Water as a Magnifying Glass
Explore how light bends when travelling through water.
What You Need
Materials per student
- Sheet of paper with words printed on it
- Sheet protector
- A glass with a bit of water
- Ruler
- String
Guide:
Safety Notes
Ensure you are familiar with Let's Talk Science's precautions with respect to safe virtual outreach to youth.
What To Do
To create a water magnifying glass, each student will:
- Place a sheet of paper in the sheet protector.
- Pick a word that's near the middle of the page and measure it - from the beginning of the first letter to the end of the last letter with a ruler or piece of string. Instruct students to record the measurement.
- Add a small drop of water near the middle of the page over the chosen word (one they just measured).
- Measure the same word again (with the drop of water over top now) and record the measurement.
- Compare the two measurements .
- Dry off the protector sheet and repeat steps 1-5 with a bigger drop of water. Did the measurement change?
Discovery
The water drop on the surface of the sheet protector creates a small curved dome over the words on the paper. Since the water is bending outwards, this is known as a convex curve. When they look at the words on the paper, light hits the curved dome and bends inwards, making the words on the paper appear larger than they actually are! The smaller the drop of water, the more light bends, which makes the words seem even larger.
What's Happening?
The water drop on the surface of the sheet protector creates a small curved dome over the words on the paper. Since the water is bending outwards, this is known as a convex curve. When they look at the words on the paper, light hits the curved dome and bends inwards, making the words on the paper appear larger than they actually are! The smaller the drop of water, the more light bends, which makes the words seem even larger.