Energy measuring is a term used to describe the light and radio waves, X-rays, and other forms of energy that transmitted through space as electromagnetic waves. These waves have alternating high and low points – crests and troughs – like actual waves. The distance between wave crests named a wavelength (metres). Frequency refers to the number of waves per second pass a certain point; measured in hertz (Hz). Below a description of the various forms of energy in order of frequency and wavelength. See remote sensing. From left to right of the illustration
- Radio waves
- These waves transmit television and radio signals. This section of the spectrum divided into bands, from VLF (low frequency) – used for time signals -to SHF (super-high frequency) – used for space and satellite communication.
- Radar and microwaves
- Radar bounces waves off objects, allowing un-seen objects; microwaves can cook food quickly. See microwaves
- Infrared waves
- all hot objects emit infrared waves.
- Visible light
- The visible light is a term to describe the scale from red to violet. The visible light human eye is 3 per cent of the full spectre. See visible light
- Ultraviolet light
- ultraviolet light is in small amounts, these waves produce vitamin D and cause the skin to tan; in more significant amounts they can damage living cells. See ultraviolet light
- Used to photograph the internal structures of the body and in scanners of body parts (images in a series making a computer 3D film), the noise comes each time a single photograph. See x-ray
- Gamma rays
- Gamma rays emitted during the decay of some radioisotopes, and these waves can be very damaging to the body.
- Cosmic rays
- Cosmic rays caused by nuclear explosions and reactions in space. Nearly all these waves absorbed by the Earth’s atmosphere.