JFK's Head Snap and the Implausible Jet-Effect and Neurospasm Theories

[Michael T. Griffith]

I suppose that some long-gunman theorists will never cease to peddle what physicist Dr. G. Paul Chambers calls the “bizarre and implausible” jet-effect and neuromuscular-reaction theories to explain JFK’s backward head snap in the Zapruder film. Recently, a forum member posted yet another defense of these nutty theories. So I thought it would be worthwhile to post some of the research that has debunked these theories.

I will present one of British researcher Martin Hay’s critiques of the jet-effect and the neuromuscular-reaction theories. Then, I will present a portion of physicist Dr. G. Paul Chambers’ critique of the neurospasm theory.

I will start with Martin Hay’s critique, which, among other things, exposes Dr. Alvarez’s concealment of ballistics tests information that contradicted his claims. Notice, also, that Hay discusses the fact that Josiah Thompson’s conclusion that JFK’s head moves approximately 2 inches between Z312-313 is wrong, and that Thompson has acknowledged his error.

Over the years, Warren Commission defenders have offered a variety of theories intended to explain why a shot from the rear would cause Kennedy's head to snap backwards. Predictably, Ayton and Von Pein invoke the two most popular of these hypotheses: the "neuromuscular reaction" and the "jet effect". (p. 96-97)

As Larry Sturdivan explains it, the neuromuscular reaction theory suggests that, "The tissue inside [Kennedy's] skull was being moved around. It caused a massive amount of nerve stimulation to go down his spine. Every nerve in his body was stimulated...since the back muscles are stronger than the abdominal muscles, that meant that Kennedy arched dramatically backwards." (NOVA Cold Case: JFK, 2013) However, as Donald Thomas explains,

"Sturdivan's postulate suffers from a patently anomalous notion of the anatomy. In any normal person the antagonistic muscles of the limbs are balanced, and regardless of the relative size of the muscles, the musculature is arranged to move the limbs upward, outward, and forward. Backward extension of the limbs is unnatural and awkward; certainly not reflexive. Likewise, the largest muscle in the back, the 'erector spinae,' functions exactly as its name implies, keeping the spinal column straight and upright. Neither the erector spinae, or any other muscles in the back are capable of causing a backward lunge of the body by their contraction." (Thomas, p. 341)

Not only is the reaction that Sturdivan describes highly implausible, it is also in conflict with the Zapruder film. It is quite clear from watching the film that Kennedy's movement did not begin with an arching of the back. As the ITEK corporation noted following extensive slow motion study, his head snapped backwards first, "then his whole body followed the backward movement." (ITEK report, p. 64)

If Sturdivan's theory seems plausible before closer analysis, that is more than can be said for Luis Alvarez's jet effect hypothesis. Alvarez, a Nobel Prize-winning physicist, suggested that in a similar fashion to the thrust developed in a jet engine in response to its exhaust, the explosive exiting of blood and brain matter from the right side of Kennedy's head created a corresponding propulsive momentum in the opposite direction, pushing it backwards. He claimed to have proven his theory by firing a rifle at melons wrapped in tape which, as Ayton and Von Pein write, were "propelled backward in the direction of the rifle." (p. 97) But, as should be immediately obvious, a melon is nothing like a human head. It weighs around half as much and so requires far less energy to set in motion. It also lacks a bone and, therefore, offers little resistance to a bullet. This means that there is little deposition of momentum and, consequently, very little force to overcome.

Alvarez first presented his theory and the results of his melon tests in the September 1976 issue of the American Journal of Physics. As author Josiah Thompson discovered a few years ago when he acquired the raw notes and photos from all of Alvarez's tests, the physicist had kept some important information to himself. Alvarez had reported on tests performed on May 31, 1970, during which 6 out of 7 melons had recoiled "in a retrograde manner."

What he did not divulge was that there had been two earlier rounds of testing which painted a very different picture. During those earlier firings, Alvarez had used larger, heavier melons which apparently did not behave the way he wanted them to. In later tests he reduced their size by half and jacked up the velocity of his bullets to 3000 fps. Alvarez also fired at a variety of other objects besides melons. There were coconuts filled with jello which were blown 39 feet forward; a plastic jug of water which went 6 feet downrange; and 5 rubber balls filled with gelatin; all of which were blown away from the rifle. In fact, as Thompson noted during his presentation at the Wecht Institutes' Passing the Torch symposium in 2013, "in these tests, every time they shot anything but a melon it went with the bullet. But Alvarez didn't tell anybody that." Nor did he disclose the fact that his JFK experiments had been funded by the U.S. Government. (Wrone, p. 103)

According to Ayton and Von Pein, "a key point that is often overlooked or downplayed by conspiracy theorists is the fact that when JFK is struck in the head with a bullet...the President's head initially moves forward, not backward...which is consistent with the head shot coming from behind..." (p. 98) Can they be serious? Far from being "overlooked or downplayed" this alleged forward motion was actually first discovered by a "conspiracy theorist," Josiah Thompson, who wrote about it in detail in his classic book, Six Seconds in Dallas. Thompson measured the forward movement between Zapruder frames 312 and 313 as approximately two inches and, together with the much larger backward motion, took it as evidence of two shots striking the skull almost simultaneously. However, Thompson has since realised that he made a crucial mistake.

In his online essay, Bedrock Evidence in the Kennedy Assassination, Thompson writes,

"In the years since those measurements were made, I've learned I was wrong. Z312 is a clear frame while Z313 is smeared along a horizontal axis by the movement of Zapruder's camera. The white streak of curb against which Kennedy's head was measured is also smeared horizontally and this gives rise to an illusory movement of the head. Art Snyder of the Stanford Linear Accelerator staff persuaded me several years ago that I had measured not the movement of Kennedy's head but the smear in frame 313. The two-inch forward movement was just not there."

Thompson further explained in his 2013 Wecht symposium presentation, "Since highly exposed areas; that is bright areas of the film; have a whole lot of energy to them, if the shutter is open and the camera moved, then those highly energized areas will intrude into low energized areas. It's a basic photographic principle." Indeed, during his presentation Thompson demonstrated how this principle affected other objects in the Zapruder film besides Kennedy's head.

What all this means according to Thompson is that "there is no longer any solid evidence whatsoever; whatsoever; that John Kennedy was hit in the head from the rear between 312 and 313." As Thompson's co-presenter, Keith Fitzgerald, demonstrated, JFK's head actually exhibits its fastest forward movement between frames 328 and 330, which just so happens to be precisely when the final shot from the Book Depository appears on the Dallas Police dictabelt recording if we align the Grassy Knoll shot with frame 313. This synchronization of audio and visual evidence fully supports the belief of Drs. Riley, Wecht, and Robertson that Kennedy's head was struck by two bullets; one from the front and one from the rear. (https://kennedysandking.com/john-f-kennedy-articles/ayton-mel-and-david-von-pein-beyond-reasonable-doubt)

And now we turn to Dr. Chambers' critique of the neuromuscular-reaction theory. Dr. Chambers is an internationally recognized expert in the field of shock physics and has performed extensive high-speed photographic studies of high-velocity impacts and deformations of solids as well as computer modeling of shock wave and matter interactions. Dr. Chambers holds a PhD in physics from the University of Maryland. He has worked in the NASA Goddard Optics Branch, in the Energetic Materials and Detonation Science Department of the Naval Surface Warfare Center in Maryland, and in the Condensed Matter and Radiation Sciences Division of the Naval Research Laboratory in Washington, DC. He now works on the development of renewable energy sources with Bellatrix Energy, LLC.

In his book Head Shot: The Science Behind the JFK Assassination, Dr. Chambers rejects the jet-effect theory and the neuromuscular-reaction theory as a “bizarre and implausible explanations” for Kennedy’s backward head movement. His refutation of the jet-effect theory is devastating, but I will just quote part of his refutation of the neurospasm theory:

In order to account for Kennedy’s backward head recoil at the moment of impact, Bugliosi resorts to bizarre and implausible explanations like supersonic jetting and freak instantaneous muscle spasms. . . .

The second theory was that the listless Kennedy experienced a muscle spasm at the precise moment of impact, caused by the bullet passing through his brain. Any theory suggesting muscle spasms or contractions has to deal with the issue of human reaction times. As discussed previously, human reaction times are not infinitely fast. The body does not react instantaneously to insult. When the doctor hits your knee with the rubber hammer, there is a noticeable delay before your leg muscles flex and your lower leg extends upward. This reaction time can be quantified by the simple experiment of dropping a ruler between your thumb and forefinger. As this experiment demonstrates, human reaction times are on the order of hundreds of milliseconds.

Zapruder film frames are snapshots taken at 54-millisecond intervals. On the very next frame after the bullet impact, frame Z314, Kennedy is already moving noticeably backward. On frame Z315, his head has moved even farther to the rear, on the order of several inches. Neck muscles are a very weak muscle group in humans, where the head is designed to rest vertically on the neck, not to be supported against gravity as in the case of nonhuman primates. For this model to be viable, it requires a muscle contraction from the waist. A backward spasm from the waist is a major movement of a large muscle group. It’s much harder to do this than it is to pinch your fingers together. Yet, for the theory of the backward muscle spasm to explain the head recoil, Kennedy’s large muscle reaction time would have to have been much faster than human reaction times in the finger pinch test, which are about 200 milliseconds. Therefore, a simple experiment in human reaction times rules out the possibility that Kennedy’s rearward head motion is due to a muscle spasm induced by the incoming bullet striking his brain. . . .

Bugliosi’s entire laborious analysis is reminiscent of the ancient practice of adding epicycles, nested circles, to planetary orbits to salvage the Ptolemaic or “earth-centered” model of the solar system. (Head Shot: The Science Behind the JFK Assassination, New York: Prometheus Books, 2012, pp. 130, 134-135)

[Joe Elliott]

In order to account for Kennedy’s backward head recoil at the moment of impact, Bugliosi resorts to bizarre and implausible explanations like supersonic jetting and freak instantaneous muscle spasms. . . .

The second theory was that the listless Kennedy experienced a muscle spasm at the precise moment of impact, caused by the bullet passing through his brain. Any theory suggesting muscle spasms or contractions has to deal with the issue of human reaction times. As discussed previously, human reaction times are not infinitely fast. The body does not react instantaneously to insult. When the doctor hits your knee with the rubber hammer, there is a noticeable delay before your leg muscles flex and your lower leg extends upward. This reaction time can be quantified by the simple experiment of dropping a ruler between your thumb and forefinger. As this experiment demonstrates, human reaction times are on the order of hundreds of milliseconds.

Dr. Chambers points out that Kennedy’s reaction within 55 milliseconds, is much faster than a normal human reaction. This is true. But the goat’s reaction in the 1948 U. S. Army film of a goat being shot through the brain shows a reaction of 40 milliseconds, which is also much faster than a normal goat reaction. Clearly, if a neuromuscular reaction occurs in an animal, it is a very fast reaction. One cannot rule out a neurological spasm in a human, on account of the super-human speed of the reaction because the goat reacts with super-goat speed.

The super-fast reaction times are not surprising when one thinks about it. For a human, or a goat, the body receives a “message”, maybe from a limb, maybe from the eyes, maybe from the ears. The three steps of the reaction are:
1.   Sending the “message” from the body to the brain. This “message” may have to travel several feet along nerves, up the spinal cord and onto the brain.
2.   The brain processes the “message”.
3.   The brain sends out commands to the body’s muscles and the “message” travels down the spinal cord to the appropriate muscle. This “message” may also have to travel several feet.

In the neuromuscular spasm, the first two steps are skipped. The brain is pushed hard by the cavity formed in the wake of the bullet. This stretches the top of the spinal cord. This generates a spurious signal down the spinal cord to all the muscles of the body, governed by the spinal cord, which is everything from the neck down. The spurious signal should start within a few milliseconds. This results in a much faster reaction time than the usual 3 step process. This explains the super-fast reactions of the goat.

Tests on animals show that the neuromuscular spasm, when it occurs, is a super-fast neuromuscular spasm. So basically, Dr. Chambers is saying that a super-fast neuromuscular spasm could not have occurred with President Kennedy because his reactions were super-fast. Dr. Chambers statements speak more of his ignorance of neuromuscular spasms then they do on reality.


Questions which Mr. Griffith is afraid to answer:

Why should Dr. Chambers, Dr. Mantik and you claim that the fast-neuromuscular spasm in a human has been established as being impossible, or highly unlikely, when this can only be established as impossible or unlikely by running tests on human subjects?

Wouldn’t one have to run these experiments first, before making these claims?

If these tests cannot be run, shouldn’t we withhold judgment?

Or is it more scientific to just guess?


Assuming it cannot happen with humans is no more scientific that assuming it can. All I ask, is for the neuromuscular spasm to be considered a possibility. And only to accept it as the most probably explanation for JFK’s backwards movement if the neuromuscular spasm hypothesis best explains his movements.

Regardless of the degrees, Dr. Chambers and Dr. Mantik do not take a scientific approach to this question. Science degrees do not necessarily confer proper scientific attitudes. There are scientists with Ph.D.’s who do not believe in the theory of evolution.

[Jerry Organ]

Josiah Thompson’s conclusion that JFK’s head moves approximately 2 inches between Z312-313 is wrong, and that Thompson has acknowledged his error.

The head moved forward between frames Z312 and Z313 in 1967. And it still moves forward today..

[Tim Nickerson]

In his book Head Shot: The Science Behind the JFK Assassination, Dr. Chambers rejects the jet-effect theory and the neuromuscular-reaction theory as a “bizarre and implausible explanations” for Kennedy’s backward head movement. His refutation of the jet-effect theory is devastating, but I will just quote part of his refutation of the neurospasm theory:

Zapruder film frames are snapshots taken at 54-millisecond intervals. On the very next frame after the bullet impact, frame Z314, Kennedy is already moving noticeably backward. On frame Z315, his head has moved even farther to the rear, on the order of several inches. Neck muscles are a very weak muscle group in humans, where the head is designed to rest vertically on the neck, not to be supported against gravity as in the case of nonhuman primates. For this model to be viable, it requires a muscle contraction from the waist. A backward spasm from the waist is a major movement of a large muscle group. It’s much harder to do this than it is to pinch your fingers together. Yet, for the theory of the backward muscle spasm to explain the head recoil, Kennedy’s large muscle reaction time would have to have been much faster than human reaction times in the finger pinch test, which are about 200 milliseconds. Therefore, a simple experiment in human reaction times rules out the possibility that Kennedy’s rearward head motion is due to a muscle spasm induced by the incoming bullet striking his brain. . .

However, an experiment cited by conspiracist Milicent Cranor demonstrates that even less time may be required.

Cranor summarizes a study published in the British journal, Brain (Brown P, Rothwell JC, Thompson PD, Britton TC, Day BL, and Marsden CD. New observations on the normal auditory startle reflex in man. Brain 1991; 114:1891-1902):

Auditory Stimulus Response Times in Milliseconds (m/s)
The following figures come from a study by Brown et al, published in the British journal, Brain. The authors tested the latency period (time it takes to respond) of the auditory startle reflex in 12 healthy volunteers ranging in age from 18 to 80 years. While relaxing in a chair, the subjects were randomly treated about every 20 minutes to a tone burst of 124 decibels, the equivalent BANG! of a car backfire 20 feet away. The average latency period of the relevant muscle groups in milliseconds:

Neck: 58 m/s (range 40-136 m/s)

Paraspinal muscles: 60 m/s (range: 48-120 m/s)

Forearm Flexors: 82 m/s (range: 60-200 m/s)

Forearm Extensors: 73 m/s (range 62-173 m/s)

Thumb: 99 m/s (range 75-179 m/s)

Back of Hand: 99 m/s (range 72-176 m/s)


https://mcadams.posc.mu.edu/jfkhit.htm

[Michael T. Griffith]

However, an experiment cited by conspiracist Milicent Cranor demonstrates that even less time may be required.

Cranor summarizes a study published in the British journal, Brain (Brown P, Rothwell JC, Thompson PD, Britton TC, Day BL, and Marsden CD. New observations on the normal auditory startle reflex in man. Brain 1991; 114:1891-1902):

Auditory Stimulus Response Times in Milliseconds (m/s)
The following figures come from a study by Brown et al, published in the British journal, Brain. The authors tested the latency period (time it takes to respond) of the auditory startle reflex in 12 healthy volunteers ranging in age from 18 to 80 years. While relaxing in a chair, the subjects were randomly treated about every 20 minutes to a tone burst of 124 decibels, the equivalent BANG! of a car backfire 20 feet away. The average latency period of the relevant muscle groups in milliseconds:

Neck: 58 m/s (range 40-136 m/s)

Paraspinal muscles: 60 m/s (range: 48-120 m/s)

Forearm Flexors: 82 m/s (range: 60-200 m/s)

Forearm Extensors: 73 m/s (range 62-173 m/s)

Thumb: 99 m/s (range 75-179 m/s)

Back of Hand: 99 m/s (range 72-176 m/s)


https://mcadams.posc.mu.edu/jfkhit.htm

One, you realize that Milicent Cranor says the neuromuscular-reaction theory is ridiculous, right?

Two, the response times you're citing are auditory startle reflex times, not muscle response times to the impact of a bullet. There's no damage to any tissue from an auditory stimulus, unlike when you have a bullet strike and damage a skull.

[Joe Elliott]

I will start with Martin Hay’s critique, which, among other things, exposes Dr. Alvarez’s concealment of ballistics tests information that contradicted his claims.

I haven’t heard of anything so low down since a Mr. Griffith’s concealment of ballistic tests information that contradicted his claims from Dr. Zacharko. I am shocked at Dr. Alvarez.

Notice, also, that Hay discusses the fact that Josiah Thompson’s conclusion that JFK’s head moves approximately 2 inches between Z312-313 is wrong, and that Thompson has acknowledged his error.

It is impossible for Thompson to acknowledge his error because these measurements were not made by him. It would be like me confessing my error in the Michelson–Morley experiment that falsely indicated that the speed of light was the same in all directions.

These measurements were made by physics graduate student William Hoffman, not Josiah Thompson. Josiah Thompson commissioned Hoffman for this work because he was better trained and had more experience making careful measurements. And no one knew about the neuromuscular spasm hypothesis back in the 1960’s so he had no motive to fake the results. In that sense, it is impossible to even get another such unbiased measurements taken again in the future.

The head moved forward between frames Z312 and Z313 in 1967. And it still moves forward today.

Yes Jerry, it does. But as they say in Michael’s favorite movie “After all tomorrow is another day”. Click on the link below to get an even clearer picture.

http://users.skynet.be/mar/Eng/Headshot/back&left-eng.htm#Sommet

[Michael T. Griffith]

I haven’t heard of anything so low down since a Mr. Griffith’s concealment of ballistic tests information that contradicted his claims from Dr. Zacharko. I am shocked at Dr. Alvarez.

You are not to be taken seriously, because you use dishonest arguments. The ballistics tests that I "concealed" from Dr. Zacharko were the irrelevant goat tests to which you keep clinging. You keep ignoring the fact that human and goat neurobiology and neurophysics are not the same. You keep ignoring Dr. Zacharko's detailed explanation of why no neurospasm could have caused the backward head movement. Etc., etc., etc.

It is impossible for Thompson to acknowledge his error because these measurements were not made by him. It would be like me confessing my error in the Michelson–Morley experiment that falsely indicated that the speed of light was the same in all directions.

These measurements were made by physics graduate student William Hoffman, not Josiah Thompson. Josiah Thompson commissioned Hoffman for this work because he was better trained and had more experience making careful measurements. And no one knew about the neuromuscular spasm hypothesis back in the 1960’s so he had no motive to fake the results. In that sense, it is impossible to even get another such unbiased measurements taken again in the future.

Thompson checked the measurements and believed they were accurate. He now realizes they were wrong, for the reasons he explains in his article (and which are quoted in my OP). I take it you have not read physicist Art Snyder's research on this issue, which research persuaded Thompson that he was wrong.

Yes Jerry, it does. But as they say in Michael’s favorite movie “After all tomorrow is another day”. Click on the link below to get an even clearer picture. http://users.skynet.be/mar/Eng/Headshot/back&left-eng.htm#Sommet

Yeah, and it looks like Organ is making the same mistake that Thompson and Hoffman made.

Frankly, I would be glad if the Zapruder film did show a 2.3-inch movement in 1/18th/second just before the backward head snap begins, because that would be a reversal of movement that could not be caused by gunfire on this planet and would be further evidence of alteration in the Zapruder film.

It might be worthwhile to read Dr. Thompson's entire section on the supposed 2.3-inch forward movement in Z312-313:

Many years ago, I concluded that the President had been struck twice in the head within approximately one-ninth of a second between Zapruder frames 312 and 314. The first shot pushed his head forward approximately two inches between frames 312 and 313. The second shot bowled him over backwards and to the left.

Although it remained a remarkable coincidence that two shots would arrive on their target from different locations and distances within one-ninth of a second, this conclusion was compelled by what I measured on sequential frames of the Zapruder film. Using two points on the back of the limousine, I measured the distance between these points and the back of the President's head. Between frames 312 and 313, this distance increased dramatically by two inches. The only way to explain this extraordinary acceleration of the President's head was to suppose he had been hit by a bullet fired from the rear.

In the years since those measurements were made, I've learned I was wrong. Z312 is a clear frame while Z313 is smeared along a horizontal axis by the movement of Zapruder's camera. The white streak of curb against which Kennedy's head was measured is also smeared horizontally and this gives rise to an illusory movement of the head. Art Snyder of the Stanford Linear Accelerator staff persuaded me several years ago that I had measured not the movement of Kennedy's head but the smear in frame 313. The two-inch forward movement was just not there.

Since that time, David Wimp has made extremely careful measurements on the film. He has determined that the upper bodies of the President and all other occupants of the limousine begin moving forward at about Z308. Except for the President, all the others keep moving forward until at least Z317. The President, of course, is bowled over backward and to the left. This retrograde motion begins at about Z314. (https://www.maryferrell.org/pages/Essay_-_Bedrock_Evidence_-_part_3.html)

[Joe Elliott]

You are not to be taken seriously, because you use dishonest arguments. The ballistics tests that I "concealed" from Dr. Zacharko were the irrelevant goat tests to which you keep clinging. You keep ignoring the fact that human and goat neurobiology and neurophysics are not the same. You keep ignoring Dr. Zacharko's detailed explanation of why no neurospasm could have caused the backward head movement. Etc., etc., etc.

The most important evidence we have is video of an animal showing the neuromuscular spasm. We only have the one video, because it’s the only video I know that shows an animal being shot by a rifle bullet through the head.

If you’re going to get me to listen to an expert, that expert had better know the best pieces of evidence that both sides have. He better know all about the best piece of evidence that our side has. He doesn’t have to accept it, but he damm well better know about it. Otherwise, I’m not listening.

I don’t want you to decide what evidence is relevant or not. I want the “expert” to decide. And to hear the “expert’s” reasons on why they feel this evidence is relevant or not.


And as far as that not being relevant, the U. S. Army took film of, as memory serves me, 10,000 goats (who were drugged unconscious) being shot in various parts of the body. This was not done because some general in the Pentagon believed that the wars of the future were going to be fought by goats. These tests were commissioned to get insight into what happens at the moment a human soldier was wounded. It might give insight on how to better treat the wounded. Or develop better bullets. Somebody thought these tests were relevant.

The army figured accurately that animals can be used for this purpose. Afterall, the military had lots of experience, not in World War II but in previous wars, were animals, mostly horses, were exposed to enemy fire and observed that the effects of bullets on animals did not seem to be vastly different than the effects on humans.

Perhaps humans and animals would react greatly differently to rifle bullets to the head but, up until 1963, no one thought so.

Questions:
Can you quote an expert who before 1963 said that humans and animals would react differently to a rifle bullet through the brain or was this an argument first developed after 1963 to bolster certain arguments on the Kennedy assassination?

Was this something that was well known before then or was it something that was first “discovered” afterwards.

Thompson checked the measurements and believed they were accurate. He now realizes they were wrong, for the reasons he explains in his article (and which are quoted in my OP).

Yeah, and it looks like Organ is making the same mistake that Thompson and Hoffman made.

Yeah. I have the same problem. A lot of us LNers have that. Trusting what my eyes tell me and not what you or Art Snyder or Thompson tell me. I’ll have to get my eyes checked out by an optometrist.

I take it you have not read physicist Art Snyder's research on this issue, which research persuaded Thompson that he was wrong.

The head seemed quite still from z304 up through z312, according to Hoffman’s careful measurements. I don’t see why these “distortions” would kick in right at z313, and cause JFK’s head to appear to move forward, while causing Jackie’s head to appear to stay still, as did JFK’s up until z313.

Does Snyder explain that?

Frankly, I would be glad if the Zapruder film did show a 2.3-inch movement in 1/18th/second just before the backward head snap begins, because that would be a reversal of movement that could not be caused by gunfire on this planet and would be further evidence of alteration in the Zapruder film.

No, you wouldn’t. You hope that there is no 2.3-inch forward movement, indicating a shot from the rear. You would wish the film would show itself to be a fake in some other way, any other way than that. That is why you argue there is no 2.3-inch forward movement.

It might be worthwhile to read Dr. Thompson's entire section on the supposed 2.3-inch forward movement in Z312-313:

Not unless he explains why this “distorted-apparent” movement is not there during z304-z312, but only kicks in at z313.

Not unless he explains why this “distorted-apparent” movement only effect JFK’s head but not Jackie’s?

You want me to except that Dr. Thompson’s arguments that the forward movement is not real. But to not accept his arguments that the film is real.

If Thompson can’t tell that the Zapruder film is an obvious fake, why are you interested on his opinion on if the head appears to move forward at z313? I would have thought that, for that reason alone, you wouldn’t be interested in what else Thompson thought of the film.


But I have some questions for you that don’t require any research. You can answer them within 5 minutes just using reasoning.


Questions:

Why should Dr. Chambers, Dr. Mantik and you claim that the fast-neuromuscular spasm in a human has been established as being impossible, or highly unlikely, when this can only be established as impossible or unlikely by running tests on human subjects?

Wouldn’t one have to run these experiments first, before making these claims?

If these tests cannot be run, shouldn’t we withhold judgment?

Or is it more scientific to just guess?