DIY NEWTON COLOR WHEEL
Why do we see 7 colors in a rainbow?
In 1966, Isaac Newton passed sunlight through a prism and it split up into its component colors. He then passed the spectrum back through another prism producing white light once again.
A Newton's color wheel is a disk with all colors of the spectrum. When the color wheel is spun round rapidly, the disk changes color and becomes practically white.
Dispersion of light, Color mixing
How is white light formed?
Newton Color Wheel
DO IT YOURSELF
1. Newton's color wheel sticker - 1 No
2. Plastic container with 2 diametrically opposite holes
& 1 hole at the bottom - 1 No
3. Lid which fits the container & has a hole at the center - 1 No
4. Cycle spoke with nut and bolt - 1 No
5. Thread - 1 Roll
Steps To Make
Cut the sticker along the circular disc as shown
Peel off the sticker
Stick the sticker on the lid of the bottle
Pass the thread from the hole in the bottom of the bottle
Pass the rod through the two holes at the top of the bottle
Tie the thread to the rod as shown
Insert the rubber piece at the end of the rod as shown
Real Life Applications
How are rainbows formed?
Immediately after a rain shower, thousands of water droplets are left floating in the air. As sunlight passes through these spherical droplets, light is bent and scattered into a continuous band of colours. This light is reflected off the back of the drop and refracted again as it leaves the drop. Thus, the light coming out of several raindrops creates a rainbow.
When the disk (which consists of seven colours: VIBGYOR) is rotated at high speed it seems as if the colours mix and we see a white disc.
When the thread is pulled, the disk unwinds and automatically winds-up due to inertia of motion. So the disk doesn’t stop immediately.