I have seen this notion of a scale-invariant power law curve exhibiting the property that $f(cx) = a(cx)^{-k} = c^{-k}f(x)$, and I am confused about how I should be thinking of this as "scale-invariant" When I see this term, scale-invariant, I think "one can zoom in or out and the picture looks e...

In a local universe empty of any matter except a Kerr black hole and an observer, that observer is spinning at the same rate as the black hole and observes it from a great distance directly above its north pole. Will he deem it to be a Schwarzschild black hole? If the observer is spinning at a di...

The Chandrasekhar limit for white dwarfs is 1.44 Solar masses, however the heaveist known white dwarf is only 1.35 solar masses. https://earthsky.org/space/smallest-most-massive-white-dwarf/ What's the cause of this gap in mass?