Recent Posts
- The Eddington Luminosity in Spherical Accretion and Beyond
- How a Molecular Cloud Collapses Into a Star
- Why $R_{\mu\nu}=0$ does not imply $R_{\mu\nu\rho\sigma}=0$
- Derivation of the Cosmic-Ray Diffusion Coefficient from Pitch-Angle Scattering
- The rubber sheet gets the geometry right and the mechanism wrong!
Tag Archives: physics
Derivation of the Cosmic-Ray Diffusion Coefficient from Pitch-Angle Scattering
Cosmic rays arrive at Earth from every direction almost perfectly evenly, to about one part in a thousand. That’s a disaster if you wanted to know where they came from, because they’re charged and the Galaxy is magnetised, so whatever … Continue reading
Posted in Expository, Projects, Research
Tagged astronomy, Astrophysics, Mathematical Physics, physics, science, theoretical physics
Leave a comment
The rubber sheet gets the geometry right and the mechanism wrong!
You have seen this demonstration. Somebody stretches a rubber sheet over a frame, drops a bowling ball in the middle, and the sheet sags. Then they roll a marble across it and the marble curves toward the bowling ball, maybe … Continue reading
Posted in Diary, Expository, Notes, Scratch essays
Tagged Astrophysics, debunking, equivalence principle, general relativity, Geodesics, gravitational waves, gravity, manifolds, Mathematical Physics, philosophy of science, physics, Schwarzschild metric, science, science writing, spacetime, spacetime curvature, theoretical physics
Leave a comment
Deriving the Euler–Lagrange Equation for Particles, Fields, and Curved Spacetime
A good way to understand the laws of motion is not to memorize a separate equation for each situation, but to notice there is really only one trick, and every equation of motion is what falls out when you apply … Continue reading