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…
When I was growing up my mother baked two particularly tasty things; whole wheat bread and Cornish pasties. I don’t know if my mother ate pasties when she was a child growing up in Anaconda, Montana, but my father certainly did when he grew up in Butte. In Butte, the Irish had co-opted the delicious pasties from the “Cousin Jacks” or the residents of Cornwall, England. The pasty was a popular lunch item, especially for school kids and underground miners.
If you search the Internet you can find many recipes for pasties, many of which will contain all sorts of additional vegetables. I’ve tasted many meat pies over the years, and I agree with the opinion of my parents that a pasty doesn’t need anything besides just the basics. The following recipe is a transcription of a letter my mother sent me some years ago. In the penultimate paragraph my mother has the chef creating an incision in the top of the pie before it’s baked. My father also made pasties for himself years ago, and suggested that one wait until the pasty is fully baked before cutting into the pie so that the moisture from the interior remains inside.
Frozen prepared pie crust may be purchased from the freezer department of a supermarket, or prepare crust using standard measurements of one cup flour and one-third cup shortening, plus ½ teaspoonful salt per pasty for plate-sized pasties.
Purchase about one or 1&1/2 pound good grade round steak, and trimming off most fat, place in freezer compartment so that it becomes about semi-frozen. It will be much easier to cut into small cubes if first frozen. It should cut up about as easily as chopping celery. Before freezing, seasoning can most easily and accurately be added by sprinkling salt and black pepper quite liberally on both sides of the meat as you would season something like a hamburger patty. Otherwise, it’s difficult to measure just how much salt and pepper you would add to the mixture Considering that you won’t need to season the potato which will be added later, on should be quite generous in applying the salt and pepper. Also consider that you will be adding butter or margarine at the last minute so that will also provide a salty flavor.
After trimming all fat off your frozen piece of round steak, cut into strips and chop meat into cubes about ¼ inch in size. Your meat will bake much faster with small, uniform pieces of meat so that you won’t over cook it, which would make it more tough. Set aside meat in a large bowl.
Peel and cube potatoes in about the same size small pieces as the meat. (A French fry cutter is ideal to form the proper sized strips for uniform chopping). Use about three large baking type potatoes. The proportion of meat to potatoes should be about half and half. Add to mixing bowl containing meat cubes.
Finely chop two large onions of the white Bermuda type and add to mixing bowl. Mix together meat, potatoes and onions. At this point, mixture can if desired be covered and refrigerated overnight to blend flavors, but is not necessary.
On a slightly floured surface, roll out pastry with slightly floured rolling pin to the approximate size of a standard dinner plate, or smaller if desired. Place one cup of meat mixture onto crust just off center to the bottom half so that when crust is placed over meat it will form a half circle. Meat mixture may be somewhat runny from onion juices, but if crust is not rolled too thin, it should hold the mixture without running out. After flopping crust over mixture, cut carefully around outside edge so that you form a neat semicircle. (I use a fluted small pastry cutting wheel). Dip fork tines into cold water and seal edges carefully all around the semicircle so that nothing drips out. Cut a small slit about one inch long in center which will be used as a steam hole escape and an opening into which you will add melted butter and a little hot water when pasties are just taken out of oven. Use about one stick plus about two tablespoonfuls hot water heated together and poured equally divided into steam holes. Oven temperature should be preheated to 375 degrees F. and pasties baked for 45 minutes or until slightly browned. Any left over meat mixture may be refrigerated and used as a single top crust meat pie baked in an oven proof deep dish.
After you have formed and sealed pasty, carefully place it on a large cookie sheet which has been pre-greased, or a parchment paper which requires no greasing. About five pasties can be placed on a standard cookie sheet. Bon Appetite!
I think I first encountered the term “thixotrope” in conjunction with epoxy and the additives you can mix it with. I remember reading about fumed silica, and was amazed that such a product could be created and sold commercially that was so small in particle size. I’ve worked with fumed silica, and indeed it is an amazing substance.
I suspect that other people might conceptualize the property of thixotropy much like I did, and imagine that it’s a property of a material. But if you look at the definition of thixotropy, at least that given by Wikipedia, you notice that it’s a property of “certain gels or fluids.” What got me thinking about this is that a material can become more or less thixotropic depending on its physical state.
I remember sitting at a Mexican restaurant in LA with some of my cousins back in the summer of 1984 and one of my cousins was pouring a carafe of frozen margarita mixture into a glass. He tipped the carafe higher and higher, but the icy mixture still wouldn’t flow. All of a sudden the mixture started flowing catastrophically, at least as far as the glass and table was concerned… One of my other cousins remarked something to the effect that “he wondered if that was going to happen.”
If I understand the concept of thixotropy correctly, then I believe that water is a sort of “auto-thixotrope” in that it’s a material that can become thixotropic depending on its physical state. A fine grained ice slush, like that in a Slurpee or a margarita, exhibits thixotropy. Neither ice nor water by itself is thixotropic, yet a mixture of the two is.
Perhaps I should qualify the last concept, as when I think about it, I suppose that a block of ice would behave differently physically than the same mass of ice broken up into cubes. Perhaps snow is thixotropic, as I think an avalanche might qualify as an example. So now I have to wonder if particle size, particle shape and temperature are factors as well. With water, or more accurately snow or ice, you have further complications conceptualizing this, as you have the molecular lattice structure on the microscopic scale, as well as the “particle” size and shape on the macroscopic scale. The drink in your hand behaves differently as a material depending on the size and shape of the ice “particles” inside. A Slurppe pours differently than Kool-Aid with ice cubes.
So it makes more sense to me how the definition of “thixotrope” is constructed broadly, to encompass “certain gels or fluids” and not strictly as a property of a material. There is a lot more going on than one simple physical property.
I remember a physics class in college where I was introduced to the fact that there was an entire branch of materials science known as “rheology.” At the time I was amazed that an entire branch of science could be devoted to such an esoteric thing as fluid flow. Now it makes more sense, as I can begin see how complex it really is!
|
|
