In the first half of this two-part series on Austin’s grind box, I explained some details relating to the design, construction and funding our big box toy. In this post, I’m going to complicate things a little bit, and get into some of the nitty gritty academic stuff that’s inherent in such an undertaking.
As always, there’s a lot to deal with, so please bear with me.
NOTE: In the picture above you can see the framing of the riser portions of the box prior to installing the outer layer of plywood. The bracing was set on 1-foot centers so that the angled portions would be skateable (See Mick Casals’ lasts tricks in the edit below).
Numbers in General
The first thing that I want to address has a lot to do with mathematical and scientistic worldviews. You may not have spent a lot of time thinking about this before, but the ways in which — and the extent to which — numbers can accurately represent reality is really more ideological than you might think. As a rhetorician (and in particular, an epistemic rhetorician) I take the view that numbers (and math) are simply A WAY of representing the world, rather than THE ONE TRUE WAY of correctly representing the world.
Take a few minutes to watch this video to get a better sense of what I’m talking about. If you’re not in position to watch a video with audio, be sure that you’re familiar with Mathematical Platonism, Nominalism, and Fictionalism before proceeding.
NOTE: this video covers three separate ideologies of math, and to some extent it implies that there are ONLY three. There are many more than three, but the guys who do Numberphile were trying to keep things manageable, and so their coverage deals with two extremes and what is often styled the “middle view.”
Now, personally, the language Dr. Tallant (the mathematician featured in the video above) uses is a little frightening. He’s a teensy bit hostile toward what he called the “Fictionalist” view, though I do think he gives the view a (mostly) fair shake. The main issue I would raise about his explanation is the way he conflates Fiction/Nonfiction with Falsity/Truth.
In my view, the two pairs of ideas are neither parallel nor corresponding. For instance, I happen to like a book of fiction by Franz Kafka called The Trial. Now, I take this book to be a work of fiction; I do not take it to be a book of falsehoods, or worse, a book of lies.
It’s a book of fiction. Fiction and falsehood don’t have anything to do with each other, and it’s only by (mis)conflating the two that someone can equate them.
This, to me, is instructive. We call a book like The Trial a book of fiction because it’s about people, places, and things that don’t have referents in our world beyond the book itself. The main character Joseph K. isn’t a lie; he’s a fiction. So when Dr. Tallant says the Fictionalist must try to “explain away” the success of math and science, he’s really misunderstanding what fiction is. Again, it’s not LIES, it’s fiction. Cell phones are great. And so are novels, plays, and essays. The bottom line here is this: loads and loads of numbers don’t have a referent in the world beyond mathematics itself. This poses significant problems for a coherent mathematical philosophy, just as Tallant explained.
Dr. Tallant is right on the money, however, when he says, “success in the world isn’t a hallmark of truth — or needn’t be a hallmark of truth.” Nothing about any tool NEEDS to be true. What’s “true” about a hex wrench? Nothing. But that doesn’t mean that a hex wrench doesn’t do a good job of turning skate bolts.
Frankly, it seems to me, too many lay users of math and science (and many experts) either misunderstand, are misinformed, or are otherwise not in tune with the last century or so of the philosophies of math and science (or, as the case may be for Dr. Tallant, it might be politically incorrect in his particular academic department to hold or be tolerant of such a view).
In any event, within the philosophies of math and science, these issues (while requiring constant upkeep) have been more or less resolved since about 50 years ago (in the case of Mathematical Nominalism) and many centuries ago (in the case of Mathematical Platonism).
NOTE: If you’re interested in seeing more about this stuff, I’ve included a whole bunch of links at the bottom of this post.
We should keep in mind though that sooner or later a better model than what Tallant called Fictionalism is bound to replace it with something more precise or more explanatory. Until then, Fictionalism strikes me as being quite appropriate, and, as crazy as this sounds, a rather realistic approach to contending with a bigger swath of what we might think of as “the whole situation.”
The second topic I want to address brings us much closer to dealing with the actual grind box we built: our representation.
Taking somewhat of a Fictionalist view (or what I would rather call an epistemic rhetorician’s view), we understand that we can’t appropriately solve all the problems associated with our box. There are simply far too many variables (some of which are even conflicting) to successfully attend to (I’m thinking of variables like friction, variable skating speed, variable weight of skaters, temperature, air pressure, the force of gravity at our exact location, energy transfer, energy absorption by the skater, etc.) So, as I said in the last post, we created a representation of our problem and solved the issues raised not by addressing the entire complexity of our problem, but by addressing the solvable issues in our representation that we take to be most immediate and relevant.
A first issue that has bearing on our little math problem here is the dimensions we were trying to achieve. What motivated the height measurement for our box was actually the picnic table in my garage — that, and a whole lot of beer. As a kind of blader hangout, my garage was home to many nights of drinking and talking about skating, standing up to explain and model exactly what someone meant by “outcab soul to backslide the hard way,” and numerous other exclamations like “Dude, I could totally do X trick on a box that high.”
As a matter of fact, the grindable portion of the box itself was modeled after the bench part of my picnic table for reasons similar to those mentioned above.
So, the height of the box sitting on the ground was designed to be exactly the height of the bench of my picnic table, and the height of the box lifted up on the risers was designed to be exactly the height of the top portion of the picnic table. After all, we’d been sitting there looking at both of them for months filled to the brim with what is often called “liquid confidence.”
But the point is, having had all of those experiences with my picnic table, the height became something of a fixed idea, which absolutely corresponds to the number we would eventually need for our riser width. Any other height would have required a slightly different answer for our riser width. So in this case, a significant portion of our representation has tremendously to do with beer—physics is actually only a part of the whole scenario.
A second main component of our representation was the equation Dmitry suggested for the calculation. According to his intuitions about both rollerblading and the grind box design, it seemed appropriate to use a “conservation of energy” model to solve our problem, rather than any number of other alternatives he could have used to produce an answer.
The thinking, there, was motivated by our knowledge of how much the box weighs. If the biggest risk to our health was the box actually falling over on one of us, the solution has to figure in the energy the box has to be able to absorb (or in this case conserve) so that “extra” energy isn’t being spent tipping over the box.
If you can read the language of math, take a look at this PDF that Dmitry sent me of his exact thought process and calculations:
skatebox (5) PDF Document
NOTE: If my memory serves me, the answer Dmitry finds in the PDF above is 0.9 meters. Our eventual answer (after number crunching once or twice more wound up being 0.95 meters, which is roughly equivalent to 37.5 inches—which is what we ultimately settled on.
The final part of the representation I want to cover here concerns the safety-related choices we made in plugging in our “reality” to Dmitry’s equation. If you recall from the last post, we picked a “worse case scenario” approach and used a Zangief-style jump attack to stand for our hypothetical skater.
The thinking there is that there is simply too much variability when dealing with the relative size of Austin’s rollerbladers. Mick Casals, for instance, is about 5’5″ tall and weighs about 130 lbs. I am 6’2″ tall and weigh about 225 lbs. If the box was going to safe for everybody to skate, we needed a better tactic than using weight to ensure safety.
What we came up with was essentially a head on collision (thus Dmitry’s use of “conservation of energy” as his model). Knowing that such a collision is highly unlikely, we chose the Zangief jump attack as the best way to include both a figure for weight (we took an average of 200 lbs.) while still providing for a “theoretically possible” scenario. If the dimensions we were going to use could ensure the box would not tip over during such a collision, we could be as sure as possible that it wouldn’t tip over during any topsoul, wallride, or whatever.
If you read the last post, you saw the part where we figured out a good estimate for the weight of the actual grind box. Given that the weight is somewhere in the neighborhood of 538 lbs., having the box tip over could actually be catastrophic — and not only that, worrying about the box falling over could seriously disrupt the act of skating the box. If you’re constantly worrying about what tricks you can do without knocking over the box, you’re spending your time thinking about the wrong things. A good box should eliminate those worries, and give the skaters to opportunity to focus solely on their skating, technique, and tricks.
So as an extra precaution, we chose to sheet the bottom of the risers with OSB plywood. If you’ve never heard of OSB, it’s a bit like particleboard and it’s made of small wooden fibers that are oriented in two directions (hence Oriented Strand Board). One aspect of it that’s appropriate for our use is that it’s much cheaper than regular CDX grade plywood. The other, perhaps more important feature of it is that it has a smooth side and a rough side. In construction, the rough side is for roofing applications and allows the singles and or felt paper to grip the roof (so that stuff doesn’t slide off during construction). For our purposes though, the super rough surface slides easier on concrete, meaning that — in addition to our riser width solution — our box should slide sideways if impacted from the side rather than tip over.
It turns out that using the rough side down is somewhat overkill because, to my knowledge at least, the box hasn’t moved an inch during skating.
So it seems, the tremendous weight of our box probably (actually) has the most bearing on its behavior. In my estimation then, someone wanting to build a similar box could do away with the whole physics problem altogether and solve the tipping problem by simply using heavy-ass sand bags in a riser of just about any size or shape to keep the box upright. Ironically, this is exactly what Dmitry (our physics expert) first proposed when I brought him the initial problem.
On the other hand, a number of people have had a lot of fun skating the sides of the riser box like a wall ride, and so the riser angle solution seems to be a good addition after all — except for the occasional scenario where you miss the coping and get a foot caught on one of the riser’s angled parts.
From start to finish the whole project has been a huge amount of fun. I think it’s worthwhile to bring in lots of perspectives and get a lot of ideas circulating. And, as hard as it can be at times to manage a democratic process in rollerblading, the outcome is usually one in which all parties involved can walk away feeling satisfied.
In our case, we took into consideration epistemic rhetoric, physics, mathematics, decades worth of experiential rollerblading, carpentry know-how, and a huge range of different rollerblading styles to create an object that would be sturdy, safe, and fun for everybody who’s had the chance to skate it.
And, while good old-fashioned experience gets really close to the answers that rhetoric, math and science can yield, those academic disciplines provide a level of confidence unmatched by any object I’ve so far skated.
So if you ever find yourself in Austin on a sunny Saturday afternoon, be sure to hit us up to join in on a weekly box session. We’re out there just about every single week.
Thanks for reading,
Post Script: As an additional bonus for this post, I was able to cajole Jan Welch out of his semi-retirement to film and edit a quick video showing what normally goes on at our weekly box sessions. Take a look!
Also, I want to offer my humble thanks one more time to all the Austin guys who’ve helped out on this project, especially Jarrod McBay, Dmitry Meyerson, Jay Geurnik, Mick Casals, Heath Burley, Cody Sanders, Barret Worley, Scott Wells, and many others.
Extra special thanks to Jay Geurink for his photo support of this whole project, and big ups to Jan Welch for coming through with a fantastic edit for everybody to watch.
Lastly, if you’re interested in seeing more about the philosophy of science, watch Bryan Magee’s conversation with Hilary Putnam from Magee’s fantastic British TV show from the 1970s. The whole thing is about an hour long. Here’re the links:
Section 1: http://www.youtube.com/watch?v=cG3sfrK5B4E
Section 2: http://www.youtube.com/watch?v=rAP4E3EpedE
Section 3: http://www.youtube.com/watch?v=PNPZDLEba44
Section 4: http://www.youtube.com/watch?v=8KzTMStETRE
Section 5: http://www.youtube.com/watch?v=MquP2kIvsMQ