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/
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/
True. But wind sheer in the lower atmosphere could be an issue. Sometimes the moon gets in the way, too.
Not just the moon. You can’t just drive here with a 46 billion light year tall lorry without crashing into some stars, galaxies, black holes and what not.
Really?
Can we calculate this? Let’s do specs first. Let’s say we only drive until the next overpass, which is likely in the next few km , let’s say 5. And we drive 40kmh so for 450 second the lory is swinging around the universe trying to hit anything. Would it?
The mass of the universe is not distributed evenly, so it gets really complex. However, as semi-qualitative assessment, I can say that the vast majority of the universe is just empty space, so you should be fine for the most part. However, the longer you allow the top of the lorry to scrape the edge of the observable universe, the more likely it is to hit something.
Think of it like throwing darts. The more you throw, the more likely it is for you to hit the bullseye. If you keep on driving your lorry for an hour or two, the top has already swept across an enormous arc and probably plowed through multiple galaxies along the way. Keep on sweeping and eventually you’ll smack into something.
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.
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.
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.
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.
Some hydrogen definitely, probably a lil helium