Anyone read this in the forums yet? I just picked it up at the local book store and saw that there are three (3) articles on or surrounding the Bigfoot phenomena in this issue. On page 5 and 6 is the News and Comment section and in it is Benjamin Radford's piece entitled the "Georgia Bigfoot Hoax Draws Global Attention". Nothing really new. On pages 11 and 12, in the same section is the longest obituary I have read on "Jon Beckjord, Advocate of a Paranormal Bigfoot (1939 - 2008)", written by Robert Sheaffer. Nothing really new in this either. But then on pages 47 to 51 is the Michael Dennett article "Science and Footprints: A recent article in a scientific journal argues that alleged footprints from the Patterson film site provide evidence for Bigfoot. A review of the circumstances suggests a different conclusion."

In this article Michael tries to further negate the film's authenticity by way of calling the tracks attributed to them as being fake. He takes to task the estimated weight of the film subject compared to eyewitness testimony (Gimlin, Patterson, Laverty) as to the differences observed in the tracks when compared to those of the horses used during the filming trip. On one hand he uses Bob Gimlin's own words against him after describing his impression of the event and then uses it to corroborate his own (Mr. Dennett's). There are no actual measurements made in any part of this article. Michael gathers what he thinks is data from three borrowed horses, for what purpose other than to show the hoove is beyond me. Every time he mentions the weight of the animals he estimates them, and all of the estimates are 200 to 500 pounds above the average riding horse weight. Michael qoutes Gimlin when he says "The horse I was riding was around 1,200 - 1,300 pounds." Bob weighed 165 lbs at the time and his horse was packed with gear. Was Bob's horse weight including all of this? I would think so since his estimate of body weight was from looking at the tracks his horse made nearby the Bigfoot tracks and he didn't get off or unpack.

Michael then goes on to describe that the front two legs of a horse carry 60% of the animal weight and figures out the psi needed to make tracks equal in depth to the multi-generational copy he had on hand. Cast copies tend to exaggerate the original depth since they have an uneven top surface and must be shored-up off a planar surface before making a mold (the picture he illustrates this with even shows this new top surface). He further describes how a horses weight is divided onto three of it's legs during travel versus the bipedal two. In my opinion all of the weight of the film subject was placed on each foot during the traverse on film. If the animal weighed 600 lbs, each track had at one point 600 lbs in it. A horse on the other hand, if weighing the average of 900 to 1,000 lbs would have between 270 and 300 lbs [(horse weight x .6f or .4r) / 2]. At no point in time is half the weight of a horse on one leg, it probably would not even be able to hold that much. The size of the foot is important, I agree with that, but the method Michael is using here leaves no room for misjudgments of his assumptions. Could the horse tracks made next to the Bigfoot tracks have been stopped from sinking in any further by a hidden obstacle underneath the creek bed sand? Rocks or logs?

This could have been a much more informative article had actual measurements been made and used. Maybe some actual test tracks made against that of a horse. I do like the direction he started with it but when there was no supporting measurements included it quickly became just his skeptical and biased opinion. To make matters even worse he even applauded Greg Long's book.

After looking at the weight issue, tracks and extensively, the film, I fail to see a problem as described in the article. As far as the transportation, development and first viewing of the film... keep looking.

IMO item's in the article needing further clarity:

Bob's memory of the horse track versus Bigfoot track depth.
Average horse weight versus estimated versus actual.
Horse weight including Bob and gear.
Weight dispersal over two versus four legs.
Weight placement longitudinally versus vertically.

IMO, any analysis of the weight of any animal based on the depth of the tracks it leaves is fatally flawed,

The reason is that there is no way to know the conditions of the soil at the time the tracks were made. Further, estimating such conditions necessarily produce large errors because the square area of each track is very small, so if you guesstimate incorrectly the depth by a small percentage, the result will be wrong by a great amount.

I've yet to see anyone (skeptical or otherwise) draw solid conclusions on just what can be gleaned or what can be safely assumed about the supposed mass of a supposed BF that has left aforementioned tracks credited to be the tracks of an unknown bipedal hominid. I very much agree with your assessment that Dennett's conclusions are fatally flawed. Dennett is guilty of making the same mistakes that virtually everyone that has written about the subject of drawing some kind of conclusion about the mass of said track depositor and the depth of the given impressions. Every analysis I've ever read pertaining to the supposed mass vs. depth of impression is based on the following two totally incorrect assumptions:

1- The track of a supposed BF can be reduced to a totally static loading analysis which tries to equate all the forces involve into a purely vertical loading component equal to the mass of supposed subject and the effect of gravity. I.e. the foot of a significantly more massive bipedal primate can be treated as if it were a static bridge piling(the proverbial "snowshoe treatment", whose bearing area is equal to that of the area of the total impression. This simply isn't the case, nor is it reasonable to assume that this model in any way/shape/form mimics anything close to reality when you really consider the dynamic resolution of forces involved in WHAT anyone who understands the dynamics involved would predict in trying to resolve the question: "How much deeper should the impressions left by the sasquatch be if said animal is real and traversed a given substrate vs the depth of impression left by known animals?"

I agree with your assessment that Dennett's trying to draw any conclusions with what we'd expect to see in terms of a rigid footed quadruped (in this case a horse) vs. what we'd expect to see in a track left by a real sasquatch are quite absurd. I can't say I agree with Krantz or Meldrum on any of their analysis of supposed sasquatch tracks or the various conclusions they both draw on why certain tracks are likely real. I do however very much agree with both their conclusions that if real, the sasquatch would HAVE to possess a significantly more flexible foot than is present in the human condition. This is a fairly simple concept, and they've both drawn detailed analysis of what structural changes the sasquatch's foot would likely have to possess compared to the human condition, as mass increases as a cubic function while the strength of bone and connective tissue increases as a square function. I really believe that the only assumption that can safely be made about the structural mechanics of the sasquatch foot (assuming the animal is real) is that it would HAVE to be infinitely more flexible than is present in the human condition. Anything beyond that IMO is purely speculation. When you fully understand the significance of this, and you then realize that the sasquatch (again if real) has to be loading/unloading it's foot under locomotion much more incrementally than humans do (let alone rigid footed quadrupeds like horses) and that the conclusions drawn by Dennett, Daeling, Farenbach te. al. are all very much akin to trying to predict which of two vehicles of differing mass will sink deeper while driving across the same mud flat at the same speed by simply considering the entire surface areas of their respective tires instead of considering that only a small percentage of those tires are acting as load bearing surfaces as the vehicles move forward. Throw in the fact that a moving sasquatch under locomotion presents something much more dynamic in terms of force vectors that are resolved in interactions with the soil than Dennett and company seem to want to believe can be resolved into simply linear equations. Not to mention that as the velocity of the supposed sasquatch increases, not only is it obvious that it would also be decreasing peroidicies of dual versus singular support, but that also the incremental nature of the resolution of the forces of the sasquatch foot vs. that of the human condition would become more prevalent. Bottomline is any analysis of the depth of impression of supposed sasquatch tracks that treats the sasquatch foot as a "snowshoe" with area equivalent to the surface area of the impression is not going to be based on sound assumptions and will simply not mimic reality.

2- The other assumption that Dennett and others seem to make that certainly isn't true is that most if not all soils behave plastically with respect to deformation. I.e. the assumption that applying force A to area B results in deformation C, and that doubling force A and applying it to the same area B should result in a similar doubling of the deformation observed. This simply isn't how soil deformation occurs and is not how most soils behave. Most soils do behave plastically over a small range of loading conditions. In very general terms, when soils are compressed, the interstitial air voids between the respective particles simply become smaller. As soils become compressed, and move more towards zero air void density, much greater force and/ or increased periods of loading are required to to increase compaction. Dennett and the others simply don't have even a rudimentary understanding of basic soil mechanics. Soil also doesn't discriminate on how it was deformed.

If the sasquatch is real, it's resultant tracks are the products of the totality of the interactions of it's foot with said substrate both on loading/unloading, and the resolution of the non vertical force components involved with a moving, purportedly massive subject, whose forceful interactions with the substrate are increasing as it's velocity also increases.

All that said, the only safe assumptions I see on the subject of the depth of sasquatch footprint impressions if the animal is real are the following:

1- Sasquatches should be leaving insanely deeper impressions in compressable substrates than humans traversing the same substrate at approximately the same velocity.

2- If the subject prints are indeed real, the sasquatches that left the prints didn't need to be anywhere near as massive as Dennett's and others conclude that they would need to be, based on their totally linear assumptions.

3- The depth of sasquatch foot impressions is much more likely a function of the width of it's foot and it's velocity than it is a function of the total surface area of it's feet.

Great, detailed explanation.

I think that in this case, it can be demonstrated by experiment that the analysis is flawed. The brilliant objections you've offered would also be true for tracks made by man. So the proponents of this analysis could have men of very different weights with similar shoe sizes create a trackway and then use their methodology to see how accurate it is in reality.

Of course, this will never be done because it would require one to leave the armchair.

I'm not to familiar with this part of the story, so maybe you can help me out here.

Is it well known how the film was transported, developed and first viewed; or is it still a mystery?

Bravo on that post Will and thanks for taking the time.

One question- doesn't this part:


...assume the same biomechanics as humans (e.g. heel strike, roll over to the ball, toe-off, sort of weight bearing)? What I mean is if they were walking as if on snowshoes (distributing their weight more broadly) this wouldn't be the expectation right?

-A

Yes.



Before he gets into that argument however, Dennett points out:





Yes, Dennett argues that based upon the evidence provided, "...the creature in the film had to exert more downward force than the horse."



Dennett refers to John Green doing the same thing during his interview with Gimlin. Green asks Gimlim about the inconsistency of a creature, that Gimlin estimated to weigh less than half the weight of the horse he was riding, leaving footprints that sank deeper than the horse priints.



Dennett describes one of the horses, Asher, as being 16.1 hands high, with a hoof covering an area of 20.5 square inches. He also describes each of Patty's feet as covering 66.3 square inches of surface area. Those don't seem like guesstimates.



I got the impression (nice pun, eh?) Dennett was pointing out the same inconsistency that John Green had noticed. Unless Patty, with her huge flat feet, weighed far more than Gimlin's horse, her tracks should not have sunk "noticeably deeper" in the soil.



Dennett indicated that Gimlin used a weight of 1,400 pounds when he did his calculations, taking that additional weight into consideration. Checking the source of Dennett's information we see that Gimlin specifically says, "Of course I rode the horse too, so there was my extra weight plus the horse's weight plus the saddle and tack and everything I had on him. There was probably a total weight of about 1400 pounds."



Can you cite the quote where he makes this comparison, I'm having trouble finding it. The only reference I see Dennett make to the copy he has on hand, is in relation to measuring "the surface area of the purported Sasquatch foot", not the depth to which the copy cast would sink.



(my bolding)

That's precisely the same conclusion Dennett comes to, and he points it out not once but twice. On page 50 he states, "The figure in the film is placing its weight on one foot at a time, so we must compare a single foot with two or three from a horse." In the footnote he refers to he states, "Unlike a primate who displaces all of its weight evenly but alternately on each foot, approximately 60 percent of the body mass of a horse is distributed over the frong legs, due to the size of the head and neck." (footnote 15, page 51).



Is it also possible the tracks were faked?



But how does one convince a squatch to agree to the testing?



If Patty and Gimlin's horse did leave tracks in similar soil, how does one account for the huge difference in depth reported by those who examined both sets of tracks?



Are you suggesting you have the answers to "how the film got to Yakima so quickly (in an era before overnight couriers), how the film was processed so quickly (in a time when development normally took a week), or even where the processing took place?"

RayG

A-

I've never given this a lot of thought, but I would actually expect something like the sasquatch to be punching significantly bigger holes in impressionable substrate than a typical unshod human would even if said creature was purposely attempting to plant it’s feet more deliberately flatter on each step forward. (i.e. attempting to walk flat footed to minimize the initial forces that result in deformation). Simply because regardless of how it’s putting it’s foot down initially, to propel itself forward, it’s going to have to resolve the forces involved in moving forward when it pushes off to step out of that track and prepares to step into the next one; those forces are likely still going to be applied to the substrate much more incrementally across the length of it’s foot moving from the heel to toe of the impression, than in the human condition where’s there significant rigidity across the arch and not as much incremental loading as would almost certainly be occurring in something that would have to possess infinitely more midfoot flexibility. I do think if making a deliberate attempt to do so, an adult sasquatch could certainly lessen the visible impact it’s having on impressionable substrate. Probably even significantly so. Never really given this much thought, but I think it’s probably unlikely that it would be able to lessen it to anywhere near the extent that a typical human, walking normally would have unless it also drastically reduced it’s velocity to a virtual crawl and reduced it’s typical stride length even more significantly, to the point where virtually no foot flexion would occur. In other words, the way I'm seeing it, the proverbial sasquatch would literally have to be moving so slowly and so deliberately that the static, linear loading analysis that Dennett and company offer up becomes the valid one.

Dennett was only comparing the depth of Patty's track to that of Gimlin's horse, not Patty vs a human. A half-ton horse is going to be significantly heavier than the vast majority of humans.

RayG

That would be very, very slow indeed. A glacial pace if you will...

Hand height does not equal measured weight. It is used to estimate, and is better suited to indicate the proper horse you should ride for your inseam. He states this clearly each time he brings it up that he was estimating the weight of the animals and for the life of me he could easily have placed at least one of the legs on a bathroom scale to get a better idea as to how much weight might be expected under the circumstances. The square surface area of the horse hoof Dennett uses is also just a flat representation when maybe he shouldn't be asking about just the shoe area or does the concave center of the foot impart some unknown floating effect. Could the sand the horse stood in have filled in after removing the hoof from the track? Was a cast made or a photograph of the two side by side made? Was the estimate made from how much of the hoof looked to be embedded into the sand? We don't know. This could also have been included in the article. I take it that Dennett didn't actually interview anybody, least of all Bob Gimlin, just read some material and went to a friends house who had horses to make his $350 writing fee.

Watching the film and the subsequent film made of Jim Mclarin, I think that the animal in the film is pretty close to 600 lbs in weight. The horses that were on that trip didn't look like draft animals (1200+ lbs), given that we can see both Bob and Roger on them at various times and both men as we know are "puny" men. They actually look on the small side of things. With the added weight of rider and gear I would figure 900 lbs for the horse, 165 for the rider and 100 lbs for the gear. 1,165 lbs overall and with the formula proposed by Dennett, would place 699 lbs on the front two feet of the horse, but he further defines the three leg distribution so that makes it 233 lbs per foot versus 350. I have known people who have had a horse step on their foot (in shoes of course) and they survived it without the foot being crushed. 420 lbs is quite different than 233 lbs. I won't even get into a horse that may not place all of its weight down on a leg unless moving or kicks up the leg when extracting it.

But then we need to look further into things. Roger used small horses. He even converted a VW van into a horse trailer for them. Why would they not have used horses that suited their stature? It would make getting on and off a lot easier, which sort of fits with Roger's plan of acting quickly should they encounter a Bigfoot (he made that quick draw holster for the camera). I think even Herionomous stated to Greg Long that Roger borrowed one of his small horses. Maybe Bob is underestimating the weight or just not remembering as accurately as he thinks. He states that quite often to people that he talks with.

I think the horse had 600 to 700 pounds, max on the front two legs, the Bigfoot, 600. A horse track would have been half the amount, 300 to 350 per track. The dynamics of a horse track versus a flat foot could have obscured any further details indicating the horse made the same or greater depth. Just take a pole and drive into sand, then pull it out. Do you get an accurate reading of how far down it went? Now walk on it with shoes and I bet you can see some detail like a heel or sole tooling marks. Horses kind of pierce the ground where as animals like bear and man compact it. Of course soil conditions can vary and what might be true in one circumstance, false in another.

Where did he suggest that it did? I was responding to your "There are no actual measurements made in any part of this article" not whether he made some sort of comparison between height and weight.



Ummm... estimates seem to be all we have.



He should interview Bob Gimlin 40 years after the fact? What would be the point?



But wasn't Gimlin a fairly experienced horseman? Why put the combined weight at 1,400?



And?



Maybe they did.



Yes, it's possible Bob Gimlin overestimated the weight of the horse he rode by nearly 300 pounds. Is it possible the tracks were faked?



Say, aren't those estimates?



And I'll bet my shoe prints will show less depth than the pole mark. Just like you would suspect Patty's prints would show less depth than the horse.



Exactly why it's so curious that the horse tracks, which pierced the ground, showed less depth than the huge, flat foot of Patty.

RayG

Ray,


Nonetheless, his analysis is fatally flawed and about as valid as a 3 dollar bill IMO. If real, the sasquatch is applying a total summation of force much greater than it's own static mass under locomotion to whatever substrate it may be traversing(as would potentially the more massive horse). Most importantly it's applying that force incrementally along the length of it's foot, in essence concentrating said force over an area much smaller than the summation of the total area of it's entire foot as it's walking. Something the rigid footed horse simply isn't capable of.

From what I'm gathering, Dennett's whole ill-founded arguement is based on his incorrect perception that it would be physically impossible for a say 600 pound biped with a flexible foot to exert more force than the more massive horse with it's smaller total foot surface area on the same substrate under what is perceived for both to be typical locomotion. An undoubtly true statement if both were rigid immovable statues that were placed on said impressionable substrate. The bottomline is that is exactly what Dennett is doing to both the horse and the supposed BF in his little excercise of linear calculator gymnastics, and it's very similar to the flawed arguement and methodology Daegling and others have been guility of.

The best analogy I can draw (that comes to mind at this moment in time) is that what Dennett is doing is akin to stating conclusively and beyond doubt, that a 600 pound stone wheel with given surface area A, cannot leave a deeper impression when rolled across a given substrate than say a pushed 1400 pound square stone that is supported by a ski or multiple skies of given surface area B (where A is significantly greater than B ). The initial assumptions Dennett is making are very uncertain propositions that in all likelyhood, simply do not mimic the reality of the situation he's pondering.

As stated, I think that if the sasquatch is real, it must possess an infinitely more flexible foot than is present in the human condition for very similar reasons that have been offered up by both Krantz and Meldrum. I see it as very much a given (and to a very large magnitude) that the sasquatch under locomotion would have to be resolving the forces associated with locomotion along the length of it's foot much more incrementally than is present in the human condition. There is no way IMO to determine with any degree of certainty to what great extent something like the sasquatch would be incrementally applying the considerable forces involved in it's locomotion along the length of it's foot without having a foot for analysis. I'm not finding it at all implausible that it would be doing so to an extent where it is indeed possible for the sasquatch to be leaving deeper impressions than the horse would. A concept that Dennett is seemingly not quite capable of understanding.

Granting that it's pretty hard to replicate the experiment, I'm personally having a bit of a time wrapping my head around a critter that was filmed in motion, guesstimated to be approximately 6 feet tall and weigh 300 pounds, leaving footprints that sunk "noticeably deeper" than those of a horse (with rider).

The locomotion of the film subject was not what I would consider slow and deliberate, but more like a brisk walk. Regardless of how flexible the foot might be, how did the film subject leave such conflicting evidence behind?

RayG

Yogic flying.

Gesstimated to be 300 lbs? I put a picture of Charles Balrkley next to her in an old thread and I think she is about 6 foot when bent over. It was to point out how much bigger she is than she appears at first glance. You might stretch her out to 6' 5" but I don't accept the notion that Patterson Gimlin couldn't measure the length of the track. The 14.5 inch track is conclusive as far as I am concerned (but her foot is slightly smaller). The fact that Gimlin? was so wrong with the weight is consistent with how we fallible humans deal with new experiences. Our first thought is what we know. She makes Barkley look anorexic and he played at 300 lbs though he looks much leaner at that time.

Ray,

Based on the scope and definitive conclusions Dennett would have you believe he could draw, replicating the experiment is immaterial.

If we're to assume that the film subject is real, is it not a fairly safe assumption that it also left the tracks attributed to the film subject? With the known length of the tracks, and subsequently the approximate length of the foot for scale, do you really believe that if it were real, the film subject is only in the 300lb range?



Agreed. I think that's quite obvious and is again WHY Dennett's article is laughable. You can't apply a static analysis to an object that not only is moving, but at visible velocity.

What Dennett is doing, is attempting to apply a static analysis to a dynamically moving object. He's simply forcing what in the real world can only be modeled via a series of very complex, differential equations, into an unrealistic conclusion that the given circumstances can be resolved with a linear algebraic model. To put it simply as possible, what Dennett is doing is not realistic and does not mimic the reality of the circumstances. In writing this article, Dennett is without question, guilty of the exact same thing he's accused the BF community of time and again: Offering up psuedo-scientific garbage as definitive proof. The assumptions Dennett makes are uncertain. His methodology is unscientific and isn't even applicable to the subject he's attempting to tackle. Dennett in writing this article, really demonstrates that he isn't even to the point where he can comprehend some basic, rudimentary articles on statics, dynamics and soil mechanics, yet has written an article that requires a working knowledge of all three.

I think that a video is worth ten thousand words...

Trotting horse slow motion video. if somebody can't understand the difference between static loading and dynamic forces after watching this video. IMO, that person is an idiot. Sorry, there is no easy way to say it and sometimes the truth hurts.

Either that or they are being intellectually dishonest, which I can't tolerate.

I'd like to say I've had an Aha! moment, but I'd be lying. I still don't get it.

I keep picturing two people standing at the edge of a field of snow. The snow is very deep. The larger of the two people (me, 250+ pounds) is wearing snowshoes, the smaller person (my 8 year-old daughter, less than 100 pounds) is wearing rubber boots. We both try to cross the snow-filled field at a brisk pace. Who should make it across the field first, and more importantly, how deep will both sets of tracks be?

RayG

I might be able to assist you if i understood exactly what you are asking or am not seeing.

Are you asking why its wholly unreliable to estimate accurate weight from a depression? ( which is totally different than who would get there first)

The reason it cant be done reliabily is because there are dozens of conditions and variables ( with an almost infinite combination of the 2) and each one will give a different depression signature.

We also need to look at whether Patty and her relatives walk heel-toe or flat-footed, and whether or not they have arches. IMO she walks like a bloke in a suit so that would be heel-toe. If that is the case then the following should apply.

Most humans walk heel-toe which creates deep heel and toe imprints. Picture yourself taking a step with your right foot. At a certain point all your wieght is on your left toes (and ball) and right heel, and your right heel is also moving down and forward so it has an added dymanic load. Only after the right heel is firmly planted do the left toes release.

Calculating the force imparted to the soil requires calculating the contact area of those 2 parts of the feet. The overall foot size really doesn't matter; what does matter is the size of the heel plus the size of the toes and ball.

But that's just for the planting and releasing portion of the step. THere is also the vertical portion of the step when all the subject's weight is directly over one foot. It should be easy enough to calculate the force on that part of the step, right? Wrong.

Human feet have arches so when we walk our arch area, which is a large portion of our feet, carries very little weight. Most of the weight is supported by the heel, ball, toes, and outer side (don't know what that's called). How much weight the arch supports depending on soil conditions and depth of the arch.

The point of all that rambling nonsense is to say that the human foot makes deeper impressions in soils than it should if you just calculate the weight of the person divided by the size of the foot, but the impressions are not uniform.

I have no idea how this relates to ape feet but since 99% of the prints are human-like I don't think we need to consider ape feet.

My bad for trying to bang out a response at the same time I'm trying to get ready to head off to work.

What I should have asked was, which set of footprints would be deeper? (considering that the only difference is the weight and footwear of the individuals participating, the soil/snow conditions are exactly the same for both)



No, I'm not asking for weight estimates, only which depression in the snow will be deeper.



Remove ALL variables except the weight and footwear of the individuals involved. Who will leave deeper tracks?

RayG

>>>Remove ALL variables except the weight and footwear of the individuals involved. Who will leave deeper tracks?

It would still be a coin toss because of this reason. Lets assume everything has a value of X ( all variables)

The snow has a uniform compaction rating- it would then depend on the ratio of area/weight of each. ( hypothetically- if you weighed #200 and she weighed #80- you could sink further OR she could because of the smaller area of her foot.)

In addition to all the mechanical properties,weight distributions, compaction/displacement properties,angles and such already mentioned ( which any 1 or combination of them can each deliver a radically different result)- you have the hardness and profile of the object doing the landing as well.

Back in my college days in statics ( which is really what is being discussed), our professor illustrated the point this way ( he was talking about building/machine footprints but the concept is the same)

we went to the sandpit at lab and he had 4 spots raked

1) a 5 gal bucket of water dropped from 1 ft

2) a 5 gal bucket ( empty) wiith a bagliner with 5 gals of water in it dropped into the bucket

3) a 5 gal bucket that was "filled" with 5 gals from 1 ft

4) a bagliner with 5 gals of water dropped from 1 ft

They all had different characteristics depending on which variable changed ( be it the area,weight,sharpness of angle etc)

So, a living thing leaving a footprint has elements from 1-3 depending on foot size, amount of padding, weight dispersal, foot loading ( and a thousand others) and even assigning the substrate properties as X ( all known and unchanged)- you can ( and probably will) have different ratios of 1-3 thus having different impact/signatures along a given trackpath even tho the actual weight of the animal never changed.

Then we did the "hammer" test ( hammer head on a gulliotine device with weights) dropped from 3 feet against nails and such to illustrate force,angles and such. ( basically the same thing)

Ok, if we replace my daughter with someone who happens to weigh exactly what I weigh, and the ONLY difference is footwear, me wearing snowshoes, him wearing rubber boots, who leaves deeper tracks?

RayG

all things being equal ( literally all of them) then the smaller the area, the greater the depth.

The article is now online. Here’s a link:
http://www.csicop.org/si/2008-06/dennett.html

In the end I’m left with a huge question mark as to how, if it takes 2,000 plus pounds of force to make the prints, did Patterson do it? As much as some people on this site have made good headway in answering this question, I’m sure we won’t be getting any details from Dennet anytime soon. Classic textbook pseudoskepticism.

I also like how he says Meldrum’s paper is “crammed with scientific jargon.” Of course it is, it was published in a science bulletin. If you don’t like science jargon, don’t read “Cenozoic Vertebrate Tracks and Traces.”

Can't say I've got a definitive opinion on your question, and literally have no idea how snow would perform under deformation relative to soil, but agree in totality with LT's comments (aside from the fact that I think this is much more of a dynamics vs a statics analysis involved), in terms of all the variables involved that Dennett would have you believe can be resolved and definitively analyzed with a simple linear algebraic model. There are a myriad of endless cases where the validity of certain "track experts" in the BF world, who have proclaimed with certainty that very questionable impressions (that IMO, have the dynamic signatures of being the products of rigid fake devices) should not only be called into question, but should also call into question the actual real world knowledge of those experts, in terms of determining what exactly they're looking at. What Dennett is clearly doing in this case, is exactly what he's accused Bf'ers of doing: Offering up psuedo scientific garbage as proof that his preconcieved agenda is valid.

As stated, if the subject in the PG film is indeed not a guy in a fur suit, I'd expect it to be leaving insanely deeper impressions than shod or even unshod humans traversing the same substrate would, and don't see it being out of the question, that the impressions could be as deep if not deeper than the impressions left by a typical horse traversing said substrate. That said, I'm not seeing the depth of the impressions as being anything approaching proof that the impressions were indeed as advertised, just that deeper impressions should be expected if the film subject was real, and that leaving deeper, convincingly looking (a very relative term) fake impressions wouldn't IMO be any more difficult than leaving shallow ones.

Can't stress enough that Dennett's (and virtually every other attempted analysis of what can be gleaned from the depth of supposed impressions left by BF, arguing either for or againist the validity of said tracks) guestimate of how massive (which goes hand in hand with how much force would be required) the film subject would have to be to leave said impressions is fatally flawed, because Dennett and company simply fail to entertain that HOW the forces are being applied to the deformable substrate (i.e. the possibility of incremental loading) is actually more important than what Dennett seems to mistakenly perceive as the total summation of forces required. Case in point, assume you've got two sets of stamped 1" thick steel, fake 15" long stompers that are cut from the same mold. One set is flat. The other is not. The one that is not flat has a parabolic profile. (i.e. Imagine holding the stomper between your hands as if it were a flexible plastic ruler, and pressing your hands together until they were only 12" apart. The stomper will still have a surface length of 15" but from heel to toe, will only measure 12" distant on the straight plane. The same 200lb man leaves impressions wearing each set traveling at the same speed over the same substrate. Which set would you expect to leave the deeper impressions? Can't say I'm in agreement that if faked, the question of how Patterson did it (the deep impressions) is an issue for me. He simply would have to have a slightly better understanding of how soils actually deform than Dennett and company seems to. And in the case of Dennett and Co, that wouldn't take anything remotely resembling applied knowledge, but merely some persistant experimentation.