Rectilinear propagation of light refers to the property that light travels in a straight line through a homogenous transparent medium without being interrupted. This can be observed through activities using a straight and bent plastic tube, where light from a candle flame can only be seen when looking through the straight tube and not the bent one, demonstrating that light travels in straight lines. Einstein's theory of light being bent by the sun's gravity was verified through observations of stars near the sun during a solar eclipse in 1919.

5. WHAT IS RECTILINEAR PROPAGATION OF
LIGHT???
 In a homogenous transparent
medium light travels in
a straight line and
the property by which light
travels in a straight line is
called rectilinear propagation
of light and also light
traveling
in straight line without being
interrupted in between is
called rectilinear propagation
of light

6. activity
Straight tube
Bent tube

7. VIDEO TIME
 ACTIVITY BIENG EXPLAINED
 https://youtu.be/4tV4HUDM1B0

8. QUIZ TIME !
What Is A Rectilinear
Propagation Of Light?
How Can We Observe That
Light Travels In A Straight
Line?
Can Anybody Tell Me What
Did You Observe In Activity
1 And 2?

9. ANSWERS..
 1]The Property Of Light To Travel In Straight Line
Is Called Rectilinear Propagation Of Light.
 2] Place a lighted Candle on a table & take a short
length of a plastic tube. Try to look at the flame
through it.
 Bend the plastic tube slightly & again try to see the
flame.
 You will not be able to see the flame while tube is
bent.
 And this proves that light travels in a straight line.

10. Verification of Einstein's theory
of light from a distant star being
bent by the sun's gravitational
potential. This was observed in
1919 during an eclipse of the sun.
The general phenomenon is
called 'Geodesic lines in curved
spaces.

11. HTTP://WWW.BBC.CO.UK/BITESIZE/
KS1/SCIENCE/LIGHT/PLAY/POPUP.S
HTML
HTTP://WWW.SCIENCEKIDS.CO.NZ/
GAMESACTIVITIES/LIGHTSHADOWS.
HTML