the answer to that would have to be infared
The part of the electromagnetic spectrum with the lowest frequency and longest wavelength is radio waves. They are used for communication, broadcasting, and radar.
Red light.
The longest wavelength of light that a human eye can perceive depends on the individual, but is generally in the neighborhood of 750 nanometers (7.5 x 10-7 m). Light with that wavelength is perceived by the retina/brain system as colored red.
red, chutiye
red,orange,yellow,green,blue,indigo,violet
-- longest wavelength -- lowest frequency
There is no longest wavelength for photons. It can be arbitrarily long.
"radio waves" have longest wavelength..
Red light has the longest wavelength.
The longest visible wavelength of light appears red. "Longest wavelength" is equivalent to 'lowest frequency'.
Red is the longest wavelength of visible light
The color red has the longest wavelength of any color.