Relativity Using the Bondi K-calculus

Although Special Relativity was formulated by Einstein (1905),…

Relativity Variables: Velocity, Doppler-Bondi k, and Rapidity

Traditional presentations of special relativity place emphasis…

Frames of Reference: Linear Acceleration View

My previous Insight, Frames of Reference: A Skateboarder's View,…

Fabry-Perot and Michelson Interferometry: A Fundamental Approach

Fabry-Perot Effect: The Fabry-Perot effect is usually treated…

The Schwarzschild Geometry: Part 4

  In the last article, we looked at various counterintuitive…

The Schwarzschild Geometry: Part 2

  At the end of part 1, we looked at the form the…

The Schwarzschild Geometry: Part 1

  Not long after Einstein published his Field Equation,…

Explaining Rolling Motion

Although rolling wheels are everywhere, when most people are…

Grandpa Chet's Entropy Recipe

How do you determine the change in entropy for a closed system…

Orbital Precession in the Schwarzschild and Kerr Metrics

The Schwarzschild Metric A Lagrangian that can be used to describe…

Precession in Special and General Relativity

The Absolute Derivative In relativity we typically deal with…

Tetrad Fields and Spacetime

A spacetime is often described in terms of a tetrad field, that…

Relativity on Rotated Graph Paper

This Insight is a follow up to my earlier tutorial Insight (Spacetime…

Basic Kinematics

There is an interesting thing in teaching of Classical Mechanics.…

Rare Kinematic Formula

Here we present some useful kinematic fact which is uncommon…

Elementary Construction of the Angular Velocity

Physics books  seldom contain accurate definition of the angular…

Frequently Made Errors in Vectors - Elementary Use

  A vector has magnitude and direction. Pictorially,…

LightCone7 Tutorial Part III - How Things are Computed

In Part I and Part II of this mini-series, we have briefly discussed…

LightCone7Combo Tutorial Part II - Charts

Part I dealt with the basic user interface of LightCone7Combo.…

LightCone7Combo Tutorial Part I

LightCone 7 Combo is a versatile tabulating/charting cosmological…

Centrifugal Force Reversal Near A Black Hole

My goal in this article is to derive a simple equation for the…

A Short Proof of Birkhoff's Theorem

Birkhoff's theorem is a very useful result in General Relativity,…
heat errors

Frequently Made Errors in Heat - Elementary Level

1. Heat, Work, Internal Energy and Kinetic Energy "If heat is…

Frequently Made Errors - Pseudo and Resultant Forces

  1. Real versus Fictitious Pseudo, or "fictitious",…

Why Renormalisation Needs a Cutoff

This is a follow on from my paper explaining renormalisation.…
errors springs

Frequently Made Errors in Mechanics - Springs

  1. Springs in Series "A spring of constant ##k_1##…
impact errors

Frequently Made Errors in Mechanics - Momentum and Impacts

    An impact is an impulse (change of momentum)…

Frequently Made Errors in Mechanics - Hydrostatics

  1. Archimedes' Principle X "When a body is placed…

A Partial "Derivation" of Gauss's Law

Gauss's law was formulated by Carl Friedrich Gauss in 1835. It…
error handling

Frequently Made Errors in Equation Handling

  1. Algebra versus Arithmetic When numerical values…
kinematic errors

Frequently Made Errors in Mechanics - Kinematics

    Kinematics is the subset of dynamics…
mistakes moments

Frequently Made Errors in Mechanics - Moments

  The term "moment" is used in various ways in Physics…

Renormalisation Made Easy

What Is The Issue With Renormalisation If you have an interest…