Debunking the "Jet Effect"?

[Andrew Mason]

Although I'm just a humble layman I'm willing to learn and don't want to pass up this chance to learn from someone who rubs shoulders with Nobel prize winners.
So, what exactly is Alvarez saying? Just a few lines would be helpful. What is the Jet Effect according to Alvarez? I'm lucky that you're such an expert.
Does it explain why in none of the examples of the Jet Effect in action you show over and over again that there is no initial movement away from the shooter as we see in the Z-film?
Have you even noticed that?


PS: I dealt with the bone that can be seen flying into the limo already

Alvarez is simply explaining why an exploding exit wound can impart much more momentum to the body in the direction opposite to the direction of ejected matter than the momentum imparted by the bullet in the direction of the bullet. 

This can more easily be shown with a soft bullet that flattens on impact and then compresses material inside a container building up pressure inside that is suddenly released explosively when container ruptures.  The difficulty is in showing jet effect when using a jacketed bullet.

Chad Zimmerman showed jet effect using his MC firing 6.5 mm jacketed bullet at a turkey to which he had strapped pork ribs on the bullet entry side (left):

[Steve Barber]

Although I'm just a humble layman I'm willing to learn and don't want to pass up this chance to learn from someone who rubs shoulders with Nobel prize winners.
So, what exactly is Alvarez saying? Just a few lines would be helpful. What is the Jet Effect according to Alvarez? I'm lucky that you're such an expert.
Does it explain why in none of the examples of the Jet Effect in action you show over and over again that there is no initial movement away from the shooter as we see in the Z-film?
Have you even noticed that?


PS: I dealt with the bone that can be seen flying into the limo already

   Hi Dan,

     Could you direct me to the bone fragment you mention dealing with?  I was the first point this out to the public several years ago.  This same fragment can be seen toppling to the floor, after striking either Nellie connaly's back, or bouncing off the top portion of her jump seat, which I also pointed out and Paul Seaton years ago, who then made a GIF of it and posted it on hi Website. 

[Steve Barber]

Does deceleration of the limousine, moments before & during the fatal headshot, disprove the so called "Jet Effect" & explains why the President & everyone else in the vehicle moved slightly forward? In this video by Gil Jesus, between frames 312 & 313 specifically, we can see this taking place. Thoughts?

Also this debunking of Lattimer and Alvarez -

 Gil Haysus doesn't know his head from a melon.  The car did not nearly come to a virtual hault.  The Zapruder, Nix, Muchmore and Bronson films all prove this.  And no one else moved " slightly forward" at the time the fatal shot struck President Kennedy, due to decceleration of the car.  The Connally's and Greer and Kellerman were already moving about prior to the fatal shot.  This is as bad as Robert Harris' 20-plus years of claiming that "Everyone in the limousine 'ducked' at Z-271" because, according to him, a shot was fired--and that Mrs. Kennedy   raised from her seat and started to crawl onto the trunk lid to grab/grabbed head matter-when nothing could be further from the truth.   Or, better still, that "Greer shot JFK".   

[Dan O'meara]

   Hi Dan,

     Could you direct me to the bone fragment you mention dealing with?  I was the first point this out to the public several years ago.  This same fragment can be seen toppling to the floor, after striking either Nellie connaly's back, or bouncing off the top portion of her jump seat, which I also pointed out and Paul Seaton years ago, who then made a GIF of it and posted it on hi Website.

Hi Steve,
In Reply#16 I explained my take on the dynamics of JFK's head wound which included this:

"A massive piece of scalp, torn at the crown of the head, is blasted to the right side of the head by the pressure wave and opens up the right side of the head as if it were on a hinge near the right ear. On the inside of this massive piece of scalp there are a couple of very large pieces of skull. On piece remains attached, as can be seen in the Z-film, the other piece comes loose as is thrown forward as the scalp opens up at tremendous speed."

John believes that this piece of skull being blown into the limo is something to do with the Jet Effect (Reply#19). Whereas I believe it is thrown from the massive flap of scalp that is blasted down the right side of JFK's head as a result of the explosion of the top of his head.

So, that was you who spotted the piece of skull bone dancing around in the back of the limo?
That was an excellent find as I remember.
It is the same piece of skull John has highlighted in Reply #19

[Dan O'meara]

In Z313–Z316 (Figure 5) an expulsion of mass (i.e., the “jet”) is observed resulting from an explosion caused in the wake of a high-speed projectile passage. Although the explosion emanates over a range of angles within a roughly conical cloud, the explosion of mass nevertheless is observed to escape from the single large wound on the right front of the President's head (described in the Autopsy Report [3, p. 540] and in Lattimer et al. [12]). Note that this is not a universal occurrence—depending on the firearm, bullet, target, entry and exit locations, etc., different “explosions” can result.8 But in this case a directional expulsion of mass is observed in the Zapruder Film. It is this escape of the explosion from one end of the cavity, but not the other, that creates a directional component to the mass expulsion, and thus a “jet.” In the author's study of the high resolution digital frames, it was noticed that there were particles that maintained their size and shape over adjacent frames, unlike the rest of the material in the cloud. It was subsequently realized that these were in fact solid skull fragments within a cloud of non-solid tissue, and the author has since learned that previous investigators had already ascertained this [52], [12], [7]. But here it is noted that because these solid particles hold together in flight, they can effectively act as tracers, whereby one may estimate the velocity of the ejected mass within the explosion (assuming they travel at the same velocity as the rest of the bulk material).
https://www.sciencedirect.com/science/article/pii/S2405844017331882

In Z313–Z316 (Figure 5) an expulsion of mass (i.e., the “jet”) is observed

There is no "jet" shown in frames z315 or z316

the explosion of mass nevertheless is observed to escape from the single large wound on the right front of the President's head

This is possibly the most important lie and needs to be dealt with as you keep repeating it.
There is no injury to the right front of JFK's head. The injury is clearly to the top of his head. Your famous GIF shows this in graphic detail:



There is no point in getting into some kind of pantomime "oh yes it is, oh no it isn't" routine.
Anyone can see that the injury extends across the top of the head. The right front of the head is perfectly in tact.
It's not up for discussion but I've not the slightest doubt you will see what you want to see.
The pressure wave blasts through the top of JFK's head as seen below:



"It was subsequently realized that these were in fact solid skull fragments within a cloud of non-solid tissue, and the author has since learned that previous investigators had already ascertained this [52], [12], [7]. But here it is noted that because these solid particles hold together in flight, they can effectively act as tracers,"

 
Solid particles that hold together in flight and can be used as tracers?
This is clearly what Alvarez is talking about:



If you believe he's talking about something else please demonstrate what you think it is.
If this is indeed the "solid particles" he is talking about, I would really like to hear about how these are emanating from the front right of the head.
How can he believe this "jet" is coming from the front right of the head?

Yeah no worries Dan, Alvarez and I go way back.
Here following is some simple math to wrap your head around, good luck!



Yes, indeed you are!

JohnM

I've read somewhere that in his calculations Alvarez never included the dominant acting force - that of the bullet as it flattened and fragmented against the skull driving JFK's head forward. He never accounted for a piece of the fragment travelling along the skull in a tangential manner imparting even more forward momentum to the head and he never accounted for the second interaction with the skull as the bullet fragments exited, creating even more forward momentum. He completely forgot to include the dominant acting force, the silly Nobel prize winner doing a study funded by the government.
This is what causes JFK's head to shoot forward, as you've so ably demonstrated:



But note, in none of the images you've posted showing the Jet Effect in action do we see this initial rapid forward movement.
So, they don't really show us what you would like to believe they do.
They're not really equivalent to what we see in the Z-film:





It's all a bit of smoke and mirrors really.
But if you want to carry on believing that JFK's head acted like a balloon released then you crack on.

PS: Why does the link you posted take me to a paper by Nicholas Nalli?

[John Mytton]

In Z313–Z316 (Figure 5) an expulsion of mass (i.e., the “jet”) is observed

There is no "jet" shown in frames z315 or z316

the explosion of mass nevertheless is observed to escape from the single large wound on the right front of the President's head

This is possibly the most important lie and needs to be dealt with as you keep repeating it.
There is no injury to the right front of JFK's head. The injury is clearly to the top of his head. Your famous GIF shows this in graphic detail:



There is no point in getting into some kind of pantomime "oh yes it is, oh no it isn't" routine.
Anyone can see that the injury extends across the top of the head. The right front of the head is perfectly in tact.
It's not up for discussion but I've not the slightest doubt you will see what you want to see.
The pressure wave blasts through the top of JFK's head as seen below:



"It was subsequently realized that these were in fact solid skull fragments within a cloud of non-solid tissue, and the author has since learned that previous investigators had already ascertained this [52], [12], [7]. But here it is noted that because these solid particles hold together in flight, they can effectively act as tracers,"

 
Solid particles that hold together in flight and can be used as tracers?
This is clearly what Alvarez is talking about:



If you believe he's talking about something else please demonstrate what you think it is.
If this is indeed the "solid particles" he is talking about, I would really like to hear about how these are emanating from the front right of the head.
How can he believe this "jet" is coming from the front right of the head?

I've read somewhere that in his calculations Alvarez never included the dominant acting force - that of the bullet as it flattened and fragmented against the skull driving JFK's head forward. He never accounted for a piece of the fragment travelling along the skull in a tangential manner imparting even more forward momentum to the head and he never accounted for the second interaction with the skull as the bullet fragments exited, creating even more forward momentum. He completely forgot to include the dominant acting force, the silly Nobel prize winner doing a study funded by the government.
This is what causes JFK's head to shoot forward, as you've so ably demonstrated:



But note, in none of the images you've posted showing the Jet Effect in action do we see this initial rapid forward movement.
So, they don't really show us what you would like to believe they do.
They're not really equivalent to what we see in the Z-film:





It's all a bit of smoke and mirrors really.
But if you want to carry on believing that JFK's head acted like a balloon released then you crack on.

PS: Why does the link you posted take me to a paper by Nicholas Nalli?

There is no injury to the right front of JFK's head.

You can't be serious, your so wedded to your fantasy that you can't see reality.

The Dealey Plaza eyewitnesses who were actually there, all describe the exact same explosion on the right side.



The Zapruder film shows a giant exposed bone flap on Kennedy's right side.



The Autopsy photo shows a huge wound on the right side

 

The injury is clearly to the top of his head. Your famous GIF shows this in graphic detail:

Yes, no one ever denied that there is a wound at the right front part at the top Kennedy's head but as shown above, the wound wraps around to the front right side. Kennedy was not shot from behind and below, he was shot from high and behind therefore the main momentum of the bullet went forward and exited on the front right side as seen by the Dealey Plaza eyewitnesses shown above and the Zapruder film and the autopsy photos.
I really don't believe that this needs to be spelt out.

But note, in none of the images you've posted showing the Jet Effect in action do we see this initial rapid forward movement.
So, they don't really show us what you would like to believe they do.

Huh? We aren't talking about the original impact but the subsequent effect cause by the jet effect.

In closing, you see a couple of bone fragments which exploded forward out the top of the right side and somehow equate that with what you perceive to be the main driver of the jet effect and while these bone fragments would have a vector force, the overwhelmingly main vector force exited the front right side. Alvarez himself says and I agree that there was an "explosion that emanates over a range of angles within a roughly conical cloud, the explosion of mass nevertheless is observed to escape from the single large wound on the right front of the President's head"

Btw since you obviously agree that Kennedy was shot from behind, what do you believe caused Kennedy's back and to the left motion?

JohnM

[Dan O'meara]

You can't be serious, your so wedded to your fantasy that you can't see reality.

The Dealey Plaza eyewitnesses who were actually there, all describe the exact same explosion on the right side.



The Zapruder film shows a giant exposed bone flap on Kennedy's right side.



The Autopsy photo shows a huge wound on the right side

 

Yes, no one ever denied that there is a wound at the right front part at the top Kennedy's head but as shown above, the wound wraps around to the front right side. Kennedy was not shot from behind and below, he was shot from high and behind therefore the main momentum of the bullet went forward and exited on the front right side as seen by the Dealey Plaza eyewitnesses shown above and the Zapruder film and the autopsy photos.
I really don't believe that this needs to be spelt out.

Huh? We aren't talking about the original impact but the subsequent effect cause by the jet effect.

In closing, you see a couple of bone fragments which exploded forward out the top of the right side and somehow equate that with what you perceive to be the main driver of the jet effect and while these bone fragments would have a vector force, the overwhelmingly main vector force exited the front right side. Alvarez himself says and I agree that there was an "explosion that emanates over a range of angles within a roughly conical cloud, the explosion of mass nevertheless is observed to escape from the single large wound on the right front of the President's head"

Btw since you obviously agree that Kennedy was shot from behind, what do you believe caused Kennedy's back and to the left motion?

JohnM

I suppose I just have to keep explaining it to you over and over again.
When JFK's head exploded we see pieces of skull being blown from the very top of his head, not the front as you and Alvarez (or Nalli) keep insisting. In an earlier Reply you posted this:

This high contrast image of Zapruder frame 313 shows a clear expulsion of matter out the front.



It is your (and Alvarez's) understanding that this image is showing an expulsion of matter "out the front".
It does not.
As I have clearly demonstrated with the graphic below, the expulsion of matter, that you believe is coming "out the front" is actually coming out of the top of JFK's head, AND FROM THE BACK HALF OF HIS HEAD. The yellow line is the center-line of JFK's head:



You're insistence that this expulsion of matter is "out the front" is ludicrous.
You have to concede that you are completely mistaken about this point.
It is also clear that Alvarez is making exactly the same mistake you are, even though it is patently incorrect.

When the pieces of bone/matter exit the top of JFK's head they rip the scalp at the same place - the top of his head.
The pressure wave, caused by cavitation, explodes through the top of JFK's head and as it does it blows a massive piece of scalp down the right side of his head.
This massive piece of scalp, which still has bone attached to it and can clearly be seen in the Z-film, is still attached to JFK's head near his right ear. This attachment acts as a 'hinge' and, as the right side of JFK's head is blown open, the massive piece of scalp and bone is left hanging downwards. This is what we see in the Z-film.
As the scalp/bone/right side of the head is ripped open there is a massive spray of blood in all directions but particularly to the front. That is the "explosion" witnessed at towards the front of JFK's head.

There is a simple fact that seems to have flummoxed both you and Alvarez - at the moment of impact JFK is looking down. His head is tilted forward.
In the image below the yellow lines give an idea of the orientation of JFK's head at the moment before the bullet impacts. The red line is an approximation of the bullet trajectory agreeing with the damage shown in the autopsy pictures:



You have fooled yourself that the injury to JFK's head extends to the front of his head and hold this picture up as evidence. However, the diamond-shaped cut extending down to JFK's forward is clearly that...a cut. It is clearly some kind of incision.



This same incision is NOT present in your renowned GIF:



All you need to do is use your eyes to see that this incision is NOT present in the GIF. The extent of the injury is exclusively contained to the top of the head.
Just use your eyes.

Btw since you obviously agree that Kennedy was shot from behind, what do you believe caused Kennedy's back and to the left motion?


Physics.