Compare the light-gathering power of the Thirty Meter Telescope with that of the dark-adapted human eye (aperture 8 mm) and with that of one of the 10-meter Keck telescopes.

Suppose that f : rn → rm and that a ∈ k, where k is a connected subset of rn . suppose further that for each x ∈ k there exists a δx > 0 such that f(x) = f(y) for all y ∈ bδx (x). prove that f is constant on k; that is, f(x) = f(a) for all x ∈ k

What does si stand for,when referring to a system of measurement

The solid that is formed and usually sinks to the bottom of a solution is the