In Science, we have
just finished the topic on Cells and Theory and we are moving onto the new
topic of Optics. In Optics, we learn our sense of sight and the behavior of
light. We know that light is electromagnetic radiation that can be detected by
the eye. With this knowledge, we needed to know whether or not light was
matter. We determined that light is not matter, but energy. We can conclude
that light is energy by using a radiometer, a device similar to the one on the
left.
We also learned that
there are two main types of light, incandescent and luminescent. Incandescent
light is created by burning or glowing through heat. Luminescent is producing
light, but not through heat. Luminescent light can be further sub-divided into
3 different groups. They are . . .
Fluorescent: produce only when electricity is provided. Electricity reacts with
chemical inside tube to produce light. Example: classroom lights
Phosphorescent: stores and gradually give off light. Works even after energy is
removed. Example: glow in the dark stuff
Chemiluminescent: creates light through chemical reaction. Example: glow sticks
We further on
learned about radiation. Radiation is energy emitted through waves. There are
different types of radiation. From the lowest radiation to the highest
radiation, it is as follows . . .
Radio waves >
Microwaves > Infrared > Visible > UV rays > X-rays > Gamma rays
Electromagnetic
radiation is made by photons, which are mass-less particles that travel at the
speed of sound. We also learned about refraction and dispersion. Dispersion is
the process of separating white light into its visible spectrum (ROY G BIV).
Refraction is changing the light’s rays as it passes through matter. Refraction
and dispersion are responsible for rainbows, since when white light enters a drop
of water, it is dispersed as it reaches the other side. The arch, in this case,
depends on the place we see it relative to the sun.
All of this information was to be on the quiz on April 17th.