this post was submitted on 28 Nov 2025
501 points (98.8% liked)

xkcd

14285 readers
165 users here now

A community for a webcomic of romance, sarcasm, math, and language.

founded 2 years ago
MODERATORS
 

xkcd #3174: Bridge Clearance

Title text:

A lot of the highway department's budget goes to adjusting the sign whenever the moon passes directly overhead.

Transcript:

Transcript will show once it’s been added to explainxkcd.com

Source: https://xkcd.com/3174/

explainxkcd for #3174

you are viewing a single comment's thread
view the rest of the comments
[–] skibidi@lemmy.world 44 points 1 month ago* (last edited 1 month ago) (2 children)

Well.. Earth's rotation would mean that the top of the lorry would be moving at 3.3 million light years per second ... Or you know, about 100 trillion times the speed of light.

That might break some things.

[–] Cocodapuf@lemmy.world 14 points 1 month ago* (last edited 1 month ago) (1 children)

At this point I'm actually curious about the mass of the lorry.

I wonder if we could estimate the mass of a lorry, 2.5 meters wide, 20 m long, 46 billion light years tall. Let's assume it's filled with jars of peanut butter.

At that size, it could well be the most massive object in the universe.

Now that I think about it, it could also be too tall, possibly a tipping hazard around turns.

[–] zabadoh@ani.social 5 points 1 month ago (1 children)

That truck tipping over could wipe out every lifeform on the planet with nut allergies.

The sheer mass of Skippy would become a fully functional ecological system of its own before cleanup was finished.

[–] Cocodapuf@lemmy.world 3 points 1 month ago* (last edited 1 month ago) (1 children)

I mean, it has the potential to wipe out all life even without nut allergies. I for one have an allergy to things falling from the sky at c fractional speeds.

Take a Claritin, you'll get over it

[–] Snazz@lemmy.world 11 points 1 month ago

Unless the lorry was driving over the exact geographic north or south pole.

Side note: the tallest lorry where the top doesn’t move faster than the speed of light at the equator is 3.8 light hours tall, which is weird to think about because the top doesn’t start moving until well after the bottom has reached it’s destination.