STEP #06-The symbol

They say "a picture is worth a thousand words", then a spectrum is worth a thousand pictures. 

When I first surfed the web, looking for any iconic images, I came across something that caught my eye. The following pic describes light dispersion through a prism and I couldn't help noticing the similitude with Pink Floyd's album cover for 'The dark side of the moon'.

light dispersion through a prism

Dark side of the moon's cover

The cover was designed by Powell and Thorgerson during a late night brainstorm. They were given limitless creative freedom as the band only suggested 'to do something clean and graphic'. Pink Floyd approved it straightaway. 

Shining a light through a prism is one of the simplest ways to see a spectrum. Many early physicists did it, including Newton. The effect reached a new level of fame when Pink Floyd released their album. That is the field of spectroscopy.

STEP #04 (II)-Spectrophotometry and its applications

Spectrophotometry deals with the measurement of the interaction of light with materials. Light can be reflected, transmitted, scattered, or absorbed, and a material can emit light, either because it has absorbed some light and it reemits it, because it has gained energy in some other way (e.g., electroluminescence), or because it emits light due to its temperature (e.g., incandescence).

The spectrophotometer is an important scientific tool, most commonly used in biology and chemistry. It usually requires expensive lab equipment, but D. Hingston designed a rig to do the job at home almost cost-free. The heart of the rig consists in a normal filament-based flashlight bulb, which produces good-quality white light containing all colors. A prism is then used to split the light into its component wavelengths, so that the sample can be tested across the whole light spectrum. It is a simple craft that can be achieved with fairly common materials, barring the prism which may need to be specially ordered. (More info on how to build your own spectrophotometer can be found in this video).

Bibliography:

 SPECTROPHOTOMETRY-Thomas A. Germer, Benjamin K. Tsai, Experimental Methods in the Physical Sciences, 2014 

HOMEMADE APPLICATIONS-How to build a spectrophotometer at home                    

ELECTROLUMINESCENCE-C. Moretti, V. Koncar, Smart Textiles and their applications, 2016.                      

WIKIPEDIA, INCANDESCENCE-https://en.wikipedia.org/wiki/Incandescence