White Light

In actuality, white light is not white. It is a colorless light that can be seen during daytime or nighttime if any laminating object emits it. White light consists of different rays of light of varying wavelengths and color at equal intensities. In short, we can say electromagnetic waves of all the frequencies that are mixed and appear white to the eye are called white light.

White light falls under visible light, which is above the infrared rays in the electromagnetic spectrum. The primary source of white light is the Sun. Studies have found that more than the visible light, the Sun emits infrared rays, which causes the warming of the Earth.
The eye can detect visible light only from the electromagnetic spectrum. The electrons of atoms and molecules of visible light and near-infrared rays absorb and emit energy from one level to another. Photosynthesis is one such phenomenon that follows these energy levels.

Electromagnetic spectrum

Electromagnetic spectrum displays wavelengths and frequencies of various sources of energies. The wavelength and frequencies in the electromagnetic spectrum are inversely proportional to each other. Therefore, we can see low frequency, a high wavelength of radio waves at the top, and high frequency, a short wavelength of gamma rays at the bottom of the electromagnetic spectrum.
Visible light covers a small distance in the electromagnetic spectrum. Electromagnetic spectrum wavelength ranges from 380 nm to 760 nm is visible to the human eye. White light consists of seven colors of different wavelengths and frequencies – violet, indigo, blue, green, yellow, orange, and red. Other wavelengths longer or shorter than visible light are not visible to the human eye.

Characteristics of white light

1. Most of the white light comes from the sky around us. It is a source of both heat and energy. It also acts as a laminating source to see in the dark.
2. The colors of the visible spectrum can be seen when the white light is passed through a diffraction grating or a prism.
3. Colors in white light vary according to their wavelengths.
4. Red has the longest wavelength and lowest frequency, whereas violet has the shortest wavelength and highest frequency.

Applications of white light

1. White light is used to illuminate a room, kitchen, house, roads, or places subjected to darkness.
2. It is used in photography to capture good photos.
3. It is used for research and study purposes to have a more transparent look at objects that we study.
4. White light brings a warming sensation if susceptible for a longer duration.

How do we see a white light?

As mentioned above, white light comprises seven colors of different wavelengths. These colors are absorbed and reflected by the eye. When our eyes reflect a particular color, say blue, then we can see the blue color. The rest of the wavelengths are absorbed by the eye, due to which we are unable to see other colors of the visible light. When we see black, it means our eyes have not absorbed any color and have ultimately reflected all the colors. The opposite goes with the white. All the colors are absorbed by the eye, due to which we see the white color.

Difference between sunlight and white light