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

[Michael T. Griffith]

Ah-ha! I knew it! I just knew it! I knew there was something wrong with Joe Elliott’s description of the 1948 U.S. Army ballistics test film of a goat being shot in the head. When I pointed out that the backward movement of JFK’s head in the Zapruder film begins too quickly (1/18th/second or 55 milliseconds) to have been caused by a neuromuscular reaction, Elliott claimed that the goat film proved otherwise:

. . . there is a video of a goat which was shot through the head which causes its body to move pretty forcibly. . . . The goat starts moving its body 40 milliseconds after the bullet struck. So, the very next frame, roughly 55 milliseconds later, JFK’s head starts moving as well.

Leaving aside the important fact that the goat’s reaction movements are very different from JFK’s reaction movements, on a hunch, I reviewed ballistics expert Larry Sturdivan’s HSCA testimony on the 1948 goat ballistics test, which I had not read for at least 20 years. I discovered that the film that Elliott has been citing was not shot in real time, and that the film that was shot in real time shows that the goat did not begin to react until about 1,000 milliseconds after the bullet’s impact.

The film that Elliott has been citing was taken at 2,400 frames per second (fps). At that film speed, yes, the goat begins to react right around 40 milliseconds after the bullet hits the goat’s head. But, as Sturdivan explained to the HSCA, when you view the real-time film of the same goat test, the one taken at 24 fps, the goat’s reaction “takes place about a second after the shot and then slowly dissipates and you will see the goat slump” (1 HSCA 416).

“About a second” equals about 1,000 milliseconds. There are 1,000 milliseconds in 1 second. So if the goat began to react “about a second after the shot,” then it began to react about 1,000 milliseconds after the shot. We can reasonably infer that when Sturdivan said "about a second," he meant 800-1100 milliseconds, or perhaps 800-1000 milliseconds, or perhaps 900-1000 milliseconds.

Sturdivan was nice enough to explain that the 24 fps film was a “normal” view and “real time”:

The first sequence will be a normal 24-frame-per-second view of this. This is a real time. (1 HSCA 416)

Sturdivan then explained that the second sequence, which is the one that Elliott has been citing, was taken at 2,400 fps, and that in that 2,400-fps film, yes, the goat’s reaction begins about 40 milliseconds, or “four one-hundredths,” after bullet impact:

Now, this sequence will show the same goat, exactly the same shot, but in this case the movies are taken at 2,400. frames per second. . . .

Four one-hundredths of a second after that impact then the neuromuscular reaction that I described begins to happen. (1 HSCA 416-417)

“Mystery” solved! I say “mystery” because I was frankly a bit baffled by the seemingly impossible speed of the goat’s reaction in the film that Elliott cited. I attributed it to the many differences between goat and human neurobiology and neurophysics (not to mention that the goat’s reaction movements differ markedly from JFK’s). But I also read that goat/sheep/dog/horse and human neuromuscular reaction times are similar—not identical, but similar. Every source I checked said that the fastest human neuromuscular reactions ranged in speed from 100 milliseconds in a few cases to around 200-600 milliseconds in most cases.

When the HSCA asked forensic pathologist Dr. Cyril Wecht about the neuromuscular-reaction theory, he rejected it because he said that the fastest time for such a reaction was about 100 milliseconds, but JFK's head starts to move just 55 milliseconds after bullet impact. Dr. Wecht's statement about human neuromuscular reaction times was correct. A study published in Scientific American found that the absolute fastest neuromuscular reaction time was 100 milliseconds, with the slower ones being 400-600 milliseconds (https://www.scientificamerican.com/article/bring-science-home-reaction-time/). And remember that we're talking about a reaction that involved moving Kennedy's head and upper body, not the flick of two fingers or an eyelid, and not a startle reflex from auditory simulation.

Anyway, to recap: The goat film that Elliott has been citing was not filmed in real time but in 2,400 fps. The real-time film of the same goat and the same test shows that the goat’s reaction did not begin until about 1,000 milliseconds after the bullet hit the skull. Therefore, the goat film argues powerfully against the theory that JFK’s backward movement could have been caused by a neuromuscular reaction. Also, in the Zapruder film, JFK's backward movement begins just 55 milliseconds after bullet impact, far too soon to have been caused by a neuromuscular reaction--the absolute fastest human neuromuscular reaction time is 100 milliseconds, and the normal range for such reactions is from 200 to 600 milliseconds.

[Tim Nickerson]

When I pointed out that the backward movement of JFK’s head in the Zapruder film begins too quickly (1/18th/second or 55 milliseconds) to have been caused by a neuromuscular reaction, Elliott claimed that the goat film proved otherwise:

You are getting that (1/18th/second or 55 milliseconds) from Chambers. He is wrong. He has Kennedy being hit at Z313 and then noticeable moving backward in the next frame. Kennedy was hit between Z312 and Z313 and the ITEK report has Z315 as being the frame where Kennedy's backward movement is clearly in progress. So, the response time was 110 milliseconds or more.

[Michael T. Griffith]

You are getting that (1/18th/second or 55 milliseconds) from Chambers. He is wrong. He has Kennedy being hit at Z313 and then noticeable moving backward in the next frame. Kennedy was hit between Z312 and Z313 and the ITEK report has Z315 as being the frame where Kennedy's backward movement is clearly in progress. So, the response time was 110 milliseconds or more.

Huh?! So now JFK's head doesn't start to move backward until 315?! You'd better go back and read what Elliott himself has acknowledged on this point, not only in this thread but in the his own thread on Dr. Zacharko.

We're not talking about when the head movement is "clearly in progress" but when it begins, and it begins at Z313. Even Nicholas Nalli, in the latest attempt to salvage the jet-effect theory, says, "In Z313 the catastrophic effect of the energy deposit from a supersonic projectile passing through a human head is clearly evident. . . . showing both the initial 'forward snap' of the President's head from Z312 to Z313, along with the 'rearward lurch' from frames Z313 to Z322." Nobody but you denies this.

[Tim Nickerson]

Huh?! So now JFK's head doesn't start to move backward until 315?! You'd better go back and read what Elliott himself has acknowledged on this point, not only in this thread but in the his own thread on Dr. Zacharko.

We're not talking about when the head movement is "clearly in progress" but when it begins, and it begins at Z313. Even Nicholas Nalli, in the latest attempt to salvage the jet-effect theory, says, "In Z313 the catastrophic effect of the energy deposit from a supersonic projectile passing through a human head is clearly evident. . . . showing both the initial 'forward snap' of the President's head from Z312 to Z313, along with the 'rearward lurch' from frames Z313 to Z322." Nobody but you denies this.

It's not just me that denies it. The ITEK panel of photo and film analysis experts denied it as well.

[Joe Elliott]

You are getting that (1/18th/second or 55 milliseconds) from Chambers. He is wrong. He has Kennedy being hit at Z313 and then noticeable moving backward in the next frame. Kennedy was hit between Z312 and Z313 and the ITEK report has Z315 as being the frame where Kennedy's backward movement is clearly in progress. So, the response time was 110 milliseconds or more.

Hello Tim

You are right. I myself refer to it as 55 millisecond delay, but it was probably longer. But I don’t know about a full 110 milliseconds.

Defining time as z-312.0 – the camera shutter first opens, z-312.5 – the shutter closes, the head was probably struck about z-312.6, giving the head about 45 milliseconds to move an inch forward by z-313.0. By z-313.5, it was now just over 2 inches forward. By z314.0, it might still be 2 inches forward, it is hard to tell. But by 314.5, the head definitely started moving backwards and had already moved half an inch.

I would guess the backwards movement may have started over the interval z-312.6-314.0, or 75 milliseconds. Perhaps over the interval z-312.5-314.0 or 80 milliseconds. But not a lot more than that. If the delay was a full 110 milliseconds, by the times of z-314.5, the head would still have been 2 inches ahead of its z-312.5 position.

Joe

[Tim Nickerson]

Hello Tim

You are right. I myself refer to it as 55 millisecond delay, but it was probably longer. But I don’t know about a full 110 milliseconds.

Defining time as z-312.0 – the camera shutter first opens, z-312.5 – the shutter closes, the head was probably struck about z-312.6, giving the head about 45 milliseconds to move an inch forward by z-313.0. By z-313.5, it was now just over 2 inches forward. By z314.0, it might still be 2 inches forward, it is hard to tell. But by 314.5, the head definitely started moving backwards and had already moved half an inch.

I would guess the backwards movement may have started over the interval z-312.6-314.0, or 75 milliseconds. Perhaps over the interval z-312.5-314.0 or 80 milliseconds. But not a lot more than that. If the delay was a full 110 milliseconds, by the times of z-314.5, the head would still have been 2 inches ahead of its z-312.5 position.

Joe

Just to make sure that I'm understanding you right, by Z-314.5 you mean what we know as Z315?

[Joe Elliott]

Hi Joe,

I'm trying to find the scientific data on the goat reflex time but can't, can you tell me where to find it. Thanks

https://mcadams.posc.mu.edu/russ/jfkinfo/hscastur.htm

Has the testimony of Larry Sturdivan for the HSCA.

Below he explains the film of the goat shot through the brain back in U. S. Army tests made in 1948.

Mr. STURDIVAN - Let me stop the film here and explain what is going to happen. This goat is standing with his horns taped to a bar, only to preserve the aiming point of the bullet, which will come in from the right this time, not from the left, from the right, will strike the goat between the eyes. The black tape is there only to show the relative motion which we were presuming was going to be small. I should say they were presuming, since this film was taken back around 1948, I believe. The first sequence will be a normal 24-frame-per-second view of this. This is a real time. First, we will observe the neuromuscular reaction, the goat will collapse then, and by the wiggling of his tail and the tenseness of the muscles we will see what I think has sometimes been called the decerebrate rigidity, and that takes place about a second after the shot and then slowly dissipates and you will see the goat slump, obviously dead. The decerebrate reaction and terminus of the decerebrate reaction. Now, this sequence will show the same goat, exactly the same shot, but in this case the movies are taken at 2,400 frames per second. I forgot to mention that the bullet is a .30-caliber military bullet. If I can stop this at an appropriate point. Now, if you will look up at the forehead of the goat you may see a very small white spot, which was not visible on the last frame. If you can't, don't worry about it. What it is is the bullet entering the head of the goat. And if I can make sure that I have it going forward now. Four one-hundredths of a second after that impact then the neuromuscular reaction that I described begins to happen; the back legs go out, under the influence of the powerful muscles of the back legs, the front legs go upward and outward, that back arches, as the powerful back muscles overcome those of the abdomen. That was it. Now, we will show a sequence here which I think will prove my assertion. This goat was shot under identical circumstances as the last one was except he is dead before the shot. The straps that you see are suspending him but he is free to swing. If you pushed on his head he would swing gently back and forth in this rack. The bullet will come in from the right, again moving toward the left. In this case, the bullet is deflected as it goes out of the skull, and impacts on the goat near the spine, and then as you may have been able to see very dimly right behind the goat the bullet emerges from the back. It has deposited another few pound-feet per second of momentum in this goat. And then let me run it on through at real speed so you can see how much displacement that goat is given by the momentum that is deposited by the bullet. If we can bring the house lights up, it will run for another 5 minutes without showing any movement in the goat.

. . .

Mr. FAUNTROY - That explains the explosion?
Mr. STURDIVAN - Yes, sir, the explosion effect and the subsequent neuromuscular reaction that occurs roughly four one-hundredths of a second later.