Understanding White Light Colors and Light Interaction

Study Notes

Colors are specific wavelengths of light reflecting off objects, or matter, that humans can see.
White light of the sun contains all the colors of the rainbow, which can be split into the visible light spectrum using a prism.
The visible light spectrum consists of red, orange, yellow, green, blue, and violet (or purple) colors.

The electromagnetic spectrum includes the visible light spectrum, as well as wavelengths of light we can't see, including x-rays, UV light, infrared light, microwaves, and short and long radio waves.

White is not a color in the classical sense, as it is not a single wavelength of light.
Instead, when we perceive an object as white, we are seeing all the colors on the visible light spectrum bouncing off the object and hitting our eye, which our brain then names as "white."
Black objects, on the other hand, absorb all the colors of the light spectrum, while pink is a mixture of red and violet light.

When light hits matter, it is either absorbed or reflected, or a combination of both.
The frequency and wavelength of light are inversely proportional, meaning that when the wavelength is higher, the frequency is lower, and vice versa.
Atoms in an object absorb light energy if the frequency of the light is the exact amount of energy needed to go from a grounded state to an excited state.
If the energy is too large or too small, the light energy is reflected, resulting in the color we see.

When white light hits a red rose, the rose appears red to our eye because the orange, yellow, green, blue, and violet light is being absorbed by the rose petals.
The leftover red light is reflected, making the rose appear red.

Opaque objects do not allow light to pass through, while transparent objects do, and translucent objects allow some light to pass through.
When light passes through an object, it bends, or refracts, depending on the material.

The molecular structure of an object determines what wavelength of light is reflected back to our eye and perceived as color.
Pigments in an object determine which wavelengths of light are absorbed and reflected, and thus, determine the color of the object.

Chlorophyll in leaves absorbs all wavelengths of visible light, except for green, which is then reflected back to our eye, making the leaves appear green.

During autumn, the chlorophyll molecule in leaves breaks down, no longer absorbing red, orange, and yellow light, resulting in these colors being reflected and creating the autumn colors.

White is not created by mixing pigments, but rather by reflecting all the colors of the visible light spectrum.
White objects have pigments that reflect all light, making them appear white to our eye.