Electromagnetic Radiation

Electromagnetic radiation is a form of energy that takes place in the form of radio waves, microwaves, visible light, x-rays, and gamma rays. Life on earth is centered around electromagnetic radiation that comes from the sun, including visible light, which humans can see.

Theory
In 1873, physicist James Clerk Maxwell developed the theory of electromagnetism, presenting how electrically charged particles interact with each other in magnetic fields. Electromagnetic radiation occurs when an electron or other atomic particle is accelerated by an electric field, causing movement that creates oscillating electric and magnet fields. These fields travel perpendicular to one another, traveling in a bundle of energy called a photon. Light energy travels at a speed of 299,792,458 meters per second, the fastest in the universe.

Spectrum
Electromagnetic radiation has a large range of frequencies and wavelengths, called the electromagnetic spectrum. As wavelength decreases, frequency (the number of waves formed in a length of time) increases, and vice versa.

Waves
Radio waves have the lowest frequencies, with the longest wavelengths. They are used for radio communications for transmitting data and media.

Microwaves are next on the spectrum, with a higher frequency and a shorter wavelength. They are commonly used to generate heat in microwave ovens.

Infrared light is between microwaves and visible light, invisible to human eyes, but we can feel intense forms of it as heat.

Visible light has wavelengths visible to the human eye, with colors commonly separated into Red, Orange, Yellow, Green, Blue, Indigo, and Violet. Ultraviolet rays are a component of sunlight that is invisible to the human eye and can damage living tissue.

X-rays can be divided into two types: soft X-rays and hard X-rays. Soft X-rays are between UV and Gamma rays, while hard X-rays are in the same region on the spectrum as Gamma rays. The difference is that hard X-rays are created by accelerating electrons, while gamma rays are produced by atomic nuclei.

Gamma Rays are have the highest frequency and the shortest wavelength, placing them at the high end of the spectrum. Gamma radiation is very damaging to human and other living tissue, but it can be used to kill cancer cells if administered safely.