Posted on 11/22/2003 9:36:29 AM PST by keving
Did anyone see the show on the History Channel about the archiving of the Zapruder film?
"Image of an Assassination"
Saturday, November 22 @ 8am ET/PT
On November 22, 1963, Dallas dress manufacturer Abraham Zapruder brought his movie camera to film President John F. Kennedy's motorcade for his grandchildren. As it turned out, Zapruder captured one of the 20th century's most important documents. In 1997, two media companies created a digital replica of the original, which is presented here, along with Zapruder's business associates, photography experts, and National Archives employees, who piece together the history of the crucial 26-second film. TV PG-V
It was very interesting. The most revealing part was that the frames that claim to be the Zapruder film are cropped copies of the original (1/3 to 1/2 screen).
The best part of the film is that the "fatal" blow when Kennedy's head explodes is cleary shown traveling from the side of the limo - grassy knoll area.
The "expanded" version or original version of the film included the trajectory of the bullet which could not be indicated on the cropped photo version.
Please view programs - it is very clear.
(Excerpt) Read more at historychannel.com ...
I have to admit - I had to look up Luis Alverez (or Alvarez). Found an article on iridium finds and the theory that a comet or large meteor collision caused the death of dinosaurs and a couple on his involvement in UFO hoaxes - debunking I'm sure. Then I found this gem on Jet Effect Theory
It discusses Alverez's Jet Effect Theory and its publication and analyzes the experiment. Some highlights:
Of course, I'm not a recognized physicist. I only took a couple years of physics as an undergrad, covered the kinematics of trauma and gunshots for medic training, studied anatomy, physiology, trauma forensics in grad school and med school. So I'm not playing physicist - I'm looking at a trauma situation and an explanation that doesn't match with my training and education.
The Earth would ring like a bell seismically - I wonder if there would be any type of precession effect? Nowhere on topic, I know, the mind just wanders sometimes. :-)
I like wandering trains of thought. My choo-choo sometimes leaves the tracks far behind.
The Earth DOES ring when struck... and as to precession, it does occur, but the amount is so slight as to be almost always immeasurable. There is conservation of the angular momentum to be considered as well. An Easterly or Westerly vectored collision might increase or retard the planetary rotation a miniscule amount, I would think. Even large meteors striking at an oblique angle would have to be VERY large to make much change in the position or orientation of the planet.
I tend to think that the random nature of the strikes would average out over any appreciable length of time making it even harder to measure.
The limo windshield hit by a shooter as it approached him/her was quickly destroyed on LBJ's order.
I seem to recall darkside stories about Texas politics where political enemies of Johnson ended up dead, before he became a senator.
From reading your posts on this thread, it appears you do not believe Kennedy was shot from behind. The forensic pathologists for the Warren Commission and the HSCA concluded that the head wound was cause by a shot from the rear. After having read what the forensic pathologists say in the reports, what is your opinion of their conclusions?
Kennedy's head moved forward on impact. Put your cursor on a object in the car and then on his head and measure it yourself.
Also there is no spray rear of the ear. It's a rear shot with white matter going upward and red mist forward.
That bullet was not "pristine." It looks pristine from one angle, and that's the image the conspiracy buffs use. The other side of the bullet looks like s**t.
It's interesting but odd. I hadn't realized until reading Best Evidence (the author escapes me at the moment)and going back to a couple online Warren Report sites that the forensic testimony wasn't based on any first hand evidence. Outside experts based their testimony upon the autopsy report and drawings of the body, not photographs, a view of the body, or x-rays, which is irregular to say the least. The lead doctor in the autopsy, Dr. Humes has been criticized as not qualified for his task, oddly remained noncommittal in his testimony. Some have pointed to discrepancies in bullet wound positions in his various testimonies (Warren vs. House Select Committee).
Now, most are familiar with the ER doctors and nurses described radically different wounds than the autopsy report. Witnesses described shots from more than the Book Depository and Kennedy being hit from the front and some say the back. But all this testimony and even the Zapruder film was not given weight by the Warren Commission because it wasn't the best evidence, in legal thinking the best evidence is the physical evidence, the body, or lacking that, the official coroner's report. That is the evidence that mattered, that is the evidence the forensic testimony was based upon.
The forensics were, shall we politely say, unconventional. The autopsy report contained some errors, some say, and it didn't always agree with the coroner's testimony. So, there is way too much room for error in the Warren forensic testimony. Importantly, why wasn't the autopsy performed in Dallas County by a forensic pathologist but moved to D.C. and performed by non-forensic doctors. I don't understand why they were so damn sloppy for something so important.
As a conclusion, I think the forensic work was oddly sloppy and subpar for a major case. When I read the forensics, I counted four or five significantly different descriptions in location and size of just the fatal head shot - so how can I take a determination of trajectory with confidence?
The HSCA forensic experts (report linked to above) had access to the photographs and x-rays in addition to the autopsy report and drawings. They also concluded that Kennedy was shot from behind.
Now, most are familiar with the ER doctors and nurses described radically different wounds than the autopsy report. Witnesses described shots from more than the Book Depository and Kennedy being hit from the front and some say the back.
I would ask you to consider The Head Wound and Dealy Plaza Earwitnessess.
Importantly, why wasn't the autopsy performed in Dallas County by a forensic pathologist but moved to D.C. and performed by non-forensic doctors. I don't understand why they were so damn sloppy for something so important.
Consider this (from here):
About 1:45 p.m.Now that Kennedy has been pronounced dead, the Secret Service renews its pressure on Johnson to leave. But Mrs. Kennedy says she will not leave without her husband's body, and Johnson says he will not leave without Mrs. Kennedy. Johnson finally agrees to go to the airport, ducking below window level in his car during the trip, and wait aboard Air Force One for Mrs. Kennedy and the president's body.
Doctors at Parkland inform the Secret Service that Kennedy's body may not be removed until an autopsy has been performed, under law.
Here is the Warren Commission explanation.
The spray of blood and brain matter flies out toward the FRONT of the car. A huge flap of the President's skull flips out and forward as well. The head actually moves FORWARD for a frame or two, then snaps violently back. I'm afraid you're the one who does not undertand physics. Nobel Prize winning physicist Luis Alvarez explained the "jet effect" that caused the spray exiting forward to propel the head back.
Furthermore, I might add, Kennedy's back brace would have restrained his torso from bending forward, but the conspiracy kooks never discuss how these sort of things might effect what happend. That and of course how there is NO evidence of any other shooter.
"...I was finally convinced that the assassination buffs were right; there had to be a real explanation of the fact that the Presidents head did not fall back, but was driven back by some real force.
And the answer turned out to be simpler than I had expected. I solved the problem (to my own satisfaction, and in a one-dimensional fashion) on the back of an envelope, as I sat in solitary splendor in the beautiful suite that the St. Louis hotel management supplied me in my capacity as president of the APS.
I concluded that the retrograde motion of the Presidents head, in response to the rifle bullet shot, is consistent with the law of conservation of momentum, if one pays attention to the conservation of energy as well, and includes the momentum of all the material in the problem. The simplest way to see where I differ from most of the critics is to note that they treat the problem as though it involved only two interacting masses: the bullet and the head. My analysis involves three interacting masses, the bullet, the jet of brain matter observable in frame 313, and the remaining part of the head. It will turn out that the jet can carry forward more momentum than was brought in by the bullet, and the head recoils backward, as a rocket recoils when its jet fuel is ejected. (Col. William H. Hanson came to the same conclusion, independently.)
If a block of wood is suspended by strings from the ceiling, it is called a ballistic pendulum, and physicists or gunsmiths can calculate the velocity of a bullet shot into it to be
vB = vWMW/MB, (1)
where vW is the velocity of the wooden block after it stops the bullet, MW and MB are the masses of the wooden block and bullet. Equation (1) follows directly from the law of conservation of momentum:
vBMB = vWMW. (2)
In using a ballistic pendulum, we normally forget that the collision of the bullet and wooden block is very inelastic. Of the incoming kinetic energy of the bullet, only a small fraction appears as kinetic energy of the moving wooden block; the remaining fraction (1 f) goes into heating the wood. If MB << MW,
KEW = f(KEB),
MWvW2/2 = f x MBvB2/2. (3)
From (3) and (2),
f = MB/MW (4)
For the case of a 10-g bullet, and a block weighing 10 kg, it can be seen that 99.9% of the incoming kinetic energy goes into heating the block, and only 0.1% appears as mechanical energy. Ballistic pendulums are designed so that they contain the inelastically dissipated energy. Unfortunately, the human head is not able to contain the major fraction of the energy carried in by the bullet. This tragic aspect of the assassination is clearly visible in frame 313 of the Zapruder film, and is discussed in detail in the reports of the autopsy surgeons.
The mechanism of the retrograde recoil turns out to be rather simple, if one remembers that 99.9% of the incoming energy must be accounted for. The momentum associated with a given amount of kinetic energy varies as the square root of the mass of the object carrying that kinetic energy:
p = (2MK)1/2 (5)
where p is the momentum, and K is the kinetic energy of the object with a mass M.
Figure 4 shows what happened when my friends and I fired bullets at melons that had been wrapped with Scotch glass filament tape, to mock up the tensile strength of the cranium. Under the influence of the bullet, some of the material making up the melon breaks through the reinforcement, and carries momentum in the forward direction. (Frame 313 of the Zapruder film shows this same phenomenon.) As we shall now see, the momentum carried forward in this way can be much larger than the momentum brought in by the bullet. For example, if the bullet weighed 0.1% of the melon weight, and if 10% of the incoming kinetic energy was used to propel 10% of the mass of the melon forward, then the momentum of the jet expelled forward would be (10)1/2 times that of the incoming bullet. (I will use subscripts, b for bullet, j for forward moving jet, and m for melon.)
Pj = (2MjKj)1/2 = (2 x 100Mb x 0.1Kb)1/2
= (10)1/2 (2MbKb)1/2 = (10)1/2pb (6)
since = Mj = 0.1Mm 100Mb, Kj = 0.1Kb. The melon would then recoil backward with about twice the velocity it would have been expected to go forward, assuming it were made of wood. This is because the melon, acting at first as a ballistic pendulum, acquires a forward velocity equal to vm|BP = pb / Mm. (The notation vm|BP means the velocity one would expect the melon to have if it contained all the kinetic energy of the bullet, as a ballistic pendulum does.) But in the center of mass of the system of the melon, which is moving forward with the expected velocity, a jet moves forward with momentum equal to (10)1/2pb---as we have just seen. It gives the melon an equal and opposite momentum, in the moving (CM) system; in that system, pm = -(10)1/2pb. If we neglect the 10% loss of the mass by the melon to the jet, the recoil velocity of the melon (in the CM system) is -(10)1/2 times the expected value. Since velocities add vectorially, the final velocity of the melon (in the laboratory system) is [1- (10)1/2]vm|BP. Since the square root of 10 is close to 3.16, the observed velocity of the melon is about 2vm|BP.
If one wants to know more about the details of the transfer mechanism of kinetic energy from the bullet to kinetic energy of the fragments thrown forward, he will have to ask someone more knowledgeable in the theory of fluid mechanics than I am. My intuitive feeling is that the conical shape of the interaction zone is the key to the nonnegligible efficiency of energy transfer. (It is clear that an appreciable mechanical energy transfer is only possible if the incoming energy can avoid being thermalized.) The conical region is defined by the small entrance hole and the much larger exit hole in the melon. Transmission lines with tapered internal conductors are efficient transformers of electrical energy, and a tapered bullwhip can smoothly transform the energy given to a large mass, by the flick of the wrist, into roughly the same energy of a much smaller mass at the tip of the whip. The crack of the whip occurs when the tip of the whip goes supersonic. I believe that in a somewhat analogous manner, but of course in the opposite direction, the kinetic energy of the bullet is given in a tapered region to a progressively larger mass in the melon, to achieve the modestly efficient energy transfer that is demonstrated in our experiments."
Kennedy Assassination Home Page
Lee Harvey Oswald's Paper Bag
Guinns neutron-activation Analysis
Warren Report: Table of Contents
One Hundred Errors of Fact and Judgment in Oliver Stone's JFK
The Academic JFK Assassination Web Site
HSCA (House Select Committee on Assassinations) Final Assassinations Report
A Critique of The Warren Report
Attempted assassination of General Walker
Oswald interviews, Acoustic studies and other information relating to the assassination of JFK
Queen of Diamonds
Zapruder 313
Head Wound
Photos and Illustrations of the JFK Assassination
Zapruder Head Shot
A Conspiracy Too Big? Intellectual Dishonesty in the JFK Assassination
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