Question

"Does light travel in a straight line? "

Explain your answer !

Thanks !!
:)

Answer 1

The question you asked was the most crucial one for the scientists in late 1880s

Light travels in a straight line as particle or as waves?

There was a lot of controversies accordingly

# Hertz, Albert Einstein, etc Believed light to be made up of particles ,and proved it using the photoelectric effect.

PHOTOELECTRIC EFFECT: pic(1)

When a beam of light of certain frequency falls on a metal such as Na,Cs, the emit electrons, this is only possible if light was a particle which can interact with the atoms and help in the ejection of electron

# Many other scientists like Thomas young,Francesco Grimaldi, Huygen,  thought light to be waves, and proved it using the Young's double slit experiment, which proved the existence of interference, diffraction.

YOUNG'S DOUBLE AND SINGLE SLIT EXPERIMENT:
Young's cut out a cardboard and made two slits and allowed a beam of light to pass through and he observed an interesting phenomena, that it formed a bright and dark fringe consecutively now know as INTERFERENCE (pic .2). Same kind of phenomena was observed with single slit now known as DIFFRACTION (pic.3).
This pattern is only possible if light was a wave, since if a beam of light is ejected the light moved through both the slit at the same time,this cannot be possible if light was a particle, and hence prove the existence of wave motion in light.


This was quite confusing to the scientists,how can light be both particle and wave which was considered to be impossible.


And after a lot of experiment and theoretical studies it was understood by both sides of the scientists ; the wave theory scientists and particle theory scientists came to the conclusion that was difficult to digest for the human mind.


CONCLUSION:

Light behaves as both particles as well as waves, under different conditions, Light behaves as particles when it interacts with matter and light behaves as waves under motion.

Answer 2

Yes light travels in a straight path.In order to prove it we conducted an experiment we placed a cardboard in the path of the light as the light beam got struck with the cardboard it deflected its path and moved straight in any other direction