
Finite Differences
Here are a few notes about the symbol $ \Delta$. This symbol appears frequently in physics. Let $ \alpha$ be a real number. This statement is equivalent to $ \alpha \in \mathbb{R}$. Then $ \Delta \alpha$ can be defined as follows. Definition 1 Define a finite difference as $ \Delta \alpha \equiv \alpha_2 – \alpha_1$.…

Remarks on the Lorentz Transformation and One Question
This is a summary of the second part of Appendix A in Albert Einstein’s book [1]. By second part, I mean the part immediately after the derivation of the Lorentz transformation. If there is no relative motion between the coordinate systems with respect to the $ y$ and $ z$ axis of $ K$, then…

The Lorentz Transformation
This is an attempt to clarify the brief derivation of the Lorentz transformation in Albert Einstein’s book [1]. Suppose that the speed of light, $ c$, is the same regardless of whether a coordinate system is or is not translating with a nonzero speed.Next consider two coordinates systems.The first is called $ K$ and…