For a long time ago, scientists had different idea about the nature light. And by the end of the eighteenth century, some physicists done some experiment about light such as:
1. Thomas Young, done an experiment about how to provide incontrovertible proof of the wave nature of light and this was his double-slit experiment and by this experiment physicists knew that light travelled as waves.
2. Albert Einstein, done an experiment about the photoelectric effect. When light intersects with substance or matter, it will showed in the form of particles. And now, most of us accept this experiment in the nature of radiation and matter.
we do double-slit experiment to observe interference and we need:
a. two sets of waves
b. the same wavelength
c. must be coherent (phase difference between the waves remain constant)
To determining the wavelength of light, we can use double-slit experiment, but we need to measured 3 quantities :
1. Slit separation
2. Fringe separation
That's all for this posting, hope it's useful
NF:i apologize to mr albaini zuhdi because i just show my summary about light today, there's a problem with my internet connection yesterday.