Luminous Body: Something that emits light (ex. The Sun)
Non-luminous Body: Something that does not emit light (ex. Nina)
Incandescent Body: Something that emits light when heated (ex. A light bulb)
Transparent Material: A material that transmits light/allows light to pass through it (ex. Polycarbonate/Plastic)
Translucent Material: A material that transmits light, but also scatters it (ex. Tissue Paper)
Opaque Material: A material that prevents light from passing through (ex. Metal)
Rays are used to represent light as light moves only in straight lines. Rays do not exist in nature!
A collection of rays is called a beam.
We also did some work on shadows:
Shadows form when an opaque object is placed in the path of light.
Umbras are areas of complete shadow.
Penumbras are areas of partial shadow.
An example that uses umbras and penumbras is a solar eclipse, where the total eclipse occurs in the umbra.
The last thing that we learned about this class was illuminance:
Illuminance is the amount of light on a surface area. It is represented by the variable (E) and is measured in lux (lx).
Photometry is the science of measuring light.
The relationship between illuminance and distance is shown by this formula:
$E \alpha 1/d^2$
This means that, if you double the distance, the illuminance decreases by 1/4 and, if you triple the distance, the illuminance decreases by 1/9.
At the end of class, we had a few extra minutes, so we looked up and videos of eclipses and researched diodes and LED's.
I have done some work with diodes and I can explain what they are. Basically, they allow current to pass through one direction while blocking current from the other side. If you have more than one energy source, you need to use diodes or you could fry your circuit. They are more complex than that, but that is their basic function.
The person to write the next blog will be whoever has the longest hair.
No comments:
Post a Comment