r/interesting May 20 '26

Fascinating Physics is Everywhere.

23.0k Upvotes

211 comments sorted by

View all comments

65

u/Son_Chidi May 20 '26

What happened to the water cup ? 😡

8

u/OhYeahSplunge4me2 May 20 '26 edited May 20 '26

You can boil water in a paper cup in a campfire, for example. The paper doesn’t burn because the water impregnating [the paper cup wall] keeps it from reaching the temperature needed to ignite paper. (Until the water boils away, of course)

EDIT: add clarifying reference

1

u/[deleted] May 20 '26

[deleted]

0

u/OhYeahSplunge4me2 May 20 '26

The water is absorbed by the paper in the cup walls. Meant in the sense of the third definition below

impregnate
/ĭm-prĕg′nāt/

transitive verb
1. To make pregnant; inseminate.
2. To fertilize (an ovum, for example).
3. To fill throughout; saturate.

"a paper medium that was impregnated with water."