The Electromagnetic Spectrum
The electromagnetic spectrum is like a massive family of waves that includes everything from radio waves to deadly gamma rays. What's brilliant is that despite their different properties, they're all essentially the same thing - electromagnetic radiation travelling at the speed of light 3ร108m/s through space.
All these waves are transverse waves, which means they wiggle up and down as they travel forward. The key difference between them is their wavelength and frequency - radio waves have long wavelengths and low frequencies, whilst gamma rays have tiny wavelengths and incredibly high frequencies.
Think of visible light as the middle child of this family. Red light has a longer wavelength than blue light, which is why we see different colours. But visible light is just a tiny slice of the whole spectrum - most electromagnetic radiation is completely invisible to our eyes.
Quick Tip: Remember the order with "Radio Microwaves Infrared Visible Ultraviolet X-rays Gamma" - or make up your own memory trick!
The spectrum goes from radio waves (longest wavelength, safest) all the way up to gamma rays (shortest wavelength, most dangerous). Each type has evolved specific uses in our technology, from broadcasting your favourite radio station to helping doctors treat cancer patients.