Unlock the Secrets of Light with These Prism Experiments | Step-by-Step Guide

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SUMMARY

This discussion outlines a series of three prism experiments designed to explore the behavior of light and color. The experiments utilize basic materials such as a prism, white paper, and a pencil to demonstrate how light bends and separates into colors. Key findings include the classification of colors into "Slow" and "Fast" families based on their attraction to light and darkness, and the relationship between color combinations, such as green being the product of cyan and yellow. The discussion emphasizes the importance of distance in observing these effects and suggests further exploration of the classic prism test.

PREREQUISITES
  • Understanding of basic light properties and refraction
  • Familiarity with color theory, specifically additive and subtractive color mixing
  • Knowledge of the Doppler effect as it relates to color perception
  • Basic drawing skills for creating experimental setups
NEXT STEPS
  • Conduct the Classic Prism Test to observe light dispersion and record distances for optimal results
  • Explore the principles of color theory, focusing on additive and subtractive mixing techniques
  • Investigate the relationship between light distance and color perception in various environments
  • Learn about the Doppler effect and its implications for color speed and perception in physics
USEFUL FOR

This discussion is beneficial for educators, students in physics or optics, hobbyists interested in light experiments, and anyone seeking to deepen their understanding of color theory and light behavior.

8LPF16
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You will need: a prism, two 3 x 5 white card or paper, pencil.

Use the Sun, or any household light, even Moon reflection
____________________________________________________________________

Test One

Step One: stand in area where the background is darker than the paper, and is evenly colored. Hold paper in one hand, and the prism in the other, about 12" from each other.

Step Two: look through prism at paper, turning prism until light is "bent" and you see this on the edges of paper

|----------red-----------------|
|------------yellow------------|
| |
| white |
| |
|------------cyan--------------|
|-------------violet-----------|

if background is lighter than paper, you will see this

|-----------yellow-------------|
|-------------red--------------|
| |
| darker |
| |
|------------violet------------|
|-------------cyan-------------|

You can hold your finger or pencil between prism and paper, and the same rule will be followed - finger is darker than paper so red and violet will "touch" on finger with yellow and cyan "pointing" towards the lighter paper.

This is the Basic prism experiment. From it we can deduce that red and yellow have opposite (attractive) values, yet are in the same "family" - called Slow. In the Slow family, red is "+",and is attracted to dark. Yellow is "-", and is attractred to light. The other family is called Fast, and in the Fast family, violet is "+", and is attracted to dark, while cyan is "-", and is attracted to light.

Test Two

Take one paper, and fold it in half. Draw a dark line 1/16th" (pencil lead width) wide and 1" long in the center of one half, and 3/16" x 1" in the center of the right half. Hold prism as in previous experiment (12" away), and observe the lines you have drawn on the left side first:

You will see three lines

--------- cyan (above line)
--------- magenta (over line)
--------- yellow (below line)

(in addition to the colors on the edge of the paper)

and, on the right side you'll see:

---------cyan
---------violet
---------black
---------red
---------yellow

From this we can deduce that magenta is a "parent" of red and violet, is neutral to them, and attracted to dark (parent quality).
By changing the distance from prism to paper, we see that this distance is a ratio to the amount (width) of darkness to distance. This ratio is the same for gravity and electricity (mass/ dist.).
This is the "anti-slit" experiment. A line is "what is not" in the slit.

Test Three

On the other paper draw two lines 3/16th" x 1", one on top of the other with 3/16th" between them, on the left half. On the right, draw the same two lines except only 1/16th" apart. View through prism in the same manner as above. The left will look like the last experiment, except doubled, while on the right side, you'll see this:

---------cyan
---------violet
---------red
---------(yellow)
<-green->
---------(cyan)
---------violet
---------red
---------yellow

Now we see that green is the "product" of cyan+yellow, and is a "neutral" to them, while being the "opposite" of magenta. Green is Slow neutral, magenta is Fast neutral. They do not appear together at the same time. This re-creates the "classic" prism test with one major difference. This one happens a "moment" in time sooner than classic. Why? - because of closer distance and not "waiting" the extra time for "reflection" off of wall. The extra distance in the classic test also causes "secondary" colors to appear blurred between "primary" ones. (orange, blue, and green)

In all three tests, you can change position regarding the light and get the same results. Except at 90 degrees to light, which then lines will just look normal (black).

We know from energy levels and logical "position", that the colors of cyan, magenta, and yellow are "faster" than those of red, green, and blue. This also fits Doppler shift, red slower in the "back", and cyan faster in the "front". All color combining rules still apply, with perhaps better understanding of why there is +/- (subtractive/additive).


Happy Bending!

LPF
 
Last edited:
Science news on Phys.org
Classic Test

It would be very helpful to re-create the Classic Prism Test (allow light through small slit pass through prism, and onto wall) AND RECORD THE DISTANCE necessary to "make a rainbow".


LPF
 

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