There is a summary of the key characteristics of astronomical telescopes in a previous post, at https://physbang.com/2026/03/15/a-level-guide-to-astronomical-telescopes/. This article builds on that general overview by explaining a specific skill; how to draw a ray diagram for a refracting telescope in normal adjustment. First, what is "normal adjustment"? It is when the objective and eyepiece lenses … Continue reading Ray Diagram for a Telescope in Normal Adjustment
Focusing EM Waves
Focusing is the term that describes parallel rays of light being brought together into a single point, known as the focal point. Electromagnetic waves can be focused using either refraction (with lenses) or reflection (with mirrors). Both of these effects can be explored in the excellent geometric optics simulation that has just been unveiled by … Continue reading Focusing EM Waves
Mr Tarrant's physbang 'blog 