Physics of the Ballistic Pressure Wave

[Michael Courtney]

Physics of the Ballistic Pressure Wave

One might wonder why a given 135 grain .40 caliber JHP bullet at 1350 FPS creates a larger ballistic pressure wave many other JHP bullets in the .40 S&W cartridge.

The origin of the pressure wave is Newton’s third law. The bullet slows down in tissue due the force the tissue applies to the bullet. By Newton’s third law, the bullet exerts an equal and opposite force on the tissue. When a force is applied to a fluid or a visco-elastic material such as tissue or ballistic gelatin, a pressure wave radiates outward in all directions from the location where the force is applied.

The instantaneous magnitude of the force, F, between the bullet and the tissue is given by

F = dE/dx,

Where E = ½ m V*V is the instantaneous kinetic energy of the bullet, and x is the penetration distance. dE/dx is the first derivative of the energy with respect to the penetration depth. In other words, it is the instantaneous rate of kinetic energy loss per inch of penetration depth. Losing 100 ft-lbs of kinetic energy in 0.02 feet of penetration would create a force of 5,000 lbs because 100 ft-lbs/0.02 ft = 5,000 lbs.

It is important to note that this force (equal to the rate of energy loss) changes continuously and depends on both the loss of velocity and the loss of mass (unless the mass is constant). By the chain rule of calculus,

F = dE/dx = ½ V*V dm/dx + m V dV/dx,

Where dm/dx and dV/dx are the instantaneous rate of mass and velocity loss with respect to penetration depth.

Applying this formula directly requires detailed knowledge of the instantaneous mass and velocity changes of a bullet at every point along the wound channel. The instantaneous force can be accurately determined by shooting the same bullet through varying thicknesses of ballistic gelatin. In other words, one might shoot through a 0.05 ft thick block of gelatin to determine the loss of energy in the first 0.05 ft of penetration. Then one might shoot through a 0.1 ft thick block of gelatin to determine the loss of energy in a 0.1 ft thick block of gelatin. Then one might shoot through a 0.15 ft thick block of gelatin to determine the loss of energy in a 0.15 ft thick block of gelatin. Repeating this process in small increments, and applying standard techniques for estimating derivatives from measured values at closely spaced points would yield an accurate measurement of the instantaneous force at every penetration depth.

There are some simple and reasonable estimates that can be made more easily.

In cases where the mass is constant, the average force Fave between the tissue and bullet is simply the initial kinetic energy E divided by the penetration depth d.

Fave = E/d.

However, in cases where the bullet loses mass along the wound channel, the average force is increased by between 1 and 2 times the fraction of mass lost. If the bullet loses 20% of its mass distributed evenly along the wound channel, it creates an average force

Fave = 1.2 E/d.

Many bullets which lose mass, lose more mass early in the wound channel rather than late. This can enhance the average force even more. If the average depth of lost mass is one third of the penetration depth (d/3), the enhancement of the average force is twice the lost mass fraction. In other words, a bullet which loses 20% of its mass at an average depth of one third the penetration depth will create an average force

Fave = 1.4 E/d.

The peak of any variable force is larger than the average value. The peak to average ratio usually occurs during or right after expansion, and most bullets have peak to average force ratios between 3 and 8. Bullets which do not expand, penetrate deeply, and lose energy gradually have a peak to average ratio close to 3. Bullets which expand rapidly, lose a lot of energy early, erode down to a smaller diameter and then penetrate deeply have a peak to average ratio close to 8. Nosler Partitions with their soft lead front section which expands rapidly and erodes away quickly leaving the base containing roughly 60% of the original mass at little more than the unexpanded diameter is an example of large peak to average force ratio. Most JHP handgun bullets have a peak to average ratio close to 5, so this can provide a reasonably accurate estimate of the peak force in many cases.

If we go with the more conservative estimate that the average distance of penetration for lost mass is the middle of the total penetration (d/2) and we call the faction of lost mass f, then we estimate the peak pressure as

Fpeak = (1 + f) 5 E/d,

This allows us to see quite simply why the 135 grain bullet has a larger peak force than other .40 caliber S&W loads. The table below shows values of mass, energy, penetration, fraction of lost mass, and the peak force estimate for several .40 S&W loads

Load m (gr) V (FPS) d (in) E (ft-lbs) f F (lbs)
DT135JHP(N) 135 1350 11.9 547 0.36 3752
Rem165GS 165 1150 12 485 0 2427
Fed155HS 155 1140 13.3 448 0 2021
Fed180HS 180 950 15 361 0 1445

This force acts as a point of origin for the pressure wave which radiates outward in all directions. The pressure falls off with distance because the area it covers increases. However, we can compare the peak pressure generated by different loads if we standardize the point of interest to be the surface of a sphere with diameter of 1” centered at the point of origin of the force. This gives peak pressure wave levels of the different loads:

Load P(1") PSI
DT135JHP(N) 1195
Rem165GS 773
Fed155HS 643
Fed180HS 460

In summary, the .40 S&W Double Tap loading of the Nosler 135 grain JHP has a larger pressure wave than many other JHP bullets in that cartridge for three reasons:

1. It has greater kinetic energy.
2. It penetrates less.
3. It fragments and loses more of its mass.

One can apply this identical analysis to other JHP loads in this and other cartridges. Doing so reveals that there are a few other JHP loads which generate comparable peak pressure levels. Among them are the 125 grain Federal and Remington JHP loads in .357 Magnum that are known for their ability to incapacitate quickly.

Michael Courtney

 

[Shear_stress]

For the third time, here are my questions about your alleged research group:

Your research group should have a list of recent publications that you can reference. What is the name of your research group? Where is it located? Also, please post a link to its website. A Google search turns up nothing.

Science is about disclosure!

Edited to add: The only reference to a "Ballistic Testing Group" I can find on the internet is a link to another one of your posts on the highroad.org!!
Edited to add: There is a lot of controverisal research going on at institutes around the country. But they still publish!
Edited once again: If your research is so risky, than why post on a public forum under what we are led to believe is your own name?

You neglected to answer these questions in your previous thread, instead preferring to start a new one. Please answer them here.

 

[Michael Courtney]

For the third time, here are my questions about your alleged research group:

You neglected to answer these questions in your previous thread, instead preferring to start a new one. Please answer them here.

Look back at the other thread. I answered the questions as best I can at the present time shortly after you asked them the first time. It is very common for researchers active in live animal research to limit public disclosure prior to publication, and even to keep some things from public disclosure after publication.

I have copied my previous answer here (from the other thread):

The Ballistic Testing Group has been active since 2001. The abstract I mentioned is for our first publication which is in preparation. We are under a non-disclosure agreement which prevents release of a certain other information prior to publication. One motive for retaining a degree of privacy at this point is to minimize interference from animal rights activists. We believe that after certain information is disclosed we will encounter a much larger rate of interference by animal rights extremists.

Check out the article on page 10 of the December 2005 American Rifleman.

A couple of quotes:

"PETA wants to stop medical advancements that use animal research in any way."

"PETA's agenda is being forced upon society with acts of violence and terrorism . . . This eco-terrorism movement is so dangerous, the FBI has declared it America's No. 1 domestic terrorist threat on American soil . . . Scientists, doctors and their families are having property destroyed and are getting hate mail, letters loaded with razor blades and rat poison, and death threats and bomb threats."

Separate local efforts to kill some of our overpopulated deer herd have met with expensive legal challenges from these people. Hunters at a nearby farm endured multiple instances of vandalism, harassment, and intimidation for each of the last 5 years. I was personally threated in an anonymous phone call. Some of the contributors to our research effort have understandably chosen to remain anonymous even after publication, and we are keeping a lot of information private prior to publication because we believe that the live animal aspects of our work may well be shut down for a time after certain details are released.

Michael Courtney

 

[Michael Courtney]

Edited to add: There is a lot of controverisal research going on at institutes around the country. But they still publish!

I have been clear that there is a paper in preparation for publication. It is not uncommon for live animal research projects to take some time from initiation to publication.

Edited once again: If your research is so risky, than why post on a public forum under what we are led to believe is your own name?

One must balance the risks of public discussion with the need to get feedback from others as work is prepared for publication. It is common practice in all areas of scientific research to discuss results in informal settings prior to pubication. This aids greatly in helping the authors anticipate possible questions and misunderstandings so that the research can be communicated more clearly when published.

In addition, discussing our work publicly has allowed us to make contact with other groups pursuing similar experiments and to advise them on aspects of experimental design that will make their results most easily comparable to our own. We also made contact with a party who has given helpful input regarding one of our future experimental designs.

We also recognize that the preparation and publication process can take considerable time from our current status (initial draft) to the work appears in print. Releasing some results now allows interested parties to begin considering and possibly applying our findings prior to publication. Science in all areas would move forward much more slowly if scientists always had to wait for publication to be aware of new results.

I post under my own name because I have a deep rooted belief that using one's real name is important to credibility and accountability if one expects to be taken seriously. Other contributors are choosing to remain anonymous for now, and some may remain anonymous after publication. It's a personal choice I have made to balance the various considerations. I certainly understand if others have not made the same choice. My main concern is to limit the potential for direct interference with the research by the animal rights activists and to minimize the potential for legal challenges. Other contributors are concerned more with their personal safety and negative professional consequences. Our funding sources are concerned with negative public relations and being sued.

It's very difficult for an animal rights group to go to court and get a restraining order with the information currently available. It's very difficult for someone to sue any party except for me, and what would they sue me for? It's very difficult for the animal rights activists to interfere with the projects we currently have under way. Likewise, it would prove quite a challenge for them to try and obstruct current grant proposals.

All the animal rights fanatics really have available is attempting professional and personal reprocussions against me personally. My qualifications are such that I am not concerned with negative professional consequences, and anyone who threatens me personally with great bodily harm is volunteering to be the next data point in my study of bullet effectiveness.

By using my own real name I am able to engage in an relatively open discourse of the important scientific issues and results while reasonably protecting the various interests.

Michael Courtney

 

[Cosmoline]

OK, I can see the need to keep mum about details if live animal testing is used. However until the full results are published and we can actually see the REAL LIFE terminal effects of various weights of bullets, I will withhold judgment on the significance of the allegedly increased pressure wave from fragmenting rounds. The relative lethality of a larger pressure wave vs. better penetration and a large exit wound need to be carefully analyzed. Biology is more important than physics in the real world.

 

[Michael Courtney]

OK, I can see the need to keep mum about details if live animal testing is used. However until the full results are published and we can actually see the REAL LIFE terminal effects of various weights of bullets, I will withhold judgment on the significance of the allegedly increased pressure wave from fragmenting rounds. The relative lethality of a larger pressure wave vs. better penetration and a large exit wound need to be carefully analyzed. Biology is more important than physics in the real world.

This is a very good point. There is a balance between penetration and pressure wave.

However, it is documented by other sources (see the other thread on this subject) that fragmenting rounds do increase the volume of tissue destroyed by the temporary cavity.

I presented a description of the physics of the pressure wave because there is a great misunderstanding by many that the pressure wave mainly depends on velocity. This misunderstanding might have its origin in a misapplication of the Bernoulli equation which in some situations (not applicable in terminal ballistics) predicts the pressure is equal to 1/2 (rho) V*V, where V is the velocity and rho is the density of the fluid. This is a misapplication of the Bernoulli equation for many reasons:

1. The Bernoulli equation assumes that the medium is incompressible. This is usually not true in terminal ballistics.
2. The Bernoulli equation assumes that no energy is lost (transferred) between the viscous medium and the solid surface. This is not true in terminal ballistics where nearly all the energy is transferred to the visco-elastic medium.
3. The Bernoulli equation assumes that no work is done on the solid surface by the viscous medium. This is not true for expanding bullets. The medium does work expanding and eroding the bullet.

The idea that the pressure magnitude depends only on velocity and that the effect turns on at some velocity threshold (2000 FPS is often mentioned) simply isn't true. Bullets with large differences in velocity can have comparable pressure wave magnitudes.

Michael Courtney

 

[Cosmoline]

There's a lot of dispute about exactly how much tissue damage is actually done by the creation of a temporary cavity, and I've never seen a solid conclusion one way or the other. As I understand it if you take the temp cavity to the extreme--as in a .50 BMG hitting a gopher--the cavity exceeds the size of the animal and it just blows up. But the temp. cavity of a "high velocity" handgun round--a projectile with far less velocity than a rifle--I strongly suspect it's not doing anything the body's systems can't recover from. Certaintly nothing that will kill quickly. There is a tremendous flexibility to the innards. They can be pushed to one side, shook up, turned upside down and all sorts of things. For the temporary cavity to really do damage it has to be so large and powerful that it pushes vital elements of a key body system so far that they start to break apart. To me that means a rifle bullet going over 2,200 fps. I've never seen any good evidence that the small, high-vel handgun rounds can have this explosive impact on flesh. Ballistic gel tests are not the same.

 

[Michael Courtney]

For the temporary cavity to really do damage it has to be so large and powerful that it pushes vital elements of a key body system so far that they start to break apart. To me that means a rifle bullet going over 2,200 fps. I've never seen any good evidence that the small, high-vel handgun rounds can have this explosive impact on flesh. Ballistic gel tests are not the same.

As far as I can tell the size of the temporary cavity correlates (evidenced by hemorrhaged tissue) much better with the peak pressure wave magnitude than with projectile velocity.
I've shot two deer with a rifle bullet at (115 grain Berger VLD from 25-06) with impact velocity near 2700 FPS. The bullets failed to expand resulting in very little hemorrhaging and tiny pencil hole wounds. In contrast, you can view the wounds from the 135 grain .40 S&W at 1350 by visiting a thread by similar name at Glocktalk.com.

I also disagree that the TC observed in gelatin is not a good predictor of wounding. From my observations of dozens of deer, it correlates very well with observed hemorrhaging in the lungs.

Michael Courtney

 

[Jeff White]

It's been proven that the ballistic pressure wave and the resulting temporary wound cavity have little effect on incapactitation. Most tissue is elastic and unless other forces, such as fragmentation of the bullet, tear the tissue when it's stretched creating a larger permanent cavity.

Jeff

 

[Michael Courtney]

It's been proven that the ballistic pressure wave and the resulting temporary wound cavity have little effect on incapactitation. Most tissue is elastic and unless other forces, such as fragmentation of the bullet, tear the tissue when it's stretched creating a larger permanent cavity.

Jeff

This is incorrect. First, it relies on the unproven presupposition that incapacitation can only result from wounding that is easily detectable to the medical examiner or trauma surgeon.

Secondly, there is a growing body of evidence that higher-energy pistol rounds do indeed destroy tissue beyond the diameter of the expanded bullet. See the other pressure wave thread for details and discussion including references to published material.

Your assertion that "Most tissue is elastic and unless other forces, such as fragmentation of the bullet, tear the tissue when it's stretched creating a larger permanent cavity" is a myth that has been abandoned by much of the terminal ballistics community.

Michael Courtney

 

[Ultima-Ratio]

Great Thread!

My reason for choosing the 10mm was the massive "pressure wave" (I like that term!) caused from the high velocity 135s and 155s.
The scientific tests included old jeans legs stuffed full of spoiled black bear, salmon (yes the freezer died ) and the much feared Alaskan Porcupine.
Some of the handgun hunters here have probably seen the blood shot meat damage caused from the 180gn 1800fps 44 Maggie on deer and elk as opposed to the neat hole from Keith/SSK/LBT cast bullets at 1200 to 1500fps.

 

[Jeff White]

Your assertion that "Most tissue is elastic and unless other forces, such as fragmentation of the bullet, tear the tissue when it's stretched creating a larger permanent cavity" is a myth that has been abandoned by much of the terminal ballistics community.

You don't mind if I run that by Dr. Gary Roberts do you? He's about the best person I know in terminal ballistics and has quite a bit of published and peer reveiwed work in the field.

Unless the tissue is stretched beyone it's capacity and tears or is torn by other forces like the bullet fragmenting, it isn't usually damaged. If the pressure wave you are suggesting was so destructive, through and through wound created by something like 147 gr 7.62 NATO would most likely remove a limb or cause very tramatic injuries. Yet this isn't the case. How do you explain that? Why doesn't your pressure wave on a through and through wound of say the calf, always cause massive tissue disruption?

Pressure waves do not always case serious tissue disruption. I would refer you to a training film produced by the Army in 1970 titled Missile Wounds. In it the doctors seemed baffled how the M193 round sometimes produced very devasting wounds and sometimes it didn't. an example they used of it producing a very simple wound was a self inflicted GSW to the foot. The bullet made a through and through wound that didn't disrupt a lot of tissue. If your theory is correct, that shouldn't have happened, you had a 55 grain bullet moving at 3250 fps. The pressure wave should have torn his foot apart, yet it didn't. How do you explain that and be consistant with your theory? Of course thanks to Dr. Fackler we now know that the bullet didn't stay in the foot long enough to yaw and fragment and create a devastating wound, simply because the foot wasn't that big.

I'm sorry but I think you're on the wrong track here. Unless you stretch the tissue beyond it's elastic limits or the strecthing tears it from other tissues, you're not getting a permanent wound.

Jeff

 

[Cosmoline]

Meh. I've heard far too much propaganda and sales pitches on behalf of high-vel handgun rounds over the years to put much much stock in this sort of thing. I'll wait for the hard data AND specific information about exactly who funded the research.

 

[Michael Courtney]

If the pressure wave you are suggesting was so destructive, through and through wound created by something like 147 gr 7.62 NATO would most likely remove a limb or cause very tramatic injuries. Yet this isn't the case. How do you explain that? Why doesn't your pressure wave on a through and through wound of say the calf, always cause massive tissue disruption?

A 147 grain FMJ .308 bullet impacting at 2500 FPS will penetrate gelatin roughly 30". Using the pressure wave estimation technique outlined above, this would create a peak pressure wave magnitude of rougnly 780 PSI on the edge of a 1" diameter circle centered at the middle of the wound tract. This pressure wave magnitude is smaller than some pistol bullets.

In addition, if a pistol bullet cannot damage tissue beyond that contacted by the expanded bullet, then how do you explain the 1.5" diameter of pulverized tissue on the inside of the rib cage and > 1.0" diameter of pulverized tissue at the medial surface of the left lung that we observed in a buck shot with a 135 grain .40 cal Nosler JHP at 1350 FPS. (See the other thread.) How do you explain hemorrhaging to the lungs far beyond this? I can attach pictures if you wish.

Michael Courtney

 

[Michael Courtney]

I'll wait for the hard data AND specific information about exactly who funded the research.

We are under a non-disclosure agreement not to reveal the identity of our funding sources. This part of the agreement is unlikely to be changed. Funding live animal research is not the best public relations and some aspects of the work attracts hassles from animal rights fanatics. We can say that the work is not supported in any way by any ammo company. (We even buy all the ammo we test.) Nor is the work funded by Marshall and Sanow.

Michael Courtney

 

[Jeff White]

In addition, if a pistol bullet cannot damage tissue beyond that contacted by the expanded bullet, then how do you explain the 1.5" diameter of pulverized tissue on the inside of the rib cage

The tissue was pulled away from the rib because it was stretched beyond the elasticity of the tissue holding it to the rib cage.

and > 1.0" diameter of pulverized tissue at the medial surface of the left lung that we observed in a buck shot with a 135 grain .40 cal Nosler JHP at 1350 FPS. (See the other thread.) How do you explain hemorrhaging to the lungs far beyond this? I can attach pictures if you wish.

Not all tissue has the same elasticity. Internal organs simply don't stretch as much. Surely the impacts received in automobile accidents and falls generate pressure waves like the impact of a high velocity bullet, yet they still cause internal organs to rupture. How much of the hemorrhaging to the lungs do you think might be caused by the resulting deflating of the lung? I seem to recall the protocall for treating a wound like that is to seal it airtight to prevent further damage as the victim breathes. I would expect to see hemorrhaging to the lungs far beyond the wound.

We are under a non-disclosure agreement not to reveal the identity of our funding sources. This part of the agreement is unlikely to be changed. Funding live animal research is not the best public relations and some aspects of the work attracts hassles from animal rights fanatics.

And you don't think you'll receive hassles from the animal rights fanatics when you publish your work? Or are you just going to post on the internet? Who is peer reviewing it?

I would think discussing these findings on open internet forums would also be in violation of the non-disclosure agreement, especially before they are published. I know someone who works in the intellectual property field and she says participation on a hobbyists forum would be enough to get someone fired and possiblly sued. Yet you post under your own name and and even give us references. I'm sorry, my sixth sense is telling me there is something wrong here. I'm going to refer this thread to Dr. Gary Roberts for his input. If anyone can tell us if there is any truth to this, he can. You don't mind a little peer review from someone who is known in the field do you?

Jeff

 

[JohnKSa]

Maybe we could listen to what he has to say for awhile before immediately going into attack mode. This appears to me to be quite a new approach (at least in terms of what we normally see here) to terminal ballistics. Clearly, there are some problems with the existing theories of terminal ballistics or the debate wouldn't have continued this long.

I would like to suggest that it might be profitable to listen to what Mr. Courtney has to say and let what he posts stand on its own merit. I don't think it's productive to immediately attempt to discredit him simply on the basis that his results don't align with a popular view.

 

[mete]

" 3. It fragments and loses more of it's mass" Certainly in a hunting situation I wouldn't want to fragment the bullet, even in a SD situation I'd like to have the bullet hold together least it break up on clothing or barriers. I carry ,but haven't shot anything with it , the 40 DPX. It apparently holds together very well which should make it very consistant.

 

[Shear_stress]

We are under a non-disclosure agreement not to reveal the identity of our funding sources. This part of the agreement is unlikely to be changed. Funding live animal research is not the best public relations and some aspects of the work attracts hassles from animal rights fanatics. We can say that the work is not supported in any way by any ammo company. (We even buy all the ammo we test.) Nor is the work funded by Marshall and Sanow.

Folks, what we have here is an artful dodge. Michael's assertions simply do not stand up. Animal research (often of a controversial nature) occurs at nearly every major research university (and at a places like Oregon's Primate Research Center--they make no bones about what goes on there--see
http://onprc.ohsu.edu/) Yet, somehow, they continue to publish data. If you check the websites at any department at any university, they will be chockfull of links to the webites of their research groups. Hell, even the famous "Body Farm" operated by the University of Tennessee Department of Anthropology has an extensive website (even featuring information that tells you how can donate your body). See http://web.utk.edu/~anthrop/index.htm.

As I said before, the "Ballistic Research Group" does not exist. Try to do a Google search for it. If it had existed since 2001, as claimed, there ought to be a substantial body of publications that he could reference. It is hard to believe that this group has been active for four years, yet has published nothing. With a track record like that, it's no wonder the group would have trouble receiving funding in the "publish or perish" environment of any research center.

 

[Jeff White]

JohnKSa,
One of the missions here at THR is to put out reliable information. There is way to much noise to signal ratio on the errornet as Pat Rogers refers to it.

I have nothing against new science. However, when it suddenly appears and goes against 30 years worth of published research, and they are posted on an internet forum without any published links to the research, or peer reviews and they are funded by unidentified parties who may or may not have a commercial interest in the shooting public accepting this information as gospel, then the alarm bells go off.

Everyone here is free to believe anything they wish. What is wrong with someone I know, who happens to be a recognized expert in the field weighing in?

Jeff

 

[Shear_stress]

Thanks, Jeff. Please run this by someone with actual, verifiable qualifications. I don't give one whit about the purported conclusions here. It's just that all of Michael's hand waving has pegged my BS-ometer something fierce.

By the way, a quick Google search gets you scads of info on Dr. Gary Roberts. At least his story checks out.

 

[Jeff White]

My friend who works in intellectual property law found me this link for Ballistic Research Group:

http://www.ioffe.rssi.ru/GASDYN/content-bg.html

It's in Russia. They deal with aerodynamics. From their site:

During the past 20 years the unique experience of free flight tests aimed at study of flight performance (stability, drag, etc.) of various objects in the area of ordnance, rocket and space technology has been accumulated (Dr. A.N. Mikhalev). Investigations are performed so as to evaluate aerodynamic characteristics of a body under study. A special advanced technique of non-linear estimation, including mathematical statistics approaches, is employed (Dr. N.P. Mende and Dr. A.B. Podlaskin). The static aerodynamic coefficients are determined with accuracy of 1-5%, the damping moment is found with accuracy of 5-10%. Among the objects studied there are various projectiles of classical sharp and blunt bodies (including spacecraft Soyuz command module), bodies with a region of spike-induced flow separation (like Trident missile), models of explosively formed projectiles and so on.

Jeff

 

[Gewehr98]

That's all well and good...

But I'm still not real keen on shooting whitetail with a .40 S&W during deer season.

Whadd'ya suppose the Ballistic Pressure Wave of a 500gr .459" swaged lead spitzer moving along at a leisurely 1300fps is?

 

[JohnKSa]

What is wrong with someone I know, who happens to be a recognized expert in the field weighing in?

Not a thing. In fact that's exactly what should happen.

However, what we've got going right now is far more like a desperate scramble to discredit someone than an analysis of the information they have provided.

goes against 30 years worth of published research

With all due respect, that's 30 years of published research based on a single point of view. There are certainly differing views on this topic or we wouldn't be having this discussion.

 

[Shear_stress]

John,

The issue is not whether anyone sides with Michael's viewpoint. I have no opinion of temporary stretch cavities and whatnot. The issue is how the information is being presented. Michael relies heavilly on a blizzard of jargon, the whole "if you can't dazzle 'em with brilliance, baffle 'em with bull****" school of thought. See above for his sudden and unsolicited mention of the Bernoulli equation, where he holds forth at length on a concept taught in first-semester fluid mechanics. When challenged, though, he tends to change his story to reflect the nature of the challenge. See how he responded to my inquiry about him doing ballistics research on fetuses that suddenly became unborn deer fetuses in his reply. Or maybe look at the backflips he had to do after I asked how exactly he was going to tell if a submerged mammal was incapacitated.

The biggest threat to his credibility is that he offers nothing in the way of published, verifiable data to back up his claims and hides behind a bizarre excuse that, if it was true, could be used by ninety percent of the researchers in the biomedical, biomechanics, and pharmaceutical fields. Michael's vocabulary is good, and obviously he has some kind of physics background, but, without published data, his is just another person spreading internet rumors.