Why do we put telescopes in space? The reason is not to get "closer" to the things we are trying to observe! Although the Earth's atmosphere extends much further, we generally think of space as starting about 100 km above the Earth's surface (see here for more details) and that's a tiny distance compared even … Continue reading Telescopes in Space
The Electromagnetic Spectrum
Given that electromagnetic (EM) waves all have various things in common*, it makes sense to put them in order. We do this using their wavelength or frequency: it doesn't matter which one we choose because as wavelength increases, frequency decreases (and vice versa). Putting the different types of EM waves in order creates a spectrum … Continue reading The Electromagnetic Spectrum
Electromagnetic (EM) Waves
Electromagnetic (EM) waves are a family of different types of waves that have some specific properties in common; they all propagate (travel) at the same speedthey are all transverse wavesthey can all propagate through free space without the need for any medium The most common examples of EM wave are the various colours of visible … Continue reading Electromagnetic (EM) Waves
Sound: A Quick Recap
Sound is the most common example of a longitudinal wave (if you need a second example in an examination, mention seismic P waves from earthquakes). It is therefore important that you can describe and explain sound waves. This includes how the human ear works (in physics terms) and how microphones and loudspeakers link sound to … Continue reading Sound: A Quick Recap
Mr Tarrant's physbang 'blog 