Hacker News new | ask | show | jobs
by RetroTechie 985 days ago
> The force that held the halves of the sphere together was the weight of the displaced atmosphere.

More precisely: the force applied by the weight of the column of air above the semi-spheres.

Weight of the column of air -> air pressure -> force on semi-spheres.

As parent noted, high up in the atmosphere that is a small force. At sea level, ~1 kg/cm^2.

So: yes, it's gravity.