The spectroscope is a crucial instrument in space science. It helps the scientist to observe lights from various stars and distant Galaxies to understands their physical composition—i.e., materials found around them.
So how does this work? White light what we see is a mixture of different colored lights. For example, when you combine red, green, and blue colors, you will see white. Similarly, what we see as white light is usually a mixture of different colors. This is why the rainbow pattern is created when white light is broken into its component colors or light spectrum.
The spectroscope uses a prism to break the incoming light into its spectral composition. Scientists use this spectrum to see the physical composition of distant stars, planets, or galaxies.
In this activity, we will construct a simple spectroscope using a Compact disk instead of a prism. When the white light gets reflected on the compact disk’s clear side, the light diffracts, creating a spectral view. This is a cool experiment for kids to understand the basic concepts of white Light composition and how rainbows are formed.
Difficulty Level: Medium
Average Time:15 – 20 Minutes
Light entering your spectroscope through a small slit is reflected off the CD and seen through the viewing tube. When light penetrates the tube, it is distributed in a spectrum perpendicular to the tracks of the CD. This is why the slit and observation hole is positioned at right angles.
Each color bends at a special angle. For you to see the spectrum, the light needs to diffract the CD and reflect into your eye. The adjustment of the inclination of the CD allows you to bounce the spectrum correctly in your eye.