Benham’s Disc

What Colors Do You See?

What Are We Doing Today?

• Today we are going to make a toy dating all the way back to the 1800s!

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• We are going to trick our eyes into seeing different colors, even when there are only two colors!

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• We are also going to learn two parts of our eye that are responsible for seeing colors and objects in low light.

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Why Are We Doing This?

• 1-PS4-3 - Plan and conduct an investigation to determine the effect of placing objects made with different materials in the path of a beam of light.
• We’ve done several experiments with light, shadows, and tricking our eyes.
• Remember the Thaumatrope?

Standards - Why Are We Doing This?

• 1-PS4-3. Plan and conduct an investigation to determine the effect of placing objects made with different materials in the path of a beam of light.
• We’ve done several experiments with light, shadows, and tricking our eyes.
• Remember the Thaumatrope?

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• 1-PS4-2. Make observations to construct an evidence-based account that objects can be seen only when illuminated.

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• SL.1.1 Participate in collaborative conversations with diverse partners about grade 1 topics and texts with peers and adults in small and larger groups. (1-PS4-1),(1-PS4-2),(1-PS4-3)

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• 4-LS1-2. Use a model to describe that animals receive different types of information through their senses, process the information in their brain, and respond to the information in different ways

Some History

• In 1894, toymaker Mr. C.E. Benham discovered that a spinning disk with a particular pattern of black and white marks could cause people to see colors.

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• Mr. Benham called his disk an "Artificial Spectrum Top" and sold it through Messrs. Newton and Co.

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• Benham's Top (or Benham's Disk) has puzzled scientists for over 100 years.

Here it is!

Materials

• A Compact Disc (CD)
• A Top
• Glue Stick
• Benham’s Disk template
• Scissors

OK, Let’s Make It!

1. Take out your scissors and cut out your Benham’s disk template
2. Take out your glue stick, apply glue to the disk template.
3. Carefully place the template on the compact disc
1. Make sure the hole in the center of the template goes through the stick of the top
2. Smooth the template down to make sure the glue and paper stick to the compact disc.
4. Now, spin your top and look at the patterns on the disc
5. What colors do you see?

Let’s Experiment!

Let’s turn out the lights and see if we can see the different colors.

It’s much more difficult to see the colors in dark or dim light. Our eyes need the bright light, so the part of our eyes that see color can see the white and black.

Could we????

What’s Going On Here?

• The retina of the eye is composed of two types of receptors sensitive to light: cones and rods.

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• Cones are important for color vision and for seeing in bright light. There are three types of cones, each of which is most sensitive to a particular wavelength of light.

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• Rods are important for seeing in low light.

What’s Going On Here?

• One possible reason people see colors may be that the rods and cones in the human eye respond at different rates to red, green, and blue.
• But honestly, we don’t really understand how this happens. It’s still a mystery to this day!

Let’s See What Else Our Eyes Can Do

What Did You See?

A sailboat