Why Do Pirates Love Parrots? (34 page)
Read Why Do Pirates Love Parrots? Online
Authors: David Feldman
We’ll leave that answer for a possible all-urination
Imponderables
book, and make an utterly smooth transition to the also less than lofty subject of manhole covers. In
When Do Fish Sleep?
we debunked many of the myths surrounding why manhole covers are round, but Kelly Mueller, who is a self-described “starving college student from Texas” and civil engineering major, read a letter from a reader chastising us, and wanted to weigh in with some support:
I would like to submit, for your arsenal of retribution, a few thoughts from a not so fresh mind of science. Beginning with the most difficult to prove and ending with the most obvious answer:
1.
The circular shape, as the traveling distributed load (i.e., weight of the vehicle) moves from the loading end to the unloading end, allows for the least possible or likely amount of recoil in the unfixed manhole. In other words, it shouldn’t spring up from the road after a vehicle drives over the manhole lid (and because this object is circular it can be approached from any direction while anticipating similar results).
2.
The circular manhole provides a sounder ratio of material area to area of supporting surface (to the incased lip that the cover rests on) than other straight-edged shapes…
3.
Cost is always a factor in design, and upkeep or maintenance is a serious expense. Imagine the number of manholes in a given downtown zone, and then imagine having to repair each of those at least once in their lifetime (and the obstruction from the crew making the repairs)—that is, if the manhole were some other shape than circular.
The steel circular support lip for the round manhole is the most worthy shape to form into concrete, or for that matter other various types of pavement, due to the shape’s resilience to withstand the continuous effects of weather…When the surface of the road expands and contracts with temperature change, the material searches for a release of the energy created by this cycle at the weakest area of its body. The shape of a circle holds and pushes at all 360 degrees of its area to resist this escape of energy, and the steel circular lip is also involved in this same proactive cycle, but at a different rate in respect to the conflicting surrounding pavement that could push or pull on its structure.
But because both components of the manhole, the pavement and the incased lip, are round, there are minimal effects on the integrity of the functioning part of the street. Think of trying to break an egg by squeezing it from all of its surface area. The simple round [but not circular!] egg is stronger than one would anticipate! If the manhole was any other shape, say a square or a triangle, given time with temperature change, a crack would originate from at least one of its corners and continue until the crack reaches a point of release.
Maybe we can convene a gathering of manhole cover and porthole manufacturers and settle this for good. We’d have a better chance of getting them together than a bunch of cowboys. Reader Harold Meyer disputes our contention in
Do Penguins Have Knees?
that the crease atop most cowboy hats is there primarily for cosmetic reasons, and contrasted the cool cowboys’ attire from the creaseless hat worn by Hoss, the character on
Bonanza:
Your answer is way out of line. Cowboys creased their hats to make them drain towards the back when it rains. A hat like Hoss wore on
Bonanza
had no crease for cosmetic reasons but if it were really worn by a cowboy out on a range there would have been a crease on it.
Speaking of drainage of liquids, we received an e-mail from Harry Gish, a longtime pharmacy owner, who read
What Are Hyenas Laughing At, Anyway?
and had some comments about why so many pharmacists stand on raised platforms:
The original reason pharmacists’ areas are raised goes back to “olden times” and is more chemistry than pharmacy (in some countries pharmacists are still called “chemists”). Back when pharmacists primarily compounded formulas rather than “pill rolling,” it was desirable to have evacuation routes for spilled liquids (and solids cleaned off by water) which often could be hazardous, such as mercury. By having the area elevated it assured easier evacuation.
One of the rarest of things nowadays is a “compounding pharmacist”—one who will make custom formulas to doctor specifications rather than just being a “dispensing pharmacist.” Besides lack of knowledge of how to compound there are fears of liability problems, along with greater governmental controls in accessing the raw ingredients.
There are a number of levels of pharmacy licensing and certification as well…Ask any pharmacist you know what a “grandfathered pharmacist” is. Pharmacists generally weren’t licensed until 1933. At that time in most states, anyone who could claim proof of having dispensed for at least three years and had a high school diploma could apply for a license.
You don’t need a license to wash windows, either, and some of you had strong feelings about an Imponderable we posed in
Do Elephants Jump?
—“Why Are Newspapers So Effective in Cleaning Windows?” All of the professionals we spoke to used squeegees, but preferred newspapers to paper towels. Reader Darin Furry of San Rafael, California, was the most vociferous in his defense of the humble paper towel:
About ten years ago,
Consumer Reports
tested window cleaners and also tested methods to clean windows. They found that newspapers were average at best, and there were much more effective ways to clean glass—paper towels, rags, squeegees, etc. Personally, I found newspapers were not very absorbent, time consuming to use, and extremely messy, so I use freshly laundered rags. Despite the myth that newspapers impart a shine, my rags leave the glass shining, streak-free, and squeaky clean. As for lint? Newspapers may be less “linty” than paper towels, but cloth does a far better job.
…the reader should have rephrased the question as: “Where did the idea originate that newspapers are effective for cleaning windows?” I think that decades ago, there weren’t paper towels and you couldn’t easily launder cloth rags (and perhaps if you had any spare cloth, you’d use it to patch clothes, not make rags out of them as we do nowadays). So newspapers were a cheap and convenient alternative…
Just to be clear, whenever possible, we phrase the Imponderables in our books as originally posed to us, even if the premise of the question is incorrect.
Speaking of rephrasing, we wish we could take back one little word in our first book: “animal.” In our chapter about how cats can see in the dark, we said:
“No animal possesses the ability to give light.”
We meant to write “mammals”—honest! But Charlie Orme of Knoxville, Tennessee caught us on it:
It is well known that several fish do in fact emit light (bioluminescence).
Right you are, Charlie. Not just fish, either—fireflies and glowworms are bioluminescent, and the ocean is full of such creatures, from fungi to cookie-cutter sharks.
Charlie Orme assumed we had also been properly rebuked, in our discussion of why the keys on the typewriter are arranged as they are (in
Why Don’t Cats Like To Swim?),
for not mentioning a salient feature of the typewriter keyboard, which we didn’t
:
Your discussion is all well and good, except you forgot to include that Mr. Sholes also, for the benefit of his sales marketing demonstrations, put all of the letters for the word “typewriter” in the top row.
Actually, we’ve never been rebuked for this omission, and we didn’t know this piece of information. Very cool, although it would have been ever hipper if the creator of the most popular keyboard could have figured out what to do with the “lame duck” Q on the top row.
We have been rebuked by left-handed string players ever since we discussed why we don’t see lefty string players in orchestras in
How Do Astronauts Scratch an Itch?
In the chapter, we cited the potential problems of bow-crashing if lefties and righties were seated next to each other, and the expense of manufacturing or retrofitting instruments specifically for lefties (although they may look symmetrical on the outside, they are asymmetrical on the inside). In
Do Elephants Jump?,
reader Michele Myhaver argued that left-handers have an advantage playing stringed instruments, since the left hand accomplishes the more complicated actions, while the right hand only needs to “saw away” on the bow. Just before the publication of
Elephants,
we heard from a “rising, left-handed seventh grader who plays the cello,” Gwendolyn Cannon of Gaithersburg, Maryland. We have a strong feeling that Gwendolyn is still rising, and in the ninth grade by now. As other readers have made clear, the audience can’t tell whether string players are left-handed or not, since the overwhelming majority are taught to bow with their right hand, and are given no choice about it. As Gwendolyn put it:
The other people don’t really care if you’re left-handed or not. Left-handed people are very good at adapting in a right-handed world. Right now, I am eating yogurt with my right hand and writing with my left hand and I only dropped a little bit on the table, which is better than I normally do [when eating it left-handed].
I’d also like to say that I can bow faster and do the fingerings faster than anyone else in the class, and still get a good tone out.
So there.
If Gwendolyn had been born at the beginning of the early twentieth century, she might have played the cello to accompany silent movies. Of course, chances are she wouldn’t have, but then how could we create a stunningly subtle segue into the next e-mail from Rich Mitchell, a film historian, editor, director, and ex-projectionist. He read our discussion of why the countdown leader on films never seems to go down to one or zero in
Why Do Clocks Run Clockwise?
The countdown leader was never intended to be shown to the public. You will note that on the rare occasion you see the leader in a theater or on television, other than when intentionally included in the program material, it is by accident.
The practice of including several feet of blank film before the official picture start goes back to the earliest days of film projection. Films were then printed (and photographed) on highly inflammable nitrate film. The projection light source was a scaled-down version of the high intensity carbon arcs formerly used in searchlights, which was focused on the projector’s aperture by a concave mirror and a series of condenser lenses that generated a lot of heat as well as a very bright light. Were the film to be exposed to this heat longer than the fraction of a second necessary for the persistence of vision phenomena, it would burst into flame. Thus, the film had to already be running through the projector before the dowser separating the projection head from the light source was opened. Early exhibitors soon realized that it was easier on the audience’s eyes in the already darkened auditorium if this start-up footage was opaque.
The practice became standardized with the introduction of the multireel feature and the use of two projectors. Silent films were shipped with cue sheets, which not only contained suggestions for the music to be played with each scene, but notations of the action or title card at the end of each reel. Three feet from the first frame of picture was a frame marked “START,” which the projectionist used to properly frame the image. At the sight of the described action or title on the previous reel, he was to start the second projector and on the count of three, make his changeover. Whenever possible, silent film reels were ended on a title card, with the same title at the start of the next reel so that, in theory, the audience would not notice the change in projectors.
The three-count was based on running three feet of film at the “official” silent speed of one foot, or 16 frames, per second. Though this standard was established in 1908, it’s now known that silent films were never consistently photographed or projected at one speed; in fact, the sound speed of 24 frames per second is a rough average of the speeds at which silent films were being photographed and projected in 1925.
The introduction of the countdown leader was necessitated by the introduction of sound film. If you’ve ever heard a projector start up in the middle of a reel with the sound turned on, you’ve heard the garbled noises and changes in pitch until the machine stabilizes. Because the sound projectors of the time needed a longer startup time, the technology council of the Academy of Motion Picture Arts and Sciences introduced what became known as the “Academy Leader” in 1930. This leader placed the “Picture Start” frame twelve feet from the first frame of a picture with the next nine feet indicated by a frame with descending numbers at every foot. The last three feet were left opaque to accommodate the start of one-reel subjects or multireel features, but since the leaders were printed up as a standard unit, they would also be attached to the other reels.