What physics reveals about the JFK event

[Andrew Mason]

Note: Detached skull fragments were drawn at a larger scale than the head.

I'm wondering if the bullet entered at the back of the skull and created a few linear fractures radiating from the impact point, that ran into the lower rear of the skull.

Some of the surface of the skull at the point of impact was pushed forward such that it jutted forward of the intact skull above (see lateral X-ray):



The bullet fragmented into multiple pieces at the entry point and may not have had enough energy to fracture the intact skull opposite the entry. Possibly it was the bullet pressure wave that caused the fragmentation of skull above the right ear, or the gaping wound.

It is hard to say exactly what happened but I expect that the copper jacket ruptured on impact and much of the lead in the front part of the bullet melted and became a lead spray.  The copper jacket and a bit of still solid lead at the base is probably what passed through the skull. 

As an aside, it would have been nice if the ballistics experts actually weighed the copper jacket part and lead part of the bullet fragments separately to determine how much copper was recovered from the fragments.  We could then determine with a bit better detail what likely happened.  It would also help determine whether the fragments were from only 1 or 2 bullets.  If the amount of copper recovered exceeded the amount of copper of a single bullet we would know that more than one bullet struck in the car.

Nalli writes:

    "It is noted that the massive “defect” was not the “exit wound”
     of the bullet (as is commonly misunderstood), but rather
     corresponded roughly to the area where the maximum
     explosive energy was deposited by the bullet during its passage "

    "Here the large wound inflicted on the President's head was not a
     bullet exit wound, but rather the region of maximum temporary
     cavitation associated with KE transfer. This KE deposit
     propagated radially outward in the form of an expanding pressure
     wave resulting in a rupture and explosion of the skull."
 
    "However, all this said, note well that because such explosions are
     not necessarily the bullet outshoots, the momentum directly carried
     forward by a given bullet during passage may not be the primary
     player in a recoil effect."

The HSCA drawing seems to imply the right-side gaping wound was caused by the path of a bullet, or more precisely, one of its fragments, that impacted the inside of the skull to fracture it.

The size of the exit wound and the ruptured skull was definitely caused by the explosive exit wound.  However, there had to have been a significant piece of the missile to compress the brain matter that exploded out of the front part of the skull. Whether the skull ruptured because of the pressure alone before the bullet struck the skull from the inside or whether it occurred with the exit of that fragment through the skull is probably not possible to determine.

[Andrew Mason]

How about this? 

• Bullet enters skull at rear, disintegrates by time it gets through the bone

What do you mean by disintegrate? The bullet will compress and the jacket will rupture and molten lead will spray out.
   

• Bullet hole at rear of skull, with a few fractures radiating downwards

If a bullet will just make a bullet sized hole in glass, why would it radiate cracks on the entrance to a skull?

[Matt Grantham]

 Ah yes the single frame of forward motion somehow takes precedence over the end result of the motion Lots of drawing from the review board folks and we all know how different those descriptions are than Parkland and Bethesda

 Where are all the nutters who believe that force in physics causes and equal and opposite reaction and like to show sheep falling towards the direction of the shot. They would of course say the initial forward motion is indicative of a shot from the front Such consistency from you folks

[Andrew Mason]

Ah yes the single frame of forward motion somehow takes precedence over the end result of the motion Lots of drawing from the review board folks and we all know how different those descriptions are than Parkland and Bethesda

 Where are all the nutters who believe that force in physics causes and equal and opposite reaction and like to show sheep falling towards the direction of the shot. They would of course say the initial forward motion is indicative of a shot from the front Such consistency from you folks

Do you mean physicists who have explained how a bullet that causes an explosive head wound can drive the head back in the direction opposite to that of the incoming bullet, because Newton's third law (for every action there is an equal and opposite reaction) requires it?

[Matt Grantham]

Perhaps you can distinguish for me when to apply the law of conservation of momentum as opposed to Newtons third law?

[John Mytton]

Jet Effect.







Also worth looking at is a comparison of the coconut explosion above and the following gif, and again we see a similar dispersal of matter.



JohnM

[Matt Grantham]

Firstly off it is interesting that no one is offering any clarification on Newton's laws and the absolute opposite interpretations that are being offered. Good old Aristotle and the law of the excluded middle is often a worthy ride at times such as these. Yes the good old jet effect. Never demonstrated other than with liquid or near liquid materials as far as I have seen. Also the jet is visible in the examples JM has offered The only jet we see from JFK's skull is heading upward so the jet effect should be driving him down into the seat. Just for the sake of ridiculous argument any such 'jet' would have come from JFK's right and therefore would have been driven back to his right

 I guess this is better than the twitch theory, but that is not saying much

 Jerry Organ said

Matter exploding out of skull creates a jet that pushes the head in the opposite direction: downward and backward after Z313.

 You would have need the right front of JFK's skull to have blown out completely to have created a jet effect that would have moved his head back and to the left. That didn't happen. You would have also needed to see a volume of jet material comparable to the examples given by JM. You would need to see a massive amount of material being blown out in the direction previously described Did not happen not even close.