Electronics
Certain electronic devices, such as photodiodes and charge-coupled devices, are designed to be sensitive to light. They are constructed to take advantage of the photoelectric effect, the emission of electrons from matter upon the absorption of electromagnetic radiation. When light (one form of electromagnetic radiation) impinges on the active surface of such a device, electrical current flowing through or electrical charge stored in the device will increase or decrease in proportion to the intensity and wavelength of the light, although there is an upper limit to the amount of electrons released vs the increased intensity of the light, this comes out of quantum mechanics. This trait allows the device to perform regulating and sensing functions of many kinds. For example, a photoresistor circuit may sense ambient light to turn on a street lamp at dusk. Digital cameras use charge-coupled devices whose extreme sensitivity to light allows them to convert incoming photons into varying electrical charges with great accuracy. The varying charges are then encoded in a binary file which can be stored and later viewed on a computer screen or other medium.
Read more about this topic: Photosensitivity
Famous quotes containing the word electronics:
“We live in a highly industrialized society and every member of the Black nation must be as academically and technologically developed as possible. To wage a revolution, we need competent teachers, doctors, nurses, electronics experts, chemists, biologists, physicists, political scientists, and so on and so forth. Black women sitting at home reading bedtime stories to their children are just not going to make it.”
—Frances Beale, African American feminist and civil rights activist. The Black Woman, ch. 14 (1970)