Recent content by GoBluePhysics

When you say "photon sphere" do you mean the sphere created by a radius such that ##r=1.5R_s## (for a black hole)? Wait. I think I understand. If I think of it in terms of Birkhoff's theorem, if the density of a black hole were expanded to have the density of another object (say, the earth)...

Hi there, I was reading one of my textbooks and I had a thought. For a black hole, there is minimum orbiting radius of ##R_{min}=3R_s## where ##R_s## is the Schwarzschild Radius. This minimum orbit is created by the fact that in order to obtain an orbit of that radius around a black hole, you...

Quick question regarding E-Cals. I am giving a presentation on them soon and I understand just about everything I am supposed to, but I keep encountering one symbol and I simply don't understand what it is supposed to mean. ##\frac{d\sigma}{dx}=\frac{A}{X_0N_A}\bigg[1-\frac{4}{3}x(1-x)\bigg] ##...

Hi there! My name's Tyler. I hope to both ask for assistance and answer questions on the site. I'm a sophomore Physics major at the University of Michigan.