The Complete Electromagnetic Spectrum
Electromagnetic waves all travel at the same incredible speed - 3 × 10⁸ m/s (that's 300 million metres per second!). What makes them different is their wavelength and frequency, which determines what we can use them for.
The spectrum ranges from radio waves with the longest wavelengths and lowest frequencies, all the way to gamma rays with the shortest wavelengths and highest frequencies. Think of it like a massive invisible rainbow that extends far beyond what your eyes can see.
Radio waves power your everyday communication - they carry signals for radio stations, TV broadcasts, mobile phones, and even help with MRI scans in hospitals. Microwaves heat your food and enable secure communications for mobile data and WiFi connections.
Infrared waves are what your TV remote uses to change channels, and they're also used in physiotherapy treatments. Visible light is the tiny portion you can actually see - everything from red to violet light that lets you navigate the world around you.
Ultraviolet waves from the sun can be captured by solar panels to generate electricity for homes. X-rays help doctors examine broken bones and internal organs, detect cracks in metal structures, and scan luggage at airports for security.
Key Point: Each type of electromagnetic wave has unique properties that make it perfect for specific applications - from heating food to saving lives in medicine.
Gamma rays are the most energetic waves, used in hospitals for treatments and to sterilise surgical equipment. They're also used in food processing to kill harmful bacteria and extend the shelf life of tinned foods you buy in shops.