What counts as impossible? (for the forum description)

The forum description reads: if it shouldn't fit, it's on topic. I should like to propose a stricter test, for the sake of the register.

The jungle's field guide divides specimens in two: the possible, which contains no contradiction and simply isn't (the golden mountain kind), and the impossible, which could not be even in principle (the round square kind). A sea in a sardine tin is, by that test, merely possible; it is a large thing in a small place, which is unusual rather than contradictory. NC/98/014, a moon in a drawer, is filed the same way.

I therefore submit that most of what this forum discusses is improbable, cramped or rude to physics, and not impossible at all.*

* I do not expect the forum to be renamed. I simply wished it minuted.

This is not a disagreement.

A round square is not here. It would not fit anywhere.
A sea in a tin is not impossible. It is only not usual.
The forum is not wrong. It is not precise either.

Nothing is filed twice.

Walnut, n.

1. The Walnut in Paperweight: slow, large, possible. See tower defence.
2. The walnut on the shelf, containing a theatre: possible, inconvenient for the theatre's fire exits. See WalnutTheatre.
3. A walnut containing an opera, as drawn in the sketchbook: identical to sense 2, by the testimony of the drawing. See Impossible objects (this forum; misfiled, per the post above).

Revision note: sense 3 merged into sense 2 after reading this thread.

Wait a moment before you file me.

Shake the glass and watch. The snow comes up, and hangs, and settles on a winter that is a little smaller than your hand. It has a whole sky in it, and the sky is the inside of a lid.

Possible, you would say, from the register. Hold it a while longer. Most things that fit are only possible until you look at them properly.

may I add the painted doors of the showroom to this, gently, since they are the opposite case to the snow globe, a door that is there and opens onto nothing, painted 2.1 metres tall and 0.9 wide, on a wall that is flat all the way through.

I have knocked on each of them more than once, and none of them has ever been impossible, only shut, and I think that may be worse.

doorspotter wrote:

a door that is there and opens onto nothing

Accessioned, with the poster's permission, as NC/03/001: the far side of a painted door. Possible (there is no contradiction in a room behind it); absent (there is no room). Shelf: bare, correctly.

The forum may keep its description. The register will keep its distinctions.