The birth of each rainbow begins with millions of tiny rain droplets.  The rain droplets serve as a type of reflector of light.  White light enters one individual rain droplet and exits as one specific color of the spectrum.  Without millions of rain droplets, a rainbow would not occur.  If you only had a few rain droplets you would only see a few colors.  This is typically why rainbow appear after a rain storm

Each rain droplet has a function in the formation of the rainbow. Sunlight enters the rain droplet at a specific angle and the rain droplet separates the white light into many different colors.  This angle is a fixed measurement between your eye

and the sun.  What color is refracted depends upon the critical angle,                   which is the angle the sunlight strikes the back of the rain droplet.  Red light bends the least, exiting the rain droplet at a 42 degree angle, while Violet light bends the most, exiting the rain droplet at a 40 degree angle.  All of the other colors of the rainbow exit the rain droplets at some angle between 40 and 42 degrees, thus making up the colors of the rainbow ROYGBIV, this order never changes.

The sense of smell is extremely important in attracting cats (and us) to food and also in aiding tasting food. Cat’s noses are many times more sensitive than our own, so it is believed that their heightened sense of smell assists a great deal in their tasting of different flavors.

Cats and dogs are just like color blind humans, seeing some colors but not all of them. For the bright daytime light, cells known as cones are needed. Humans have three kinds of cones, enabling them to see blue, red and green.

Cats and dogs, on the other hand, have just two kinds of cone cells (blue and green sensitive), allowing them to see only partial color.

while we’re on the subject, contrary to the legend that cats can see perfectly in total darkness, they do not have those superpowers. But cats require only about one-sixth of the light that humans do, making their night vision a whole lot better than ours

For starters, cats’ visual fields are broader than ours, spanning roughly 200 degrees instead of 180 degrees, and their visual acuity isn’t as good. So, the things humans can sharply resolve at distances of 100-200 feet look blurry to cats, which can see these objects at distances of up to 20 feet. That might not sound so great, but there’s a trade-off: Because of the various photoreceptors parked in cats’ retinas, they kick our asses at seeing in dim light. Instead of the color-resolving, detail-loving cone cells that populate the center of human retinas, cats (and dogs) have many more rod cells, which excel in dim light and are responsible for night-vision capability. The rod cells also refresh more quickly, which lets cats pick up very rapid movements — like, for example, the quickly shifting path a marauding laser dot might trace. Lastly, cats see colors differently than we do, which is why the cat-versions of these images look less vibrant than the people-versions. Scientists used to think cats were dichromats — able to only see two colors — but they’re not, exactly. While feline photoreceptors are most sensitive to wavelengths in the blue-violet and greenish-yellow ranges, it appears they might be able to see a little bit of green as well. In other words, cats are mostly red-green color blind, as are many of us, with a little bit of green creeping in.

Bones are flexible enough to give a bit when physical force is applied, but if that force is too great, they’ll snap like a plastic ruler bent too far. Luckily, they also repair themselves naturally (even better with a cast). Here’s how bones heal. 1. Immediately after a fracture occurs, a blood clot and callus form around it. 2. New “threads” of bone cells start to grow on both sides of the fracture line toward one another. 3. Eventually, the fracture closes up and the callus is absorbed by the new cells. This process may take from six weeks to a year.

If you experience engine trouble, you take your car to a mechanic. If your pipes leak, you call a plumber. And if you fracture a leg, the usual course of action is to visit a doctor. But unlike other things that may break in life, bones begin healing on their own before you even set foot in a waiting room.The human body possesses amazing healing powers that enable it to bounce back from a vast array of illnesses and injuries. Sometimes broken bones can heal so thoroughly within a few months that even an x-ray can't determine the original fracture line.Doctors often play a vital, sometimes lifesaving, role in a bone's healing process. But, these experts basically help the body heal itself. Doctors provide optimal conditions for bone repair and healing to take place. The rest is up to your cells.But how does this amazing biological process work? How can a fractured limb grow back to its former strength? To understand, you first have to take a closer look at just what bones are made of and how alive they really are.