The top of the globe stands above the surface of the ocean, and running through the centre is a tower to add strength, and to provide space for homes, offices and even an amusement park for five thousand underwater residents.
A cylinder on the other hand does take advantage of some of the arch-like characteristics of a bathysphere, but aren't as effective in spreading out the pressure exerted on them as a completely rounded sphere.
When the outer panels are closed, it shows a monochrome painting of the creation of the world, on a flat landscape enclosed in a transparent sphere with God the father looking down.
This rests inside another vessel filled with normal water, which helps support the weight of the inner sphere, as well as providing further shielding from any stray radiation.
If you stay outside for an hour or two, you'll notice something else that's pretty obvious: the stars move, like the sky is a gigantic sphere wheeling around you over the course of the night.
A duckling that was first shown two green spheres, in other words, was more likely to move toward a pair of blue spheres than a mismatched pair of orange and purple spheres.
The action we're talking about here is a result of interacting physical forces, a moving ball's tendency to stay in motion, or its force of momentum vs. the constant force of gravity bringing it back down Earth.
In the 1960s, Dyson proposed that an advanced planetary civilization could engineer an artificial sphere around their main star, capturing all of its radiated energy to satisfy their needs.