this post was submitted on 08 May 2025
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submitted 1 day ago* (last edited 1 day ago) by xkcdbot@lemmy.world to c/xkcd@lemmy.world
 

Title text:

Frankly, given their extreme gravitational fields and general instability, even 12-inch globes should probably be banned.

Transcript:

[A standard globe of the Earth is shown. It stands on a typical stand which holds it by two arms at the poles, so it can turn around like the Earth does. The Earth is turned so it shows Australia at the bottom and most of Asia, including the entire India to the left. Only the very tip of Alaska can bee seen of the Americas. Above the globe there is a double arrow that goes to two small lines that align with the edges of the globe (indicating the diameter). The arrow has been split in the middle and two lines of text is written in the gab. Above this text there is another line of text.]
Remember:
4 inches minimum

[Beneath the globe there are two small drawings. The left shows the Earth and to the left of the Earth there is a double arrow ending at two lines that indicated the diameter of the Earth going from top to bottom. The distance of this is written in inches to the left. From the Earth an arrow points to another drawing, this time the typical depiction of a black hole, with the "hat" shape. A warning sign is shown a the top right of the black hole with an exclamation mark inside.]
7/10"

[Caption Below the Panel:] The Earth's Schwarzschild radius is about 0.35 inches, which is why safety regulations require desktop globes to be at least 4 inches in diameter.

Source: https://xkcd.com/3086/

explainxkcd for #3086

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[–] uriel238@lemmy.blahaj.zone 6 points 17 hours ago

That Schwarzschild radius is larger than I expected. I was expecting sub-molecular.

[–] tiredofsametab@fedia.io 73 points 1 day ago (3 children)

9mm for those wanting sane units. Edit for clarity: this refers to the fractional inches, not the 4 inch figure which, as another poster points out, is a bit north of 10cm.

[–] 01189998819991197253@infosec.pub 23 points 1 day ago (1 children)

That's "American" for a round used in a personal protection weapon. So, who is sane now?

[–] frigidaphelion@lemmy.world 3 points 16 hours ago (1 children)

Lmao I knew your username was a familiar sequence to me and I started to say it out loud. Next thing I knew I went full Richard Ayoade with it. 10/10.

Goal: Achieved

Hahahaha

[–] DopeWeasel@lemmy.world 0 points 14 hours ago* (last edited 14 hours ago) (1 children)

Not even close? If you meant CENTImeters then it's closer to 10cm. EDIT: four inches = 10.16 centimeters

[–] tiredofsametab@fedia.io 2 points 14 hours ago (1 children)

The radius is about .35 inches

Which is 9mm. I have edited my post to indicate this for clarity. I had assumed that "fractional inches" was the part that was least sane and thought others would think the same.

[–] match@pawb.social 1 points 1 hour ago

as an American i can recognize 9mm because that's the size of a handgun bullet :3

[–] SCmSTR@lemmy.blahaj.zone 9 points 1 day ago

Pfft. There's nothing sane here.

[–] pastermil@sh.itjust.works 8 points 1 day ago (2 children)

There's also the fact that people might not be able to use it if it's too small.

[–] SaharaMaleikuhm@feddit.org 17 points 1 day ago (2 children)

4" is a respectable size, okay? It's nothing to scoff at.

It's all about your spin game anyways

[–] Flocklesscrow@lemm.ee 3 points 1 day ago

subdued scoffing

[–] smokinliver@sopuli.xyz 3 points 1 day ago

Maybe its less about the size and more about the technique?

[–] abfarid@startrek.website 9 points 1 day ago (3 children)

Shouldn't 7/10" actually be 7/20"?

[–] vivendi@programming.dev 20 points 1 day ago (1 children)

What in the motherfuck are those numbers

What the fuck is wrong with your units

[–] LanguageIsCool@lemmy.world 6 points 16 hours ago

They’re literally called rational numbers

[–] EmptySlime@lemmy.blahaj.zone 12 points 1 day ago

Notice how the lines the 7/10" is attached to go from one side of the miniature globe to the other? This indicates that measurement is meant to be a diameter. Looking back at the paragraph before he talks about 0.35" being Earth's Schwarzschild Radius. Radius is half of diameter so doubling that radius you get 0.7 or 7/10" across at which the Earth would become a black hole.

That's what that mini diagram is showing.

[–] Gieselbrecht@feddit.org 16 points 1 day ago (1 children)

The same question is in the discussion section in ExplainXKCD, so I can confidently use the reply given there: No, 7/20" is the radius, but 7/10" is correct for the diameter.

[–] abfarid@startrek.website 2 points 1 day ago

Oh right, didn't pay enough attention. But it was the first thing I saw in the morning.