Here are three reports of the work of Luis W. Alvarez. Alvarez was a physicist who studied the jet effect of exit materials, and how they could cause reverse movement, namely that an object could move toward the shooter. The guy is no slouch. You can read about him here and at the links provided.
He voiced a theory and ran physical experaments proving it sound.
In the last report, please note a conflict that may or may not cast doubt on his conclusions. The doubt was caused by a motor officer to the left rear of Kennedy's limo, who was sprayed by material from Kennedy's wound. With his limo moving forward and the officer coming along behind to the side, it doesn't surprise me that the office may have driven through spray and other airborn materials. From observation of the video, it's clear there was considerable blowout.
At any rate, there are some pretty smart people out there who have proven that reverse movement is possible.
Wikipedia
Luis W. Alvarez (June 13, 1911, San Francisco, California – September 1, 1988) was an American experimental physicist and inventor, who spent nearly all of his long professional career on the faculty of the University of California, Berkeley. The American Journal of Physics commented, "Luis Alvarez (1911–1988) was one of the most brilliant and productive experimental physicists of the twentieth century."[1]
He was the author of 168 published papers in scientific journals, mostly in the field of physics, and was elected to the National Academy of Science in 1947 and the National Academy of Engineering in 1969. He was a member of the American Physical Society, a fellow in 1939, and served as President in 1969. He was awarded the Collier Trophy by the National Aeronautics Association in 1946. The trophy was presented by President Truman; and won the Presidential Medal for Merit in 1947. In 1960 he was named California Scientist of the Year; in 1961 he won the Albert Einstein Award. In 1963 he was presented the National Medal of Science by Lyndon B. Johnson; in 1965 the Michelson Award; in 1978 he received the University of Chicago Alumni Medal and was inducted into the National Inventors Hall of Fame. In 1987, the US Department of Energy granted him its Enrico Fermi award.[2]
He won the Nobel Prize in Physics in 1968, and received over 40 patents, some of which proved commercially viable.
In November 1966, Life Magazine published a series of photographs from the famous film that Abraham Zapruder took of the Kennedy assassination. Alvarez, an expert in optics and photoanalysis, became intrigued by the pictures and began to delve deeply into what could be learned from the film. The result of this was that Alvarez proved conclusively both in theory and experiment that the backward snap of the President’s head was completely consistent with his being shot from behind, which would have been the case if Lee Harvey Oswald were the assassin. He also investigated the timing of the gun shots and the shockwave which disturbed the camera, the speed of the camera, and pointed out a number of things which the FBI photoanalysts either overlooked or got wrong. While the results were not of enormous importance (the paper was intended as a tutorial), the pedagogical aspect of the paper, as well as its informal advice for the physicist intent on arriving at the truth is compelling.[2]
He voiced a theory and ran physical experaments proving it sound.
In the last report, please note a conflict that may or may not cast doubt on his conclusions. The doubt was caused by a motor officer to the left rear of Kennedy's limo, who was sprayed by material from Kennedy's wound. With his limo moving forward and the officer coming along behind to the side, it doesn't surprise me that the office may have driven through spray and other airborn materials. From observation of the video, it's clear there was considerable blowout.
At any rate, there are some pretty smart people out there who have proven that reverse movement is possible.
Wikipedia
Luis W. Alvarez (June 13, 1911, San Francisco, California – September 1, 1988) was an American experimental physicist and inventor, who spent nearly all of his long professional career on the faculty of the University of California, Berkeley. The American Journal of Physics commented, "Luis Alvarez (1911–1988) was one of the most brilliant and productive experimental physicists of the twentieth century."[1]
He was the author of 168 published papers in scientific journals, mostly in the field of physics, and was elected to the National Academy of Science in 1947 and the National Academy of Engineering in 1969. He was a member of the American Physical Society, a fellow in 1939, and served as President in 1969. He was awarded the Collier Trophy by the National Aeronautics Association in 1946. The trophy was presented by President Truman; and won the Presidential Medal for Merit in 1947. In 1960 he was named California Scientist of the Year; in 1961 he won the Albert Einstein Award. In 1963 he was presented the National Medal of Science by Lyndon B. Johnson; in 1965 the Michelson Award; in 1978 he received the University of Chicago Alumni Medal and was inducted into the National Inventors Hall of Fame. In 1987, the US Department of Energy granted him its Enrico Fermi award.[2]
He won the Nobel Prize in Physics in 1968, and received over 40 patents, some of which proved commercially viable.
In November 1966, Life Magazine published a series of photographs from the famous film that Abraham Zapruder took of the Kennedy assassination. Alvarez, an expert in optics and photoanalysis, became intrigued by the pictures and began to delve deeply into what could be learned from the film. The result of this was that Alvarez proved conclusively both in theory and experiment that the backward snap of the President’s head was completely consistent with his being shot from behind, which would have been the case if Lee Harvey Oswald were the assassin. He also investigated the timing of the gun shots and the shockwave which disturbed the camera, the speed of the camera, and pointed out a number of things which the FBI photoanalysts either overlooked or got wrong. While the results were not of enormous importance (the paper was intended as a tutorial), the pedagogical aspect of the paper, as well as its informal advice for the physicist intent on arriving at the truth is compelling.[2]
http://en.wikipedia.org/wiki/Luis_Walter_Alvarez#cite_note-Trower-1
Physics Buzz / Physics Central
The JFK Assassination Video Tapes:
The immediate wave of conspiracy theories in the murder of John F. Kennedy in 1963 were often based on one seemingly disturbing fact: video footage of Kennedy being shot showed his head bucking forward, in the direction of the bullet, and then back toward the shooter. Intuition told people that his head should only move in the direction of the bullet, and that it’s motion backward suggested a second shooter somewhere on the scene that day.
Having also explored the physics of photography (what hasn’t he studied?) but really only needing basic mechanics, Alvarez thought he could explain the puzzle in the video. If a bullet strikes an object and sticks to it perfectly, the motion of the combined object-bullet will only be in the initial direction of the bulle. The bullet's momentum has to be conserved. But the energy of the bullet is changed into heat and damage to the object: so in the case of a human head, the bullet causes jets of blood and brain matter (pardon the gore) to also move in the direction of the bullet (away from the shooter). These jets also have momentum that must be conserved. So, the jets push the head back toward the shooter, causing a seemingly counterintuitive motion. It may seem hard to believe, but both mathematics and demonstrations (they used melons wrapped in filament tape) illustrated Alvarez’s point.
Alvarez did additional analysis of the film, but nothing to settle the conspiracy theories or bring us any closer to really understanding what happened that day. The paper emphasizes that even if a bullet from one direction were responsible for the motion of JFK’s head, it can't actually tell us the number of shooters at the scene. Such mysteries may remain unsolved.
http://physicsbuzz.physicscentral.com/2007/11/its-physics-my-dear-watson-or-pyramids.html
knowledgerush.com
Luis Walter Alvarez (1911 - 1988) of San Francisco, California was a famed physicist who worked at the University of California, Berkeley.
Alvarez won the 1968 Nobel Prize in Physics for "the discovery of a large number of resonance states, made possible through his development of the technique of using hydrogen bubble chamber and data analysis." Specifically, his research made it possible to record and study the short lived particles created in particle accelerators.
Alvarez and his student Lawrence Johnston designed the detonators for the spherical implosives used on the Trinity and Nagasaki bombs.[1]
With geologist son Walter, Luis proposed the asteroid-impact theory to explain the iridium anomaly of the K-T extinction boundary. An impact by an extraterrestrial body is now widely accepted as causing the extinction that killed the dinosaurs.
Alvarez also proposed a jet-recoil theory to explain why Kennedy's head jerked the wrong way if Oswald was the shooter. Known somewhat disparagingly as the "Jet-wash theory", it suffers the evidentiary problem that motorcycle patrolman Bobby Harkis was thoroughly splattered by Kennedy's brain matter—ie, by the presumed jet— but Harkis was to Kennedy's left rear, implying the jet was in the opposite direction to that needed by the theory.
http://www.knowledgerush.com/kr/encyclopedia/Luis_Alvarez/