It is typically 30 km to 50 km thick.
I'm assuming it was to keep the data consistent? The further you are from a heat source the less heat will get to you as the temperature tries to reach equilibrium and the waves start to spread out, so you should keep everything the same distance to get consistent results. I don't have any information so this is just my assumption
The water in a dish evaporates quickly as the surface area of dish is greater than cap which enables the water to evaporate quickly
earth still is not solid ... core is molten ... volcanoes, sea is liquid
at v v v beginning was gas ????
