If we think about a specific wavelength of light as it interacts with an object, it can be: Reflected (reflection) – electromagnetic radiation/light bounces off the surface of the object. Absorbed (absorption) – energy from the electromagnetic radiation/light is taken up/’soaked up’ by the object (provide Ex.)

The absorption of light makes an object dark or opaque to the wavelengths or colors of the incoming wave: Wood is opaque to visible light. Some materials are opaque to some wavelengths of light, but transparent to others. Glass and water are opaque to ultraviolet light, but transparent to visible light.

The act of ‘seeing’ an object is the result of light from any luminous source e.g. the Sun, a glowing candle or a torch, radiating outwardly from the source until it strikes the object and is reflected to travel to the observer’s eyes where if it retains sufficient intensity it will form an image on the retina at the …

When light hits the retina (a light-sensitive layer of tissue at the back of the eye), special cells called photoreceptors turn the light into electrical signals. These electrical signals travel from the retina through the optic nerve to the brain. Then the brain turns the signals into the images you see.

Which of the following is the best example of an object absorbing light? A black sweater in the sun.

The more light the object absorbs, the more heat absorbed since light is energy. If you consider it a color, black absorbs the most heat. A black object absorbs all wavelengths of light and reflects none. Objects that are white, on the other hand, reflect all wavelengths of light and therefore absorb the least heat.

The key is that colors do not absorb different amounts of heat, only heat from light. Dark and light colored clothes coming out of a dryer will be the same temperature. However, because light clothes reflect more light when a person is outside, the accompanying heat from the sun is reflected as well.

White light

yellow

Light energy can be converted into heat energy. A black object absorbs all wavelengths of light and converts them into heat, so the object gets warm. A white object reflects all wavelengths of light, so the light is not converted into heat and the temperature of the object does not increase noticeably.

“A black object is black because it’s absorbing all the light; it’s not reflecting any color,” Chandrasekhar says. White objects reflect all color. While black objects absorb the energy from all colors and become hot, the objects gradually release some of that energy back into the air around it.

It doesn’t really matter. You can see the light which enters in your eye and is absorbed by your retina. So you cannot see the light passing by because it is not going towards your eye. If it meets an object, however, light will be reflected or scattered and part of it will go towards your eye.

Blackness is the absence of light, so turning on a light of any visible frequency would mean that you don’t have black. White is a mixture of all frequencies; black is no frequency.

As any rainbow will demonstrate, black isn’t on the visible spectrum of color. All other colors are reflections of light, except black. And many do consider black to be a color, because you combine other pigments to create it on paper. But in a technical sense, black and white are not colors, they’re shades.

True black is the absence of electromagnetic waves – it has no frequency. Also, how close a color is to black depends only on the intensity of the electromagnetic waves that make it up. Dark colors are “made of” the same frequencies as their vibrant counterparts, except that their waves are weaker.

Color is the frequency of visible light, and it ranges from 430 trillion Hertz (which is red) to 750 trillion Hertz (which is violet). Waves can also go beyond and below those frequencies, but they’re not visible to the human eye.

A commonly taught acronym that helps people remember the colors in the visible spectrum is ROY G BIV which stands for Red, Orange, Yellow, Green, Blue, Indigo, and Violet.

Wait a minute, not nearly so many wave peaks have gone by in one second like before with the shorter wavelength. That means that longer wavelengths have a lower frequency. Conclusion: a longer wavelength means a lower frequency, and a shorter wavelength means a higher frequency!

On one end of the spectrum is red light, with the longest wavelength. Blue or violet light has the shortest wavelength. White light is a combination of all colors in the color spectrum.

Radio Waves

Visible light is one way energy moves around. Blue and purple light have short waves, around 400 nm. Shorter waves vibrate at higher frequencies and have higher energies. Red light has a frequency around 430 terahertz, while blue’s frequency is closer to 750 terahertz.

The amount of energy in a light wave is proportionally related to its frequency: High frequency light has high energy; low frequency light has low energy.

Visible light has a wavelength range from ~400 nm to ~700 nm. Violet light has a wavelength of ~400 nm, and a frequency of ~7.5*1014 Hz. Red light has a wavelength of ~700 nm, and a frequency of ~4.3*1014 Hz….The EM spectrum.

The EM spectrum is generally divided into seven regions, in order of decreasing wavelength and increasing energy and frequency. The common designations are: radio waves, microwaves, infrared (IR), visible light, ultraviolet (UV), X-rays and gamma rays.

The electromagnetic spectrum includes, from longest wavelength to shortest: radio waves, microwaves, infrared, optical, ultraviolet, X-rays, and gamma-rays.

The higher the frequency, the faster the oscillations and thus the higher the energy. Therefore, the highest-frequency ultra-violet light (or the lowest wavelength) is violet. However, the highest-frequency visible light would have to be roughly blue.