We can define a wave as something that carries energy from one place to another without the transfer of physical matter. To understand this definition it is useful to think about two different ways of feeling heat. In a shower, heat is created by an energy exchange inside the storage tank or shower unit and … Continue reading Key Facts: Waves
Electromagnetic Waves (overview)
We think of light as being special - but that's only because our eyes respond to it, allowing us to see the world around us. In fact, light is just one example of an electromagnetic wave. Other electromagnetic (EM for short) waves include infra-red, ultra-violet, radio and x-rays. The range of EM waves, known as … Continue reading Electromagnetic Waves (overview)
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
Speed of Sound in an Iron Bar
Sound travels at different speeds in different materials. We often think only of sound moving through the air (a gas) but in fact it also moves through both liquids and solids. Note that there is a difference between sound moving through a liquid and waves that can be seen on the surface of a liquid. … Continue reading Speed of Sound in an Iron Bar
Speed of Water Waves
For hundreds of years, water waves have been used to understand wave behaviour in general. This is understandable given that water waves are a natural phenomenon that can also be created artificially and studied in the lab. On the simplest level, a stone thrown into the middle of a pond will create waves that extend … Continue reading Speed of Water Waves
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