They use Schrodinger's equation to calculate different waves that describe a quantum mechanical system, like that electron you've been trying to measure.
No one's ever managed to cool anything down that much, but even if we could, molecules would still move due to a quantum mechanical principle called zero-point energy.
That probability is predicted by the wavefunction, an equation that relates some of the properties of a quantum mechanical system, like an electron or atom.
It makes no sense in the context of how we normally experience the world, but that’s just the tip of the very, very strange quantum mechanical iceberg.
So there's really a plethora, every single challenge that we currently face that's either limited by data or limited by an understanding of the world around us, a quantum mechanical world around us.
In type 2, the star runs out of nuclear fuel, so the gravitational forces pulling in overwhelm the quantum mechanical forces pushing out, and the stellar core collapses under its own weight in a hundredth of a second.