Here is the Canton map of Slat, the 3rd of its kind to be finished (out of 11). Warning: PDF file is 38.8 megabytes! Make sure your computer is as prepared to see Slat as you are.
Monthly Archives: June 2008
[I wrote this as part of a 45-minute physics lesson for inner-city middle schoolers.]
“The Mechanics of Flight”
Building a Better Baking Soda and Vinegar Bomb
It might not be gunpowder. It may not even match dry ice. But in the world of backyard explosives, baking soda and vinegar is still one of the best (and most fun) ways to create an ear-pounding boom.
There’s no end to the ways by which one can make use of these two substances. Sodium bicarbonate and acetic acid combine to make fizzy volcanoes in first grade, cork guns in seventh grade and a cleaning substance in middle age. This article won’t touch on those, but it will provide a quick, simple and satisfying means for making a small-scale explosive.
First, you’ll need an empty 500 ml (16.9 oz) plastic bottle. Those of you in America know this size as the bottle Diet Coke 6-packs usually come in. It should have a flexible plastic body and a hard plastic cap, usually as tall as it is wide. (If the cap is flimsy or see-through, you probably don’t want to use it.)
Got it? Excellent. It’s now time for a quick trip to the grocery store. On your shopping list are two items: baking soda, preferably in a large box, and a jug of vinegar. In the latter’s case, you’ll want to get the highest concentration possible. 5% vinegar is fine, but see if you can’t find something higher, like 10%.
This is where the instructions begin to diverge from your expectations. Chances are, you figured that I would ask you to pour in the vinegar, pour in the baking soda and watch it all fizz out the top. Not quite. You’ll want to pay close attention from here on out.
Having uncapped the bottle, pour in vinegar until it’s about a quarter full. (This isn’t an exact science, and I welcome you to experiment with different amounts.) Next, take the open bottle and stick it in your freezer. Wait until that vinegar is completely frozen before taking it back out.
Once your acetic acid has turned to ice, pull the bottle out and grab your baking soda. Take out a wide-mouthed funnel (or your hand) and stick it through the bottle’s top. If you’re sure that the vinegar is frozen, start pouring baking soda through the funnel/hand until the bottle is about ½ to 2/3 full. (Again: experiment with your measures.) Now screw the cap on, and tight!
It should now become clear why I asked you to freeze the vinegar. Had you poured the baking soda into liquid vinegar, the whole concoction would have begun to fizz before you screwed on the cap, wasting precious carbon dioxide. (That’s right, environmentalists! In this situation, CO2 is a good thing.) By freezing the acetic acid, you delayed the chemical reaction long enough to get the baking soda in on time.
With your cap screwed on, take the bottle outside and wait for it to melt. Do not point the cap or the back of the bottle at you; carry this thing as you would a loaded gun. Once the vinegar his begun to liquefy, shake the bottle so that you mix the two substances together. Shake the bottle left and right, not up or down or towards you and away from you.
If you’ve followed all these instructions well, the plastic should begin to harden—as if something’s pushing at it from the inside. (That would be the CO2 gas, a byproduct of the acetic acid/sodium bicarbonate reaction.) Keep on shaking or rolling it until the contents seem evenly mixed.
You are now ready to reap the fruits of your labors. Find a hard surface outdoors that’s at least 20 yards away from any people, cars or other valuable items. Hold the bottle at the neck and chuck it—with as high a trajectory as possible—towards the isolated surface.
I won’t spoil the ending. 🙂
Tunesticking: A Primer
Chances are, you have already played the instrument about which I am writing. If you have tapped a pencil on a table edge, played imaginary drums with a ruler or a paintbrush, then you may consider yourself an expert. There is no newfangled technology involved in the “Tunestick;” rather, it’s an idea that the cavemen probably picked up on.
Tunesticks, as I like to call them, are any sort of long, thin dowel or rod that produce resonant sounds when hit on a table. Tunestick playing could not be simpler; by grasping the edge of the dowel with one’s thumb and index finger and hitting the thing on a table, one can produce any number of sounds depending on just where the thing is struck. If the point of contact is close to the thumb, the note is low; if the point is further away, the note is high. The idea, of course, is to change the position of contact with every note so as to produce a piece of music.
That is Tunesticking at its very basics. I don’t claim ownership over the concept; indeed, I don’t know anyone who hasn’t tapped a pen or pencil in such a fashion. What sets me apart from the rest is that I had the free time to write about it.
What counts as a good tunestick? Just about anything that would also make a good writing instrument, or a good television antenna, or a good dowel. This is not the rarefied world of string instruments or woodwinds; no, this is an instrument that’s about as diverse as they come. Anything from a television antenna to a ruler can do the job, though some items—no doubt—sound better than others.
The teeming mass of “instruments” that qualify as tunesticks can be divided into two main categories: wood and metal. (I have yet to see a porcelain or clay tunestick perform.) Wood has a number of redeeming qualities to it; the material is quite resonant, durable to some extent and has a satisfying bend to it. There are downsides to match the positives, however. Most wooden dowels are lightweight, meaning the sound does not carry all that well. Wood does not bend as easily as do metal tunesticks, but it has the unfortunate quality of snapping quite easily. There are also the issues of splinters and water damage.
Metal sticks aren’t perfect, but they do seem to perform better than dowels. Their greatest asset may very well be their amplitude: just about any moderate-weight tunestick crafted out of metal can produce a satisfactory volume if struck hard enough. It’s also nearly impossible to outright snap a tunestick in two, though lightweight versions have an annoying tendency to warp and bend after extended sessions. Metal tunesticks also have a somewhat duller sound than wood, in the sense that their notes aren’t quite as pronounced and distinct. There exists no clear winner among the four most widely used metals (copper, brass, aluminum and steel), but brass is an excellent type with which to start; it’s heavier and more durable than aluminum, but more resonant than steel and copper.
A tunestick’s size greatly impacts its sound. The most practical length for an instrument is 6-20 inches; 12 inches is an accepted standard. Nearly all tunesticks are less than a half inch in thickness, with ¼ to 3/8 of an inch being the usual size. Thinner sticks tend to have a richer sound, but wider ones are usually more durable. Finally, before picking a stick, one must make an important decision: hollow or solid? The former delivers better sound quality, but the latter is stronger (and, in the case of wood, much easier to find).
Going beyond the fundamentals
The great beauty to tunesticking, if any exists, is the great potential of the instrument for manipulation. No technical knowledge, no extensive practice is necessary for one to form their own distinctive style.
So far, this article has covered only one-handed tunesticking. One doesn’t have to major in math to realize the potential exists for two-handed “Doubletuning” in which two instruments are struck at once. This takes some coordination, but allows for a “base” beat and a “harmony” beat at the same time. Additionally, the thumb and index finger need not stay at the bottom of the rod. By shifting their position closer to the top, the overall sound of the instrument is changed. An extreme shift (in which the thumb and forefinger lie at the top half of the tunestick) can produce a very unique sound—reminiscent of an alien transmission, almost. With practice and an extra hand, one can change the sound of the instrument by moving their fingers while keeping the tunestick in place.
To put it bluntly, tunesticking is a rough science. There exists no universal standard for notes, no international association, no copyright bills and legal disputes. Chances are, the tunestick will never share equal ground with the electric guitar or clarinet; there’s simply too much deviation and diversity within the field. That, however, is its greatest asset. By stretching the boundaries of the field and taking an otherwise blunt, simple instrument to new levels of complexity, the full potential of the lowly tunestick can be realized. Happy tapping!
For earthquakes, there’s the Richter scale. Tornadoes, the Fujita scale. Hurricanes? Saffir and Simpson took care of that. To this day, though, there remains no universally accepted scale for measuring the output of thunderstorms. Though the following certainly isn’t scientifically developed, nor is it detailed and researched enough to become a standard, it is one option that weather aficionados like myself can use.
Thunderscale: a means for categorizing thunderstorms by intensity
Note: all but one point of criteria for each level (TS1-Ts6) must be met over a given location for a storm to fall into the level for that spot. This means that a thunderstorm can have different TS levels depending on the location of the observer, an important thing to note. What might be a TS2 storm for one viewer might be a TS5 storm just 20 miles away.
For observers, thus, this system becomes personalized. (Example: “I experienced TS3 conditions yesterday.”) However, for newscasters and storm overviews, it’s best to use what one might call Max Thunderscale, or MTS, in reference to the storm’s center. (Example: “The storm reached a MTS of 6 yesterday before dissipating.”)
–Drizzle or no rainfall
–Generally calm winds
–Widespread breaks in cloud cover
–Thunder is faint or imperceptible
–Rain is light, but steady
–Noticeable winds (3+ mph)
–Some breaks in cloud cover
–Thunder and lightning are noticeable, but distant
–Moderate rainfall with some heavy bursts
–Winds gusting to 10 mph or more
–Sky is mainly overcast, except for one or two breaks
–Consistent perceptible thunder
–Rainfall thick enough to blur out distant locations
–Winds gusting to 15 mph or more
–Sky is both overcast and noticeably dark
–Lightning is visible and persistent; thunder jarring at times
–Downpours of rain
–Winds gusting over 30 mph
–Sky nearly black
–Thunder in immediate vicinity; less than three seconds in between lightning and thunder
–Hail at times
–Rain and hail fall in visible sheets; nearly impossible to see over 50 meters
–Winds gusting at 50 mph or more
–Sky is all but black; green tint possible
–Constant, immediate lightning with booming thunder
–Hail larger than a centimeter
–Tornadoes reported in the area