Shear_stress said:
Here is your original post with emphasis added. The physics are: I shot a deer as part of a youth hunt.
You are continually misrepresenting what I have written. I wonder if it is a reading comprehenion problem, or intellectual dishonesty. Earlier you tried to claim that I hadn't mentioned female deer. Now you are trying to claim that I shot a deer as a part of a youth hunt. This is incorrect.
I clearly wrote:
Michael Courtney said:
This buck was shot during a special youth-only hunt, and the young hunter was gracious enough to allow a couple of scientists access to his deer.
The buck was shot by a youth hunter, not by me. Yet here you are (making me out to be an outlaw by shooting a buck during a "youth-only" hunt) misrepresenting the original post on the other thread. In addition, the original post on the other thread was about observed wounding. The original post on this thread is about the Physics. I made no representation in the initial post of the other thread to the effect of "the physics are: I shot a deer . . ." The Physics is described in the first post of this thread. The wounding is described in the first post of the other thread.
Shear_stress said:
The wounding I measured is different than predicted by Fackler. Ergo: a pressure wave responsible for the damage.
I was clear that some of the wounding we observed might be interpreted as resulting from the TSC. However, we also observed wounding beyond the reach or either the TSC or PCC. The only ballistic effect that reaches beyond the TSC and the PCC is the ballistic pressure wave, and the only wounding we ascribe with certainty to be caused by the pressure wave is that beyond the reach of the TSC and PCC.
Michael Courtney said:
What we actually observed is a truncated cone region of pulverized tissue with a diameter of 1.5” on the entrance side, and gradually narrowing to 0.58” on the exit side of the rib cage. The actual volume of this truncated cone of pulverized tissue is 12.18 cubic inches, or nearly 4 times the volume predicted by the PCC-only view of wounding via handgun bullets.
In addition, we observed a region of severe to moderate hemorrhaging along the wound channel that was 5” in diameter at entrance, narrowed to roughly 3” in diameter at the medial surface of the left lung and gradually shrank in size to merge with the bullet diameter where the bullet exited the rib cage. This region of hemorrhaging has an approximately truncated cone shape with a volume of 119.3 cubic inches.
We believe that the pressure wave is responsible for this hemorrhaging, though we cannot rule out the temporary stretch cavity for some regions. However, the 5” diameter of hemorrhaging of the muscular tissue surrounding the entrance wound is much larger than the expected TSC at this point. This is the effect that hunters associate with high-velocity rifle bullet wounds and refer to as bloodshot meat. Since the pressure wave is more strongly directed backward than the TSC, it makes sense that this hemorrhaging is due to the pressure wave.
We also observed mild hemorrhaging along the abdominal walls and rear rib cage on the right side. This is the area directly opposite from the entrance wound, but considerably rearward from the point where the bullet exited the rib cage. Thus this region was out of reach of both the permanent crush cavity and the temporary stretch cavity, and it seems that the most likely cause of the hemorrhaging was the pressure wave.
Shear_stress said:
That's your argument. Most of the physics you have shown here have been to prove and describe the existence of a pressure wave. The existence of a pressure wave is not in doubt and the equations are what they are.
To my knowledge, the only published equations regarding the pressure resulting from a bullet impact are derived from a misapplication of Bernoulli.
If you are aware of the development of the equations presented in the "Physics of the Pressure Wave" being previously published by someone else, I would dearly appreciate a reference to the article, because it should be referenced in our papers. The equations are indeed correct, but to my knoweldge, they have not been correctly applied to the ballistic pressure wave until now.
Shear_stress said:
However, you make frequent references to your "experiment", but have never actually described a systematic experimental procedure and a process in which you actually *prove* anything.
All one needs to do to reproduce our observations is obtain access to a deer shot through the chest with the same bullet at the same impact velocity and make some observations of wounding including:
1. Measuring the diameter of pulverized tissue along the wound channel
2. Measuring the diameter of hemorrhaged tissue around the entrance
3. Measuring the diameter of hemorrhaged tissue along the wound channel
4. Carefully looking for other hemorrhaged tissues in areas remote from the wound channel.
Shear_stress said:
The above is simply a declaration, not a proof. You claim to be debating the merits of an experiment, yet shift the debate to physics no one has questioned.
My goal of the additional thread was to describe the physics, not to "shift the debate" which is why I began a new thread to describe the physics. I was quite willing to continue discussion of the wounding and its interpretation in the original thread.
Shear_stress said:
Besides, what makes you think that if your results are different from those predicted by Fackler or whoever, than the mechanism of wounding is automatically different? You have so far neglected any mention of a null hypotheses, what kind of animals are you using, if deer, why your results seem to coincide with hunting season, how many deer you're using, what breed they are (wildtype, or engineered hybrid), references to any papers showing that deer wounding is a good model for human wounding, your experimental groups, your control, the p and power of each result, your rationale for using muzzleloaders to model centerfire handgun rounds, what calibers you are looking at and why, how you define "pulverized" tissue, how you actually measure the intensity of a pressure wave in live animals that are apparently free to run after being shot, your actual predictions of the pressure wave in a wound, the kind of equipment you are using
These are relevant questions and will be addressed in the published work. Answering every possible question of this type would require basically posting the complete paper, which is prevented by both practical considerations and our non-disclosure agreement. The paper is thousands of words long and contains figures and equations that are difficult to reproduce in this forum.
I will briefly address some of the issues you raise, but you are going to have to be patient and wait for the publication.
Shear_stress said:
You have so far neglected any mention of a null hypotheses,
Not completely. We have pointed out observations with lower pressure wave projectiles fail to produce the effects we ascribe to the pressure wave. In specific, when we were asked how we know that the hemorrhaging is not caused by lung collapse, I answered that we observe very little hemorrhaging with broadhead arrows which deflate the lung but produce only a very small pressure wave. When asked how we know that the 10-20 lbs mammals are incapacitated by the pressure wave and not some other factor, I answered that we observe zero incapacitation when using a low-pressure wave bullet. There is more to say, of course.
Shear_stress said:
You have so far neglected any mention of . . . why your results seem to coincide with hunting season
The original post in the other thread was clear as to why the observations reported coincide with hunting season. Didn't I write that the deer was shot during a special youth-only hunt? In light of this clear fact, it seems dishonest for you to write that I did not "mention . . . why your results seem to coincide with hunting season."
We are conducting these experiments on wild, free-ranging deer for several reasons:
1) This maximizes the opportunity for other researchers to repeat our work. Deer are abundant and widely available. In addition, the shooting of wild, free ranging deer is not covered by the animal research guidelines of the National Academy of Sciences which some have asserted prohibits the shooting of live, unanethetized animals in a laboratory setting.
2) One aspect of our work is to test the widely circulated hypothesis that the Strasbourg Goat Tests were a fraud. Using goats is much more expensive because of the the bureaucratic requirements and using goats would likely provoke a legal challenge (via the NAS guidelines), as well as provide a central, well-localized target for animal rights fanatics. We believe that deer are sufficiently similar to goats to allow us to test the hypothesis that the Strasbourg Goat Tests were a fraud.
Shear_stress said:
your rationale for using muzzleloaders to model centerfire handgun rounds
We have developped techniques for shooting deer at a fixed, known range, but that range is not zero. This being the case, we needed a method to create an impact velocity in deer equal to the muzzle velocity of the load in a pistol. We also needed a method to reliably keep the shots in a small region comparable to the impact region used in the Strasbourg Goat Tests.
It is widely believed in the ballistics community that bullet performance doesn't depend on what it is fired from, only on the bullet itself and the impact velocity. We considered various options for getting the bullet to impact the test subject at a given range with great accuracy and the correct velocity. These included using longer barrels (such as Thompson Contender), moving up in cartridge volume (such as using a 10mm to test .40 S&W impact velocities), etc.
The most convenient approach seemed to be saboting the pistol bullets and shooting from a muzzleloader. A scoped muzzleloader can hit the target very accurately at ranges out to 100 yards. Using a chronograph, it is easy to develop loads to reproduce the proper impact velocity.
The muzzleloader also maximizes the ease of reproducing and extending our work by other researchers. Widely available sabots allow for testing .40, .429, and .451 caliber pistol bullets in a .50 caliber muzzleloader and .355, .357, and .40 caliber pistol bullets in a .45 caliber muzzleloader. With two muzzleloaders, any interested party can repeat and extend our work to every service cartridge except for the .41 magnum.
Using a muzzleloader provides an effective work-around for states whose laws prohibit handgun hunting completely, or prohibit handgun hunting with certain service calibers. It also extends the season in which testing can be conducted.
Shear_stress said:
how you actually measure the intensity of a pressure wave in live animals that are apparently free to run after being shot, your actual predictions of the pressure wave in a wound
In the initial post of this thread, I made the case that the peak pressure wave magnitude can be reasonably estimated from the kinetic energy, the fraction of lost mass, and the penetration depth. You have acknowledged that this description of the Physics is valid, and this description includes predictions for the pressure wave magnitude in a wound. The accuracy of these estimates can be also be confirmed by instrumenting ballistic gelatin with a PZT-based high speed pressure gauge.
We are developping acoustic techniques for detecting the pressure wave in the test subject. we don't believe that these acoustic techniques will be more accurate than our current estimates for peak pressure magnitude. However, these acoustic techniques will be useful for detecting the spread of the wave as it moves through the test subject, understanding the isotropy of the wave, better understanding the frequency spectrum and velocity of different components of the wave, and better understanding the wave dynamics as the wave reflects around in the thoracic cavity.
Shear_stress said:
how you will to continue to work at your apparently anti-gun college after your paper is published
I fully realize that I might be fired. I considered waiting for tenure prior to going public with my involvement in this project, but then I decided that the need to publish sooner outweighed my professional considerations, and that if the college wanted to fire me, it was probably best to move on. I am fully prepared to seek employment at a new institution that will allow me to continue with this work.
Shear_stress said:
how you will be free from the scourge of animal rights activists *after* your work is published, etc., etc.
We have a very careful plan in place. I have mentioned that we expect that live animal experiments will be forced to stop for some time after publication, and we have prepared for this by planning work that does not involve live animal experiments. I have described these researh ideas previously when I wrote about the internal ballistics, external ballistics, and forensic ballistics projects we have planned. However, the effectiveness of other aspects of our plan depends on our plans remaining private.
Shear_stress said:
You claim to be a scientist, make repeated mention of your qualifications
Including how to verify my previous publications on wave dynamics and statistics in the peer-reviewed journals.
Shear_stress said:
You invite others to reproduce your work, and yet have not described how to do so systematically.
Repeating the observations from the 135 grain .40 caliber Nosler JHP impacting at 1350 really isn't that complicated.
In addition, when we've been contacted privately by researchers intent on performing similar work, we have communicated substantial details of our work beyond what I've written here. We have reviewed the experimental designs of other groups and made suggestions on how to ensure their results can be compared with ours.
Michael Courtney