Sunday, March 13, 2011


What order do you do operations in, in math, when you've got a lot of them? Please excuse my dear Aunt Sally. er, I mean, Parenthesis, Exponents, Multiplication, Division, Addition, Subtraction. See how the first memorable phrase starts with the first letters of the words in the second?
Mnemonics are a psychological trick where you remember something by associating it with something novel, which your brain expects to do. The more associations (and the stranger), the better you can remember it. They're named after Mnemosyne, the Greek goddess of memory (and apparently, arbitrary spelling. Pronounced "Nem-o-seen.")
Okay, so what kind of stars exist? Oh be a fine girl, kiss me. Ouch. Hey, I'm not literally hitting on you, it's the mnemonic. Lists their orders from hottest to coldest. Our sun's a G. Specifically, G2V, a little cooler than the average G, main sequence.
Okay, music. Those lines stand for notes, but which ones? Well, in the treble clef, "every good boy does fine." In the base clef, "Grizzly bears don't fly airplanes." Oh, and sharps appear in a particular order too: "Father Charles goes down and ends battles." (Flats are in the opposite order, if you'd care to write a mnemonic for that.)
In chemistry, equations always obey OIL-RIG. That is, oxidation is loss (of electrons), reduction is gain. Redox!
Mechanics. Which way do I turn the screw again? Righty tighty. So therefore, lefty loosy.
Electronics? They're color coded: "Bright Boys Rave Over Young Girls But Veto Getting Wed."
Biology? All life is elaborately classified. "Kings Play Chess On Fine Grained Sand." (Although the last two, Genus and Species, are unique enough to identify pretty much anything in existence.)
And if this isn't circular enough, remember this poem and all your circles will be correct:
Sir, I bear a rhyme excelling
In mystic force, and magic spelling
Celestial sprites elucidate
All my own striving can't relate
Or locate they who can cogitate
And so finally terminate.

(Which, if you count the letters in each word, becomes Pi, to 31 digits, which is accurate enough for any dimensions of a circle the size of the universe, accurate to the width of a hydrogen atom. Trying to be more accurate than that in engineering is just being pedantic.)
Why do mnemonics work? Well, our brains are designed to keep novel and well connected information. any of these facts by themselves would just be discarded, but this gives a startling and well connected way of remembering, and any one component can bring the entire chain to mind. Also, because of a quirk of psychology, a dirty one works way better than a clean one.

Saturday, March 12, 2011


I hate waking up with a runny nose. Should invent something to deal with it.
I'm thinking gentle vacuum with tiny hose. Kind of like a reverse Neti-pot, or something like that.

Saturday, March 5, 2011

Sci-Fi Strikes Again

According to a coworker of mine, a physicist has a device the size of a small car, which holds some ten trillion positrons in containment, and has a wand attachment that can fire them. Positrons, are, of course, anti-electrons, and annihilate electrons on contact, producing a burst of energy, usually heat, light, or sound. (Although sometimes you only get neutrinos out of it.) So when fired, this produces a little beam of light from annihilating the air that it touches, and a strange sucking sound as air rushes in to fill the vacuum.
He then pointed out that technology tends to, over time, cheapen and miniaturize. This machine might be the size of a car and cost more than the entire neighborhood that I live in, but one hundred years from now it'll probably be the size of a flashlight, and be purchasable for a few of whatever they use as currency then in a corner store. It would be useful as a cutting tool, as it would make a tiny part of anything you touched to it literally cease to exist.
So in short, this machine is the precursor of George Lucas's lightsabers. With one major distinction. Lucas's lightsabers could be stopped by each other. This thing's beams would go right through each other if you had more than one.
This would not be the first time that science fiction inspired a real world invention. Plasma shields existed in various sci-fi productions for years before NASA built a real one to deal with the real problem of space dust. (Because collisions with even tiny chunks of dust are a problem when they occur at hundreds of thousands of miles per hour.)

Friday, March 4, 2011

Carbonated Fruit

At Hack A Day, I've learned of a new and impractical but fun snack: fizzy fruit.
The mechanism takes water-rich fruit, such as citrus fruits or, if scaled up, watermelon, and carbonates them in a method similar to the way that sodas are carbonated. High pressure carbon dioxide is diffused through the fruit, producing a fruit that fizzes when eaten like a soda.
Even better, all of the parts for this are available in a regular hardware store. A water-filter casing holds the fruit. Tubes lead to a CO2 canister, which can be bought at all kinds of places. (Apparently paintball guns have a good CO2 source and aren't terribly expensive.) Fruit's cheap in the United States, and all but the poorest houses have refrigerators to keep it cold.
The only way this could be better is if there was some way of refilling the CO2 yourself, but that probably requires a factory....
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