https://trojanpt.github.io/en/ Recent content in Home on Trojan TeaHouse Hugo en © 2025 TrojanPoint Tue, 19 Aug 2025 00:00:00 +0000 https://trojanpt.github.io/en/jottings/wigner-rotation/ Tue, 19 Aug 2025 00:00:00 +0000 https://trojanpt.github.io/en/jottings/wigner-rotation/ The Wigner rotation states that the successive action of two Lorentz boosts in arbitrary directions is equivalent to a single Lorentz boost followed by a spatial rotation. This article discusses the general case. https://trojanpt.github.io/en/jottings/normal-mode/ Wed, 23 Jul 2025 00:00:00 +0000 https://trojanpt.github.io/en/jottings/normal-mode/ For the first-order small vibrations of a mechanical system near its stable equilibrium position, there exist normal modes equal in number to its degrees of freedom. https://trojanpt.github.io/en/jottings/smooth-insulated-piston/ Thu, 26 Jun 2025 00:00:00 +0000 https://trojanpt.github.io/en/jottings/smooth-insulated-piston/ If the pressures on both sides of a smooth adiabatic piston are equal but the temperatures are unequal, energy will transfer from the higher-temperature gas to the lower-temperature gas through microscopic vibrations of the piston, even when all heat conduction is neglected. https://trojanpt.github.io/en/jottings/vibration-of-elasticbody/ Thu, 26 Jun 2025 00:00:00 +0000 https://trojanpt.github.io/en/jottings/vibration-of-elasticbody/ Small-amplitude vibrations of an incompressible elastic rope in a gravitational field. https://trojanpt.github.io/en/about/ Sun, 22 Jun 2025 00:00:00 +0000 https://trojanpt.github.io/en/about/ https://trojanpt.github.io/en/copyright/ Sun, 22 Jun 2025 00:00:00 +0000 https://trojanpt.github.io/en/copyright/ https://trojanpt.github.io/en/jottings/amperes-law/ Sun, 22 Jun 2025 00:00:00 +0000 https://trojanpt.github.io/en/jottings/amperes-law/ This article introduces the derivation process of the original form of Ampere’s Law and discusses its relationship with the modern form.