ELECTROMAGNETIC SPECTRUM

Electromagnetic Spectrum

is a continuous range of waves arranged according to wavelength and frequency. All EM waves travel at the speed of light in a vacuum but differ in wavelength, frequency, and energy.

Radio Waves

are transmitted across the air quickly. If absorbed by the human body, they do not cause harm, and they can be mirrored to alter their course. These qualities make them perfect for interactions.

Longest wavelength, lowest frequency

Microwaves

Shorter than radio waves, higher frequency

Examples: Microwave ovens, radar, satellites.

Due to their higher frequency, _ can penetrate obstacles that interfere with radio waves such as clouds, smoke, and rain. _ carry radar, landline phone calls and computer data transmissions as well as cook your dinner.

Infrared Waves

Associated with heat, longer than visible light

Examples: Remote controls, night vision, thermal imaging.

Infrared waves are in the lower-middle range of frequencies in the EM spectrum, between microwaves and visible light. The size of infrared waves ranges from a few 4 millimeters down to microscopic lengths. The longer-wavelength infrared waves produce heat and include radiation emitted by fire, the sun, and other heat-producing objects; shorter-wavelength infrared rays do not produce much heat and are used in remote controls and imaging technologies.

Visible Light

Detectable by the human eye (red to violet)

Examples: Vision, photography, illumination.

Visible light waves let you see the world around you. The different frequencies of visible light are experienced by people as the colors of the rainbow. The frequencies move from the lower wavelengths, detected as reds, up to the higher visible wavelengths, detected as violet hues. The most noticeable natural source of visible light is, of course, the sun. Objects are perceived as different colors based on which wavelengths of light an object absorbs and which it reflects.

Ultraviolet

Higher energy than visible light

Examples: Sterilization, black lights, tanning beds.

Ultraviolet waves have even shorter wavelengths than visible light. UV waves are the cause of sunburn and can cause cancer in living organisms. High-temperature processes emit UV rays; these can be detected throughout the universe from every star in the sky. Detecting UV waves assists astronomers, for example, in learning about the structure of galaxies.

X-ray

High energy, penetrates soft tissue

Examples: Medical imaging, airport security scanners.

X-rays are extremely high-energy waves with wavelengths between 0.03 and 3 nanometers not much longer than an atom. X-rays are emitted by sources producing very high temperatures like the sun's corona, which is much hotter than the surface of the sun. Natural sources of x-rays include enormously energetic cosmic phenomena such as pulsars, supernovae, and black holes. X-rays are commonly used in imaging technology to view bone structures within the body.

Radio Waves

Radio, TV, Cellphones

Microwaves

Microwave ovens, Radar

Infrared

Remote Controls

Visible Light

Human Vision, Photography

Ultraviolet

Sterilization, Tanning beds

X-rays

Medical imaging

Gamma Rays

Cancer treatment, radioactive decay