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How would the weather on Earth be different if it were a cube?

Hi, I'm T---- and I'm a sixth grader. I was just wondering how weather would change if the earth was shaped like a cube.

This is such an interesting question that I have been discussing it with a lot of my friends in the Astronomy department at Cornell this week. We have been trying to think through all the different effects that you might experience. Living on a cubed shape planet would be pretty weird to those of us used to the more conventional sphere!

How the weather would be different depends a lot on how the cube rotates. I made a diagram of that which I you can see below. If if rotates about an axis through the centre of two of the faces then the "top" and "bottom" faces would have weather pretty much like that found on the poles on Earth, and the "side" faces would have more equatorial weather. There wouldn't be many places with temperate weather like that found in Europe and North America. If the cube rotates instead through two corners, then all of the faces would pretty much have temperate weather and there would be no regions with polar or equatorial weather.

The Cubical Earth, by Karen

The Cubical Earth as imagined by Karen.

I wonder how you imagined the oceans looking on your cubical planet? Physically there is no way that they could be in a cube (since they are liquid), so what the planet might look like would be a cube with oceans at the centre of each face. The corners would seem like enormous mountains to the inhabitants! I think that weird things would happen at the edges between sides. The wind which had previously been going along the ground would suddenly be going straight up as the ground changed direction! That would have to have some odd effects on the weather right at the edges I'm sure. Also the atmosphere, like the oceans, would 'want' to be a sphere. Let's assume that the atmosphere goes up 1000 km above the Earth (when it is a sphere), and so is a sphere itself of radius 6400km+1000km=7400km. This should be about the right number. A cube with the same volume as the spherical Earth would have a side 10,000 km (6,400 miles) long so the corners are 8700 km from the centre! They would definitely stick out above the atmosphere.

Anyway cool question! I hope I satisfied your curiosity. I probably didn't think of every effect, and didn't take into account all of the details (e.g. the oceans and atmosphere couldn't be exactly spheres on a cubical Earth and the climate probably wouldn't be exactly the same everywhere on a side), but I hope I've given you a flavour of the answer.

Apparently this is not an uncommon question and is often suggested as a science fair project, which is weird in my opinion since it's totally unphysical (although interesting to think about). Here is the USATODAY.com weather team's answer.

By the way, you can read about why planets and stars are all pretty much found to be round (and not cubical) in this question from our archive linked below.

December 2002, Karen Masters (more by Karen Masters) (Like this Answer)

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