Research

# This Year-ish in Theoretical Physics

The previous episode of “this week-ish” was posted on June 5. Its been six months since then. I guess its time to post another volume but to be fair the title of this post has been changed to reflect the longer time span its contents refer to. Gravity as Quantum Computation (contd from Vol. 1)… Continue reading This Year-ish in Theoretical Physics

Research

# Negative Temperatures

The thermodynamic concept of temperature is defined by the following equation: $$T = \frac{\partial E}{\partial S}$$ where $E$ is the energy of the system and $S$ is the entropy. Now usually when the energy of a system increases or decreases it’s disorder, and hence it’s entropy, also increases or… Continue reading Negative Temperatures

Research

# Euler’s Theorem and the Smarr Relation

The area of a charged rotating (Kerr) black hole is given by $$\label{eqn:kerr-area-relation} A = 4\pi \left[ 2 M^2 + 2 (M^4 – L^2 – M^2 Q^2)^{1/2} – Q^2 \right]$$ This relation can be inverted to express the mass $M$ as a function of charge $Q$, area $A$ and angular momentum $L$: … Continue reading Euler’s Theorem and the Smarr Relation