expressions - What is the word describing impossible phenomenon such as "This page [is] intentionally left blank"?

You can find in book's pages a single sentence: This page intentionally left blank. It is interesting to note that this statement is false, since the page contains text.

Here are two (somewhat) similar examples: This is a secret encoded message which you cannot read, comprehend, or make of any sense! (You can read it, and it makes perfect sense); and This is a short description of the Fraser spiral illusion which, like as Zöllner's illusion and the café wall illusion are based on a principle, like many other visual effects, in which a sequence of tilted elements causes the eye to perceive phantom twists and deviation. (This is a lengthy description).

What is the word (maybe a collective noun?) describing such impossible claims/events/phenomena? The closest word I can think of is oxymoron:

A figure of speech in which apparently contradictory terms appear in conjunction (e.g., faith unfaithful kept him falsely true).

However, the problem with oxymoron is that it somehow requires two terms to contradict with each other. Here the text contradicts with itself.

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Well, I almost deleted my draft prior post, since it seemed plausible, that this is a self-contradiction:

Inconsistency between aspects or parts of a whole.

However, this (somewhat lengthy) wikipedia talk page suggests that this is not a self-contradiction. A self-contradiction would be a sentence something like: Bob is a married bachelor.

Then what are these sentences called?

Answer

Paradox is likely what you are looking for:

1. a statement or proposition that seems self-contradictory or absurd but in reality expresses a possible truth.


2. a self-contradictory and false proposition.


3. any person, thing, or situation exhibiting an apparently contradictory nature.

(From Dictionary.com)