Optics

 

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.