Seeing Colors
Some of us come on earth seeing – some of us come on earth seeing color.
Louise Nevelson
How Animals See Color
Dogs, cats, mice, rats and rabits have very poor color vision. In fact, they see mostly greys and some blues and yellows.
What about bulls? Does a red cape make them angry? Does a red cape make them want to attack it?
Bulls are color-blind. They charge the red cape because it is moving, not because it is red.
Some animals do have good color vision. Monkeys, ground squirrels, birds, insects, and many fish can see a fairly good range of color. In some cases it’s not as good as what we humans see - but it’s much better than cats and dogs.
Scientists say that good color vision helps animals find food on the land or in the water. For land animals, good color vision helps to tell the difference between ripe red fruit and unripe green fruit. Colors can also make animals more attractive to each other when they mate. Finally, the ability to see colors helps animals identify predators (other animals who may attack them).
Who has super color vision?
Bees and butterflies can see colors that we can’t see. Their range of color vision extends into the ultraviolet. The leaves of the flowers they pollinate have special ultraviolet patterns which guide the insects deep into the flower.
Another example is how a diving bird can see under water without goggles ... and you can’t.
Fish have a spherical eye which allows in more light than ours, therefore, they can see in lower light levels than us. The lens moves back and forward for focusing, unlike ours, which is stretched to alter the shape.
Most fish are receptive to UV light, with some receptive to IR light and some can probably use both forms. It has also been discovered that the Scabbardfish has evolved to see violet light.
The deeper you go, the larger the fish eye becomes until you reach the point at which light no longer penetrates. Many fish at these depths have either pretty useless eyes or have no eye at all.
Brightly colored fish tend to inhabit the more shallow waters.
Which animal doesn’t need eyes to see?
A pit viper sees by feeling the heat in an object.
Think about the last time you were really sick. Did you check your forehead to see if you were running a temperature? That «fever-heat» is what gives a pit viper a different kind of vision. This is called “thermal vision.”
Ultraviolet Flowers
Ultraviolet light makes patterns on flowers, helping honeybees distinguish these flowers from others that to the human eye may look much the same. It makes intricate patterns on butterfly wings that look drab to our limited vision. Ultraviolet light also guides monarch butterflies in their extraordinary two thousand mile migrations.
We’ve developed instruments that help us to detect the presence of ultraviolet light, but we can only guess at what it looks like to those creatures that can really see it.
THE SPECTRUM
Here is a well-known mnemonic for remembering the order of the seven colors visible within the spectrum of light (as seen in rainbows etc):
“Richard of York Gave Battle in Vain” (Red, Orange, Yellow, Green, Blue, Indigo, Violet).
The sentence makes reference to Richard III, an English King who was defeated by Henry VII (the first Tudor monarch) at Bosworth in 1485.
<>p>Alternative sentences are:“Run Off You Girls – Boys In View!”
Some may find it easier to remember the spectrum in reverse-order as a single word:
“V i b g y o r!”
Here comes another way to recall the spectrum:
Remember it as a person’s name:
“Roy G. Biv”
First name = Roy – red, orange, yellow, Middle initial = G – green, Surname = Biv – blue, indigo, violet
How We See Color
Daylight (white light) is made up of numerous waves or impulses each having different dimensions or wavelengths. When separated, any single wavelength will produce a specific color impression to the human eye. What we actually see as color is known as its color effect. When an object is hit (bombarded) with light rays, the object absorbs certain waves and reflects others, this determines the color effect.
For example, what we actually see when we observe a blue ball is that the ball appears blue because it reflects only blue light and absorbs all other light.
The ball does not have color in itself. The light generates the color. What we see as color is the reflection of specific wavelength of light rays off an object.
Look Inside the Eye
Color vision can be defined by what kind of color-detecting equipment exists inside the eye of a human or non-human animal. Some species see no colors, some see a few colors, some see all colors, and some see colors that are not visible to the typical human eye.
The color-detecting equipment inside an eye is called a “cone.” (The rods are for night vision.)
The number of visible colors is defined by the kinds of cones in the eye.
Humans have three kinds of color receptor cells – or “cones” – in their eyes. Each type of cone contains a different visual pigment. These three cone types are called “red”, “green” and “blue”. Therefore, we are “trichromats” (tri = 3, chroma = color).(All hues can be produced by mixing red, green and blue light.)
Some people have a genetic defect that makes one or more of the cones fail. This condition is known as color deficiency. You may have heard it called color blindness. Color blindness is fairly common, affecting about nine percent of all humans. It is much more common in men than in women.
Visible light is only a small portion of the total wavelength of light.
Specific Visible Colors
Note: Ultraviolet and infrared are given as a point of reference.
They are not visible colors.
Everything that you can see in the world around you presents itself to your eyes only as an arrangement of patches of different colors.
John Ruskin
Orange is the happiest color.
Frank Sinatra
What Is a Rainbow? or What Happens When Light, Water and Air Meet?
When a shaft of sunlight enters a drop of water, a part of it does not pass directly through but is reflected from the inner surface and emerges from the side from which it entered. Moreover, it is refracted both on entering and leaving the water drop. This process, repeated in the same manner for an immense number of drops, produces the primary rainbow, which appears in front of the observer, who has his back to the sun. It has the red band on the outer edge which are long light waves and the blue-to-violet on the inner edge which are short light waves.
Another larger bow is often seem outside the primary rainbow and parallel to it. This secondary rainbow is produced in a similar way, but the sun’s light is reflected twice before emerging from the raindrop. For this reason, the color sequence is reversed; red is on the inside edge. And because there is a loss of light with each reflection, it is not as bright as the primary rainbow. The region between the two bows is comparatively dark, for it lacks entirely both the once and the twice reflected rays. There is theoretical evidence for a tertiary rainbow, but it would be so faint as to be rarely seen in nature.
People have been asking questions about rainbows since the beginning of time. One question frequently asked is,
Where is that pot of gold? The idea that a pot of gold can be found at the rainbow’s end originated somewhere in old Europe. In Silesia, an obscure area of eastern Europe, it was said that the angels put the gold there and that only a nude man could obtain the prize. Hmm.....
Can you go under a rainbow’s arch and come out the other side? Not according to the laws of physics. A rainbow is all light and water. It is always in front of you while your back is to the sun. However, there is an old European belief that anyone passing beneath the rainbow would be transformed, man into woman, woman into man!
Do two people ever see the same rainbow? No. As the eyes of two people cannot occupy the same place in space at the same time, each observer sees a different rainbow. Why? Well, because the raindrops are constantly in motion so its appearance is always changing. Each time you see a rainbow, it is unique in its own spectacular way! Many people consider rainbows to be an omen of some kind. It is an ancient desire rooted in cultural mythologies.
Why is a rainbow shaped like a half circle? The answer is forty-two. Forty-two degrees is the angle that we see colors refracted from a raindrop. The only way to have exactly forty-two degrees from the point you are standing is to draw a half circle.