Cards no human
can see

Introduction

The latent image

When you take a photograph nothing appears. The shutter opens, light does its work on the silver, and the film comes out looking exactly as blank as it went in. The picture is there — every grain of it, fully determined, unrecoverable by staring. It takes a different substance in a different room to make it a thing anybody can look at.

This project has spent five days discovering that most of its faults are that. Not missing data. Not wrong data. Correct, complete, continuously updated data with no developer. And the developer, on every single occasion, has been a person.

The frames below are that week's contact sheet. Each one was exposed properly. None of them could be seen.

The sheet

Eight frames

I

The one that happened today

Four windows were added to the HUD this afternoon, and one more this morning. They were created. They were given content. They were updated on every frame with the right lines in the right colours. And they were attached to nothing, because the line that puts cards on the screen was this:

A hand-written list of which cards to show. Make a card and forget the list, and you have built a window into a wall.

This is the fifth time this repository has produced that exact fault. A menu that named eleven of twenty-nine actions. A five-building list found “for the third time”. A tool ladder that existed twice. An index of the documents complaining about those, maintained in two places until they disagreed. And now this — committed three hours after publishing the sheet that warned about it, by the hand that wrote the sheet.

The mounting reads the register now. Every card that is made is a card that is shown, by construction, and there is no second list to fall out of step with the first.

II

What development actually costs

The pattern in all eight frames is the same and it is not carelessness. Every one was a successful write. The tally was written. The sheets were pushed. The towers went up. The cards were built. In each case the operation returned, the state was correct, and a check — had one existed — would have passed.

A write that succeeds is not a read that happens.

And the developer was a person every time. Not a test. A person looking at a screen and saying are those granaries, or which page has all of them, or I think you made cards no human can see. Seven of the eight frames above were developed by a sentence typed by somebody who could not see the source and was looking at the thing.

The eighth was developed by a probe, and the probe only exists because of the fourth. That is the whole of the improvement this week has managed: not fewer latent images, but one more room in which to develop them.

That last line is frame five. The card built this morning so that nobody would have to suspect a kiln had no corner to hang from, opened at the origin, and spent its entire life underneath the settlement card. It was found in the same minute the others were fixed, by looking rather than by believing, and only because somebody had made looking necessary.

III

The rooms that now exist

Five days of this has produced, almost by accident, a small collection of developers — places where a latent thing becomes visible without anybody having to suspect it first:

Each was written the day after a person found the thing it now finds. That is the honest shape of the week: the tooling is a fossil record of what somebody noticed.

Of the run ids: the two probes used for this sheet wrote eight lines each into the record and are identifiable to the character, which is the first time in this project's life that a test could run against the live log without spoiling it.