(via Sabine Hossenfelder) Is the universe really infinite? Or could it close back on itself like a sphere? If it’s infinite, how can it expand? And is it true that there might be copies of you in it?

The question of whether the universe has an edge touches one of the deepest mysteries in cosmology. It’s the kind […] ...

Mathematician Per Enflo, who solved a huge chunk of the 'invariant subspaces problem' decades ago, may have just finished his work. When you purchase through links on our site, we may earn an ...