Electromagnetic waves form from the vibrations of electric and magnetic fields. Unlike mechanical waves, electromagnetic waves do not need a medium to propagate, allowing them to travel through air, solids and even outer space.
Electromagnetic fields occur when electric and magnetic fields couple together. These fields align perpendicular to each other as the electromagnetic radiation travels to a certain point. Electromagnetic fields have their own alignment, called polarization, that scientists can measure.
Light is another concept that further exemplifies electromagnetic radiation. Light, which is made up of photons, shows how electromagnetic waves can have both wave-like and particle-like properties. Light can be refracted into a spectrum to analyze its wave-like properties, while scientists can also use digital cameras to capture the particle movements of photons liberating electrons. Light has its polarization, as well, another feature of electromagnetic waves. This is why sunglasses can refract light while still having visibility. The sunglasses are able to eliminate the painful glare of sunlight by absorbing the polarized portion of light.
From a mathematical standpoint, electromagnetic energy is made up of three parts: frequency, wavelength and energy. Frequency measures the number of crests of the wave as it passes through a second in time, written out as hertz. Wavelength measures the space between these crests. Amazingly, wavelength can be as short as the size of atoms and as long as the diameter of planets. Electromagnetic waves also can be defined by their amount of energy, measured in electron volts. This unit measures the required kinetic energy for moving through one volt of potential energy.