 |
 |
 |
|
 |
|
 |
|
 |
|
 |
|
 |
 |  |  |
| This is a short introduction about two very important topics in physics: optics and heat. First, what are you doing right now? Of course, you are reading, but really you are looking and seeing. Your eyes allow you to do this. The eyes have so many names and features. Let's see, there's the retina, lens, optic nerve, cornea, iris, rods and cones. |
Heat also plays a very important role in our daily life, as it keeps us alive and warm. Think about it! Without heat, we would never survive her on earth. The world would be ...ICE! Heat helps us do and make many things. Toys, machines, automobiles all run because of heat! Heat surrounds us. Even if it's snowing outside, we still have heat. Heat is the built up of molecules. These molecules are exposed to energy, which causes heat to have an effect. Which means, cook our meals, run machines, etc.
Read on about heat and optics below!
Heat
Life on earth would be impossible without heat. All of our
energy and all of our heat comes from one initial source...
the sun. The ground, plants, oceans and atmosphere all
absorb the sun's heat. It is by this that we know heat
exists. Heat itself is not visible; however, the work heat
does is. The burning of fuel in engines, creates hot gases,
which provides the power to move an automobile. We easily
see the outcome of heat in this example.
Long ago people simply knew heat by that which kept them
warm. A primitive source of heat is called friction.
Though early humans did not term rubbing their hands
together nor two sticks to create a fire and ultimately
heat a method of friction; it truly was. For more
information on friction, click here.
When we think of heat, we often think of temperature.
However, they really are two separate ideas. To understand temperature, we must first understand a few basic ideas. Molecules are exposed to energy. When that happens, the molecules absorb the energy and become active. They then move around faster. Temperature measures how fast the molecules are moving.
Heat measures the energy contained
within the object, because of the moving molecules. Did you
know that there is more heat in an iceberg than a pot of
boiling water? The pot of water actually has a higher
temperature, but the iceberg is much bigger; and therefore,
contains far more molecules (though they move at a much
slower rate). Let's recap this information. The faster the
molecules in matter, the higher the temperature. The slower
the molecules in matter, the lower the temperature. The
larger the item the more molecules it contains and therefore
more heat. The smaller the item the fewer molecules it
contains and therefore less heat. Wow!
OPTICS
Several optical examples listed above work because of the use of lenses or mirrors.
Lenses have a main function which is to bend light. One of the most common items that
comes to mind would be eyeglasses. They are specifically designed to help people see
more focused and do so by bending light.
There are many examples of optics. Some are mirrors, microscopes, cameras, eyeglasses,
and even your very own eyes. We even see "example... of natural optical phenomena
that happen everyday, in your backyard or right over your head."
Some of those
include rainbows, sunsets, harvest moons, and the Aurora Borealis.
* Lenses can work in different ways. The three main types of lenses are: concave, convex, and planar. Concave lenses are "curved like the inner surface of a sphere," while convex lenses have "a surface or boundary that curves or bulges outward, as the exterior of a sphere." Planar is simply "having a two-dimensional (flat) characteristic." Basically, when we think of something being planar, a bedroom mirror comes to mind. Though those are the three main types of lenses, we should also mention prisms. Prisms work quite differently. They refract light twice and show the beautiful colors we often see in a rainbow.