What is rectilinear propagation of light? How will you prove it?

What is rectilinear propagation of light? How will you prove it?
Answer:
Light travels in a straight line. This is called rectilinear propagation of light.
Activity:

  • Take a straight straw and look at the light rays through it.
  • Take another straw which is bent and try to look at the light rays through it. You will observe that when the straw was straight you could see the light and when the straw was bent you could not see the light.
  • This means that we cannot bend the ray of light to travel through the bent straw.
  • Thus, this activity proves that light travels in a straight line.