Solved cryptogram
A black hole's edge is not a surface. It is the boundary past which nothing can ever turn back.
Astronomy Facts, sourced to NASA.
What it means
The event horizon is a place where the geometry of space and time has tipped over, so that every possible path leads inward. Crossing it, an astronaut would notice nothing special at the moment of passage, at least for a sufficiently large hole. It is not a wall and there is nothing there to touch. What is there is a one way condition on the future.
The claim comes from NASA, and the page it comes from was read on 2026-08-27 to confirm it still says this.
This is not the kind of claim that goes out of date, which is why it was set as a puzzle rather than a fact with a shelf life.
Solve it yourself
This fact is a cryptogram here: 74 letters over 21 different ones, graded medium.
- SourceNASA
- CollectionAstronomy Facts
- Difficultymedium
- Length74 letters, 21 of them different
Nearby in the collection
The facts either side of this one.
About as hard as this one
Scored closest to it by the model behind our guide to solving cryptograms.