Can Water Bend a Straw Video
Supplies Needed
- Empty Glass
- Water
- Plastic Straw
Experiment Instructions
Step 1 – Observe the straw and notice that it is perfectly straight. Next, place the straw in the empty glass and take note that the straw is still straight
Helpful tip: Use a large plastic straw from a water bottle to see the results more clearly.
Step 2 – Pour water into the glass until it is nearly full. Look directly at the side of the glass at the straw. What do you see?
Step 3 – You will notice that near the top of the water line the straw appears to bent. Remove the straw from the water. Is it still bent?
How Does the Experiment Work?
When you added the water to the glass, the straw appears to bend, but once you remove the straw you see that it isn’t really bent at all. This is because the straw is not not bending, but the light around it is. This is because of refraction.
Refraction is the bending of light as it passes from one medium into another (i.e. Air to Water, Water to Air).
We need light in order to see. When we look at a straw outside of the water, light from the straw travels through the air and straight to the eye. However, when we look at the straw in the water, light from the straw is refracted when it passes from the water into the air. Because of this, the straw appears to be bent even though it isn’t.
I hope you enjoyed the experiment. Here’s some printable instructions
Can Water Bend a Straw Experiment
Materials
Instructions
Optical illusion