Why does light usually appear to travel in a straight line inspite of its wave nature?
Answers
In a dusty atmosphere it is sometimes possible to see light travelling and it does appearto be moving in a straight line. The fact that light travels can be demonstrated by putting an object in its path. ... As light does appear to travel in straight lines then light is usually modelled as straight lines in drawings.
Explanation:
When wave is obstructed by an obstacle or an aperture diffraction of the wave occurs.
The diffraction depends on the size of the obstacle or the aperture which in turn relates to the wavelength of the wave.
If the aperture or the obstacle is larger than the wavelength of the wave then minimal diffraction which is not easily noticed occurs.
In this case the wave will appear to travel in straight line.
This is the case of light whereby the wavelength of light is small compared to any available obstacle and aperture.
Therefore when light is obstructed minimal unnoticeable diffraction occurs and in that case light appears to travel in straight line.