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Talk:Hydrostatic shock

Hydrostatic vs Hydrodynamic
So why former and not the latter? — Preceding unsigned comment added by 65.94.23.207 (talk) 00:57, 18 September 2015 (UTC)

More Specific?
"The debate between proponents of bullets that are "light and fast" versus bullets that are "slow and heavy" often refers to this phenomenon.

Which bullets cause more hydrostatic shock? —Preceding unsigned comment added by 65.13.133.70 (talk) 02:03, 20 June 2010 (UTC)

I'm not sure, but I would think the bullet with the higher kinetic energy would cause greater pressure waves. Thus it is not really a question of "light and fast" vs. "slow and heavy." 81.209.35.6 (talk) 14:15, 8 August 2010 (UTC)

ETHICS?
Wikipedia is a fully-public entity, and is used for research purposes by people of all ages - particularly students doing research for schoolwork.

Keeping that in mind - is it truly necessary to describe scientific experimentation on animals in full detail? I'm a male, mid-30s, and I perused this article looking for information on tissue damage caused during sonic treatment of kidney stones. I have seen and read enough about human and animal suffering over the years that I consider myself strong enough to read material that most might find disturbing, and I fully realize that a lot of research goes on that many would consider inhumane.

Despite all that, I still found it gruesome and disturbing when I was reading the article and got to the description of pigs being deliberately shot in the thigh - obviously a non-lethal but very painful injury - all in the name of "science."

Whether or not you consider the practice of using live animals for ballistics research to be ethical is totally irrelevant. BUT, describing the procedure in print in an article such as this seems a little excessive to me. Not because it is describing scientific research, ethical or not - it is not meant to be deceiving, as far as I can tell.

Anyway - my suggestion - and I WON'T change it myself, since I am not an expert... I see no reason why the experimentation couldn't be described in a manner such as "research on animal tissue has shown that injury to the hippocampus....." - and THEN following that with a footnote reference OR a direct link where the reader can find more information.

In that way, the information is still given and made available - maybe even more so than as originally written - but is less likely to cause sensitive readers any grief.

I'm not writing this as an anti-gun activist in any way. But I do know that there are many people in the general population who are disturbed by material that refers to scientific experimentation on animals, especially when such material can come off as sounding inhumane. - DM

 * There are a number of Wiki pages which describe animal research with a comparable level of detail. Some give even more detail.  Effectively communicating a scientific result often requires describing the experiment.  An article on wound ballistics is going to describe wounds.
 * Definitely more detail in the experiment is better when it shows how it relates to the rest of the evidence. Since later in the article, hydrostatic shock is described with people being hit in the chest, it's important to show that this experiment shoots pigs in a different area.
 * Michael Courtney (talk) 12:20, 11 April 2008 (UTC)

—Preceding unsigned comment added by Crux1234 (talk • contribs) 04:34, 5 April 2008 (UTC)

So if the bullet lodges in a person’s body, does the shock wave still do as much damage as if the bullet passes through the body?

 * Since the shock wave does precisely zero damage, yes. The shockwaves of being shot with an anti-aircraft gun with several thousands of rounds per day, over a period of years, may cause some slight loss of innervation and circulation to the kidneys, but that is all. -Arrkhal 00:49, 23 January 2006 (UTC)

Why does the article link to a page that contains simply a copy of it, crediting Wikipedia? Seems kind of pointless. --Vadim

Perhaps someone with medical training could elaborate? --Anders Törlind

I found a few web pages that contend the hydrostatic shock effect of bullet penetration; that is they do not believe that bullets damage humans in this way. No real science or pathology either way though. --drj

Merge?
Discussion on whether to merge this article with stopping power:
 * No - Hydrostatic shock, while closely associated with stopping power, is a concept in its own right, and merging it would make stopping power a bit of an omnibus article. --Orborde 22:16, 12 September 2005 (UTC)
 * I meant merge the section on hydrostatic shock from stopping power to here, not vice-versa. ··gracefool |☺ 06:49, 13 September 2005 (UTC)
 * No - Even with this new information regarding the original intention of merging, the article stopping power needs some sort of summary. Although some of the information in stopping power could be merged, bullets have special regard to hydrostatic shock, and that information should be kept in the article stopping power. --DarthFredd
 * No - Hydrostatic shock is extra wounding caused by the shock waves inside the body, caused by the passage of the bullet. Any scientific evidence I've read suggests that Stopping Power (the damage that puts a target down) is loss of blood, nerve function and shock. --Eon
 * Okay, I've removed the merge templates. ··gracefool |☺ 23:55, 18 October 2005 (UTC)

Can anymore evidence be cited in this topic? I have personal experiances that would suggest to me the validity of the workings of hydrostatic shock, though it takes a round of considerably higher velocity then anything that can be fired from a handgun. Try instead a 200 grain round from a .30-378 Weatherby traveling at around 3,400 fps. I have personally seen this combination drop deer and larger size animals instantly, even when no wounds were inflicted that should have been immediatly fatal. I'm not saying one way or another if the subject in question is a valid idea, however if someone knows of some more evidence it would be nice to see it.

 * Blunt trauma to the spinal cord due to temporary cavity. Damage inflicted by the temporary cavity is limited to stretching damage, and blunt trauma.  The blunt trauma component can extend for a couple inches around the temporary cavity due to tissue compression.  If this "wave" of compression hits the spinal cord, it can cause instant unconsciousness, exactly like a "rabbit punch."  Arrkhal 01:09, 30 December 2005 (UTC)

Ok, but what about the exist wounds. I think hydrostactic may be a misnomer but parts of the body have a resonance.

Baloney
Who ever says that hydrostatic shock has been dis-proven is full of bologna. This is only true for wounds caused by small caliber low velocity nonexpanding bullets. These wounds are refered to in medical literature as an "ice pick wound". Wounds caused by high velocity big bore expanding bullets resemble an explosion. There is tremendous tissue damage far from the axis if bullet penetration. Those supposed idiots that write for gun magazines know exactly what they're talking about. They have seen the effects of these weapons many times on the bodies of big game animals.

204.227.223.74 21:05, 21 June 2006 (UTC)Tlaloc

 * {sigh}. Another person who either didn't read or didn't comprehend the article.  Go read stopping power as many times as it takes to understand what's written there, and get back to me.  Arrkhal 22:40, 22 June 2006 (UTC)

"Tissue does behave similarly enough to water that a sonic pressure wave can be created by a bullet impact, generating pressures in excess of 100 atmospheres. However, a device known as the lithotriptor, commonly used to break up kidney stones, produces sonic pressure waves of approximately 5 times the amplitude of those caused by bullets. Up to 2000 such pressure waves are used in a single treatment session, with no damage to soft tissues whatsoever." - This comparison is ludicrous.

A lithotriptor prodcues tiny, highly focused waves from a small emitter. A 5.56mm bullet travelling at over 900 m/s results in a near-instananeous energy transfer in the order of 1800 joules, nothing like what a lithotriptor can generate. And since it's a broad spectrum physical impact, the affected tissues, because the shock waves generated are of far lower frequency than those produced by an ultrasonic instrument, are wrenched back and forth over a much greater distance by the pressure wave. It is usually localised by the shock absorbing affects of tissue, and therefore does not merit much discussion, however, in an area such as the brain, the pressure waves generated cannot dissipate, and cause severe damage as the brain tissue is compressed against the hard cranium. As a footnote, lithtriptors have been known to cause renal capillary damage, among other problems, which can lead to renal failure.

Dallas 01:24, 24 July 2006 (UTC)

Yeah, this doesn't exist. Take two beer cans. Drink one. Go ahead and open the other one. Sit them both side-by-side down range. Shoot each of them with a high power (1000+ ft/s) .177 pellet rifle. The empty can will have a small entry hole and a somewhat bigger exit hole. The other can will be torn almost in half. Here's the kicker: The tear in the can most of the time is nowhere near the exit hole. Its usually near the entrance. What's tearing the can?

209.134.164.170 20:31, 3 August 2007 (UTC)

What's tearing the can? The same stuff that makes you burp after you have drunk the first can before handling your gun: carbon dioxide. When it's released by the entry of the pellet, the pressure will tear the can wall (same as if you open the can, but the top is stronger than the wall). Not convinced? Alright: Try shooting a plastic bag filled with water (entirely) and closed tight with your pellet rifle. Does the bag burst, or does it just leak water from two holes? Herringgull2 (talk) 12:33, 9 January 2009 (UTC)

The same results can be obtained by filling the can with water, milk, diesel or any other fluid, with the lid open or closed doesn't matter much, therefore the theory that carbon dioxide is responsible is disproven, as eliminating that factor does not alter the effect.

This effect isn't related to carbon dioxide. This is simply the projectile transferring kinetic energy to the liquid, causing it to move radially away from the projectile, causing pressure within the can. — Preceding unsigned comment added by 50.142.9.22 (talk) 15:13, 7 January 2015 (UTC)

Incompressible fluid
I have a problem with the statement: "The claim that tissue behaves like water is obviously false. Water is an incompressible fluid, while tissue is a compressible solid." First of all, nothing in science is obvious, and the first sentence could be changed into "evidence shows that..." or sth like that. No one claims that tissue behaves like water all the time, but that they can have similar behaviours under some circumstances. Then, saying that water is incompressible is simply wrong. Nothing is incompressible. If water really was, the oceanic level would be roughly 30m higher than it is now, there would be no shock wave in water, and the speed of sound in it would be infinite (later the article correctly quotes the speed 1500 m/s). "less compressible than tissue" would be more appropriate. Finally, I'm not sure that opposing tissue as a solid to water is relevent either. Water is a liquid for most applications, but when very quick phenomena are studied, like the penetration of a bullet, it can behave similarly to a solid. In the end, I think a sentence like "Experiments show that tissue and water behave differently, because they have different compressibility values" would be better. Chacal 00:00, 20 September 2006 (UTC)

Tone
"The claim that tissue behaves like water is obviously false..." That entire line (if not section) has POV and tone issues. I think it should be deleted/rewritten. Adropofreason 23:16, 10 April 2007 (UTC)

Debates in the Gun Community are Funny
So, how long has this hydrostatic shock [sic] debate been going on, and how contentious will it get before it is finally resolved? Will those on either side ever be able to admit that they were wrong?

Anyway, the actual article needs a serious rewrite to get it up to the standards of the better articles on Wiki. —Preceding unsigned comment added by 64.179.121.20 (talk) 16:48, 11 November 2007 (UTC)

 * I'm reasonably certain the debate has been going on for roughly a century. Rsemmes92 (talk) 16:14, 2 November 2022 (UTC)

There have been many debates in the history of science where the side that is wrong never really admits that they were wrong. However, eventually all scientists die, and the new generation of scientists tends to believe the side that has better support in the published data. Sometimes it takes a generation or two for wrong ideas to fall out of favor. But repeatable experiment usually wins in the end. The scientific method is a slow process; in many cases revolutions are quick; in other cases, change takes a generation.Michael Courtney (talk) 23:13, 22 December 2007 (UTC)

Random collection of thoughts
I've been thinking recently about the topic of hydrostatic shock, and I figured I'd go ahead and do a brain dump, with some observations and questions that I have.

High speed projectiles appear to have three distinct effects when hitting an object. We'll assume ballistic gelatin for now, as it's standardized and roughly replicates tissue. All of these are demonstrable, and measurable. A hydrophone will measure the hydrostatic shock in μPa, the temporary cavity can be seen in high speed photographs (and its size and speed estimated from them), and the permanent cavity volume is readily measured by filling with fluid, and its perimeter may be estimated if a transparent medium is used. That these phenomena exist is pretty much beyond question. The question is, how much impact does each have in relation to wounding? This is where the issue becomes very murky.
 * 1) Hydrostatic shock. This is a compression wave that travels through the medium--in other words, a sound wave.  And with regards to comments above, water IS slightly compressible, otherwise compression waves would NOT travel through it.
 * 2) Temporary cavitation. This is tissue that is displaced by the projectile, but springs back.  Unlike the compression wave, which travels at the speed of sound in the medium, this is a displacement wave, and travels much slower, though it can readily exceed the speed of the projectile.  This effect only exists in elastic mediums, like ballistic gelatin, which will spring back wherever the tensile strength of the material is not exceeded.
 * 3) Permanent cavitation. This is the hole that remains after the medium comes to rest.  This is cause by stressing the material to beyond its elastic limits, typically by direct contact of the projectile, but may also result from remote stretching exceeding the material strength, such as the "splash" of a high speed impact crater.

Permanent cavities are sufficient to cause lethal wounds; this can be readily demonstrated by looking at wounds by low velocity penetrations, such as knife wounds and similar mechanical trauma. These impacts produce negligible amounts of hydrostatic shock and temporary cavities, and kill by direct destruction of vital organs and blood loss.

Temporary cavities are more contentious, but are again sufficient to cause lethal wounds. Many organs are relatively inelastic, and can be damaged by stretching; this damage may arguably be called a permanent cavity, and shows up in ballistic gelatin as radial tears along the wound path, largest near the point of entry. A good example of a temporary cavity with little or no hydrostatic shock or permanent cavity is blunt trauma such as a punch to the abdomen. This elastically displaces the tissue, tears blood vessels, and can rupture organs. An example of this is the ruptured appendix said to have claimed Houdini's life.

Now for the most contentious part, the effect of hydrostatic shock on wounding. Various assertions are made about wave pressures required for incapacitation, ranging from 45 psi to 1500 psi. Information on where the pressure is measured, or how the pressure waves attenuate as they propagate through the body, doesn't seem to be available. The body is not a homogeneous medium, and compression waves reflect and refract significantly at the junction between areas of dissimilar density. This doesn't necessarily cause greater attenuation, however. Just like the internal reflection in an optic fiber, certain conditions in an acoustic medium can reduce attenuation and cause sound to travel much farther than the inverse square law would predict.

A lithotripter, according to one reference I found, generates pressure waves on the order of 100 MPa, while the hydrostatic shock causing value of 1500 psi you cite translates to 10 MPa. While some tissue destruction has been shown to happen from lithotripter use, the most significant side effects appear to be greater risk for hypertension and adult onset diabetes, not sudden loss of consciousness. An examination of the methods by which these shockwaves can cause cell damage and hemorrhaging showed that it was due to cavitation, which is caused by negative pressure waves in excess of 1 MPa. This damage was only seen in areas adjacent to the application of the shockwave. Lithotripsy also involves thousands of these 100 MPa shockwaves in a session.

None of the cited papers I've looked at claiming to show incapacitation from remote injuries appear to decouple hydrostatic shock (sound waves) from effects caused by the temporary or permanent cavitation, which are both dynamic effects (pushing material around). This should be simple enough to do, simply by using a lithotropter or other similar device to apply hydrostatic shock waves to the central nervous system of a suitable test subject. Since hydrostatic pressure is easily measured, and appears to be readily decoupled from other variables, it seems irresponsible to draw any conclusions from the existing data. If hydrostatic shock can be shown to be a significant wounding factor, then it should be simple enough to design bullets to maximize the level of hydrostatic shock; certainly there are designs intended to maximize temporal cavities (like the THV and Devel concave ogive bullets) and permanent cavities (like large meplat, flat nosed solids) so there is no reason there could not be a design to maximize hydrostatic shock. Bullet shape will certainly have an effect on hydrostatic shock; just listen to the sound waves generated by a diver entering the water in different ways. The energy and velocity will be the same for a given diver falling the same distance, but the sound levels between a clean, head-first dive and a belly flop will be very different (as will penetration and splash). Based on the diving analogy, I suspect that hydrostatic shock will be strongly coupled to the temporary cavity size. I also suspect, based on the use of lithotripsy to remove stones from areas very near the central nervous system, such as the salivary glands, that hydrostatic shock will be found to have little or no immediate impact on incapacitation.

One possibility that popped into mind when mentioning the optic fiber above is the soliton wave. These waves, in their fluid form, are unique not only in the fact that they suffer far reduced attenuation, but also because they result in a significant shift of mass; the discoverer originally called them a "wave of translation" because of this property. It seems that temporary cavity formation in any region containing large blood vessels, especially in the thorax, could create an unusually large soliton in the circulatory system. There are a number of papers that provide some tangential support for this, comparing normal blood flow to soliton waves, where the elasticity of the blood vessels allows the blood to travel in waves of translation, rather than pressure driven flow, and there are a number of other papers that provide the mathematical solutions for generating solitons in thin walled, elastic tubes. A soliton would also provide a pressure peak detectable with a transducer, but the soliton would travel far slower than the compression wave of hydrostatic shock wave, which (by definition) travels at the speed of sound in the medium.

Well, that's it. Anyone out there who might, say, have a research laboratory and the means do some testing is welcome to have a go at the problem. Unless one has an infinite supply of goats then it's probably best to first approach the issue of relative incapacitation effects of dynamic vs. static pressure waves, using non-ballistic means. That knowledge in hand, a set of pressure transducers embedded in a block of ballistic gelatin could be used to measure and differentiate between static and dynamic pressure waves, allowing a reproducible medium to be used for further testing. scot (talk) 14:51, 28 March 2008 (UTC)

 * Much of the theoretical discussion of wave-propagated damage emphasizes momentum transfer while neglecting thermodynamic aspects of bullet impact. The foot-pound traditionally used to describe bullet energy can be translated to thermal calories, with three foot-pounds being approximately equal to one calorie.  Calories can raise the temperature of tissue fluids and convert them to steam.  The requirement for doing so is energy release focused on a small area so heat transfer away from that area will not be fast enough to prevent development of a temporary steam bubble.  The released energy is mathematically represented as one-half bullet mass times bullet velocity squared; but, for the area of interest, the velocity translated to energy is the difference between the entrance velocity and the exit velocity.  A penetrating bullet carries some of it's energy away as it leaves.  The most effective thermodynamic energy transfer results from a high velocity bullet disintegrating into small particles stopping near the point of disintegration.

 * This type of bullet is likely to generate a high-pressure steam bubble which momentarily expands radially to approximate atmospheric pressure, and then condenses to leave the wound cavity characteristic of high-velocity expanding bullets. The phenomena is very similar to an explosion, with the difference that the gas generated as steam will rapidly re-condense into water following expansion rather than remaining as carbon dioxide like conventional explosives.  Hydrostatic shock could be transmitted through blood vessels, perhaps in the form of a soliton wave as you suggest.  Assuming fixed steam bubble pressure transients for similar energy release in similar tissues, a variable factor would be dissipation from fluid flow resistance between the steam bubble location and the vulnerable parts of the central nervous system.  Central nervous system effects should be most evident from steam bubbles generated near large arteries and veins.

 * This appears to be a neglected interdisciplinary interpretation of observed results. I suggest editors review engineering publications on thermodynamics and fluid flow (momentum, heat and mass transfer) for reference citations.Thewellman (talk) 22:49, 11 January 2011 (UTC)

 * Instantaneous condition of the heart is another variable for consideration with vascular transmission of bullet energy. Hydraulic pressure transients coinciding with systolic ventricular contraction would be additive to peak blood pressure, while transients arriving when the heart was diastolic might be dissipated by expanding the relaxed heart rather than transmitted to rupture capillaries in the brain.Thewellman (talk) 22:40, 13 January 2011 (UTC)

I haven't read the work of Suneson, but if the article writer is explaining it accurately, it's bad science. If you shoot a pig -even an anaesthetised pig- in the leg, well, you'll get a massive spike in intra-cranial pressure (which is what the researcher's transducers are measuring). But you'd get that same spike if you passed a suction catheter down the animals' throat- discomfort causes spikes in ICP. That's nothing new (and doesn't really justify shooting pigs). It doesn't in itself indicate the presence of a pressure-wave emanating from the axis of injury up to the brain; why didn't the researchers think of placing intra-abdominal and intra-thoracic transducers which would be able to demonstrate the transmission of a pressure-wave?

As for the resultant rise in ICP (intra-cranial pressure), you'd need a sustained- not fleeting- pressure of 20-30 mm Hg to disrupt cognitive function. And the effects would take too long to manifest themselves to alter the outcome of a firefight. The fact is, raised ICPs are only witnessed (in the context of smallarms) after direct head-trauma, not after thoracic or abdominal wounds. It's just a fact. Check with any reputable neurosurgeon who's treated gunshot victims. Similarly, if effects of hydrostatic shock can damage the brain from afar, how come anyone ever survives a penetrating head wound from a bullet? (Admittedly rare, but I've known a few). Doesn't the Kellie-Monroe principle apply? However, you don't need a neurosurgeon to tell you that being shot hurts- this is more than enough to explain any momentary pausing by a wounded man; it doesn't require pseudo-science and the sacrifice of pigs. And if- as proponents of 'hdrostatic shock' claim, these pressure-waves travel via major blood vessels (and apart from via cerebro-spinal fluid in the case of the spine being hit, there doesn't seem to be any other credible mechanism)- why aren't the lungs / heart damaged? No immediate trauma, no thrombo-embolytic events, no raised troponin-T, no disruption of cardiac pacing. Most significantly, there's no loss of blood-pressure autoregulation (and resultant neurogenic cardiac shock), although such a pressure-wave would presumably impinge on baro-receptors which are sensitive to, er, pressure. As for apnea in shot pigs- well, if I was shot, I might gasp or briefly hold my breath too.

The fact is, if hydrostatic pressure-waves occur during smallarms injury, they seem to have little clinical effect. —Preceding unsigned comment added by Cappuchin (talk • contribs) 03:12, 29 March 2008 (UTC)

My understanding is that discussion on the Talk page should be confined to discussing improvements to the article. The last few posts seem more of a general discussion on the hydrostatic shock topic. To be sure, some interesting points are raised that are worthy of discussion. I propose moving the discussion to a more appropriate forum. This space should be used mainly for discussing article improvements. Since there is already a discussion on the topic at www.thehighroad.org I will answer the points that have been raised there. See: http://www.thehighroad.org/showthread.php?p=4343280&posted=1#post4343280 Michael Courtney (talk) 13:48, 29 March 2008 (UTC)

Above comment read as: "Too many people here think I am full of crap. Please come over to a forum filled with more similar basement-dwelling firearms know-it-alls who will shower you with insults until you stop bothering to post, and I win." This poster has apparently started this little pissing contest over what is at best a theory elsewhere, with the apparent misapprehension that so long as a smarty-looking guy in a lab coat has a test indicating something, it becomes fact. This is not, nor hopefully will it ever, be the way scientific research operates. The place to discuss the content, or more specifically, the validity of Wikipedia articles is Wikipedia. NOT a topical forum elsewhere. —Preceding unsigned comment added by 24.255.205.234 (talk) 00:46, 6 May 2008 (UTC)

 * I doubt that you can cite many references that meet Wikipedia standards for reliable sources that disagree with the numerous references cited in the Hydrostatic Shock article. There are sufficient references to the peer-reviewed literature to support the article.  Certainly, contrary views can be included in the article, provided that they meet Wikipedia standards for reliable sources.  Scientific research operates based on published data.  There is quite a bit of published data supporting remote pressure wave effects.  To date, we have found no published data contradicting remote neural effects of ballistic pressure waves.Michael Courtney (talk) 19:57, 6 May 2008 (UTC)

 * Good job avoiding the issue on that one. The point remains: 'please follow me and discuss this on another page' is not a good response to an argument here - it's tantamount to 'let's take it to the parking lot.' I am not saying that anything isn't properly sourced or doesn't belong or even that anything in article should be changed - just that debating the issue should be done here not on a page you already know is overrun with people who agree with your position. —Preceding unsigned comment added by 24.255.205.234 (talk) 05:33, 8 May 2008 (UTC)

 * This Wikipedia talk page is for discussing article improvements, not for general discussion of the topic. My intent was to steer more general topic discussion to an alternate forum, so that the discussion here could focus on more specific suggestions for improvements to the article.  If your point is that the hydrostatic shock article is somehow wrong or incomplete, you need to bring reliable sources to the discussion if you are suggesting that the existing article be modified to include information from additional sources.  If your point is a general discussion to better understand the topic, then it is appropriate to suggest an alternate forum.  All this is established Wikipedia policy.Michael Courtney (talk) 17:17, 8 May 2008 (UTC)

 * 'Does the evidence cited actually show this' is a pretty legitimate 'article improvement' discussion. Removing potentially spurious claims that may or may not conform with basic logic is as well. —Preceding unsigned comment added by 24.255.205.234 (talk) 09:17, 9 May 2008 (UTC)

Introduction
The first sentence defines the term as a theory and briefly describes it. The second sentence states that there is supporting evidence (Many references are cited later in the article). The third sentence gives some context. Given the amount of supporting evidence cited in the main body, asserting that the theory is supported with scientific evidence is a reasonable component of the introduction. Remote wounding effects are not seriously doubted in the scientific literature, and the last significant objection was published 19 years ago and relied on a personal communication that did not agree with the findings that were published the following year (by RF Bellamy). This objection is discussed frankly.Michael Courtney (talk) 03:16, 14 July 2008 (UTC)

FBI
The article contains this wording:

"The FBI recommends that loads intended for self-defense and law enforcement applications meet a minimum penetration requirement of 12” in ballistic gelatin [8]. Maximizing the ballistic pressure wave effects requires transferring maximum energy in a penetration distance that meets this requirement. In addition, bullets that fragment and meet minimum penetration requirements generate higher pressure waves than bullets which do not fragment."

Correct me if I'm wrong, but if it's the FBI article I've read regarding 'stopping power' the author goes out of his way to assert that HS does not exist. He spends entire pages describing how the only reliable ways to stop a human being are incapacitation through CNS disruption (fast) or blood loss (slow). The requirements for deep penetration and fragmentation were in order to directly impact major organs, not induce HS. This is a hell of a spin job, however. —Preceding unsigned comment added by 214.13.82.22 (talk) 10:06, 4 May 2009 (UTC)

 * The article seems to be full of that kind of thing. 96.242.81.80 (talk) 19:40, 9 January 2011 (UTC)

Tone and Impartiality
As a casual reader with no knowledge of the area, I cannot help but notice that whoever wrote this article is firmly of the opinion that hydrostatic shock exists. Note that where opinions supporting this point of view are cited, the author(s) are keen to point out evidence which backs up those opinions, while dissenting opinions are attacked. Furthermore, there is a clear difference in the use of language: the two major dissenters here (Fackler and McPherson) both 'claimed', while supporters of the theory 'noted', 'described', 'showed', 'demonstrated'; in other words, the case against hydrostatic shock is given as opinion, while the case for hydrostatic shock is given as fact.

I know little about the subject, but I can spot a biased article. If there is no real debate in the scientific community as to the existence of hydrostatic shock, then this should be stated. If there is debate, the reader should know why without clear bias.

I am interested to note that one of the contributors to this discussion is Michael Courtney, whose own work is frequently cited in the article and who has an obvious professional bias towards the existence of hydrostatic shock. While it is pleasing that an expert in the field is contributing to this page, the fact that he is so clearly on one side of the argument could itself suggest bias. (It is, perhaps, more worrying that, while Courtney and Courtney are cited in footnote 15 as a source for the repudiation of Fackler's opinion, there is no such suggestion in the body, where their research is regurgitated as fact.)

I think this needs a clean up by a neutral party. It certainly is curiously schizophrenic at the moment; on the one hand debating the existence of hydrostatic shock, and on the other hand giving some detailed outcomes for recent research. One way or another, the linguistic bias should be cleaned up. 62.253.112.209 (talk) 04:52, 21 September 2009 (UTC)

Okay, I've noticed that THE contributor is Michael Courtney. Which means that this article desperately needs a skilled editor to meet encyclopedic standards. Wouldn't you agree? 62.253.112.209 (talk) 04:58, 21 September 2009 (UTC)

It's been well over a decade since Fackler, MacPherson, and Patrick last published their contra-claims. Even as of 1996, there were many more scientific voices in the reliable sources supporting remote wounding effects. In the last 13 years, all the new data published in reliable sources has been supportive of remote wounding effects, and the body of scientific literature supporting remote wounding effects has grown considerably. The article gives proportional weight to the reliable sources: three or four authors and papers against the idea, lots of scientists and papers published providing supporting evidence. I don't think they are all mentioned in the current article, but I could list 30-40 scientific articles and 30-40 scientists on record in reliable sources giving support to remote effects of ballistic impacts.Michael Courtney (talk) 13:39, 7 October 2009 (UTC)

The problem with Dr. Courtney is that he has repeatedly shown a willingness to bury the opposition in citation that ultimately lead nowhere, while being consistently unable to produce a single source that demonstrates what he wants it to after an actual analysis of the content (in once instance on M4Carbine.net claiming remote wounding effects to the brain based on a case study of bullet that passed through the targets skull). The result seems very credible to the casual observer but his conclusions are rejected by the vast majority of professional ballisticians and physicists note that the energy needed to cause such tears simply is not present. He also has been known to cite this wikipedia page (as noted entirely his own creation) as evidence of his claims. The FBI and almost all world militaries have been highly successful using Permanent Cavitation to determine which arms are most effective, where as rounds such as the Glaser Safety Slug (which should produce tremendous hydrostatic shock effects if they had any significance) have been rejected by absolutely everyone. —Preceding unsigned comment added by 96.242.81.80 (talk) 22:41, 21 December 2010 (UTC)

 * Courtney and Courtney have had their terminal ballistics work related to the topic published in medical journals including Neurosurgery, NeuroImage, Brain Injury, and Injury. Are these journals not peer-reviewed?  Then how can one argue that no one agrees with it?  Since their findings were first published, has there been any credible disagreement published in a peer-reviewed journal?  Other viewpoints meeting Wikipedia standards for reliable sources can certainly be included, but gun discussion forums do not meet Wikipedia standards as reliable sources.  —Preceding unsigned comment added by 24.255.94.205 (talk) 05:41, 27 December 2010 (UTC)

 * I was drawing attention to Dr. Courtney's long established history of going online and deliberately using floods of irrelevant citations to create imaginary support for his beliefs. He should not be allowed to control this article unchallenged. I would point to this articles mention of the Borden institute's studies on wound ballistics (he uses them to support hydrostatic shock) in fact the paper's content is quite clear in its rejection of ballistic pressure waves as an important mechanism of wounding due to the incredibly small number of cases where it is even a possible explanation. The specific reference to 10% of fractures being indirect is hugely out of context, failing to note work that showed the pressure wave falling with with incredible speed, so much that the fractures would require bullets passing within less than a centimeter of the bone. His references to the lithotripsy imply that it causes wounding, that is not what the linked papers assert. As for publications by his team in the journals you named, on topics related to ballistics, I can't find any reference to them. His own website links to arXiv preprints rather than to the appearances in peer-reviews journals. Discussion of the validity of hydrostatic shock is secondary to this element of the discussion, we are trying to establish if Dr Courtney is a trustworthy source (given his clear propensity for cherry picking data I would say he is not) and even if he is if he should be allowed the near total authorship of this article that he appears to have. —Preceding unsigned comment added by 96.242.81.80 (talk) 05:01, 28 December 2010 (UTC)

 * Assuming that editors are acting in good faith is a key idea on Wikipedia. You do not seem to be extending that assumption in this case.  There isn't much in the article that isn't well supported by the citations. Google scholar searches on "Courtney ballistic pressure wave" and "Courtney hydrostatic shock" provide links to their material that has appeared in peer reviewed journals as well as the arXiv material.  The Bellamy material available from the Borden institute seems to be quite open minded toward ballistic pressure waves as a wounding mechanism.  Please provide a page number and a more detailed citation to support your claim if you've found a clear outright "rejection of ballistic pressure waves as an important wounding mechanism" in the Borden Institute material cited in this article.  Have you read the recent article in Neurosurgery on hydrostatic shock?  It seems pretty much in agreement with the current article here.Support.and.Defend (talk) 02:33, 1 January 2011 (UTC)

 * I'm not making the assumption that he's acting in good faith because, provably, he is not. Evidence against hydrostatic shock has been carefully excised from the article when he makes citation to papers that specifically deny that hydrostatic shock is capable of reliably causing damage (Bellamy 136 and 153, http://www.bordeninstitute.army.mil/published_volumes/conventional_warfare/chapter4/Pages26-49.pdf [unless we count "within a centimeter" as remote wounding and if we do it should be noted because the result is hugely misleading otherwise]; from the FBI field manual page 16, http://www.bordeninstitute.army.mil/published_volumes/conventional_warfare/chapter4/Pages26-49.pdf [noting methodological flaws in the idea of hydrostatic shock as a reliable wounding mechanism]). Several section of the article are taken whole cloth from Courtney's work without noting that fact (about half the article is stolen from here: http://www.scribd.com/doc/21502666/Scientific-Evidence-for-%E2%80%9CHydrostatic-Shock%E2%80%9D). Wikipedia is not the place for Dr Courtney to attempt republishing his material to a larger audience. Why would the article from Neurosurgery *not* be in agreement with his page? They were written almost entirely by the same person. —Preceding unsigned comment added by 96.242.81.80 (talk) 05:12, 3 January 2011 (UTC)

WDMET data
The issue of whether the article text accurately reflects the cited sources should be discussed without making personal attacks. The article cites Bellamy in the paragraph that reads

So the key question seems to be whether Bellamy supports the Fackler claim of “no cases of bones being broken, or major vessels torn, that were not hit by the penetrating bullet. In only two cases, an organ that was not hit (but was within a few cm of the projectile path), suffered some disruption” or whether they provide supporting evidence for distant injuries.

The Bellamy citation does not deny hydrostatic shock as a wounding mechanism. Bellamy cites Harvey's conclusion that “stress waves probably do not cause any tissue damage” (p. 136), but Bellamy seems to have an open mind that Harvey's interpretation might not be definitive because he also writes “the possibility that stress waves from a penetrating projectile might also cause tissue damage cannot be ruled out.” (p. 136) The WDMET data includes a case of a lung contustion resulting from a hit to the shoulder. If Bellamy is so convinced that distant injuries do not occur, then why does the figure caption (4-40, p. 149) say, “The pulmonary injury may be the result of a stress wave.”  He also describes the possibility that hit to a soldier's trapezius muscle caused temporary paralysis due to “the stress wave passing through the soldier's neck indirectly caused cervical cord dysfunction.” (p. 155)

In addition to stress waves, Bellamy also describes shear waves as a possible mechanism of indirect injuries in the WDMET data. The distance of 1 cm for breaking human bones on p. 153 is an extrapolation from a Chinese experiment in animals. How does this effect Bellamy's estimate that 10% of the fractures in the WDMET data may be the result of indirect injuries? Does Bellamy state that in each case in the WDMET data the fracture was within 1 cm of the bullet path? In addition, even if there is a 1 cm distance maximum for broken bones due to shear waves, this maximum does not seem to apply in abdominal injuries. Bellamy writes, “The abdomen is one body region in which damage from indirect effects may be common.” (p.150) Bellamy describes the injuries shown in Figures 4-42 and 4-43 writing, “The damage shown in these examples extends far beyond the tissue that is likely to direct contact with the projectile.” (p. 150)

In addition to providing examples from the WDMET data for indirect injury due to propagating shear and stress waves, Bellamy also expresses an openness to the idea of pressure transients propagating via blood vessels can cause indirect injuries. “For example, pressure transients arising from an abdominal gunshot wound might propagate through the vena cavae and jugular venous system into the cranial cavity and cause a precipitous rise in intracranial pressure there, with attendant transient neurological dysfunction.” (p. 154)

In summary, at no point does Bellamy suggest that indirect injuries due to hydraulic effects in tissues do not occur. He points out numerous examples in the WDMET data of cases of that seem to be examples of indirect injuries. The WDMET data definitely does not support the Fackler claim of “no cases of bones being broken, or major vessels torn, that were not hit by the penetrating bullet. In only two cases, an organ that was not hit (but was within a few cm of the projectile path), suffered some disruption.”Support.and.Defend (talk) 15:18, 10 January 2011 (UTC)

 * Please tell me this is some kind of performance art about scientific illiteracy. Bellamy is very clear about the non-existence of strong evidence for stress waves as a wounding mechanism. His "openness" to the idea is blatantly twisted by the article into outright support. At every stage he points out that the evidence is weak. People can go read this is they want to. Finding things that haven't been properly explained but might what we might expect from something is not evidence in favor of it. As for Fackler's unfortunate choice of words I would not that Bellamy's ability to find only ten cases or so of things that *MIGHT* be evidence for hydrostatic shot in the entire Vietnam War is strong evidence that stress waves are the least reliable wounding mechanism possible.

To ignore this is terribly dishonest. —Preceding unsigned comment added by 96.242.81.80 (talk) 20:29, 30 January 2011 (UTC)

Sorry to intrude on your discussions, but I have a question regarding this WDMET data collected in Vietnam during the USA occupation... was there not a convention which forbade the use of soft point/hollow point/flat point projectiles in war?(or any other projectile which imparts significant kinetic energy or momentum of the projectile to the target) Of the data collected, what portion was the result of injury from bullets encased in a full metal jacket, and as a full metal jacketed round has a tendency to do, pass through without imparting a significant amount of the projectiles energy to the target, and what effect has this on propogating a pressure wave in the target? If there is an effect of limiting the pressure wave by using FMJ, can this data be used to invalidate the proposed wounding mechanism? — Preceding unsigned comment added by 173.180.126.62 (talk) 19:10, 14 November 2011 (UTC)

That would be The Hague_Conventions_(1899_and_1907), but the main parties of the war were not signatories to it. The standard South Vietnam-allied military round for most of the war was 5.56%C3%9745mm_NATO, and the standard North Vietnam-allied round was 7.62%C3%9739mm. Both are full metal jacket bullets. Davethehorrible (talk) 09:03, 6 February 2014 (UTC)

Grenade in a swimming pool
In the book Neuromancer, a character states that he had once seen a multiple assassination in Ankara in which a single grenade was tossed into a swimming pool and killed the people in it via hydrostatic shock. This article only discusses the term in the context of a bullet hitting a single target. Did the Neuromancer character use the term incorrectly, or should there perhaps be a disambiguation sentence at the top of this article redirecting to a differently titled article for the other phenomenon, of a shock wave traveling through a body of water? Comet Tuttle (talk) 22:03, 17 March 2011 (UTC)

Yes and no. In the specific case of the swimming pool there are several different wound mechanisms so it is difficult to tell which one kills. At close range to a blast, a bubble of hot gasses form within microseconds, displacing water outwards. A hydraulic shock. This causes a pressurewave that will squash people in the water. After the bubble have finished expanding, the displacement shockwave turns into a soundwave, and this propagates outwards even though no water is moving. This is the hydrostatic shock. It can kill for quite a distance, and does so by shredding the lungs and bowels of the victim. That happens because when the wave passes tissue it will behave like water and so the energy is not released. But at any point of a water/gas interface, like in tha alveolas, the tissue around the gas pockets will compress violently and then be pressed out again after the wave has passed by the now high pressure gasses. So if one swimmer has his chest high in the water, and another is fully submerged, the former might be completely unharmed then the latter id killed immediately. — Preceding unsigned comment added by 83.252.164.222 (talk) 20:28, 31 July 2011 (UTC)

Changed cartridge comparison in first paragraph.
I changed this sentence in the first paragraph: "Proponents of bullets that are "light and fast" such as a .22-250 remington versus bullets that are "slow and heavy" such as a 9mm pistol round often refer to this phenomenon."

To: "Proponents of cartridges that are "light and fast" such as the 9x19mm Parabellum versus cartridges that are "slow and heavy" such as the .45 ACP round often refer to this phenomenon."

Hydrostatic shock discussions do go back and forth with the size vs speed argument, but comparing a high velocity rifle round like the .22-250 to a pistol round is comparing apples to oranges.

First, the bullet is only the projectile, which has little to do with its speed. The cartridge is what goes into the firearm and contains the bullet and powder. Second, the applications of the cartridges are completely different and not comparable. The .22-250 is a very high velocity rifle round often used as a varmint cartridge. The 9mm is a high velocity pistol round. There are rifles in a chambered for 9mm, and many sub-machine guns, but they would never be used in place of a .22-250. Third, the 9mm is often often used as a proponent of the hydrostatic shock discussion when comparing it to larger and slower rounds. Most often in the firearm community the (sometimes heated) discussion and comparison is 9mm vs .45 ACP.

This is my first non-typo edit, so this long justification may not be necessary, but I wanted to explain myself. Also, I don't mean the above to sound snippy, no offense intended to the original author. Kolvir (talk) 07:53, 25 May 2011 (UTC)

Hydrostatic shock is a general term
Hydrostatic shock describes the damaging or destructive effects of abrupt pressure changes in a semi- or incompressible medium. Hydrostatic shock is what makes the pipes knock in your house when you rapidly shut off a faucet. It is also what sometimes blows out the seals in a power steering pump or automatic transmission.

The problem is that if someone read this article they would never know that the general definition of hydrostatic shock has nothing to do with gun-nut talk.

Bigdumbdinosaur (talk) 01:25, 28 September 2012 (UTC)

Ammo Manufacturers - Hydrostatic shock as a factor in selection of ammunition
The hooey published by ammunition manufacturers or their spokesman, such as Chuck Yeager, should be removed from this. This isn't a billboard for their products and the fact that they have an agenda should disqualify their comments. If they have hard, fast data and experimental results to share then they should publish those but leave their products out.

This entire section should be expunged and doing so would raise the quality of the article considerably. — Preceding unsigned comment added by 66.68.11.35 (talk) 22:35, 30 April 2013 (UTC)
 * Agreed, and I just removed the advertising. Actually, the whole article has serious neutrality and sourcing issues, and needs to be cleaned up. ROG5728 (talk) 22:39, 30 April 2013 (UTC)

Good. I was going to put a "caveat emptor" section there but prefer that it just be removed. Obviously if there are still serious questions about the existence of hydrostatic shock, its causes and effects - velocity, mass, and penetration to name just a few - any claim at having designed or engineered something that actually causes it is absurd. Even if it were well understood and bullets had been manufactured that could produce it, it isn't clear why that would be relevant to wikipedia. — Preceding unsigned comment added by Ranx0r0x (talk • contribs) 23:21, 30 April 2013 (UTC)

Claim of NPOV issue

 * Agreed, and I just removed the advertising. Actually, the whole article has serious neutrality and sourcing issues, and needs to be cleaned up. ROG5728 (talk) 22:39, 30 April 2013 (UTC)

 * The debate is well known. The trouble is a lot of support for the theory has been published in the last decade, and the naysayers have published almost nothing in venues that qualify as reliable sources per wikipedia standards.  Discussion forum posts don't count, and Gary Roberts has published nothing in a peer reviewed journal or other scholarly venue.  Wound Ballistics Review is defunct.  The evidence that has been published in the last decade seems fairly convincing, and most of the "other side" of the story (HWFE, etc.) is over 20 years old.  This older material seemed compelling at the time, but compared with more recent articles in NeuroImage, Brain Injury, Neurosurgery, forensic studies from Iraq and Afghanistan, and evidence from Europe, the old material is just weak.  The older material basically was an argument from absence, and now that there is published data, the old arguments from absence just don't hold water.  Face it, the naysayers could have easily published replies in the peer reviewed journals answering the new findings.  The fact that they choose not to speaks volumes.  If you have new negative information from the last decade from a verifiable source that meets wikipedia standards as a reliable source, feel free to add it.  But as far as I can tell, all the reliable sources are well represented in the article.Support.and.Defend (talk) 02:15, 3 May 2013 (UTC)
 * WP:NPOV states, "Editing from a neutral point of view (NPOV) means representing fairly, proportionately, and as far as possible without bias, all significant views that have been published by reliable sources." The claim of "serious neutrality and sourcing issues" needs to be supported by citing reliable sources with significant views which have not been represented in the article.  If the editor(s) claiming that the neutrality is in dispute are unable to provide reliable sources to other significant views that are not represented in the article, then the POV tag should be removed.  Support.and.Defend (talk) 09:21, 4 May 2013 (UTC)

There are plenty of sources already in the article -- you just twisted them, downplayed them, or misrepresented them in every way imaginable. The "company advertising" junk I removed was just one example of the serious issues plaguing this article. I know who you are, I know you have a close personal connection to this topic, and I know you wrote the entirety of this article without any outside input. Please see WP:COI. Editing with a conflict of interest is disruptive to Wikipedia. ROG5728 (talk) 18:01, 4 May 2013 (UTC)
 * How many of the original sources have you actually read? I've fact checked many of them and find them to be accurately represented in there use here.  For example, how do you think the J. Krajsa citation twists or misrepresents the original source?  How does the Col. Frank Chamberlain, M.D. citation misrepresent the original source?  How does the citation of Historical Overview of Wound Ballistics Research misrepresent the original source?  Support.and.Defend (talk) 21:26, 4 May 2013 (UTC)
 * Again, you wrote the entire article so of course you don't see its issues. A number of those issues have already been described here on the talk page, but there are too many to list. Lots of weasel wording, misrepresented sources, poor use of quotes (and overuse of quotes), etc. The whole article is a mess. ROG5728 (talk) 22:16, 5 May 2013 (UTC)

Michael Courtney
I propose that everything on this page authored by Michael Courtney be removed. He uses "citations" to assert statements that are not in line with the linked material. Furthermore, there is a conflict of interest here: Michael and Amy Courtney sell ammunition based upon their "hydrostatic shock" theory. There are significant problems with his references, including the Krajsa reference. Half of the patients selected in this reference were intoxicated at their time of death, indicating a high likelihood of alcoholism. Abuse of alcohol increases the likelihood of small subcortical infarcts and primary subcortical haemorrhages. Even moderate drinking of alcohol increases risk of both intracerebral and subarachnoid hemorrhage. The presence of micro-hemorrhages does not constitute any reasonable expectation of increase incapacitation potential in a firearm. — Preceding unsigned comment added by 50.13.84.20 (talk) 12:41, 14 July 2014 (UTC)

 * , the other major contributor to this article, appears to be an undeclared sockpuppet of . There also seem to be serious POV and COI issues with these accounts and their contributions to the article. --Epipelagic (talk) 05:13, 18 August 2014 (UTC)

 * Heh, no wonder this page is so heavily in favour of hydrostatic (or more accurately hydrodynamic) shock. Michael Courtney seems to have authored almost all of it 222.164.146.23 (talk) 12:13, 20 March 2024 (UTC)

Misleading article title
As was mentioned in a comment several years ago,hydrostatic/hydraulic shock is a more general term than its application to theories of firearm wounds. For examplic, "hydraulic shock" is a common term (sometimes called water hammer) regarding the movement of pressurized fuilds in conduits, etc. The article (which honestly, is pretty POV....no objective comparison between stances is given...anything not supporting the theory seems to be explained away or spun) is only dealing with the application of a concept to a specific medium. Either the article title should change (suggest move to hydrostatic shock (firearms), or something similar) or disambiguation should be included. this reads like an advertisement for certain types of firearms/ammunition.12.11.127.253 (talk) 19:00, 26 August 2014 (UTC)

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Suggest complete rewrite
"This is the talk page for discussing improvements to the Hydrostatic shock article. This is not a forum for general discussion of the article's subject."

Yet it seems to have become just that.

I found the article very hard to read. It's thread is hard to follow, and the material mixes discussion of subsonic and supersonic projectiles in a manner making it difficult to determine which statements apply to which type, etc. It gave me a headache of tl;dr magnitude.

Seems to need a rewrite in general to make it easier to follow. After all, this is an encyclopedia, the purpose being that John Q can read it and get a general idea of the subject matter. If further, more technical information is desired, he can look up the citations, or go to a University library and look up peer reviewed, scholarly papers published in relevant journals.

The discussion by scot, "Random Collection of Thoughts," although out of the scope of the Talk page, was very easy to read. The construction and style were well thought out, and it flowed well, especially for a random set of ideas.

Perhaps he can do a rewrite and submit it for Wikipedia publication. -- "But it wasn't the bullet that laid him to rest, Was the low spark of high-heeled boys." Steve Winwood 104.174.70.130 (talk) 00:50, 7 September 2019 (UTC)

Redirect changed
I changed the page hydraulic shock, which previously redirected here, to a disambiguation page, as the term may also refer to a water hammer according to that page. The redirect shock effect may also warrant review to see if it has a more general meaning. TornadoLGS (talk) 18:40, 19 June 2021 (UTC)

title: Talk:Hydrostatic shock


text:
Hadith

Hadith (حديث) or Athar (أثر,, lit. 'remnant' or 'effect') is a form of Islamic oral tradition containing the purported words, actions, and the silent approvals of the prophet Muhammad. Each hadith is associated with a chain of narrators (a lineage of people who reportedly heard and repeated the hadith, from which the source of the hadith can apparently be traced). Compilations of hadith were collected by Islamic scholars in the centuries after Muhammad's death. Hadith are widely respected in mainstream Muslim thought and are central to Islamic law.

is the Arabic word for things like a report or an account (of an event). For many, the authority of hadith is a source for religious and moral guidance known as Sunnah, which ranks second only to that of the Quran (which Muslims hold to be the word of God revealed to Muhammad). While the number of verses pertaining to law in the Quran is relatively small, hadith are considered by many to give direction on everything from details of religious obligations (such as or, ablutions for  prayer), to the correct forms of salutations and the importance of benevolence to slaves. Thus for many, the "great bulk" of the rules of Sharia are derived from hadith, rather than the Quran. Among scholars of Sunni Islam the term hadith may include not only the words, advice, practices, etc. of Muhammad, but also those of his companions. In Shia Islam, hadith are the embodiment of the sunnah, the words and actions of Muhammad and his family, the (The Twelve Imams and Muhammad's daughter, Fatimah).

Unlike the Quran, not all Muslims believe that hadith accounts (or at least not all hadith accounts) are divine revelation. Different collections of hadīth would come to differentiate the different branches of the Islamic faith. Some Muslims believe that Islamic guidance should be based on the Quran only, thus rejecting the authority of hadith; some further claim that most hadiths are fabrications (pseudepigrapha) created in the 8th and 9th centuries AD, and which are falsely attributed to Muhammad. Historically, some sects of the Kharijites also rejected the hadiths, while Mu'tazilites rejected the hadiths as the basis for Islamic law, while at the same time accepting the Sunnah and Ijma.

Because some hadith contain questionable and even contradictory statements, the authentication of hadith became a major field of study in Islam. In its classic form a hadith consists of two parts—the chain of narrators who have transmitted the report (the ), and the main text of the report (the ). Individual hadith are classified by Muslim clerics and jurists into categories such as ("authentic"),  ("good"), or  ("weak"). However, different groups and different scholars may classify a hadith differently. Historically, some hadiths deemed to be unreliable were still used by Sunni jurists for non-core areas of law.

Western scholars are generally skeptical of the value of hadith for understanding the true historical Muhammad, even those considered by Muslim scholars, due to their first recording centuries after Muhammad's life and the unverifiability of the claimed chains of transmission, and the widespread creation of fraudulent hadiths. Western scholars instead see hadith as more valuable for recording later developments in Islamic theology.

Etymology
In Arabic, the noun (حديث  ) means "report", "account", or "narrative". Its Arabic plural is (أحاديث ). Hadith also refers to the speech of a person.

Definition
In Islamic terminology, according to Juan Campo, the term hadith refers to reports of statements or actions of Muhammad, or of his tacit approval or criticism of something said or done in his presence.

Classical hadith specialist Ibn Hajar al-Asqalani says that the intended meaning of hadith in religious tradition is something attributed to Muhammad but that is not found in the Quran.

Scholar Patricia Crone includes reports by others than Muhammad in her definition of hadith: "short reports (sometimes just a line or two) recording what an early figure, such as a companion of the prophet or Muhammad himself, said or did on a particular occasion, preceded by a chain of transmitters". However, she adds that "nowadays, hadith almost always means hadith from Muhammad himself."

In contrast, according to the Shia Islam Ahlul Bayt Digital Library Project, "... when there is no clear Qur'anic statement, nor is there a Hadith upon which Muslim schools have agreed. ... Shi'a ... refer to Ahlul-Bayt [the family of Muhammad] to derive the Sunnah of the Prophet"—implying that while hadith is limited to the "Traditions" of Muhammad, the Shi'a Sunna draws on the sayings, etc. of the  i.e. the Imams of Shi'a Islam.

Distinction from
The word is also used in reference to a normative custom of Muhammad or the early Muslim community.

Joseph Schacht describes hadith as providing "the documentation" of the.

Another source (Joseph A. Islam) distinguishes between the two saying: "Whereas the 'Hadith' is an oral communication that is allegedly derived from the Prophet or his teachings, the 'Sunna' (quite literally: mode of life, behaviour or example) signifies the prevailing customs of a particular community or people. ... A 'Sunna' is a practice which has been passed on by a community from generation to generation en masse, whereas the hadith are reports collected by later compilers often centuries removed from the source. ... A practice which is contained within the Hadith may well be regarded as Sunna, but it is not necessary that a Sunna would have a supporting hadith sanctioning it."

Some sources (Khaled Abou El Fadl) limit hadith to verbal reports, with the deeds of Muhammad and reports about his companions being part of the, but not hadith.

Distinction from other literature
Islamic literary classifications similar to hadith (but not ) are and. They differ from hadith in that they are organized "relatively chronologically" rather than by subject. Other "traditions" of Islam related to hadith include:
 * (literally "way of going" or "conduct"), biographies of Muhammad, written since the middle of the eighth century. Similar writings called (literally "raid") preceded the  literature, focusing on military actions of Muhammad, but also included non-military aspects of his life.  Therefore, there is overlap in the meaning of the terms, although  suggests military aspects rather than general biographical ones.
 * (literally news, information, pl. ) may be used as a synonym for hadith, but some scholars use it to refer to traditions about Muhammad's companions and their successors from the following generation, in contrast to hadith as defined as traditions about Muhammad himself. Another definition (by Ibn Warraq) describes them as "discrete anecdotes or reports" from early Islam which "include simple statements, utterances of authoritative scholars, saints, or statesmen, reports of events, and stories about historical events all varying in length from one line to several pages."
 * Conversely, (trace, remnant) usually refers to traditions about the companions and successors, though sometimes connotes traditions about Muhammad.

Hadith compilation
The hadith literature in use today is based on spoken reports in circulation after the death of Muhammad. Hadith were not promptly written down during Muhammad's lifetime or immediately after his death. Hadith were evaluated orally to written and gathered into large collections during the 8th and 9th centuries, generations after Muhammad's death, after the end of the era of the Rashidun Caliphate, over 1,000 km (600 mi) from where Muhammad lived.

"Many thousands of times" more numerous than the verses of the Quran, hadith have been described as resembling layers surrounding the "core" of Islamic beliefs (the Quran). Well-known, widely accepted hadith make up the narrow inner layer, with a hadith becoming less reliable and accepted with each layer stretching outward.

The reports of Muhammad's (and sometimes his companions') behavior collected by hadith compilers include details of ritual religious practice such as the five (obligatory Islamic prayers) that are not found in the Quran, as well as everyday behavior such as table manners, dress, and posture. Hadith are also regarded by Muslims as important tools for understanding things mentioned in the Quran but not explained, a source for (commentaries written on the Quran).

Some important elements, which are today taken to be a long-held part of Islamic practice and belief are not mentioned in the Quran, but are reported in hadiths. Therefore, Muslims usually maintain that hadiths are a necessary requirement for the true and proper practice of Islam, as it gives Muslims the nuanced details of Islamic practice and belief in areas where the Quran is silent. An example is the obligatory prayers, which are commanded in the Quran, but explained in hadith.

Details of the prescribed movements and words of the prayer (known as ) and how many times they are to be performed, are found in hadith. However, hadiths differ on these details and consequently is performed differently by different hadithist Islamic sects. Quranists, on the other hand, believe that if the Quran is silent on some matter, it is because God did not hold its detail to be of consequence; and that some hadith contradict the Quran, proving that some hadith are a source of corruption and not a complement to the Quran.

Non-prophetic hadith
Joseph Schacht quotes a hadith of Muhammad that is used "to justify reference" in Islamic law to the companions of Muhammad as religious authorities—"My companions are like lodestars."

According to Schacht, (and other scholars) in the very first generations after the death of Muhammad, use of hadith from ("companions" of Muhammad) and  ("successors" of the companions) "was the rule", while use of hadith of Muhammad himself by Muslims was "the exception". Schacht credits Al-Shafi'i—founder of the Shafi'i school of (or )—with establishing the principle of the using the hadith of Muhammad for Islamic law, and emphasizing the inferiority of hadith of anyone else, saying hadiths: "'...from other persons are of no account in the face of a tradition from the Prophet, whether they confirm or contradict it; if the other persons had been aware of the tradition from the Prophet, they would have followed it'."

This led to "the almost complete neglect" of traditions from the Companions and others.

Collections of hadith sometimes mix those of Muhammad with the reports of others. Muwatta Imam Malik is usually described as "the earliest written collection of hadith" but sayings of Muhammad are "blended with the sayings of the companions", (822 hadith from Muhammad and 898 from others, according to the count of one edition). In Introduction to Hadith by Abd al-Hadi al-Fadli, is referred to as "the first hadith book of the  (family of Muhammad) to be written on the authority of the Prophet". However, the acts, statements or approvals of Muhammad are called, while those of companions are called (موقوف) , and those of Tabi'un are called  (مقطوع).

Impact
The hadith had a profound and controversial influence on tafsir (commentaries of the Quran). The earliest commentary of the Quran known as Tafsir Ibn Abbas is sometimes attributed to the companion Ibn Abbas.

The hadith were used the form the basis of sharia (the religious law system forming part of the Islamic tradition), and fiqh (Islamic jurisprudence). The hadith are at the root of why there is no single fiqh system, but rather a collection of parallel systems within Islam.

Much of the early Islamic history available today is also based on the hadith, although it has been challenged for its lack of basis in primary source material and the internal contradictions of available secondary material.

The hadith have been called by American-Sunni scholar Jonathan A. C. Brown as "the backbone" of Islamic civilization.

Types
Hadith may be hadith qudsi (sacred hadith) — which some Muslims regard as the words of God — or hadith sharif (noble hadith), which are Muhammad's own utterances.

According to as-Sayyid ash-Sharif al-Jurjani, the hadith qudsi differ from the Quran in that the former are "expressed in Muhammad's words", whereas the latter are the "direct words of God". A hadith qudsi need not be a sahih (sound hadith), but may be da'if or even mawdu'.

An example of a hadith qudsi is the hadith of Abu Hurairah who said that Muhammad said: "When God decreed the Creation He pledged Himself by writing in His book which is laid down with Him: My mercy prevails over My wrath."

In the Shia school of thought, there are two fundamental viewpoints of hadith: The Usuli view and the Akhbari view. The Usuli scholars emphasize the importance of scientific examination of hadiths through ijtihad while the Akhbari scholars consider all hadiths from the four Shia books as authentic .

Components
The two major aspects of a hadith are the text of the report (the matn), which contains the actual narrative, and the chain of narrators (the isnad), which documents the route by which the report has been transmitted. The isnad was an effort to document that a hadith actually came from Muhammad, and Muslim scholars from the eighth century to the present have never ceased to repeat the mantra "The isnad is part of the religion — if not for the isnad, whoever wanted could say whatever they wanted." The isnad literally means "support", and it is so named because hadith specialists rely on it to determine the authenticity or weakness of a hadith. The isnad consists of a chronological list of the narrators, each mentioning the one from whom they heard the hadith, until mentioning the originator of the matn along with the matn itself.

The first people to hear hadith were the companions who preserved it and then conveyed it to those after them. Then the generation following them received it, thus conveying it to those after them and so on. So a companion would say, "I heard the Prophet say such and such." The Follower would then say, "I heard a companion say, 'I heard the Prophet. The one after him would then say, "I heard someone say, 'I heard a Companion say, 'I heard the Prophet... '' " and so on.

Hadith literature by branch or denomination of Islam
Different branches of Islam refer to different collections of hadith, although the same incident may be found in hadith from different collections. In general, the difference between Shi'a and Sunni collections is that Shia give preference to hadiths attributed to Muhammad's family and close companions (Ahl al-Bayt), while Sunnis do not consider family lineage in evaluating hadith and sunnah narrated by any of twelve thousand companions of Muhammad.

Sunni

 * In the Sunni branch of Islam, the canonical hadith collections are the six books, of which Sahih al-Bukhari and Sahih Muslim generally have the highest status. The other books of hadith are Sunan Abu Dawood, Jami' al-Tirmidhi, Al-Sunan al-Sughra and Sunan ibn Majah. However the Malikis, one of the four Sunni "schools of thought" (madhhabs), traditionally reject Sunan ibn Majah and assert the canonical status of Muwatta Imam Malik.

Shia

 * In the Twelver Shi'a branch of Islam, the canonical hadith collections are the Four Books: Kitab al-Kafi, Man la yahduruhu al-Faqih, Tahdhib al-Ahkam, and Al-Istibsar.
 * The Ismaili shia sects use the Da'a'im al-Islam as their hadith collection.

Ibadi

 * In the Ibadi branch of Islam, the main canonical collection is the Tartib al-Musnad. This is an expansion of the earlier Jami Sahih collection, which retains canonical status in its own right.

Others

 * Some minor groups, collectively known as Quranists, reject the authority of the hadith collections altogether.

History
Traditions of the life of Muhammad and the early history of Islam were passed down mostly orally for more than a hundred years after Muhammad's death in AD 632. Muslim historians say that Caliph Uthman ibn Affan (the third khalifa (caliph) of the Rashidun Caliphate, or third successor of Muhammad, who had formerly been Muhammad's secretary), is generally credited with urging Muslims to record the hadith just as Muhammad had suggested that some of his followers to write down his words and actions.

Uthman's labours were cut short by his assassination, at the hands of aggrieved soldiers, in 656. No direct sources survive directly from this period so we are dependent on what later writers tell us about this period.

According to British historian of Arab world Alfred Guillaume, it is "certain" that "several small collections" of hadith were "assembled in Umayyad times."

In Islamic law, the use of hadith as it is understood today (hadith of Muhammad with documentation, isnads, etc.) came gradually. According to scholars such as Joseph Schacht, Ignaz Goldziher, and Daniel W. Brown, early schools of Islamic jurisprudence used the rulings of the Prophet's Companions, the rulings of the Caliphs, and practices that “had gained general acceptance among the jurists of that school”. On his deathbed, Caliph Umar instructed Muslims to seek guidance from the Quran, the early Muslims (muhajirun) who emigrated to Medina with Muhammad, the Medina residents who welcomed and supported the muhajirun (the ansar) and the people of the desert.

According to the scholars Harald Motzki and Daniel W. Brown the earliest Islamic legal reasonings that have come down to us were "virtually hadith-free", but gradually, over the course of second century A.H. "the infiltration and incorporation of Prophetic hadiths into Islamic jurisprudence" took place.

It was Abū ʿAbdullāh Muhammad ibn Idrīs al-Shāfiʿī (150-204 AH), known as al-Shafi'i, who emphasized the final authority of a hadith of Muhammad, so that even the Quran was "to be interpreted in the light of traditions (i.e. hadith), and not vice versa." While traditionally the Qur'an has traditionally been considered superior in authority to the sunna, Al-Shafi'i "forcefully argued" that the sunna was "on equal footing with the Quran", (according to scholar Daniel Brown) for (as Al-Shafi'i put it) “the command of the Prophet is the command of God.”

In 851 the rationalist Mu`tazila school of thought fell out of favor in the Abbasid Caliphate. The Mu`tazila, for whom the "judge of truth ... was human reason," had clashed with traditionists who looked to the literal meaning of the Quran and hadith for truth. While the Quran had been officially compiled and approved, hadiths had not. One result was the number of hadiths began "multiplying in suspiciously direct correlation to their utility" to the quoter of the hadith (Traditionists quoted hadith warning against listening to human opinion instead of Sharia; Hanafites quoted a hadith stating that "In my community there will rise a man called Abu Hanifa [the Hanafite founder] who will be its guiding light". In fact one agreed upon hadith warned that, "There will be forgers, liars who will bring you hadiths which neither you nor your forefathers have heard, Beware of them." In addition the number of hadith grew enormously. While Malik ibn Anas had attributed just 1720 statements or deeds to the Muhammad, it was no longer unusual to find people who had collected a hundred times that number of hadith.

Faced with a huge corpus of miscellaneous traditions supporting different views on a wide variety of controversial matters—some of them flatly contradicting each other—Islamic scholars of the Abbasid period sought to authenticate hadith. Scholars had to decide which hadith were to be trusted as authentic and which had been fabricated for political or theological purposes. To do this, they used a number of techniques which Muslims now call the science of hadith.

The earliest surviving hadith manuscripts were copied on papyrus. A long scroll collects traditions transmitted by the scholar and qadi 'Abd Allāh ibn Lahīʻa (d. 790). A Ḥadīth Dāwūd (History of David), attributed to Wahb ibn Munabbih, survives in a manuscript dated 844. A collection of hadiths dedicated to invocations to God, attributed to a certain Khālid ibn Yazīd, is dated 880-881. A consistent fragment of the Jāmiʿ of the Egyptian Maliki jurist 'Abd Allāh ibn Wahb (d. 813) is finally dated to 889.

Shia and Sunni textual traditions
Sunni and Shia hadith collections differ because scholars from the two traditions differ as to the reliability of the narrators and transmitters. Narrators who sided with Abu Bakr and Umar rather than Ali, in the disputes over leadership that followed the death of Muhammad, are considered unreliable by the Shia; narrations attributed to Ali and the family of Muhammad, and to their supporters, are preferred. Sunni scholars put trust in narrators such as Aisha, whom Shia reject. Differences in hadith collections have contributed to differences in worship practices and shari'a law and have hardened the dividing line between the two traditions.

Extent and nature in the Sunni tradition
In the Sunni tradition, the number of such texts is somewhere between seven and thirteen thousand, but the number of hadiths is far greater because several isnad sharing the same text are each counted as individual hadith. If, say, ten companions record a text reporting a single incident in the life of Muhammad, hadith scholars can count this as ten hadiths. Thus, Musnad Ahmad, for example, has over 30,000 hadiths—but this count includes texts that are repeated in order to record slight variations within the text or within the chains of narrations. Identifying the narrators of the various texts, comparing their narrations of the same texts to identify both the soundest reporting of a text and the reporters who are most sound in their reporting occupied experts of hadith throughout the 2nd century. In the 3rd century of Islam (from 225/840 to about 275/889), hadith experts composed brief works recording a selection of about two- to five-thousand such texts which they felt to have been most soundly documented or most widely referred to in the Muslim scholarly community. The 4th and 5th century saw these six works being commented on quite widely. This auxiliary literature has contributed to making their study the place of departure for any serious study of hadith. In addition, Bukhari and Muslim in particular, claimed that they were collecting only the soundest of sound hadiths. These later scholars tested their claims and agreed to them, so that today, they are considered the most reliable collections of hadith. Toward the end of the 5th century, Ibn al-Qaisarani formally standardized the Sunni canon into six pivotal works, a delineation which remains to this day.

Over the centuries, several different categories of collections have emerged. Some are more general, such as the muṣannaf, the muʿjam, and the jāmiʿ, and some more specific, characterized either by the subjects covered, such as the sunan (restricted to legal-liturgical traditions), or bytheirs composition, such as the arbaʿīniyyāt (collections of forty hadiths).

Extent and nature in the Shia tradition
Shi'a Muslims seldom if ever use the six major hadith collections followed by the Sunnis because they do not trust many of the Sunni narrators and transmitters. They have their own extensive hadith literature. The best-known hadith collections are The Four Books, which were compiled by three authors who are known as the 'Three Muhammads'. The Four Books are: Kitab al-Kafi by Muhammad ibn Ya'qub al-Kulayni al-Razi (329 AH), Man la yahduruhu al-Faqih by Muhammad ibn Babuya and Al-Tahdhib and Al-Istibsar both by Shaykh Muhammad Tusi. Shi'a clerics also make use of extensive collections and commentaries by later authors.

Unlike Sunnis, the majority of Shia do not consider any of their hadith collections to be sahih (authentic) in their entirety. Therefore, each individual hadith in a specific collection must be investigated separately to determine its authenticity. The Akhbari school, however, considers all the hadith from the four books to be authentic.

The importance of hadith in the Shia school of thought is well documented. This can be captured by Ali ibn Abi Talib, cousin of Muhammad, when he narrated that "Whoever of our Shia (followers) knows our Shariah and takes out the weak of our followers from the darkness of ignorance to the light of knowledge (Hadith) which we (Ahl al-Bayt) have gifted to them, he on the day of judgement will come with a crown on his head. It will shine among the people gathered on the plain of resurrection." Hassan al-Askari, a descendant of Muhammad, gave support to this narration, stating "Whoever he had taken out in the worldly life from the darkness of ignorance can hold to his light to be taken out of the darkness of the plain of resurrection to the garden (paradise). Then all those whomever he had taught in the worldly life anything of goodness, or had opened from his heart a lock of ignorance or had removed his doubts will come out."

Regarding the importance of maintaining accuracy in recording hadith, it has been documented that Muhammad al-Baqir, the great grandson of Muhammad, has said that "Holding back in a doubtful issue is better than entering destruction. Your not narrating a Hadith is better than you narrating a Hadith in which you have not studied thoroughly. On every truth, there is a reality. Above every right thing, there is a light. Whatever agrees with the book of Allah you must take it and whatever disagrees you must leave it alone." Al-Baqir also emphasized the selfless devotion of Ahl al-Bayt to preserving the traditions of Muhammad through his conversation with Jabir ibn Abd Allah, an old companion of Muhammad. He (Al-Baqir) said, "Oh Jabir, had we spoken to you from our opinions and desires, we would be counted among those who are destroyed. We speak to you of the hadith which we treasure from the Messenger of Allah, Oh Allah grant compensation to Muhammad and his family worthy of their services to your cause, just as they treasure their gold and silver." Further, it has been narrated that Ja'far al-Sadiq, the son of al-Baqir, has said the following regarding hadith: "You must write it down; you will not memorize until you write it down."

Modern usage
Hadith as an Interpretation of the Holy Quran: "Move not your tongue with it, to hasten with recitation of it. Indeed, upon Us is its collection and its recitation. So when We have recited it, then follow its recitation. Then upon Us is Interpretation. Surah Al Qiyamah, verse 16-19." The mainstream sects consider hadith to be essential supplements to, and clarifications of, the Quran, Islam's holy book, as well as for clarifying issues pertaining to Islamic jurisprudence. Ibn al-Salah, a hadith specialist, described the relationship between hadith and other aspects of the religion by saying: "It is the science most pervasive in respect to the other sciences in their various branches, in particular to jurisprudence being the most important of them." "The intended meaning of 'other sciences' here are those pertaining to religion," explains Ibn Hajar al-Asqalani, "Quranic exegesis, hadith, and jurisprudence. The science of hadith became the most pervasive due to the need displayed by each of these three sciences. The need hadith has of its science is apparent. As for Quranic exegesis, then the preferred manner of explaining the speech of God is by means of what has been accepted as a statement of Muhammad. The one looking to this is in need of distinguishing the acceptable from the unacceptable. Regarding jurisprudence, then the jurist is in need of citing as an evidence the acceptable to the exception of the later, something only possible utilizing the science of hadith."

Western scholarship
Western scholarly criticism of hadith began in colonial India in the mid 19th century with the works of Aloys Sprenger and William Muir. These works were generally critical of the reliability of hadith, suggesting that traditional Muslim scholarship was incapable of determining the authenticity of hadith, and that the hadith tradition had been corrupted by widespread fabrication of fraudulent hadith. The late 19th century work of Ignaz Goldziher is considered seminal in the field of Western hadith studies. Goldziher took the same critical approach as Sprenger and Muir, suggesting that many hadith showed anachronistic elements indicating that they were not authentic, and that the many contradictory hadith made the value of the entire corpus questionable. The work of Joseph Schacht in the 1950s sought to obtain a critical understanding of the chains of transmission of particular hadith, focusing on the convergence of transmission chains of particular hadith back to a single "common link" from who all later sources ultimately obtained the hadith, who Schacht considered to be the likely true author of the hadith, which could allow dating of when particular hadith began circulating. This method is widely influential in Western hadith scholarship, though has received criticism from some scholars. Some modern scholars have contested Schacht's assertion that the "common links" were likely forgers of the hadith, instead suggesting that they were avid collectors of hadiths, though their arguments for this have been criticised by other scholars.

Studies and authentication
Authenticity of a hadith is primarily verified by its chain of transmission (isnad). Because a chain of transmission can be a forgery, the status of authenticity given by Muslim scholars are not generally accepted by Orientalists or historians, who largely consider hadith to be unverifiable. Ignaz Goldziherr demonstrated that several hadiths do not fit the time of Muhammad chronologically and content-wise. As a result, Orientalists generally regard hadiths as having little value in understanding the life and times of the historical Muhammad but are instead valuable for understanding later theological developments in the Muslim community. According to Bernard Lewis, "In the early Islamic centuries there could be no better way of promoting a cause, an opinion, or a faction than to cite an appropriate action or utterance of the Prophet." To fight these forgeries, the elaborate tradition of hadith studies was devised to authenticate hadith known as ilm al jarh or ilm al dirayah  Hadith studies use a number of methods of evaluation developed by early Muslim scholars in determining the veracity of reports attributed to Muhammad. This is achieved by:
 * the individual narrators involved in its transmission,
 * the scale of the report's transmission,
 * analyzing the text of the report, and
 * the routes through which the report was transmitted.

Based on these criteria, various classifications of hadith have been developed. The earliest comprehensive work in hadith studies was Abu Muhammad al-Ramahurmuzi's al-Muhaddith al-Fasil, while another significant work was al-Hakim al-Naysaburi's Ma‘rifat ‘ulum al-hadith. Ibn al-Salah's ʻUlum al-hadith is considered the standard classical reference on hadith studies. Some schools of Hadith methodology apply as many as sixteen separate tests.

Biographical evaluation
Biographical analysis (‘ilm al-rijāl, lit. "science of people", also "science of Asma Al-Rijal or ‘ilm al-jarḥ wa al-taʻdīl ("science of discrediting and accrediting"), in which details about the transmitter are scrutinized. This includes analyzing their date and place of birth; familial connections; teachers and students; religiosity; moral behaviour; literary output; their travels; as well as their date of death. Based upon these criteria, the reliability (thiqāt) of the transmitter is assessed. It is also determined whether the individual was actually able to transmit the report, which is deduced from their contemporaneity and geographical proximity with the other transmitters in the chain. Examples of biographical dictionaries include: Abd al-Ghani al-Maqdisi's Al-Kamal fi Asma' al-Rijal, Ibn Hajar al-Asqalani's Tahdhīb al-Tahdhīb and al-Dhahabi's Tadhkirat al-huffaz.

Scale of transmission
Hadith on matters of importance needed to come through a number of independent chains, this was known as the scale of transmission. Reports that passed through many reliable transmitters in many isnad up until their collection and transcription are known as mutawātir. These reports are considered the most authoritative as they pass through so many different routes that collusion between all of the transmitters becomes an impossibility. Reports not meeting this standard are known as aahad, and are of several different types.

Analyzing text
According to Muhammad Shafi, Hadith whose isnad has been scrutinized then have their text or matn examined for:
 * contradiction of the Quran;
 * contradiction of reliable hadith;
 * making sense, being logical;
 * being a report about the importance of an individual (or individuals) which is transmitted only through their supporters or family, and which is not supported by reports from other independent channels.

Terminology: admissible and inadmissible hadiths
Having been evaluated, hadith may be categorized. Two categories are: Other classifications include: Both sahīh and hasan reports are considered acceptable for usage in Islamic legal discourse.
 * ṣaḥīḥ (sound, authentic),
 * ḍaʿīf (weak)
 * ḥasan (good), which refers to an otherwise ṣaḥīḥ report suffering from minor deficiency, or a weak report strengthened due to numerous other corroborating reports;
 * mawḍūʿ (fabricated),
 * munkar (denounced) which is a report that is rejected due to the presence of an unreliable transmitter contradicting another more reliable narrator.

Criticism
The major points of intra-Muslim criticism of the hadith literature is based in questions regarding its authenticity. However, Muslim criticism of hadith is also based on theological and philosophical Islamic grounds of argument and critique.

Historically, some sects of the Kharijites rejected the Hadith. There were some who opposed even the writing down of the Hadith itself for fear that it would compete, or even replace the Qur'an. Mu'tazilites also rejected the hadiths as the basis for Islamic law, while at the same time accepting the Sunnah and ijma. For Mu'tazilites, the basic argument for rejecting the hadiths was that "since its essence is transmission by individuals, [it] cannot be a sure avenue of our knowledge about the Prophetic teaching unlike the Qur'an about whose transmission there is a universal unanimity among Muslims".

With regard to clarity, Imam Ali al-Ridha has narrated that "In our Hadith there are Mutashabih (unclear ones) like those in al-Quran as well as Muhkam (clear ones) like those of al-Quran. You must refer the unclear ones to the clear ones."

Muslim scholars have a long history of questioning the hadith literature throughout Islamic history. Western academics also became active in the field later, starting in 1890, but much more often since 1950.

Some Muslim critics of hadith even go so far as to completely reject them as the basic texts of Islam and instead adhere to the movement called Quranism. Quranists argue that the Quran itself does not contain an invitation to accept hadith as a second theological source alongside the Quran. The expression "to obey God and the Messenger", which occurs among others in 3:132 or 4:69, is understood to mean that one follows the Messenger whose task it was to convey the Quran by following the Quran alone. Muhammad is, so to speak, a mediator from God to people through the Quran alone and not through hadith, according to Quranists. Both modernist Muslims and Qur'anists believe that the problems in the Islamic world come partly from the traditional elements of the hadith and seek to reject those teachings.

Among the most prominent Muslim critics of hadith in modern times are the Egyptian Rashad Khalifa, who became known as the "discoverer" of the Quran code (Code 19), the Malaysian Kassim Ahmad and the American-Turkish Edip Yüksel (Quranism).

Western scholars, notably Ignaz Goldziher and Joseph Schacht among others, have criticised traditional hadith studies as being almost entirely focused on scrutinizing the chain of transmittors (isnad) rather than the actual contents of the hadith (matn), and that scrutiny of isnad cannot determine the authenticity of a hadith. Many Western scholars suspect that there was widespread fabrication of hadith in the early centuries of Islam to support certain theological and legal positions. In addition to fabrication, it is possible for the meaning of a hadith to have greatly drifted from its original telling through the different interpretations and biases of its varying transmitters, even if the chain of transmission is authentic. While some hadith may genuinely originate from firsthand observation of Muhammad (particularly personal traits that were not of theological interest, like his fondness for tharid and sweets), Western scholars suggest that it is extraordinarily difficult if not impossible to determine which hadith accurately reflect the historical Muhammad. Hadith scholar Muhammad Mustafa Azmi has disputed the claims made by Western scholars about the reliability of traditional hadith criticism.

Online

 * Hadith Islam, in Encyclopædia Britannica Online, by Albert Kenneth Cragg, Gloria Lotha, Marco Sampaolo, Matt Stefon, Noah Tesch and Adam Zeidan
 * Hadith by Topics and advice of PBUH

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Hadith