually distorted regions of spacetime might permit matter to reach distant locations in less time than light could in normal ("undistorted") spacetime.


title: Faster-than-light

text: As of the 21st century, according to current scientific theories, matter is required to travel at slower-than-light (also STL or subluminal) speed with respect to the locally distorted spacetime region. Apparent FTL is not excluded by general relativity; however, any apparent FTL physical plausibility is currently speculative. Examples of apparent FTL proposals are the Alcubierre drive, Krasnikov tubes, traversable wormholes, and quantum tunneling.


title: Faster-than-light

text: In the context of this article, FTL is the transmission of information or matter faster than "c", a constant equal to the speed of light in vacuum, which is 299,792,458 m/s (by definition of the metre) or about 186,282.397 miles per second. This is not quite the same as traveling faster than light, since:


title: Faster-than-light

text: Neither of these phenomena violates special relativity or creates problems with causality, and thus neither qualifies as "FTL" as described here.


title: Faster-than-light

text: In the following examples, certain influences may appear to travel faster than light, but they do not convey energy or information faster than light, so they do not violate special relativity.


title: Faster-than-light

text: For an earth-bound observer, objects in the sky complete one revolution around the Earth in one day. Proxima Centauri, the nearest star outside the Solar System, is about four and a half light-years away. In this frame of reference, in which Proxima Centauri is perceived to be moving in a circular trajectory with a radius of four light years, it could be described as having a speed many times greater than "c" as the rim speed of an object moving in a circle is a product of the radius and angular speed. It is also possible on a geostatic view, for objects such as comets to vary their speed from subluminal to superluminal and vice versa simply because the distance from the Earth varies. Comets may have orbits which take them out to more than 1000 AU. The circumference of a circle with a radius of 1000 AU is greater than one light day. In other words, a comet at such a distance is superluminal in a geostatic, and therefore non-inertial, frame.


title: Faster-than-light

text: If a laser beam is swept across a distant object, the spot of laser light can easily be made to move across the object at a speed greater than "c". Similarly, a shadow projected onto a distant object can be made to move across the object faster than "c". In neither case does the light travel from the source to the object faster than "c", nor does any information travel faster than light.


title: Faster-than-light

text: The rate at which two objects in motion in a single frame of reference get closer together is called the mutual or closing speed. This may approach twice the speed of light, as in the case of two particles travelling at close to the speed of light in opposite directions with respect to the reference frame.


title: Faster-than-light

text: Imagine two fast-moving particles approaching each other from opposite sides of a particle accelerator of the collider type. The closing speed would be the rate at which the distance between the two particles is decreasing. From the point of view of an observer standing at rest relative to the accelerator, this rate will be slightly less than twice the speed of light.


title: Faster-than-light

text: Special relativity does not prohibit this. It tells us that it is wrong to use Galilean relativity to compute the velocity of one of the particles, as would be measured by an observer traveling alongside the other particle. That is, special relativity gives the correct velocity-addition formula for computing such relative velocity.


title: Faster-than-light

text: It is instructive to compute the relative velocity of particles moving at "v" and −"v" in accelerator frame, which corresponds to the closing speed of 2"v" > "c". Expressing the speeds in units of "c", "β" = "v"/"c":


title: Faster-than-light

text: If a spaceship travels to a planet one light-year (as measured in the Earth's rest frame) away from Earth at high speed, the time taken to reach that planet could be less than one year as measured by the traveller's clock (although it will always be more than one year as measured by a clock on Earth). The value obtained by dividing the distance traveled, as determined in the Earth's frame, by the time taken, measured by the traveller's clock, is known as a proper speed or a proper velocity. There is no limit on the value of a proper speed as a proper speed does not represent a speed measured in a single inertial frame. A light signal that left the Earth at the same time as the traveller would always get to the destination before the traveller.


title: Faster-than-light

text: Since one might not travel faster than light, one might conclude that a human can never travel further from the Earth than 40 light-years if the traveler is active between the age of 20 and 60. A traveler would then never be able to reach more than the very few star systems which exist within the limit of 20–40 light-years from the Earth. This is a mistaken conclusion: because of time dilation, the traveler can travel thousands of light-years during their 40 active years. If the spaceship accelerates at a constant 1 g (in its own changing frame of reference), it will, after 354 days, reach speeds a little under the speed of light (for an observer on Earth), and time dilation will increase the traveler's lifespan to thousands of Earth years, seen from the reference system of the Solar System — but the traveler's subjective lifespan will not thereby change. If they were then to return to Earth, the traveler would arrive on Earth thousands of years into the future. Their travel speed would not have been observed from Earth as being supraluminal — neither for that matter would it appear to be so from the traveler's perspective– but the traveler would instead have experienced a length contraction of the universe in their direction of travel. After the traveler reverses course, the Earth will seem to experience much more time passing than the traveler does. So while the traveler's (ordinary) coordinate speed cannot exceed "c", their proper speed, or distance traveled from the Earth's point of reference divided by proper time, can be much greater than "c". This is seen in statistical studies of muons traveling much further than "c" times their half-life (at rest), if traveling close to "c".


title: Faster-than-light

text: The phase velocity of an electromagnetic wave, when traveling through a medium, can routinely exceed "c", the vacuum velocity of light. For example, this occurs in most glasses at X-ray frequencies. However, the phase velocity of a wave corresponds to the propagation speed of a theoretical single-frequency (purely monochromatic) component of the wave at that frequency. Such a wave component must be infinite in extent and of constant amplitude (otherwise it is not truly monochromatic), and so cannot convey any information.


title: Faster-than-light

text: The group velocity of a wave may also exceed "c" in some circumstances. In such cases, which typically at the same time involve rapid attenuation of the intensity, the maximum of the envelope of a pulse may travel with a velocity above "c". However, even this situation does not imply the propagation of signals with a velocity above "c", even though one may be tempted to associate pulse maxima with signals. The latter association has been shown to be misleading, because the information on the arrival of a pulse can be obtained before the pulse maximum arrives. For example, if some mechanism allows the full transmission of the leading part of a pulse while strongly attenuating the pulse maximum and everything behind (distortion), the pulse maximum is effectively shifted forward in time, while the information on the pulse does not come faster than "c" without this effect. However, group velocity can exceed "c" in some parts of a Gaussian beam in vacuum (without attenuation). The diffraction causes the peak of the pulse to propagate faster, while overall power does not.


title: Faster-than-light

text: The expansion of the universe causes distant galaxies to recede from us faster than the speed of light, if proper distance and cosmological time are used to calculate the speeds of these galaxies. However, in general relativity, velocity is a local notion, so velocity calculated using comoving coordinates does not have any simple relation to velocity calculated locally. (See Comoving and proper distances for a discussion of different notions of 'velocity' in cosmology.) Rules that apply to relative velocities in special relativity, such as the rule that relative velocities cannot increase past the speed of light, do not apply to relative velocities in comoving coordinates, which are often described in terms of the "expansion of space" between galaxies. This expansion rate is thought to have been at its peak during the inflationary epoch thought to have occurred in a tiny fraction of the second after the Big Bang (models suggest the period would have been from around 10 seconds after the Big Bang to around 10 seconds), when the universe may have rapidly expanded by a factor of around 10 to 10.


title: Faster-than-light

text: There are many galaxies visible in telescopes with red shift numbers of 1.4 or higher. All of these are currently traveling away from us at speeds greater than the speed of light. Because the Hubble parameter is decreasing with time, there can actually be cases where a galaxy that is receding from us faster than light does manage to emit a signal which reaches us eventually.


title: Faster-than-light

text: However, because the expansion of the universe is accelerating, it is projected that most galaxies will eventually cross a type of cosmological event horizon where any light they emit past that point will never be able to reach us at any time in the infinite future, because the light never reaches a point where its "peculiar velocity" towards us exceeds the expansion velocity away from us (these two notions of velocity are also discussed in Comoving and proper distances#Uses of the proper distance). The current distance to this cosmological event horizon is about 16 billion light-years, meaning that a signal from an event happening at present would eventually be able to reach us in the future if the event was less than 16 billion light-years away, but the signal would never reach us if the event was more than 16 billion light-years away.


title: Faster-than-light

text: Apparent superluminal motion is observed in many radio galaxies, blazars, quasars, and recently also in microquasars. The effect was predicted before it was observed by Martin Rees and can be explained as an optical illusion caused by the object partly moving in the direction of the observer, when the speed calculations assume it does not. The phenomenon does not contradict the theory of special relativity. Corrected calculations show these objects have velocities close to the speed of light (relative to our reference frame). They are the first examples of large amounts of mass moving at close to the speed of light. Earth-bound laboratories have only been able to accelerate small numbers of elementary particles to such speeds.


title: Faster-than-light

text: Certain phenomena in quantum mechanics, such as quantum entanglement, might give the superficial impression of allowing communication of information faster than light. According to the no-communication theorem these phenomena do not allow true communication; they only let two observers in different locations see the same system simultaneously, without any way of controlling what either sees. Wavefunction collapse can be viewed as an epiphenomenon of quantum decoherence, which in turn is nothing more than an effect of the underlying local time evolution of the wavefunction of a system and "all" of its environment. Since the underlying behavior does not violate local causality or allow FTL communication, it follows that neither does the additional effect of wavefunction collapse, whether real "or" apparent.


title: Faster-than-light

text: The uncertainty principle implies that individual photons may travel for short distances at speeds somewhat faster (or slower) than "c", even in vacuum; this possibility must be taken into account when enumerating Feynman diagrams for a particle interaction. However, it was shown in 2011 that a single photon may not travel faster than "c". In quantum mechanics, virtual particles may travel faster than light, and this phenomenon is related to the fact that static field effects (which are mediated by virtual particles in quantum terms) may travel faster than light (see section on static fields above). However, macroscopically these fluctuations average out, so that photons do travel in straight lines over long (i.e., non-quantum) distances, and they do travel at the speed of light on average. Therefore, this does not imply the possibility of superluminal information transmission.


title: Faster-than-light

text: There have been various reports in the popular press of experiments on faster-than-light transmission in optics — most often in the context of a kind of quantum tunnelling phenomenon. Usually, such reports deal with a phase velocity or group velocity faster than the vacuum velocity of light. However, as stated above, a superluminal phase velocity cannot be used for faster-than-light transmission of information.


title: Faster-than-light

text: The Hartman effect is the tunneling effect through a barrier where the tunneling time tends to a constant for large barriers. This could, for instance, be the gap between two prisms. When the prisms are in contact, the light passes straight through, but when there is a gap, the light is refracted. There is a non-zero probability that the photon will tunnel across the gap rather than follow the refracted path. For large gaps between the prisms the tunnelling time approaches a constant and thus the photons appear to have crossed with a superluminal speed.


title: Faster-than-light

text: However, the Hartman effect cannot actually be used to violate relativity by transmitting signals faster than "c", because the tunnelling time "should not be linked to a velocity since evanescent waves do not propagate". The evanescent waves in the Hartman effect are due to virtual particles and a non-propagating static field, as mentioned in the sections above for gravity and electromagnetism.


title: Faster-than-light

text: In physics, the Casimir–Polder force is a physical force exerted between separate objects due to resonance of vacuum energy in the intervening space between the objects. This is sometimes described in terms of virtual particles interacting with the objects, owing to the mathematical form of one possible way of calculating the strength of the effect. Because the strength of the force falls off rapidly with distance, it is only measurable when the distance between the objects is extremely small. Because the effect is due to virtual particles mediating a static field effect, it is subject to the comments about static fields discussed above.


title: Faster-than-light

text: The EPR paradox refers to a famous thought experiment of Albert Einstein, Boris Podolsky and Nathan Rosen that was realized experimentally for the first time by Alain Aspect in 1981 and 1982 in the Aspect experiment. In this experiment, the measurement of the state of one of the quantum systems of an entangled pair apparently instantaneously forces the other system (which may be distant) to be measured in the complementary state. However, no information can be transmitted this way; the answer to whether or not the measurement actually affects the other quantum system comes down to which interpretation of quantum mechanics one subscribes to.


title: Faster-than-light

text: An experiment performed in 1997 by Nicolas Gisin has demonstrated non-local quantum correlations between particles separated by over 10 kilometers. But as noted earlier, the non-local correlations seen in entanglement cannot actually be used to transmit classical information faster than light, so that relativistic causality is preserved. The situation is akin to sharing a synchronized coin flip, where the second person to flip their coin will always see the opposite of what the first person sees, but neither has any way of knowing whether they were the first or second flipper, without communicating classically. See No-communication theorem for further information. A 2008 quantum physics experiment also performed by Nicolas Gisin and his colleagues has determined that in any hypothetical non-local hidden-variable theory, the speed of the quantum non-local connection (what Einstein called "spooky action at a distance") is at least 10,000 times the speed of light.


title: Faster-than-light

text: The delayed-choice quantum eraser is a version of the EPR paradox in which the observation (or not) of interference after the passage of a photon through a double slit experiment depends on the conditions of observation of a second photon entangled with the first. The characteristic of this experiment is that the observation of the second photon can take place at a later time than the observation of the first photon, which may give the impression that the measurement of the later photons "retroactively" determines whether the earlier photons show interference or not, although the interference pattern can only be seen by correlating the measurements of both members of every pair and so it can't be observed until both photons have been measured, ensuring that an experimenter watching only the photons going through the slit does not obtain information about the other photons in an FTL or backwards-in-time manner.


title: Faster-than-light

text: Faster-than-light communication is, according to relativity, equivalent to time travel. What we measure as the speed of light in vacuum (or near vacuum) is actually the fundamental physical constant "c". This means that all inertial and, for the coordinate speed of light, non-inertial observers, regardless of their relative velocity, will always measure zero-mass particles such as photons traveling at "c" in vacuum. This result means that measurements of time and velocity in different frames are no longer related simply by constant shifts, but are instead related by Poincaré transformations. These transformations have important implications:


title: Faster-than-light

text: Special relativity postulates that the speed of light in vacuum is invariant in inertial frames. That is, it will be the same from any frame of reference moving at a constant speed. The equations do not specify any particular value for the speed of light, which is an experimentally determined quantity for a fixed unit of length. Since 1983, the SI unit of length (the meter) has been defined using the speed of light.


title: Faster-than-light

text: The experimental determination has been made in vacuum. However, the vacuum we know is not the only possible vacuum which can exist. The vacuum has energy associated with it, called simply the vacuum energy, which could perhaps be altered in certain cases. When vacuum energy is lowered, light itself has been predicted to go faster than the standard value "c". This is known as the Scharnhorst effect. Such a vacuum can be produced by bringing two perfectly smooth metal plates together at near atomic diameter spacing. It is called a Casimir vacuum. Calculations imply that light will go faster in such a vacuum by a minuscule amount: a photon traveling between two plates that are 1 micrometer apart would increase the photon's speed by only about one part in 10. Accordingly, there has as yet been no experimental verification of the prediction. A recent analysis argued that the Scharnhorst effect cannot be used to send information backwards in time with a single set of plates since the plates' rest frame would define a "preferred frame" for FTL signalling. However, with multiple pairs of plates in motion relative to one another the authors noted that they had no arguments that could "guarantee the total absence of causality violations", and invoked Hawking's speculative chronology protection conjecture which suggests that feedback loops of virtual particles would create "uncontrollable singularities in the renormalized quantum stress-energy" on the boundary of any potential time machine, and thus would require a theory of quantum gravity to fully analyze. Other authors argue that Scharnhorst's original analysis, which seemed to show the possibility of faster-than-"c" signals, involved approximations which may be incorrect, so that it is not clear whether this effect could actually increase signal speed at all.


title: Faster-than-light

text: The physicists Günter Nimtz and Alfons Stahlhofen, of the University of Cologne, claim to have violated relativity experimentally by transmitting photons faster than the speed of light. They say they have conducted an experiment in which microwave photons — relatively low-energy packets of light — travelled "instantaneously" between a pair of prisms that had been moved up to apart. Their experiment involved an optical phenomenon known as "evanescent modes", and they claim that since evanescent modes have an imaginary wave number, they represent a "mathematical analogy" to quantum tunnelling. Nimtz has also claimed that "evanescent modes are not fully describable by the Maxwell equations and quantum mechanics have to be taken into consideration." Other scientists such as Herbert G. Winful and Robert Helling have argued that in fact there is nothing quantum-mechanical about Nimtz's experiments, and that the results can be fully predicted by the equations of classical electromagnetism (Maxwell's equations).


title: Faster-than-light

text: Nimtz told "New Scientist" magazine: "For the time being, this is the only violation of special relativity that I know of." However, other physicists say that this phenomenon does not allow information to be transmitted faster than light. Aephraim Steinberg, a quantum optics expert at the University of Toronto, Canada, uses the analogy of a train traveling from Chicago to New York, but dropping off train cars from the tail at each station along the way, so that the center of the ever-shrinking main train moves forward at each stop; in this way, the speed of the center of the train exceeds the speed of any of the individual cars.


title: Faster-than-light

text: Winful argues that the train analogy is a variant of the "reshaping argument" for superluminal tunneling velocities, but he goes on to say that this argument is not actually supported by experiment or simulations, which actually show that the transmitted pulse has the same length and shape as the incident pulse. Instead, Winful argues that the group delay in tunneling is not actually the transit time for the pulse (whose spatial length must be greater than the barrier length in order for its spectrum to be narrow enough to allow tunneling), but is instead the lifetime of the energy stored in a standing wave which forms inside the barrier. Since the stored energy in the barrier is less than the energy stored in a barrier-free region of the same length due to destructive interference, the group delay for the energy to escape the barrier region is shorter than it would be in free space, which according to Winful is the explanation for apparently superluminal tunneling.


title: Faster-than-light

text: A number of authors have published papers disputing Nimtz's claim that Einstein causality is violated by his experiments, and there are many other papers in the literature discussing why quantum tunneling is not thought to violate causality.


title: Faster-than-light

text: It was later claimed by Eckle "et al." that particle tunneling does indeed occur in zero real time. Their tests involved tunneling electrons, where the group argued a relativistic prediction for tunneling time should be 500–600 attoseconds (an attosecond is one quintillionth (10) of a second). All that could be measured was 24 attoseconds, which is the limit of the test accuracy. Again, though, other physicists believe that tunneling experiments in which particles appear to spend anomalously short times inside the barrier are in fact fully compatible with relativity, although there is disagreement about whether the explanation involves reshaping of the wave packet or other effects.


title: Faster-than-light

text: Because of the strong empirical support for special relativity, any modifications to it must necessarily be quite subtle and difficult to measure. The best-known attempt is doubly special relativity, which posits that the Planck length is also the same in all reference frames, and is associated with the work of Giovanni Amelino-Camelia and João Magueijo.


title: Faster-than-light

text: There are speculative theories that claim inertia is produced by the combined mass of the universe (e.g., Mach's principle), which implies that the rest frame of the universe might be "preferred" by conventional measurements of natural law. If confirmed, this would imply special relativity is an approximation to a more general theory, but since the relevant comparison would (by definition) be outside the observable universe, it is difficult to imagine (much less construct) experiments to test this hypothesis. Despite this difficulty, such experiments have been proposed.


title: Faster-than-light

text: Although the theory of special relativity forbids objects to have a relative velocity greater than light speed, and general relativity reduces to special relativity in a local sense (in small regions of spacetime where curvature is negligible), general relativity does allow the space between distant objects to expand in such a way that they have a "recession velocity" which exceeds the speed of light, and it is thought that galaxies which are at a distance of more than about 14 billion light-years from us today have a recession velocity which is faster than light. Miguel Alcubierre theorized that it would be possible to create a warp drive, in which a ship would be enclosed in a "warp bubble" where the space at the front of the bubble is rapidly contracting and the space at the back is rapidly expanding, with the result that the bubble can reach a distant destination much faster than a light beam moving outside the bubble, but without objects inside the bubble locally traveling faster than light. However, several objections raised against the Alcubierre drive appear to rule out the possibility of actually using it in any practical fashion. Another possibility predicted by general relativity is the traversable wormhole, which could create a shortcut between arbitrarily distant points in space. As with the Alcubierre drive, travelers moving through the wormhole would not "locally" move faster than light travelling through the wormhole alongside them, but they would be able to reach their destination (and return to their starting location) faster than light traveling outside the wormhole.


title: Faster-than-light

text: Gerald Cleaver and Richard Obousy, a professor and student of Baylor University, theorized that manipulating the extra spatial dimensions of string theory around a spaceship with an extremely large amount of energy would create a "bubble" that could cause the ship to travel faster than the speed of light. To create this bubble, the physicists believe manipulating the 10th spatial dimension would alter the dark energy in three large spatial dimensions: height, width and length. Cleaver said positive dark energy is currently responsible for speeding up the expansion rate of our universe as time moves on.


title: Faster-than-light

text: The possibility that Lorentz symmetry may be violated has been seriously considered in the last two decades, particularly after the development of a realistic effective field theory that describes this possible violation, the so-called Standard-Model Extension. This general framework has allowed experimental searches by ultra-high energy cosmic-ray experiments and a wide variety of experiments in gravity, electrons, protons, neutrons, neutrinos, mesons, and photons.


title: Faster-than-light

text: The breaking of rotation and boost invariance causes direction dependence in the theory as well as unconventional energy dependence that introduces novel effects, including Lorentz-violating neutrino oscillations and modifications to the dispersion relations of different particle species, which naturally could make particles move faster than light.