Light is how we see the universe. It is one of the most vital parts that enables us to see objects and colors around us. We see through our eyes due to the reflection of light from an object traveling to our retina. Objects such as chairs, buildings, trees reflect an image of the object itself so we can see it. When light travels from the reflected object to our eyes, it travels in a straight line.

The speed of light is probably the fastest ever known to humans. Due to this speed, we perceive objects around us in near real-time. But this is not the case with light from distant stars or galaxies. For example, the distance between the sun and earth is 91 Million Miles. It takes almost 8 min of sunlight to reach the earth. This means we see the sun nearly 8 min after the sunrise. Isn’t this fascinating?

In this activity, you can experiment, how light from a light source travels in a straight line.

Difficulty: Medium

Average Time: 10-15 Minutes

MATERIALS

• Index card
• Clay
• Hole Puncher
• Flashlight
• Ruler 

PROCEDURE:

DISCUSSION

In this demonstration, you can see how light travels in a straight line. In step 6, if you try changing the middle card’s hole alignment out of sight and repeat the experiment, You will notice that light will never reach card #3. This indicates that light travels in a straight line until it gets blocked (In this case, card #2)