Radio waves and microwaves are good at transferring information long distances.
This is because they dont get absorbed by the Earth's atmopshere as much as waves in the middle of the EM spectrum (e.g. heat), or those at the high-frequency end of the spectrum (e.g. gamma rays or x-rays).
When a wave comes up against something that has a different density, it changes speed. If the wave hits the new substance at an angle, it changes direction. This is refraction.
- If the wave hits the boundry 'face on', it slows down but carries on in the same direction. It now has a shorter wavelength, but the same frequency.
- But if a wave…