Deathstar Earth

I dunno, I tend to believe that itd work out closer to Brooks prediction than Hitmans. People near the top wouldn't feel much gravity, especially near the equator. People near the top damn well better turn around, or their gonna fall on their heads, because, just like inside any spinning huge torus, the outside bulkhead becomes the floor by centrifugal force, and itll be worst at the equator. I have no idea how many Gs your gonna be pulling on the inside surface of a spinning sphere with a 20,000 mile diameter, but if its travelling as fast as an object would have to in order to orbit at that altitude, I suspect you might be a tad on the heavy side. I suspect that you would find a region somewhere between the roof and the basement where gravity and centrifugal force cancel each other out and you reach a state of equilibrium- for all intent and purposes, weightless, but Im not mathematician enough to figure where.

> are we all going to fly at the higher elevations, 'cause we ought to be weightless.
No, because even at the highest elevations, you won't be at GEO.
Well, folks float in LEO, and on the vomit comet, and anywhere else where youre falling free. As I conjectured above, at some point between the current ground level and the Roof of the World, 8,000 miles up, there will be a point where the centrifugal force pressing you outward and the force of Gravity, pulling you groundward will be completely equal and at that level you should experience weightlessness. above that point, centrifugal force will grow so you better flip over and start using the roof as a floor.

That's an interesting thought though: building beyond GEO to get reverse gravity from the spin -- just like in an O'Neill cylinder.
The gravity in an ONeill cylinder is centrifugal force, pressing outward so that the inside hull of the cylinder becomes the surface. This artificial gravity decreases as you move inward toward the long axis of the cylinder until you have a practical weightless recreation zone down the axial core, where pedal powered planes or scooters can be flown, or, I suppose you could tie on some wings and add flippers to your hands or feet and just fly. The only place that I can figure you might find such conditions on your buffed out Earth would be the levels closely adjacent to the point of equilibrium above.