9/18/09

Science Ideas We Learnt???

1. Properties of Darkness

2. Lasers

3. Shadows of Objects

Our first experiment with light was to find out if we could see in complete darkness. To do

this, we turned off all the lights, and went under a table that was covered by a big blanket. We proved that it is impossible to see in complete darkness; without light, our eyes cannot adjust. Total

darkness can be used to create terrifying experiences for entertainment, like the Twilight

Zone Tower of Terror, where audiences are taken from total darkness to light and back to darkness.

Our second experiment dealt

with lasers. This experiment had two parts to it. The first part was to see the path of a laser.

The second part was to see why everyone could see the laser point on the wall. For the first part, we clapped chalk erasers to get dust particles in the air. Then we shone our laser pointer at the chalk dust particles.

The path of the light was revealed because the light waves were reflecting off of the dust particles and into our eyes. We concluded that the laser

beam traveled in a straight line. For the second part, we didn’t really do an experiment but instead we brainstormed. We concluded that when the light hits an object, it starts bouncing

everywhere and eventually the light waves hits our eyes enabling us to see the dot. In laser tag, there are a lot of dust

particles so the players can see the laser's path to help them hit the opponent.

Our third experiment had to do with the light bulb. This experiment also had two parts to it. The first part of the experiment was to find out why a shadow of an object gets bigger and blurrier when it gets close to a light, and why a shadow get smaller and clearer the farther away it is from light. We eventually concluded that this is because the more closer the object gets to the light, the more rays can get behind the object making the object blurrier. The second part was to figure out if the light was a single ray of light or millions of light rays. We did not come to a conclusion but my guess is that there are millions of light rays.

For example, if you squint at a light bulb, you would see lots of rays of light coming from different spots on the bulb. This is important in real world applications if you ever go into architectural and theatrical lighting.