TIERRA DEL FUEGO. WEATHER AND CLIMATE. In spite of its incendiary name, Tierra del Fuego -as well as the rest of Patagonia- has low temperatures and strong winds, sudden changes of weather, going from strong winds to complete calm, or from sunny to rainy conditions being very common.
Theories of Color Vision. 1  In 1802, Thomas Young proposed that all human vision occurred through the combination of sensitivity to red, green, and blue. This theory, modified by Hermann von Helmholtz in 1852, came to be known as the Young-Helmholtz or trichromatic (three-color) theory of color vision.
One type of cone perceives blue light, another perceives green and the third perceives red. When you look at an object, light enters your eye and stimulates the cone cells. Your brain then interprets the signals from the cones cells so that you can see the colour of the object. The red, green and blue cones all work together allowing you to see the whole spectrum of colours. For example, when the red and blue cones are simulated in a certain way you will see the colour purple. The exact physical causes of colour blindness are still being researched but it is believed that colour blindness is usually caused by faulty cones but sometimes by a fault in the pathway from the cone to the brain.