Light Box: Difference between revisions
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imported>Stwikiadmin m Created page with "{| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right" | Physics: | Colors of Light |- | Grade Range: | Elementary School, [[Midd..." |
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{| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right" | {| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right" | ||
| [[Physics]]: | | [[Physics]]: | ||
| | | Color Addition | ||
|- | |- | ||
| Grade Range: | | Grade Range: | ||
| Line 24: | Line 24: | ||
Please read the General Safety Precautions section of the [[Demonstration Safety]] page before performing this demonstration. | Please read the General Safety Precautions section of the [[Demonstration Safety]] page before performing this demonstration. | ||
== Demonstration == | == Demonstration == | ||
# | ;Presentation (Stage): | ||
# | # Set up the light box in front of the audience, making sure there are no color filters in yet. Turn on the three lights to show that they are all white light bulbs. | ||
# | # Stick a red filter, a green filter and a blue filter into the three slots. Then, turn on the lights in the following order, asking students to predict what colors they should see on the screen when you turn on: | ||
#* The red and blue lights. | |||
#* The blue and green lights. | |||
#* The green and red lights. | |||
#* The red, blue and green lights. | |||
# Ask the students about the colors they saw. What colors did they predict? What colors did they not expect? | |||
;Presentation (Hands-on): | |||
# Set up the light box with the filters set next to it. When students come up, ask them to use the filters to create new colors with the lights. | |||
# Give each student a slip of paper, and have them use the crayons to draw the colors that they used and the colors they made. Ask them if the colors mix the same way with crayons, and to think about why they mix differently. | |||
== Why This Works == | == Why This Works == | ||
Light waves all have a color to them. The primary colors of light are red, blue and green. The reason why green is a primary color of light is because color mixing with light is ''Additive'', meaning that the colors "add" together to get brighter shades of color. We notice this when we have the colored lights mix together, and get some colors that we might not have expected: | |||
{| class="wikitable" style="color:black; background-color:#ddd; text-align: left; margin-right: 20" | |||
| Colors Mixed | |||
| Result | |||
{| class="wikitable" style="color:black; background-color:#ddd; text-align: | |- | ||
| | | Red + Blue | ||
| | | Indigo, Violet, Pink | ||
|- | |||
| Blue + Green | |||
| Teal, Cyan | |||
|- | |||
| Red + Green | |||
| Orange, Yellow, Golden Brown | |||
|- | |- | ||
| | | Red + Blue + Green | ||
| | | White | ||
|} | |} | ||
When mixing light, it is impossible to get a true "black" light. This is because the color black indicates no light being reflected, so a "black" light wouldn't give any light at all! Instead, the black lights that we have are violet lights. | |||
== Additional Information == | == Additional Information == | ||
* This demonstration pairs well with the [[Color Mixing]] demonstration. | |||
* This demonstration | |||
Latest revision as of 20:08, 1 September 2016
| Physics: | Color Addition |
| Grade Range: | Elementary School, Middle School |
| Format: | Hands-on, Stage |
As a stage demonstration, the light box works only for small, single class audiences. As a hands-on demonstration, be sure to have each light turn off at least once every 10 minutes, to prevent overheating.
Materials
- Light Box
- Color Filters
- For Hands On
- Slips of Paper
- Crayons
Safety Precautions
Please read the General Safety Precautions section of the Demonstration Safety page before performing this demonstration.
Demonstration
- Presentation (Stage)
- Set up the light box in front of the audience, making sure there are no color filters in yet. Turn on the three lights to show that they are all white light bulbs.
- Stick a red filter, a green filter and a blue filter into the three slots. Then, turn on the lights in the following order, asking students to predict what colors they should see on the screen when you turn on:
- The red and blue lights.
- The blue and green lights.
- The green and red lights.
- The red, blue and green lights.
- Ask the students about the colors they saw. What colors did they predict? What colors did they not expect?
- Presentation (Hands-on)
- Set up the light box with the filters set next to it. When students come up, ask them to use the filters to create new colors with the lights.
- Give each student a slip of paper, and have them use the crayons to draw the colors that they used and the colors they made. Ask them if the colors mix the same way with crayons, and to think about why they mix differently.
Why This Works
Light waves all have a color to them. The primary colors of light are red, blue and green. The reason why green is a primary color of light is because color mixing with light is Additive, meaning that the colors "add" together to get brighter shades of color. We notice this when we have the colored lights mix together, and get some colors that we might not have expected:
| Colors Mixed | Result |
| Red + Blue | Indigo, Violet, Pink |
| Blue + Green | Teal, Cyan |
| Red + Green | Orange, Yellow, Golden Brown |
| Red + Blue + Green | White |
When mixing light, it is impossible to get a true "black" light. This is because the color black indicates no light being reflected, so a "black" light wouldn't give any light at all! Instead, the black lights that we have are violet lights.
Additional Information
- This demonstration pairs well with the Color Mixing demonstration.