# How would Weather and Regional climate work on a Flat world?



## Logos&Eidos (Sep 7, 2015)

For my WIP's setting I'm using a variation of the Sky World concept. The cosmos looks very similar to the Astral Sea.

The shape of the cosmos akin to a torus and filled with a silvery ether a thin, cool, omnipresent plasma. The cosmos has seven nested layers/dimensions of which only the fourth has human(oid) tolerable conditions. The mortal races dwell on living island enclosed by Shrouds,a force field generated by the islands, that in addition to being a defense mechanism trap a breathable atmosphere.

The axis upon which the cosmic torus rotates is the Empyrean, the source of heat,light and the basic building blocks of matter. It is visible no matter what layer one happens to be on, though the further one is from the Empyrean dimmer it becomes. The natural ebb and flow of the Empyrean's power creates a day/night and season cycle on a cosmic scale.

Despite the very fantastical nature of the setting I still would prefer to only handwave or say "cause reasons" when it is absolutely necessary. So I'm asking the question "how do Weather and Regional climates work on a Flat world"?


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## valiant12 (Sep 12, 2015)

My advice is if you want realism you should make your world a round earth like planet.
I suggest watching the video below


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## psychotick (Sep 12, 2015)

Hi,

OK, having understood one word in ten of your description here's the weather in a nut shell for a flat - plate like I assume - world with a single sun somewhere above the centre of the plate. There isn't much, but as a person wanders away from the centre of the plate, the amount of sunlight falling on him and thus the warmth he experiences, decreases. Warmer middle, colder edges. This is purely a matter of geometry and angles. Shine a typical torch on a wall and the beam is brightest in the middle. The rest of the weather depends on local terrestrial conditions.

Also, there's no night.

Cheers, Greg.


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## valiant12 (Sep 13, 2015)

> Also, there's no night.



This creates more problems than it solves. How would the people measure time without the day and night cycle , the season cycle or the rotation of the earth around the sun




> world with a single sun somewhere above the centre of the plate. There isn't much, but as a person wanders away from the centre of the plate, the amount of sunlight falling on him and thus the warmth he experiences, decreases. Warmer middle, colder edges.



It will be very hot directly under the sun. In our own planet there isn't a spot where the sun rays constantly heath the surface. IF the planet doesn't rotate around its sun then the sun must rotate in a circle above the flat world.


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## K.S. Crooks (Sep 13, 2015)

The two primary causes of weather patterns on earth is the sun and the earth's rotation. Sunlight provides heat which causes air and water to move to new areas (convection currents towards the poles). The earth's rotation creates bands in those currents causes the air or water to cycle back to the equator sooner. The third major factor is large bodies of water. Water has a higher heat capacity, meaning compared to land it takes longer to heat and to cool. If a world is flat and spinning then centripetal force will be a major factor in pushing material towards the edge. There could even be a constant tide towards the edge.


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## psychotick (Sep 13, 2015)

Hi,

Forgot to factor in one thing. If the world is flat where does gravity come from? Centripetal force will send people off to the outer edge of the plate and then presumably off the edge into space, but what holds people down to the ground? If the answer is nothing, then forget about weather - you've got no atmosphere!

Cheers, Greg.


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