3D Aphelion

[kailhofer]

Admittedly the metric system makes a heckuva lot more sense than the old English system that Amerikanos still use...

Donald

<br>This doesn't carry on the humorous theme, but there is no defense against thread drift.<br><br>I freely admit some units in the English system don't make much sense. The mile, for example. Who in the heck figured that 5,280 feet=1 mile was a good idea, anyway?<br><br>But the champion to anyone who ever built anything out of wood is the inch (that's 25.4mm to those metric out there) Centimeters divide well by 10, 5, or 2 & that's it. Inches (and that other handy unit, feet), are divisible into a nearly infinite number of even fractions. 1/2, 1/4, 1/16, 1/128... it's all easily possible.<br><br>Obviously, things are built to metric specs out there, and the whole base 10 things makes it easier to add in your head... but for building cabinets, desks, corner cupboards, etc. I just can't picture doing it the metric way.<br><br>And since I deal with paper all day... How in metricville did someone invent A4 sized paper as a standard??<br><br>Nate

[kailhofer]

As a representative of those darn metric Europeans, I have to ask a question. Correct me if I'm wrong, but a foot equals 12 inches, right? So I suppose that means that 1/16th of a foot is 3/4 of an inch (which doesn't sound all that easy to me). But 1/128th of a foot? In decimal figures it comes out as 0.09375 inches. Which brings me to my next question. You mentioned mm (milimeters), and they are necessary for any sort of precision work. But what's the subdivision of an inch? And how many of them are there to an inch?

<br>Actually, that was 1/128th of an inch, not a foot. In a nutshell, feet and inches are a fraction-oriented, base-12 numbering system. That inch can be evenly divided in half by the markings on any ruler, or in quarters, eighths, sixteenths, thirty-seconds, etc., etc. Most inch rulers are marked out to sixteenths & in practical usage you can extrapolate smaller distances by constantly guessing half the distance between measurements to get smaller and smaller.<br> <br>Hypothetically speaking, let's say you were laser cutting a piece of 1 inch (1") metal stock into 2, 4, 8, or 16 smaller, even layers (as if it were a veneer, and using a laser so there wasn't a loss due to the kerf of a sawblade) with just the markings on any ruler. You could (but not that you would, really, in this example). Without going to decimal measurements, you can't split up a centimeter's worth of similar stock the same way. In half, in 5ths, or 10ths, sure. <br><br>Feet, by being composed of 12 inches are similarly divisible, with the addition of 3rds, 6ths, 12ths, etc. This recipe is better for more efficient at subdividing raw material into equally usable chunks. <br><br>If I recall correctly, Leo Frankowski, in his Cross-Time Engineer series, remade the Polish numbering system to be base12, because it was a more efficient way to do math than by 10s. Harder to understand, perhaps, but more efficient.<br><br>

Forgive me my ignorance, but why? Why is it harder to measure out 60cm than to measure out 2 feet (not accurate)? Or, for that matter 38,1cm rather than 1'3" (I think that's how you write it). Of course, when you build stuff using the metric system, you tend to use even measurements, so that rather than 38,1cm you'd probably use 40cm. But if you need something that needs to fit into something else, you just measure the length you need and make it that length. I don't see the difficulty. Except of course that you already have lots of stuff that made to even measurements as measured in feet/inches.

<br>It's all in how you look at it, and it might not be any different really in practical use. Given 1'3", that's 15 inches, or 1-1/4 feet. If I have a 5-foot board (12 inches x 5 feet or 60 inches=1.524 meters), I know I'll get exactly four 1'3"-sized pieces out of it. Could you spit a meter into four even parts easily? I can split a 3 foot, 4 foot, a 5 foot, or 6 foot etc. evenly and quickly into 4 parts. 9", 12", 15", or 18". The 3-foot one (a "yard") is closest to a meter, and has 36 inches in it.<br><br>

Seriously, the A4 standard is brilliant, but you need to look at the complete ISO paper standard (A0, A1...A4...An)to see exactly how brilliant it is.

The brilliant thing about it is the ratio of the two sides. It is the ratio of 1 to the squareroot of 2, or 1,414. The reason this is brilliant is that it means that if you put two pieces of A4 paper together along the long side, you wind up with a piece of A3 paper, which, not only is exactly twice as large, but also has the exact same ratio of the two sides.

There are all sorts of benefits from this. I'll try to list a few of them.

Let's say you have made some sort of document, a chart, an invitation, whatever. Now you need a copy of it that is larger than A4, for instance if you want to hang it up somewhere for people to read, but think that A4 is a bit too small. No problem, you just print it in A3 format, which is easy to do, because everything is just scaled up 200%. This means that your margins, your fonts, your lines, your graphics, are all exactly as you designed them.

Or, from a writer's point of view. The standard paper size to work in (here) is A4. Let's say I've written a book in MS Word. I might have specific ideas about the visual layout of the book. Like, I don't want this paragraph broken up over two pages, or I want all the chapters to begin on uneven pages. When I print all or parts of it myself in A4 (which I probably have to, because that's the standard paper size for home printers) it looks like it does on screen. And here's the brilliant thing: when the publisher prints the book, it's in A5, which ensures that all my formatting is intact. The chapter that started on page 57 still starts on page 57.

Here's a few links related to this.

Explanation of the ISO paper standard:
http://www.cl.cam.ac.uk/~mgk25/iso-paper.html

A discussion of A4 vs. US Letter:
http://betweenborders.com/wordsmithing/a4-vs-us-letter/

- Wishbone

<br>Ok, I like the consistent enlargement percentage. That's a clear advantage to your side.<br><br>As I said, I deal with paper sizes every day because I'm an estimator for a printing company. As such, from a manufacturing standpoint, the English sizes shown in the table are flawed. They are not commonly produced sizes above 17x22 (4 8.5x11's). The most common paper stocks I deal with are 8.5x11 (letter), 8.5x14 (legal), 11x17 (tabloid, or 2 8.5x11s side-by-side), 17x22, 23x35, 25x38, & 26x40. Anything of 17x22 size or smaller is not actually manufactured at that size, but is instead cut out of one of the larger-sized sheets in the list.<br><br>It's nice that an A0 sheet could be cut into what looks like 16 A4s, but must not be very practical for the printing industry in Europe. We start with sheets that are deliberately larger than we'll need in the end to allow for bleed (when ink prints right past the trimmed edge of paper) at a standard size. That is, on our Italian-made press, which by the way would not fit the A0 sheet (33.11"x46.811"), we generally run 25x38 sheets. That allows to fit 8 8.5x11s with bleed all sides on the sheet, with room for a color calibration bar along the top edge and gripper at the bottom. ("Gripper" is the space on a sheet where the press will grip hold of it & pull it through the press, and thus can't be printed on.) We also can allow for extra paper to be left between the letter pieces for a later folding and trimming process, where multiple sheets are folded up to form signatures (such as books are printed of). That extra is then trimmed off the folded signature after its assembly, leaving nice, straight edges & bleed effects in someone's magazine or book.<br><br>This A0 size doesn't seem to allow for that extra space necessary for the manufacturing process, at least, efficiently. With any kind of bleed space, you won't get 16 out, and perhaps, a lot of wasted paper. I've not done the math to figure out how much.<br><br><br>In short, neither metric or english is perfect. As a silly American, I think in inches and feet, and favor that system of measurement. Perhaps someone who uses both can offer a different perspective.<br><br>Nate

[kailhofer]

My memory is getting lousy in my old age, but I seem to remember that not too long ago NASA gave a contractor some specifications in English measurement, but the contractor built the parts using the metric system, or perhaps vice versa. Anyway, the result was a big SNAFU.

Donald

<br>I believe that would be the Mars Climate Orbiter. The contractor used English measurements, & the rest of NASA was metric.<br><br>The result was a $125,000,000 fireball in the Martian atmosphere. Our tax dollars at work.<br><br>Nate

[kailhofer]

I agree. But for calculation purposes, I'd prefer base 10.

<br>Sure. I'd agree wholeheartedly. Base12 or higher would make for a large-scale calulation nightmare for us primitive ape creatures with ten fingers. Once you get past the Inch and the foot, the English system gets very hard to figure out.<br><br>Don't even get me started on pints to pecks or bushels, rods & furlongs, troy ounces versus regular ones, and all the other weird measures that are still out there, lurking... <br><br>

Now that we know how printing works, I think I can safely say that the same rules apply here. The ISO sizes are end product sizes, not production sizes. Of course European printers (the printing industry, that is) have to take all the things you mention into account, bleed and so on.

I'm not in the printing business, but as I said, the ISO sizes are end product, not production. Even if they were, I'm guessing they might leave out a row and a column and get 9 finished A4 prints instead. But if that generates too much wasted space, you can bet that their raw material is of a size to take that into account.

- Wishbone

<br>I'm sure they would, and paper is manufactured in rolls, not sheets anyway, so clearly they could be getting it in whatever size they need. If European printers weren't efficient, they wouldn't stay in business--and there are some very successful printers in Europe. It's just that an A0 sheet doesn't seem very practical to my mind. That, and as I said, the Italian-made press we use (and the previous one we had before that where the schematics were all in Italian & had to use European voltage) wouldn't take such a size. The largest it would go is 660.4x1016mm (26"x40").<br><br>Nate

[kailhofer]

what the hell are you people on?

Lee

<br>We've all got a Cliff Clavin-esque (from Cheers) desire to know all the minutiae we can cram into our aching noggins.<br><br>Don't you?<br><br>After all, you never know when you might need to know something for a story, like what they make those science class black tables out of...<br><br>Nate

[Robert_Moriyama]

Someone who uses both? That would be Machinists, like my Dad. He regularly makes airplane parts that have to have tolerances that measure in ten thousandths or or hundred thousandths of either inches or centimeters. Obviously, 1/10,000 of a centimeter is smaller than the 1/10,000 of an inch. 2.2 centimeters to an inch is all he has to remember to convert from one scale to another....

Dan

<br><br>"2.2 centimeters to an inch"???? And he makes airplane parts???? Suddenly, I feel the urge to run (not walk) away from my job at the airport (where our office building is not that far from a runway), because with crosswinds, some of those falling airplane parts could easily wind up coming through our windows. <br> :o<br><br>Robert "I am shocked that nobody else caught this" M.

[Robert_Moriyama]

All right. The mistakes are mine.

Screw this.

<br><br>Would that be a metric-gauge screw or an imperial-gauge screw? (And why is the U.S. using 'imperial' measurement units (aside from a few things like gallons) anyway? I'd a' thought they'd have come up with something different back in 1777 or thereabouts ...)<br><br>Dan, I prescribe a hug from Lyn, a romp with the dog (or a romp with Lyn, for that matter), and a viewing of the Bill Murray classic, 'Meatballs', where you will learn the mantra that soothes all wounds:<br><br>"It just doesn't matter! It just doesn't matter!"<br><br>(repeat until hypoxia sets in)<br><br>Robert M.

[Robert_Moriyama]

1 inch does indeed equal 2.2 cm. I was right all along. 2.2 is the most common metric to English conversion factor.

Dan

<br><br>Ah, you were referring to the 'short inch' (analogous to the 'long' and 'short' tons in Imperial measure, and, of course, the approximation for converting kilograms to pounds). If only you had the Bush White House Ministry of Truth to make sure that your statements were 100% accurate and unambiguous, we wouldn't have this hyar failure to communicate. ::)<br><br>Robert "Where do I get one of those metal umbrellas from the Max Headroom TV series?"* M.<br><br>*They became popular when the frequency of deorbiting space junk got to be a nuisance.