Users Currently Browsing This Topic:
0 Members

Author Topic: JFK's Head Snap and the Implausible Jet-Effect and Neurospasm Theories  (Read 26516 times)

Offline Tim Nickerson

  • Hero Member
  • *****
  • Posts: 1824
Advertisement
No. I am not measuring time to the nearest frame, but to the nearest tenth of a frame. Each tenth of a frame is roughly 5 milliseconds long.

z-312.0 is when the shutter opens for frame 312. Roughly 27 milliseconds later the shutter closes at z-312.5. Frame z-312 shows images from time z-312.0 through z-312.5.

I believe the bullet struck at z-312.5, or there abouts, right when the shutter closed or very shortly after. Below is a possible, approximate, time scale. Basically, my best very rough estimate:

Vis    Time    Time
able    in      in
        sec.    Zap         Event
----  -----    -------     ---------------
       0.000   z-312.5   Shutter closes.
       0.000   z-312.5   Bullet impact.
       0.001   z-312.5   Bullet leaves head,
                                momentum has been deposited into head,
                                the head starts moving at a steady speed forward.
       0.027   z-313.0   Shutter opens.
vis   0.027   z-313.0       Head is now 1 inch in front of z-312 position, same steady speed
vis   0.055   z-313.5       Head is now 2 inches in front of z-312 position, same steady speed
       0.055   z-313.5   Shutter closes.
       0.077   z-314.0   Shutter opens.
vis   0.082   z-314.1   Neuromuscular spasm commences,
vis                                 Head starts moving back, initially slowly.
vis   0.110   z-314.5   Head is now 1.5 inches ahead of 312.5 position.
       0.110   z-314.5   Shutter closes.

“vis” refers to events that may be visible, because the shutter was open.

Again, this is not to represent exact locations. I don’t have the timing down to the nearest 5 milliseconds. Just a possible scenario consistent with what the Zapruder film shows and William Hoffman’s data.

In this scenario, the neuromuscular spasm started 82 milliseconds after the bullet impact. The real time  of reaction could be a little more, or less.

Thanks for clarifying.

I think that we have been wrongly assuming that the start of the backward head movement was the initiation of the neuromuscular spasm. That backward motion was from the jet effect and the neuromuscular reaction initiated a couple of frames later.

JFK Assassination Forum


Offline Tim Nickerson

  • Hero Member
  • *****
  • Posts: 1824

Then please explain what Sturdivan meant when he stated in pretty plain English that in "real time" the reaction took about 1,000 milliseconds. Is "real time" really not real time? Did Sturdivan just egregiously misspeak?

From "the time that the bullet struck" to the "terminus of the decerebrate reaction" took about 1,000 milliseconds. That's what Sturdivan was saying.
« Last Edit: June 30, 2020, 11:27:22 PM by Tim Nickerson »

Offline Tim Nickerson

  • Hero Member
  • *****
  • Posts: 1824
First, let's read Sturdivan again:

"About one-tenth of a second after the shot, the goat goes into what one Biophysics Lab colleague, Bob Clare, described as a "swan dive", which results in him leaping out of the back part of the sling." -- page 165, The JFK Myths: A Scientific Investigation of the Kennedy Assassination, by Larry Sturdivan

https://www.amazon.com/JFK-Myths-Scientific-Investigation-Assassination/dp/1557788472

JFK Assassination Forum


Offline Joe Elliott

  • Hero Member
  • *****
  • Posts: 1656

Actually, I don’t think Mr. Sturdivan made an ambiguous statement.

Quote
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.

What is the definition of “decerebrate rigidity”?

I looked it up and it is as follows:

decerebrate rigidity a posture found in those with lesions of the upper part of the brainstem. . .

“decerebrate rigidity” is a posture. It is a posture that one assumes, as a result of damage of the brainstem, or severe bilateral lesions of the cerebrum.

When did the goat assume this posture? One second after impact. Not, it started to assume this posture after one second. It means it had reached this posture, with the limbs sprayed out, one second after impact.
« Last Edit: June 30, 2020, 11:59:00 PM by Joe Elliott »

Offline Joe Elliott

  • Hero Member
  • *****
  • Posts: 1656

From "the time that the bullet struck" to the "terminus of the decerebrate reaction" took about 1,000 milliseconds. That's what Sturdivan was saying.

Clearly yes. The end of the decerebrate reaction took place 1,000 milliseconds after impact. The “decerebrate rigidity”, or what I call “the decerebrate posture” was reached 1 second after impact.

decerebrate rigidity: a posture found in those . . .

A animal does not reach this posture the instant they start moving. They reach this posture after the movement is done. Like after 1 second.
« Last Edit: July 01, 2020, 12:08:37 AM by Joe Elliott »

JFK Assassination Forum


Offline Michael T. Griffith

  • Hero Member
  • *****
  • Posts: 927
Okay, let us back up and summarize a bit because you two, Joe Elliott and Tim Nickerson, keep jumping around when you are caught in errors and when you cannot provide answers for evidence that contradicts your claims.

* You did not understand that Sturdivan was saying that the neuromuscular reaction was a decerebrate reaction. Not all neuromuscular reactions are decerebrate reactions, but Sturdivan recognized that the goat’s reaction was decerebrate. You, Joe Elliott, erroneously assumed that Sturdivan was describing two sets of reactions, that the decerebrate reaction was separate from the neuromuscular one, that the decerebrate reaction followed the neuromuscular one, and that the decerebrate reaction alone did not begin until about 1,000 milliseconds after bullet impact—in real time.

* If Sturdivan had said that in the 24 fps film the reaction started in X milliseconds but that in the 2400 fps film it started in Y milliseconds, that would be one thing. But he noted that the 24 fps film was “real time.” You can play a real-time film in slow motion to determine how soon a given reaction starts after a stimulus. You do not just play it at normal playback speed and guess. You can slow it down considerably, and Sturdivan obviously did this. He certainly would not have just guessed after merely viewing the film at normal playback speed.

* The goat’s reaction is nothing like JFK’s reaction. JFK’s arms don’t splay and his back does not arch, unlike the goat’s limbs and back. Furthermore, the goat’s head and neck do not jerk backward, unlike JFK’s head and upper body.

* There is no large explosion of particulate matter from the goat’s head, whereas such an explosion on JFK’s head is obvious in the Zapruder film.

* For the last week or two, you, Joe Elliott, have insisted that JFK’s head begins to move backward 55 milliseconds after bullet impact. You said this over and over. But, well, now that you realize that you need that backward movement to start much later, suddenly you are suggesting that it could have occurred 82 milliseconds after bullet impact, an increase of 48%--that’s a big difference.

* The only two neuroscientists who have commented on JFK’s backward head snap (Robert Zacharko and Joseph Riley) have said that the neuromuscular-reaction theory is “nonsense,” “implausible,” etc., etc., and one of them, Dr. Riley, dismisses the goat test as irrelevant.

* Most of the physicists who have commented on JFK’s backward motion have rejected the neuromuscular-reaction theory. Those few who have not rejected it outright have declined to cite it as the only cause of JFK’s backward movement. Even the HSCA experts hedged their bets and said the movement was caused by one or the other or by a mix of both. Physicists Mantik, Costella, Chambers, Snyder, and Riddle insist that neither phenomena could cause a person’s body to behave the way Kennedy’s body behaves in the Zapruder film from Z312-321 but that this movement must have been caused by contact with an external force in obedience to the laws of physics.

* Human neuromuscular reactions that involve more than an eyelid or two fingers, and that are not the result of auditory stimulus and that do not involve damage to the body, are not going to occur in 55 milliseconds, much less in 40 milliseconds. Not on this planet. The fastest time for such a reaction might be—just might be—100 milliseconds, but more likely 200-600 milliseconds in the majority of such cases.

Offline Joe Elliott

  • Hero Member
  • *****
  • Posts: 1656

*splayed out

--  MWT  ;)

PS  Great post!

Hey, you would be praying, maybe even splaying, if something like that happened to you.  :)

JFK Assassination Forum


Offline Joe Elliott

  • Hero Member
  • *****
  • Posts: 1656

You know Tim, it doesn’t matter if the goat starts moving after 40 or 140 milliseconds. Why? Because we can always say the apparent motion during z313-314 was nothing more than camera blur. If the CTers can claim a two inch movement was camera blur, I don’t know why we couldn’t claim the same for a half inch movement.

Fortunately, we don’t have to resort to the desperate arguments of a Josiah Thompson, who said it was the blurriness of z313 that made it appear that the head had moved forward. And the blurriness of z314. And the blurriness of z315. Why as soon as one accepts the notion that all three frames are blurry, the forward movement problem just goes away. Not until frame z316 could he breathe easy again.