The entire range of all the various kinds of radiation; light (or the visible spectrum) comprises just one small segment of this much broader spectrum.

Wavelength increases…………. Frequency decreases………..

The range of electromagnetic waves that can be detected by the human eye. The wavelengths of visible light are in the middle range of wavelengths/frequencies of electromagnetic waves. The longer the wavelength, the lower the energy of the wave is.

A Human’s Vision is called Visible Light The human eye reacts to different energies and frequencies of light so that different colors are seen. o Higher frequencies (shorter wavelengths) are perceived as colors toward the blue-violet range and have higher energy. o Lower frequencies (longer wavelengths) are perceived as colors toward the orange-red range and have lower energy.

What do dogs and cats see? Us……………………. Them Us……………………. Them

The range of electromagnetic waves with frequencies lower than red on the visible spectrum, thereby having longer wavelengths and less energy than red wavelengths.

Infrared Waves Detects heat being released from a house. Detects heat being released from a house.

Infrared Radiation The image on the left shows an optical view of a star forming region. The image on the right is the same region in infrared. The infrared observations penetrate the obscuring cloud to reveal many new details.

Gemini All objects emit infrared radiation, and hotter objects emit more infrared radiation than cooler objects. Heat energy is transmitted by infrared radiation. When objects absorb infrared radiation, they become warmer. Since atmospheric water vapor absorbs, or "soaks-up", infrared radiation, this was a very important consideration when selecting the sites for the Gemini telescopes.

More Infrared Images The image below on the left is a man holding a lit match. Compare the heat of his glasses to his face and hands. The image below on the left is a man holding a lit match. Compare the heat of his glasses to his face and hands. On the right: Where is the cat the coldest?

The range of electromagnetic waves with frequencies higher than violet on the visible spectrum, thereby having shorter wavelengths and more energy than violet wavelengths.

The image below is of the Sun taken at an Extreme Ultraviolet wavelength. The image below is of the Sun taken at an Extreme Ultraviolet wavelength. Because of the high energy of ultraviolet radiation, too much exposure is damaging to the eyes and skin.

A Bee’s Vision is in Ultra-Violet

Computer simulation: How bees perceive the world v. Humans Computer simulation: How bees perceive the world v. Humans A - Flower seen through the human eye. B – Flower seen through bee’s eye. AB

More bees vs. humans More bees vs. humans

What’s so bad about UV waves? Can cause skin damage – Solar Keratoses Can cause skin damage – Solar Keratoses

Eye Anatomy – open up your Glencoe book to p. 519

Color Fatigue Effect Fatigue in cone cells due to staring at a certain color for a prolonged period of time. Fatigue in cone cells due to staring at a certain color for a prolonged period of time.

Blind Spot Close your right eye. Close your right eye. With your left eye, look at the +. With your left eye, look at the +. You should see the red dot in your peripheral vision. You should see the red dot in your peripheral vision. Keep looking at the + with your left eye. Keep looking at the + with your left eye. The red dot will move from the left to the right and disappear and reappear as the dot moves into and out of your blind spot. The red dot will move from the left to the right and disappear and reappear as the dot moves into and out of your blind spot.