What is the connection between electromagnetic radiation and the electromagnetic spectrum?
The electromagnetic spectrum is the range of different electromagnetic radiations ordered by either frequency or wavelength (or both). Ranging from low-frequency (high wavelength) radio waves, through microwaves, infrared waves, light (the visible spectrum – red, orange, yellow, green, blue, indigo and violet), continues through ultra violet waves and X-rays, to very high frequency (short wavelength) gamma rays. In general, electromagnetic waves are set up by electrical and magnetic vibrations occurring in atoms. Travelling at the speed of light the electric and magnetic fields are propagated through time and space at right angles to each other and to the direction of propagation in discontinuous units called photons. The connection between the electromagnetic spectrum and radiation is best served with an example: when an object is inadvertently heated the radiation is predominately emitted in the infrared, placing your hand over the object one can feel but not observe the effects of i
