Assuming that outside the vacuum chamber there is some gas or liquid, then indeed there is a force that pushes on the walls to collapse. If it doesn't collapse, that means the walls are strong enough to withstand that force: weak walls would collapse.
central supports are blown up causing weak points near the inside of the building. This destabilization causes the building to (hopefully) collapse on itself.
There is no pressure in a vacuum, a vacuum is the absence of anything, there is nothing there to push. Air from a pressurized space that becomes open to a vacuum may push you into the vacuum, but the vacuum itself does nothing as it is literally nothing.
It is possible for a medium itself to travel, but in that case case it isn't called a wave, but a current. For example, water flowing in a river.
It means the nail that was holding it was not set well, nothing more.
Nothing will move on its own due to inertia. Inertia refers to objects already in motion. So, a chair that was already moving will keep moving, but it won't begin movement on its own.
caldera
When a volcano collapses on itself a caldera is then formed.
a strong gravitational force which means that the star will collapse in on itself
It forms a 'caldera'.
The molten material that you find in the magma chamber is the magma itself.
The gases in the fuel chamber of the rocket combust and push on the inside of the rocket, propeling it forward or upward. This is because in space there is nothing for a rocket to push of off, except itself.
Gravitational instability theory
it doesnt.
Not. Galaxies do not collapse in on themselves
it doesnt
it doesnt stop
A few billion years. When the sun runs out of hydrogen, it will collapse on itself, then expand. At that point, the inner planets will be destroyed. However, it is virtually certain that nothing we now think of as human will be around to see it.