Main Page

Welcome to the explain xkcd wiki! We already have 12 comic explanations!

(But there are still 3246 to go. Come and add yours!)

Latest comic

Go to this comic

Plate Flip

|< < Prev #3258 (June 12, 2026)

Title text: It's great for exfoliating your skin, bones, houses, cities, landscape, etc.

|< < Prev Random Explanation

Explanation

Ponytail resumes her role as a cosmic home inspector.

She asks Cueball when the last time he flipped the tectonic plates, because they look heavily eroded. This may be an allusion to the practice of turning mattresses over every few months. This was common until the 20th century, to even out the wear and tear, and prevent permanent body impressions. When modern box springs became common, the practice became unnecessary.

Flipping mattresses only makes sense because both sides are similar to each other, but the "underside" of a plate is nothing like the surface. The current side that Cueball and Ponytail are standing on is the outermost layer of the crust. However, the "underside" of the plate reaches until the solid layer of the mantle, whose temperature can reach over 1000 °C. As Cueball points out, if you could flip a continent over, the new surface would be molten rock, not a surface suitable for life. Ponytail thinks the warmth would be soothing, and that walking on it would exfoliate your feet, but at hundreds of degrees, it would do far more damage than just removing dead skin.^{[citation needed]}

The title text expands on this joke, saying that it would "exfoliate" just about everything on the surface (which would somehow have to stay in place while the plate below it is flipped).

Transcript

Ponytail: These tectonic plates look pretty eroded. When did you last flip them?

Cueball: Flip them?

Ponytail: Yeah, to use the underside of the continent.

Cueball: ...Never?

Ponytail: Wow. Explains the eons of weathering, debris basins, and ... is this isostatic depression?

Cueball: It's rebounding!

Ponytail: You should really flip it. You'll get a whole new landscape!

Cueball: But I like this landscape!

Ponytail: Just think how warm and fresh the other side will feel.

Cueball: A sea of molten rock?

Ponytail: Good for the feet. Helps exfoliate.

New here?

Feel free to sign up for an account and contribute to the explain xkcd wiki! We need explanations for comics, characters, themes, memes and everything in between. If it is referenced in an xkcd web comic, it should be here.

• If you're new to wikis like this, take a look at these help pages describing how to navigate the wiki, and how to edit pages.

• Discussion about various parts of the wiki is going on at Explain XKCD:Community portal. Share your 2¢!

• List of all comics contains a complete table of all xkcd comics so far and the corresponding explanations. The red links (like this) are missing explanations. Feel free to help out by creating them!

Rules

Don't be a jerk. There are a lot of comics that don't have set in stone explanations, feel free to put multiple interpretations in the wiki page for each comic.

If you want to talk about a specific comic, use its discussion page.

Please only submit material directly related to—and helping everyone better understand—xkcd... and of course only submit material that can legally be posted (and freely edited.) Off-topic or other inappropriate content is subject to removal or modification at admin discretion, and users posting such are at risk of being blocked.

If you need assistance from an admin, feel free to leave a message on their personal discussion page. The list of admins is here.

Logo

Explain xkcd logo courtesy of User:Alek2407.