Glossary · E01 · Everything Is Numbers

The trade

The exchange the whole course is built on: something turned into numbers, and something got left behind so that could happen. Every strange thing one of these machines does comes back to it, which is why the useful question about any file, and about any AI, is what it threw away to answer you.

Bit

The smallest possible fact there is, one answer to one question, a switch that is open or a switch that is closed. Put a row of them beside each other and the row as a whole says a number, and every position you add doubles how far the row can count, which is why a small handful of zeros and ones will hold your age, or a color, or the price of your coffee.

The file

A sequence of numbers, in a particular order, plus an agreement about how that list gets read, and nothing else in there at all. The icon on your screen, the little sheet of paper with the corner folded over, was drawn decades ago precisely so that you would not have to look at that, and it was a kind decision, but it is still a drawing.

The table

The agreement that decides which letter gets which number, written by people, with a counted number of seats in it. The trade calls it a standard, or an encoding, words that sound like nature reporting itself; the American standard written in the nineteen sixties had seven bits and a hundred and twenty-eight seats, and the border around it was drawn by a committee, in a room, in one country, on a particular afternoon.

Pixel

Not a tiny picture but three readings about one tiny location on a grid, how much red is here, how much green, how much blue. Zoom into any photograph on your phone far enough and the picture stops being a picture and becomes flat squares, and inside a single square there is no drawing left at all.

Sampling

Choosing how often to measure something continuous, which means picking these instants here and not the ones in between them. There is real mathematics behind how often is often enough, from Nyquist and from Shannon, which says roughly that you have to measure more than twice as often as the fastest thing you want to keep.

Quantization

Choosing how finely to record each measurement, so that every reading gets snapped to the nearest rung on a ladder of levels somebody settled on beforehand. The word sounds like a measurement and it is a budget, which is the distinction the lesson keeps insisting on: how often to measure is mathematics, and how finely is what somebody could afford.

Organized forgetting

The kind of shrinking that decides which numbers you are not going to miss and then throws them away for good. The trade calls it compression, and that one word covers two different things, the honest bookkeeping that finds a shorter way to write the same numbers and can hand the original back exactly, and the irreversible kind that makes streaming and scanning and pocket photography possible, where the discarding is the whole point.

A bet about your ears

What a compressed sound file actually holds, since it does not hold the music. The trade calls the mechanism a psychoacoustic model, which sounds like a description of hearing, and what it is is a prediction that a loud sound masks the quieter ones sitting next to it, so the encoder spends almost nothing on what the model says you cannot hear anyway. The same kind of bet gets made about your eye in a photograph, that you notice brightness more than color and broad shapes more than fine grain.

The stamp

How the photocopiers of twenty thirteen shrank a scan: marks that looked repeated were stored once as one clean stamp, and that stamp was reused everywhere the pattern seemed to come back. When the matcher decided a scanned six sat close enough to a stamp it already had, and the stamp it already had was an eight, the page came out clean, legible and wrong, and the maker's own notice called it a scanning issue, although nothing had malfunctioned.

The shavings on the floor

Under the bench where the world gets turned into numbers there is always a floor of material that had to be cut away so the pieces could travel, and it is not waste, it is a record of decisions: what a formula predicted you would not notice, what a table had no seat for, what a sampling rate was never fast enough to hear. Every file you own is standing over a floor like that one.

The part this lesson earns on the map

THE FRAME (E01)

Everything here is numbers, and something was discarded to make them.

Carried in from earlier lessons

This is the first lesson of the course, so nothing is carried in yet, and everything above is what the other nineteen parts will lean on.