Monthly Archives: May 2024

The purpose of this post is to review the classical theory of rigid body dynamics by working through a few illustrative problems in that regard. Problem #\(1\): What defines a rigid body? What is an immediate corollary of this? Solution … Continue reading →

A collection of books/videos/resources for learning various topics in math/physics/computer science/other fields that I currently do not have the time to study deeply, but seem sufficiently interesting/useful that one day I hope to!

Newton’s second law in its most basic form states that for a single point mass, \(\dot{\textbf p}=\textbf F\) in any inertial frame. Combining this with Newton’s third law (antisymmetry of forces \(\textbf F_{i\to j}=-\textbf F_{j\to i}\), similar to many other … Continue reading →

The purpose of this post is to appreciate that the familiar idea of non-interacting particles from e.g. statistical mechanics manifests in the context of QFT as a free quantum field theory. Problem #\(1\): What defines a free classical field theory? … Continue reading →

Consider an arbitrary worldline \(\{(t,\textbf x)\}\) of a classical system of particles in configuration spacetime. In general, this worldline need not correspond to any physical/on-shell trajectory; it can be as wildly off-shell as one likes, the only caveat being that … Continue reading →

In linear elasticity theory, recall that the Cauchy stress field \(\sigma(\textbf x, t)\) is defined as the unique linear transformation that maps any unit vector \(\hat{\textbf n}\) (thought of as being rooted at position \(\textbf x\) in a material at … Continue reading →