The Electromagnetic Spectrum

Understanding Electromagnetic Spectrum

Electromagnetic waves are a spectrum of waves that transfer energy and information through empty space and through matter.
These waves are all transverse waves that move at the speed of light.

Radio waves are the longest wavelength and are used for broadcasting to radios and televisions.
Microwaves are used for satellite communications, mobile phones and cooking food.
Infrared waves are used for thermal imaging and fibre optic communications.
Visible light is the small part of the spectrum human eyes can detect.
Ultraviolet waves can cause skin tans and also skin cancer.
X-rays are used for medical imaging.
Gamma rays have the shortest wavelength and can be used for killing cancer cells but can also cause cancer.

All electromagnetic waves can be reflected and refracted.
Their speed is maximum in a vacuum, and slows in various materials causing refraction.
They can also be absorbed or transmitted by materials, leading to differential effects.

Overexposure to X-rays and gamma rays can damage living cells, cause cancer and can be lethal.
Protective measures including lead aprons can shield against X-ray damage.
Ultraviolet rays can lead to skin cancer and cataracts, hence it is important to safeguard skin and eyes when in intense sun.