Yes, this track is real! It’s a depression in the ground, and as such is a physical fact. But was it made by Sasquatch? That’s the sixty-four dollar question. With virtually all tracks attributed to Sasquatch, we don’t have a film or video record of what actually made the track at the time the track was made. We have to infer what might have made the track after the event.
First off, the track in question was part of a series videotaped by Paul Freeman. An edited portion of this video surfaced some years ago in a TV and DVD documentary entitled Legend Meets Science, produced by Doug Hajicek. The video that this screen grab was taken from was recently uploaded to YouTube, and contains shots of a trackway that appears very ‘Squatchy.
One track in particular caught my eye, and it appears at about 43 seconds into the video. The track contrasts strongly with the surrounding forest litter, as there is very little debris in the track itself. To me it appears to have been excavated rather than created by compression. I came to this conclusion because some years earlier I had made various tests using large prosthetic feet. One test I performed in my front yard. As you can see in my photo, there is plenty of green moss and fine vegetation in both the bottom of the track and the soil surrounding it. I made this track by repeatedly stomping on a Ray Wallace style wooden prosthetic. If you look closely you can see an impression of my own size 12 shoe to the right of the track.
Various details can be gleaned from this simple test, but the obvious one here is that a compressive event, such as a heavy mass pressing into the earth should mash the vegetation in with it, and the vegetation should remain. From this I would conclude that the track seen in the Freeman video was not made by a singular or even multiple compressive event, and as such cannot be attributed to an animal.
I’m not the only person who concluded that Paul Freeman’s tracks were fake. In 2005 a fascinating book entitled Tracker was published by Joel Hardin (ISBN 0-9753460-0-8) which included a chapter entitled Tracks of Bigfoot. Hardin details personally investigating a trackway associated with Paul Freeman in the Mill Creek watershed near Walla Walla, Washington in 1982. Hardin devoted 20 pages to detailing an extensive onsite investigation into this trackway. Unlike me, Hardin is a professional tracker, and perhaps not surprisingly concluded that the trackway was fake. It’s an excellent book, and deserves wider recognition within both the Bigfoot and skeptic communities. After reading Hardin’s book, the notion that an 8 foot tall monster could wander the North American continent and remain impossible to track becomes rather ludicrous.
Despite Hardin’s professional appraisal, the evidence put forth by Freeman has been taken quite seriously by Bigfoot advocate Jeff Meldrum, who devoted a considerable portion of his 2006 book Sasquatch Legend Meets Science (ISBN 0-765-31216-6) to arguing that Freeman’s evidence was real.
From time to time I receive requests from sideshow performers for me to build them a pump for their own gavage acts. I am not in the business of manufacturing such devices. You will have to find a machinist to fabricate this for you, or else have the tools and skills to do it yourself. I can only describe what I did to build my own. I did not have a lathe, only a drill press. You will almost certainly have better results if you use a lathe instead of a drill press. The dimensions I am giving work for a particular sized barrel; I just happened to pick up an acrylic cylinder as scrap of this size. If you start with a different sized cylinder none of the following dimensions will work, and you will have to modify everything.
I built two pumps back in the early 1990s when I invented this stunt. One was stolen in Copenhagen, and the other remains with me. Both were essentially the same size. I started off with a clear acrylic cylinder 10” in length, 4.485” OD, and 3.975” ID. Clearly this is a 4” ID nominal tube. From there I used a drill press to machine an end cap, again out of clear acrylic, to seal one end. This was the most labor-intensive part of the fabrication, as I had to machine it to a few thousandths of an inch over the ID of the barrel. If you plan to do this yourself, you will need a reliable dial or digital caliper. The end cap on my unit was .675” thick, again made of clear acrylic. When your end cap almost fits into the barrel, use a heat gun to soften the end of the barrel. I chose not to use adhesives to secure the end cap into the barrel, but perhaps one could; I honestly don’t know what would work best. Both of my pumps held liquid under pressure for years with no leakage or malfunctions. You will notice the presence of “crazing” on the end of my barrel; this is a common phenomenon with all many plastics under stress. I suppose one could further secure the end cap with a metal band, or drill screws or pins into the plastic, but I didn’t need to.
From there a brass plumbing fitting was installed in the end cap. This was threaded with pipe thread, so you will need a pipe tap that corresponds to the threads on the fitting you are are using. The fitting needs to dimensionally match the tubing you will be using. Since I used tubing whose ID was 3/16” you will need to choose a metal fitting that will allow that size of tubing to slide over the hose barb. The tubing is elastic, and will expand a bit to fit over a hose barb. I sealed the junction of the threaded hose barb and the acrylic end cap with plumber’s epoxy on the outside of the unit. Black vinyl tape was wrapped around the junction of the hose barb and tubing to provide strain relief. If I were doing this today I would probably use silicone tape instead.
The plunger of the pump is a series of acrylic disks which hold the O-rings in place on a stainless steel rod. The opposite end of the rod is a plastic T-handle. There are two sizes of disks, which are sized to allow just a portion of the O-ring to be exposed to the inner surface of the pump. Again, the dimensions I’m providing are for a barrel whose nominal ID is 4”. The inner disk is 3.550” across and .229” thick. The thickness is nominally ¼”. The larger disk is 3.917” across and the same thickness. I started out using 4 O-rings, but later on found I could get by with just 3. For a 3 O-ring stack you will need 4 large disks and 3 small disks. I chose to tap the centers of these disks to match the threads on the stainless steel rod, which in this case was 3/8” coarse threads.
Believe it or not I was initially unable to find O-rings that fit this application! I fabricated my own using over-sized O-rings and Loctite Prism cyanoacrylate (superglue) #11. The ends must be diagonally tapered at the butt joint. I’m quite confident that anyone building a gavage pump in the 21st century should be able to find 4” OD O-rings commercially. Obviously the thickness of the O-rings needs to match the thickness of the plunger spacer disks. The ones I used were .240” thick.
The stainless steel rod I used was 14” by 3/8”. Both ends were tapped for 3/8” coarse threads. The plunger disk end was tapped 3” and the T-handle end was tapped 2 & ¼” or just a tad longer than the T-handle is thick. I ground a couple of flat spots on the rod to allow the rod to be chucked into a vice while I tapped the rod. This will also allow the use of a crescent wrench to hold the rod while assembling and disassembling the plunger handle. While I used galvanized washers, I wouldn’t recommend it for anyone building one today. I would stick with all stainless steel washers and nuts. On the plunger disk end I used an ordinary stainless steel nut in the middle, with nylon locking nuts at the end. If I was building this today, I would use nylon locking nuts at all four points; two on the plunger end and two on the T-handle end. Use a washer under all four nuts. Besides a crescent wrench, you will need a socket wrench to access and rotate the nut on the outside end of the T-handle.
The T-handle I used was also plastic, in this case a section of polyethylene whose dimensions are 6” by 1& ¾”. The center hole was counter sunk to allow the nuts and washers to fit inside elegantly and to prevent the center rod from biting into the flesh of the gavage assistant. In my case the countersink was a 1” wide bore.
The tubing I used was Tygon R-1000, 5/16” OD and 3/16” ID. The part number I used was AAU00012. As of this writing, this part number is still current. The tubing length I used was 7’. The end was tapered, and a series of cuts were made into the sides near the end to facilitate fluid flow. These cuts were made with a diagonal wire cutter.
I used PAM brand non-stick spray to lubricate the plunger when performing my act.
I was skeptical Jan Gregor was going to get us there on time. I heard his vintage alarm clock go off early in the morning; genuine brass bells and a clapper making the ringing noise. By then I saw sunlight coming through my window and thought we might be running late. The Google map directions said it would take an hour and 48 minutes to drive to the Leatherman factory in Portland, and I thought we should have given ourselves more time.
I had booked this tour about two months previously. Leatherman offered it only on Wednesdays, and the available openings closed up fast. Looking at this trip in another way, I’d been waiting for this moment for more than 20 years…
I discovered the Leatherman tool sometime in the late 1980’s. Back then I didn’t read any hype or promotion about the tool, I just bought it because it looked worthwhile. I quickly realized that this tool was a game changer, a tool so incredibly useful that I’ve carried incarnations daily on my belt ever since. The robust elegance of the tool was immediately obvious; it didn’t have twee little thingies like toothpicks that the Swiss Army knife did. I found myself using the needle nosed pliers much more than the knife. The way that the pliers folded into the handle was remarkable, it was robust as a tool yet it folded neatly and compactly into its own handle.
The first incarnation of the Leatherman tool was about 90% perfect. I can think of only three drawbacks. The most important was that the folding tools, especially the knife blade, did not lock into place. The second was that the edges of the handles were not rounded. Gripping the tool was a bit uncomfortable when the pliers were unfolded. The last issue was that the tool was just a tad too small. Over the years Leatherman corrected all these issues, and the current model I carry on my belt is the “Core.” The Core is a full-sized tool, slightly bigger than the original model. Its folding blades lock out, and the handle channel edges are rounded.
As Gregor and I drove towards Portland, I sipped coffee from his Thermos. I tried to mask the anxiety I was developing about being late. The e-mail from Leatherman said that if we weren’t there by 9:55 we were out of luck. Jan tried to reassure me; “this clock is 10 minutes fast, we should be there in plenty of time.” What if a semi truck jackknifed in the road? What if it was transporting watermelons that splattered everywhere? There were too many things that could go wrong; we should have left a half-hour earlier…
We dutifully followed the Google directions, and lo and behold we found the Leatherman plant on time! We actually arrived early, and decided to enjoy a couple of egg McMuffins at the nearby McDonalds. While most corporate tours end in the gift shop, this one started there as well. We looked at all the snazzy new models on display, as well as prototypes that Tim Leatherman created back in the 1970’s. Our tour guide Meei arrived, and we all put on wireless headsets in order to hear her voice over the din of the plant. We all put on protective eyeglasses as well. We entered the floor of the huge plant, which employs several hundred workers. The first stop was a large blanking machine, which punched out tool components from a strip of steel wound on a large roll. We were handed a rough blank and we passed it around. Not surprisingly, every blank that is punched out has a significant burr on one edge, which much be removed.
Then we were led to a polishing-deburring machine. This was a large vibratory tub that contained small ceramic cylinders. A gritty paste was added which we were told was silica. Hundreds of tool components were added, and a large cover was dropped over the vat so that blobs of paste wouldn’t escape. A magnet was later used to separate the blanks from the abrasive. Another station used glass impact bead to create a matte finish on some components.
Other stations along the tour featured both automated and hand-fed punches that folded the flat steel into channeled handles. Random pieces were pulled from the line to visually inspect for cracks that might result. Other blanks were cut by a high power laser beam. Surprising, we were able to watch the laser beam cutting the metal without needing darkened welding goggles. A laser beam was also used in another station to cut through the anodizing on tool handles to create custom engraving.
One station included workers that loaded rough pliers into a conveyer belt. The belt fed a robotic arm that quickly passed the pliers over a rotating abrasive belt. Watching the robot was mesmerizing.
Perhaps not surprisingly, the tools had to be assembled by hand. This was done in U-shaped work stations that allowed 4 or 5 workers at a time. Some handles were held in customized jigs while the fold-out tools and washers were aligned by a drift pin. Most Leatherman tools are held together by rivets, but some are joined by threaded fasteners. Thankfully Loctite is applied to the fastener threads during assembly! Years ago I had purchased various non-Leatherman multitools for comparison. One was a unit that used proprietary threaded fasteners. I happened to be in Europe when one of the threaded fasteners came apart, thus leaving me dead in the water. That episode put the kibosh on my celebration of multitool diversity…
About an hour after we started, our tour came to an end, back in the gift shop were we started. It was by far the most impressive corporate tour I’ve ever been on! I ended up buying a t-shirt and a small “Squirt ES4” which included useful wire stippers. No photographs were allowed of the shop floor, so I’m afraid I wasn’t able to illustrate this blog entry. Later on Jan took me to an excellent pie shop in Portland, and wondered aloud if Leatherman workers might assemble “Frankenstein” tools of their own design…
If you like machines, power tools, robots, steel, and live in the Pacific Northwest, I highly recommend taking this tour!
I purchased several books while I was at TAM 9 in Las Vegas, one of which was Daniel Loxton’s recent book Evolution. Ostensibly written for kids, it’s a winner both for its accessible scientific content and its artistic merit. I finished reading the book thinking how much anguish I could have avoided if I were exposed to a book like this when I was about 15!
The scientific concepts are explained simply and fundamentally. On page 17 the process of natural selection is broken down into just three simple steps. Because the fundamental principals are so powerful and encompassing the explanatory power is enormous. Loxton uses straight exposition as well as question and answer to explain the phenomena that result from the simple principles of natural selection. Much to the book’s credit, a number of these questions directly address classic creationist arguments against evolution. Loxton devotes two pages to the question “how could evolution produce something as complicated as my eyes?” I found this particularly moving, as I had been exposed to creationist literature as a child that raised this same point. Oh, to have had this book as a youth! Not content to simply give an abstract rebuttal, Loxton provides two examples of creatures that have functional “eyes” with lower structural complexity than human eyes. One is the chambered nautilus, which I was not familiar with even as scientifically literate adult.
I had the benefit of speaking to Daniel at the meeting after I had read his book. Indeed, he told me that he often writes for kids in such a way as to provide resources that he wished he had as a youth. I suspect that many young people who read this book will have been exposed to creationist concepts, so it’s entirely appropriate that the perennial arguments are addressed.
This book is also an artistic triumph. There are multiple forms of illustration, including landscape photography, conventional illustration, digital illustration, and photographed sculptures. Clearly an illustrated book on evolution should include depictions of extinct species, often extinct for millions of years. In most cases Loxton created a digital illustration and composited it into a photographed background. This techniques has multiple risks, all of which Loxton has overcome. First off, the animals must be believable, both in gross morphology and surface texture. On both counts the illustrations work. The fine skin detail on the stubby-legged creatures on page 31 is stunning. Even the convoluted textures on the foreground plants are outstanding. I spoke to Daniel about this specific issue and indeed he devoted a great deal of effort into producing believable textures.
Most of the digitally created animals are composited into landscape photographs. Artistically this runs the risk of looking like a typical Hollywood CGI action movie. To look realistic, a composited scene must have a single focal plane, as that matches how the human eye works. All too often in shoddy CGI images both the foreground image and the background plane are in perfect focus. Thankfully Loxton chose to have his foreground animals in focus and his backgrounds correctly out of focus. His composited images also exhibit correct aerial perspective with regards to luminosity and detail.
The conventional illustrations are obviously quicker studies. Loxton has a unique drawing style in which his lines are particularly bold. Despite this his illustrations are able to convey a surprising depth of subtlety, as in his illustration of a woman on page 44. Though it’s a small drawing, there is a hint of epicanthic folds in eyes of the figure. At points, though, the luck runs out, as on page 15 where the outlines of a boy’s hands are so thick it’s slightly distracting.
Not content with a two dimensional triumph, Loxton exhibits his skill as a sculptor on page 32. A hominid’s head is shown with strong lateral lighting. Loxton used a Crayola sculpting compound for a resounding success. There is some digital post processing occurring in this image, and if I recall correctly the eyes were digitally composited in. Once again, Loxton’s attention to surface detail is seen in the bust, as well as his own self confidence in his creation to allow it to be seen in a strongly lit close up.
All in all, this book is a winner. It explains a powerful scientific theory in elegantly simple ways. It touches on creationist arguments without being contentious. The illustrations are superbly integrated with the text, and are an artistic triumph. This book needs to be in every school library.
Update: Some time after this review was written, Loxton’s book generated some controversy but went on to win a literary award.
I’ve been in Las Vegas the last few days, taking in my first TAM. For those who don’t know, TAM stands for The Amazing Meeting, an annual conference put on by the James Randi Educational Foundation. This years meeting was “TAM 9 From Outer Space” with presentations having a space-based theme. One speaker was Bill “The Science Guy” Nye. I hadn’t seen Bill Nye in person in many years, and I thought his presentation was great. Funny and inspiring at the same time. His talk reminded me of a strange criticism I once heard.
Years ago I was watching a sideshow performer demonstrate an amazing new stunt that involved red hot metal. To get his steel red hot he had to use a small forge which ran on propane and air. This was back in the 1990’s, long before the Station Nightclub fire which killed 100 people. That fire pretty much put the kibosh on indoor performances that involved fire of any kind. This gentleman was going to walk on red hot steel, or so he said. As with any sideshow stunt that has any element of danger, the stunt must be hyped beforehand for maximum effect. The hype in this case took a strange turn, as the performer began to criticize Bill Nye.
Unfortunately I don’t know what Bill Nye said in the first place. Frankly I never caught his TV show, only his early work with Almost Live, a local TV comedy show based in Seattle. I suspect, but do not know that Nye probably offered the common “explanation” for fire walking, namely that it’s a matter of the low heat conductivity of the wood embers that fire walkers walk on. A classic analogy is that it’s possible to leave your hand in a hot oven as long as you don’t touch the hot metal. Both the air and the metal in the oven are at the same temperature, but the metal is a much better conductor of heat.
In any event, the sideshow performer suggested that Bill Nye was wrong, that it was possible to walk on hot steel without searing the skin. At this point we should consider the social nature of such a performance. The goal of a showman’s pitch is to create tension, to hype the act, and hopefully to leave a lasting impression in the minds of the audience members. It shouldn’t be intended as formal physics presentation! Consider that when an audience enjoys a comedian, a certain suspension of disbelief is in effect. We are OK with a comedian telling a story that may be complete fiction, as long as the punch line is funny. An audience accepts this kind of thing in a comedian that wouldn’t be accepted in a scientist. But was the criticism of the sideshow performer valid? Is the “official explanation” of firewalking wrong? Well, sort of…
As our sideshow performer kept his bally going, his steel slats began to glow red hot. Coupled with the roaring sound of the forge on stage it was an awesome psychological setup. Soon his slats were set into a frame on the floor. In what must have been no more than a second or two the act was over. Indeed, our brave performer had “walked” on the hot steel slats. Only he didn’t really walk so much as hop. And therein is the crux of this whole essay, namely that sometimes simple “explanations” for phenomena fall short, and that the true description is more complex. What our performer was effectively utilizing was a low exposure time. Had he actually “walked” on the hot slats he would have surely gotten burned.
This is not to take anything away from our performer! It was an outstanding stunt, one which I’d never seen before and one which I haven’t see other performers doing. But for our purposes, let’s take a closer look at the physics involved, and what we can learn from it. A good resource on the subject is the Wikipedia article on Thermal Conductivity. A key passage is this:
For general scientific use, thermal conductance is the quantity of heat that passes in unit time through a plate of particular area and thickness when its opposite faces differ in temperature by one kelvin.
Note the critical variable of “unit time.” If we lower the time of exposure to a heat source, we lower the quantity of heat that flows to that which is being heated. A commonplace demonstration of this is running fingers through a candle flame. If you keep your fingers moving you can avoid a burn. The variable of time is often missing in explanations of firewalking. Indeed, the stunt is firewalking, not “firestanding!” Walking provides a series of exposures to the heat instead of one continuous exposure.
It should also be pointed out that skeptics have done an excellent job of debunking the claim that some sort of special mental or “spiritual” state is required to walk on hot coals. Skeptics Ben Radford and Joe Nickell have both performed this feat, and neither needed “chi” powers or motivational seminars to do it. I was amused at Radford’s account of his own fire walk, as he had organized it as something of a house party affair!
I actually began to think about these issues many years ago, way back in high school. Sometime in the late 1970’s I recall reading in Scientific American magazine the suggestion that firewalking could be “explained” by the “Leidenfrost effect.” Indeed, suggestions are still being made that this is the correct explanation. In my opinion this makes no sense as an explanation for the simple reason that any putative hovering water droplets would quickly be smashed into the sole of the foot or the wood embers by the walker’s body weight!
There is a temptation to glom onto “explanations” of seemingly mysterious phenomena. It’s unsettling to witness things that we don’t understand or can’t explain. But when incorrect or incomplete explanations are offered, it can backfire. A classic example in UFOlogy is “swamp gas” which became a term of derision for UFO advocates. I think skeptics are entirely justified in calling out those who would charge money for staging fire walking demonstrations, especially when it’s couched in terms of nonsense like “chi” energy. Today practitioners of marshal arts would call chi “bullshido.”
I would like to suggest that we get our physics correct when we suggest what is really going on…
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