Having previously covered waves in general (https://physbang.com/2023/04/13/key-facts-waves/) it is now time to look at electromagnetic waves in particular as this is a topic in its own right. Electromagnetic waves are created by the movement of electrons in different situations. The electrons can be moving in an electric circuit, to produce or receive radio waves, or … Continue reading Key Facts: Electromagnetic Waves
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
Properties of EM Waves
Electromagnetic (EM) waves are generated by the movement of electrons. In an electric circuit, visible light can be generated when electrons (a current) move through a lamp. Electric circuits can also generate infra-red waves (TV remote controls), microwaves (ovens), x-rays (medical scanners) and radio waves (aircraft ground-to-air communications). These different types of EM waves have … Continue reading Properties of EM Waves
The Sand and the Swimming Pool
Here’s an interesting problem that is directly applicable to the behaviour of light. Suppose that you want to get from point A to point B, what is the fastest route? The most common answer is “in a straight line” but this isn’t always true. Let’s put our points A and B on a sandy beach … Continue reading The Sand and the Swimming Pool
