In my story, humans are testing AIs by placing them inside of a simulated universe and seeing how their society evolves. However, to save on processing power, the scientists have reduced the size of their world and upped the density to ensure an earth-like gravity and atmosphere. The rest of the solar system isn't being simulated in detail, and the sim will shut down as soon as it takes up too much processing power (basically once the AIs develop space travel and advanced computers).
Given that my world is only about 2-million square km in surface-area (2,500 km in circumference), and is mostly land, how will it affect seasons and climates? It seems like it wouldn't have icy "poles" or hot "tropics" because, while they all get different levels of sunlight, they're so close together that the heat would circulate and mostly even things out. Or does the lack of large oceans prevent this?
My objective is to make this simulated planet as earth-like as possible, but I'm not sure about the optimal planet-size for this. In theory I could "cheat" and have the simulation simply decree that certain biomes exist, but that might tip the AIs off that they're living in a simulation. Are there any other "realistic" scientific levers I can pull to make this work?
Finally, are there any other pitfalls in having a tiny earth-like planet that I'm not thinking of? Thanks!
Edit: OK, you've all convinced me to just run a plain old "flat earth" sim and hack the rest. This makes everything easier. It does mean the AIs will eventually have to explain their weird laws of physics, but that could itself be interesting. That also means this post is moot. Thanks for the input!