by Tom Rogers
Careful analysis of the magic bullet’s path by a number of investigators has shown that Kennedy’s throat wound does indeed line up with Connelly’s numerous wounds. These investigators used photographic evidence for their analysis, including the Zapruder film and 3-D computer graphics simulations18.
Sophisticated FBI testing with neutron-activation analysis in 1964 and again in the late 1970s showed that the lead alloy in the magic bullet was consistent with lead fragments collected from Connolly’s wounds.The testing also showed that bullet fragments found in the limousine matched with fragments taken from Kennedy’s head wound. There’s no evidence to suggest that any other bullets struck objects in the limousine. Both the magic bullet and other bullet fragments could be traced to Oswald’s rifle.
Yes, some conspiracy buffs still reject all of the above evidence, but to do so usually requires them to claim that the evidence was faked or modified. Many—including Oliver Stone—think the magic bullet was planted. This means conspirators had to fire bullets through Oswald’s rifle ahead of time in such a way that the bullets tumbled sideways and were flattened on one side. Confederates with the proper credentials to approach wounded victims would then have needed to wait near possible hospitals for just the right moment and then plant one of the faked bullets. They would have needed to know that none of the real bullets ended up in a recoverable form. Planting an extra bullet would have created all kinds of problems if all the real ones were found.
The additional shooters who supposedly shot Kennedy from the front would have needed disappearing bullets. Any recovered bullet with a caliber other than 6.5 millimeters or micro-scratch marks different from those made by Oswald’s rifle would have been a dead giveaway that another shooter was involved. Controlling the final position and condition of a bullet once it’s fired would have been problematic at best. If sophisticated conspirators had set Oswald up as the lone assassin, why would they have given him a $12.78 rifle mounted with a supposedly defective $4.58 scope, which according to Stone’s movie could not possibly have made the shots? At the time, military surplus semiautomatic M1 carbines mounted with scopes and thirty-round magazines were popular and readily available for under $75—not a huge investment for a group of conspirators. One of these rifles could have spit out at least eight bullets in the time it took Oswald to fire three with his bolt-action rifle. Certainly, an M1 carbine would have been at least as accurate as the 6.5 52-millimeter Italian Carcano and far easier to shoot in rapid fire, hence, far less controversial. Had Oswald rapidly fired eight or more shots, witnesses could not possibly have kept an accurate count. It would have been easy to fire a couple of extra shots undetected from a different location, if needed.
Some conspiracy buffs also claim the crime’s Rosetta Stone— the Zapruder film—has been deliberately modified as part of a coverup along with x-rays of the president’s head, autopsy photographs, and various other forms of evidence. Again, who knows? All this data modification and faking would have required a coordinated effort by all kinds of government groups and individuals, but so what. These are, after all, the same type of groups and individuals who thwarted the Japanese plan to bomb Pearl Harbor, pulled off the Bay of Pigs invasion of Cuba, prevented the 9-11 terrorist attacks, and coordinated the timely hurricane Katrina relief efforts in New Orleans, to name a few known highlights.
How did the Jim Garrison character count shots in the movie? Why, in true Hollywood fashion, of course. According to him there were six, not three, shots fired resulting in seven wounds (he counts entrance and exit points as two wounds). In the movie, Garrison argues against the magic bullet theory using a blatantly incorrect diagram. It shows Connelly seated directly in front of Kennedy at the same height—a position where the so-called magic bullet would have needed to make impossibly sharp turns to have caused the “seven” wounds. In reality, Connolly was seated in a folding jump seat, 3 inches lower and 6 inches to the left of Kennedy.These seats were used inside the limousine to accommodate the president’s entourage but were placed lower so that people seated in them would not block an onlooker’s view of the president. Just before he was wounded, Connelly had also turned noticeably to his right.
As for the bullet fragment analysis, the movie has Garrison ranting that
“ . . . the government says it can prove [the single-bullet theory] with some fancy physics in a nuclear laboratory. Of course they can. Theoretical physics can prove an elephant can hang from a cliff with its tail tied to a daisy . . .”
What an insightful comment. Obviously, all forensic experts who use theoretical physics to guide their conclusions are simpletons. So what are they supposed to use? We’re never told, but perhaps it’s an ultra reliable tool like personal opinion.
The movie’s most brilliant analysis occurs when Garrison and an assistant are shown peering out the window of the book depository building overlooking the assassination site. Their dialogue informs us that the Zapruder film established that three shots were fired in 5.6 seconds. (Careful analysis of the Zapruder film indicates that the last two shots were fired within about eight seconds of the first.) The assistant, pretending to be Oswald, then aims, dry-fires, and cycles a rifle identical to Oswald’s as Garrison times him. Garrison announces that the time is between six and seven seconds. If you actually time the scene, however, it turns out that the assistant fired the simulated shots in the 5.6 seconds that was supposedly impossible. In a serious moment, comicmagicians Penn and Teller conducted the same dry-firing experiment in under 3.5 seconds19. Keep in mind that the clock starts with the first trigger pull, hence, it’s only necessary to cycle and aim the rifle twice during the time interval. Naturally, one also wonders about the other three of the six shots Garrison later claimed were fired. If the Zapruder film established that three shots were fired, then what happened to the others?
IT’S ONLY A MOVIE—THE JFK RESPONSE
Inaccuracy in the movie JFK goes beyond stupid movie physics, matters of artistic license, or even of interpretation. The movie’s problems mired it in controversy even before it was released. It was attacked in the New York Times, Washington Post, and Time magazine while still in production. Entire Web sites have been devoted to debunking virtually every scene in the film20.For example, the movie insists that the president’s motorcade route was secretly altered at the last minute to slow the motorcade with a sharp turn and guide the president directly into a killing zone at Dealey Plaza. Yet, the route was not only unaltered but widely publicized ahead of time. It was the only way the motorcade could get from Dallas’s Main Street to their desired exit route down the Stemmons Freeway.
The movie centers on Jim Garrison’s investigation of an alleged conspiracy to assassinate President Kennedy. Garrison once described the assassination as a homosexual thrill killing and, at various other times, indicated that the CIA, FBI, NASA (yes, the space guys), secret service, Cuban exiles, aerospace industry, Dallas police, Lyndon Johnson, neo-Nazis, and many others too numerous to mention had had a role in the assassination and/or coverup. Of all the suspects he named, he was only able to bring one, Clay Shaw, to trial.The jurors found Garrison’s evidence against Shaw so compelling that they took a whopping forty-five minutes to acquit him.
Not to be outdone as a conspiracy theorist, Stone not only tries to convince us that the Kennedy assassination was a conspiracy, but that Lee Harvey Oswald was nothing but a patsy who was unjustly vilified. The movie goes beyond absolving Oswald of guilt as the lone assassin—it actually tries to create reasonable doubt that Oswald murdered police officer J. D. Tippit. When Tippit tried to question Oswald following the assassination, Oswald pulled out a revolver and cold-bloodedly shot Tippit multiple times, finishing him with a shot to the head as he lay helpless on the street. Never mind that it was in broad daylight in front of numerous witnesses; never mind that at least six people picked Oswald out of a lineup and at least two others identified him from pictures21; never mind that he had the murder weapon on him when arrested; and never mi
nd that he tried to use it on a second policeman during the arrest—Stone would have us believe that Oswald might have been framed. And what does Stone offer for creating reasonable doubt? Two witnesses who either couldn’t or wouldn’t identify Oswald, a less-thansterling job of crime scene investigation by the police, and an unusually large number of police officers showing up for Oswald’s arrest. The police presence probably had something to do with the numerous officers already in the neighborhood investigating the Tippit murder, the possibility that many Dallas policemen wanted the distinction of collaring the president’s killer, and the radio call that an assassination suspect had entered a nearby theater.
Hollywood responded to the film’s controversy by giving it Academy awards for Best Cinematography and Best Film Editing, along with nominations for Best Actor in a Supporting Role (Tommy Lee Jones), Best Director, Best Music: Original Score, Best Sound, Best Writing: Screenplay Based on Material from Another Medium, and, of course, Best Picture. As for the audience, they awarded the film with over $205 million in earnings during its initial movie run.
Naturally, everyone who saw the film dismissed it saying, “It’s only a movie.” Oddly however, Congress rammed through a bill that formed the U.S. Assassination Records Review Board (ARRB) shortly after the film came out—what a coincidence.The ARRB consumed taxpayer money for about six years and made many government documents on the assassination more accessible to the public, including at least some of the previously sealed materials, but was not mandated to draw conclusions and didn’t.
Did Stone’s movie unravel a conspiracy, help us understand the assassination, or have any impact whatsoever? Historian Michael Beschloss summarized its impact like this: “the problem that I and most historians would have with Oliver Stone is not his talent—he’s a wonderful filmmaker—but that he’s used this to put certain myths into the American blood stream that abide to this day.”
Summary of Movie Physics Rating Rubrics
The following is a summary of the key points discussed in this chapter that affect a movie’s physics quality rating. These are ranked according to the seriousness of the problem. Minuses [–] rank from 1 to 3, 3 being the worst. However, when a movie gets something right that sets it apart, it gets the equivalent of a get-out-of-jail-free card. These are ranked with pluses [+] from 1 to 3, 3 being the best.
[–] [–] Using bad physics as justification for defective historical analysis.
[–] [–] Using Hollywood depictions of shootings as though they were real forensic analysis.
[–] [–] Assuming a shooting victim will always be blown in the same direction that the bullet is moving.
CHAPTER 14
SCENES WITH REAL GRAVITY:
Celebrating Disasters with Happy Hollywood Endings
ESCAPE VELOCITY ON ASTEROIDS
When killer chunks of space junk threaten Mother Earth, what should we do? Dial NASA, slap together a mission, land a spacecraft on the offender, and nuke it. In Armageddon it’s a Texassized rock. In Deep Impact a 7-mile-long rock filled snowball. Thanks to gravitational effects, both pose considerable challenges to landing parties.
The daring crew in Armageddon had to land on a foreboding spike-covered asteroid. Their choice of landing craft: a space shuttle, of course. At the Kennedy Space Center landing such a craft requires a 15,000-foot-(4,572-m-) long, 300-foot-(91.4-m-) wide specially constructed runway and parachutes for a touchdown at speeds of 213 to 226 miles per hour (343–364 kph). Who knows what the shuttle’s speed was in the movie, but a closing speed of over 200 miles per hour was well within reason. The main shuttle boosters were pointed backward, so the shuttle had no means of slowing down upon landing other than applying brakes or running into rock formations. Certainly, parachutes would have been worthless since there was no atmosphere. Airliners touching down on smooth water at similar speeds routinely disintegrate, but not— by golly—our hope-of-all-humanity space shuttle when landing on misshapen rock formations.
Once on the asteroid, crew members walked around normally in spite of the reduced gravity. In fact, gravity would have been about 10 percent of the level on Earth, assuming the asteroid’s density was the same as Earth’s. By comparison, the moon’s gravity is only 17 percent of Earth’s—an amount less than the smaller-sized asteroid due to the moon’s lower density.
G-FIELD BASICS
According to Newtonian mechanics, any mass, such as a planet, creates a gravitational force field around it. The strength of the force field is usually represented by the symbol g, generally referred to as the acceleration due to gravity. Although g has units of acceleration, an object’s acceleration in a gravitational field will only be equal to g when it is free falling. The gravitational force acting on an object will be mg (where m is the object’s mass) regardless of whether the object is freefalling with an acceleration of g or sitting on the ground with an acceleration of zero. It’s more accurate to refer to g as the gravitational field strength.
GRAVITATIONAL OR WEIGHT FORCE ON A PLANET, MOON, OR ASTEROID
To find the gravitational force acting on an object, in other words its weight, multiply its mass times g as follows:
Where:
F = force due to gravity
m = mass of the object in a gravitational field
g = the strength of the gravitational field (g = 9.8 m/s2 for Earth)
GRAVITATIONAL FIELD STRENGTH—AROUND A PLANET, MOON, OR ASTEROID
For any spherical-shaped celestial object, the gravitational field strength g at a specific location on or above the surface can be calculated as follows:
Where:
G = the universal gravitational constant
MP = the mass of the planet
r = the distance from the center of the planet
Note that if the distance from the center of the planet is doubled, the gravitational force decreases by a factor of 4. Gravitational field strength drops quickly as one moves away from the planet.
GRAVITY FIELD STRENGTH—INSIDE A PLANET
If a shaft is drilled into the interior of the planet, g can be found as follows (assuming that the density of the planet remains constant):
Where:
RP = the radius of the planet
Note that the gravity level actually increases as one moves away from the center of the planet, that is, until reaching the surface. Then, at the surface, equation 15-2 takes over and the gravity level starts dropping.
The movie at least has one of the two shuttles crash, but, of course, all hands are not lost. The surviving crew members set out in a rover hoping to join up with members of the intact shuttle. Faced with crossing a deep chasm, they simply rev up the rover and roar over the side.With the low gravity and no air resistance, the rover supposedly goes into a close-to-surface orbit, easily crossing the chasm without falling into it. If an object close to the surface has no horizontal velocity and is dropped, it will fall straight down. Give it a horizontal velocity, and it will fall in a parabolic arc. Give it enough horizontal velocity, and it will “fall” in a stable circular orbit. Yes, such an orbit is possible on the surface of a planet or asteroid and requires a much lower horizontal velocity on the asteroid than on Earth. On our Texas-sized asteroid, however, the rover would have to travel at a speed of 1,800 miles per hour (2,900 kph) to reach the required critical velocity—a little fast for the typical rover.
Astronauts on the surface of the Texas-sized asteroid could jump up and down as much as they wanted with no danger of reaching escape velocity and accidentally floating off into space. Escape velocity is proportional to the square root of the gravitational field strength and, surprisingly, the gravitational field of the asteroid would be a little stronger than on the Moon, assuming the asteroid’s density matched that of Earth rather than the lower value of the moon. On Earth escape velocity is slightly over 25,000 miles per hour (40,000 kph). On the asteroid it’s greatly reduced but still over 2,500 miles per hour (4,000 kph). Taking off from the surface in a horizontal dir
ection would make reaching escape velocity a real challenge.
CRITICAL VELOCITIES RELATED TO GRAVITY
There are two critical velocities related to gravity that determine how and if an object orbits a celestial body. (A celestial body in this case refers to a spherical body like a planet.)
LOWEST CIRCULAR ORBIT VELOCITY
An object could conceivably orbit a planet a fraction of a millimeter off the surface, if the planet were perfectly spherical, uniform in density, and had no air resistance to slow the object’s speed. The horizontal velocity required for the lowest possible circular orbit defines the first critical velocity. This velocity is perpendicular to a radial line drawn from the center of the celestial body.
If a spacecraft attempts to take off in a horizontal direction on a celestial body that has no atmosphere, the craft’s velocity will have to exceed the first critical velocity. Without a lengthy wellmaintained runway, a horizontal takeoff is next to impossible, which is why missions to asteroids, moons, or planets with thin atmospheres will require vertical takeoffs and landings. On Earth, airplanes can take off at relatively low horizontal velocities thanks to the atmosphere, which provides lift.