Of not-so-tiny bubbles, infinities, and other news

Catching up with items of fascinating physics ...
Click here to enlarge"Despite extensive analysis, Fermi bubbles defy explanation." Fermi bubbles (named for the Fermi gamma-ray observatory that first spotted them) are structures 30 thousand light-years across lying both above and below our galaxy. They emit incredible amounts of gamma-ray energy. (Gamma rays are extremely high-energy photons, more energetic even than hard X-ray photons.) Why are the bubbles there? How did they come to be? The...