A world that exists within the crust of the earth [closed]

Let's say that world was created where life existed within the crust of the planet, rather than on the outside, what would the ramifications be? I am hoping for someone with an education in some of these areas to dive deep into the possibilities and possible pitfalls of this kind of world.

What I am visualizing is that the world would actually be a large machine (unbeknown to the inhabitants) that is situated close to a star. The energy from the star would fuel a light at the center. A large stone slab, of sorts, would rotate around this light/heat source, providing the day and night cycle.

Gravity would be produced by the spinning of the planet, meaning it would be stronger at the point furthest from the axis' and weaker the closer you get to them. I am also assuming, due to the changes is gravity, that life closer to the axis would be taller and lankier, less dense.

So here is what I can't figure out:

If the world were about the size of earth (inverted) and the spin was fast enough to produce 1g gravity at the strongest point, how far would you need to travel before noticing a difference?

Would there still be weather patterns? The "sun" at the center would provide a constant amount of heat, so the changes we experience with earth's tilt to the sun would not exist.

If the slab rotating around the "sun" was small, giving a 9 hour night, and 18 hour day, what would the ramifications of that be on plant life and human productivity?

I am assuming the atmosphere would also weaken the closer you got to the axis. Would cause places where it would freeze and even snow, as it does in the mountains?

Thank you in advance! Sorry if this is a lot.

• If it's the size of the Earth, then why would you need to spin to get gravity? Should have all the requisite mass. – Halfthawed Apr 28 '20 at 17:50
• Do you mean that they would be living on the inside of the sphere, with their feet on it and their heads towards the center? No known material would be strong enough to make this world from to stop it tearing itself apart - that being said see Ringworld by Larry Nivven, it's a small slice of that. Made of an unobtanium called Scrith. – A Rogue Ant. Apr 28 '20 at 18:18
• @NR Johnson you should split this into separate questions, I was trying to use this artificial gravity calculator for the first part of your question but its above my head how to work out gravity at different latitudes space.geometrian.com/calcs/artificial-gravity.php – user69935 Apr 28 '20 at 18:33
• Related question worldbuilding.stackexchange.com/questions/1347/… – user69935 Apr 28 '20 at 18:59