Gravity Defying Water
Initial Publication Date: August 25, 2009
Summary
In this demonstration, students will be amazed by how water reacts to this "magic trick." By combining atmospheric pressure and the water's unique property of surface tension, students will be able to see water defying gravity.
Collapse
Learning Goals
Students will be able to witness and recognize one of water's unique properties called surface tension.
If you teach a weather unit, you can also tie in atmospheric pressure.
If you teach a weather unit, you can also tie in atmospheric pressure.
Context for Use
You will only need about 3 minutes to demo this for your class. I will be doing it within my classroom in front of about 30 students. You will need water, a goblet, handkerchief, and your best magician skills.
Description and Teaching Materials
Taken from Stevespanglerscience.com, under the chemistry experiments.
Anti-gravity Water
1. Drape the handkerchief over the glass making sure that you push the center of the handkerchief down into the glass.
2. Fill the glass 3/4 full with water by pouring water into the middle of the handkerchief.
3. Slowly pull the handkerchief down the sides of the glass making it taut (stretched tightly across the surface of the glass). Anti-Gravity water grips the ends of the handkerchief at the bottom of the glass.
4. Place one hand over the mouth of the glass and turn it over with the other hand.
5. Pull the lower hand away from the glass (slowly) and the water should stay in the glass! This just goes to prove that the handkerchief has anti- gravity properties. The thunderous applause will drowned out the cries of, "How did you do that?"
6. For the big finish, put your hand over the mouth of the glass and turn the glass right side up. Remove the handkerchief from the glass and pour the water back into the pitcher. Of course, take your well-deserved bow.
How does it work?
Most people predict that the water will leak through the holes in the handkerchief because the water leaked through the holes as it was poured into the glass. The holes in the handkerchief literally disappeared when the cloth was stretched tightly across the mouth of the glass. This action allowed the water molecules to bond to other water molecules creating was it called surface tension. The water stays in the glass even though there are tiny holes in the handkerchief because the molecules of water are joined together to form a thin membrane between each opening in the cloth. Be careful not to tip the glass too much because you'll break the surface tension and surprise everyone with a gush of water!
Anti-gravity Water
1. Drape the handkerchief over the glass making sure that you push the center of the handkerchief down into the glass.
2. Fill the glass 3/4 full with water by pouring water into the middle of the handkerchief.
3. Slowly pull the handkerchief down the sides of the glass making it taut (stretched tightly across the surface of the glass). Anti-Gravity water grips the ends of the handkerchief at the bottom of the glass.
4. Place one hand over the mouth of the glass and turn it over with the other hand.
5. Pull the lower hand away from the glass (slowly) and the water should stay in the glass! This just goes to prove that the handkerchief has anti- gravity properties. The thunderous applause will drowned out the cries of, "How did you do that?"
6. For the big finish, put your hand over the mouth of the glass and turn the glass right side up. Remove the handkerchief from the glass and pour the water back into the pitcher. Of course, take your well-deserved bow.
How does it work?
Most people predict that the water will leak through the holes in the handkerchief because the water leaked through the holes as it was poured into the glass. The holes in the handkerchief literally disappeared when the cloth was stretched tightly across the mouth of the glass. This action allowed the water molecules to bond to other water molecules creating was it called surface tension. The water stays in the glass even though there are tiny holes in the handkerchief because the molecules of water are joined together to form a thin membrane between each opening in the cloth. Be careful not to tip the glass too much because you'll break the surface tension and surprise everyone with a gush of water!
Teaching Notes and Tips
Everything you might need to do this experiment is on Steve Spangler's website. If you are feeling unsure, there is also a very short video clip to watch how he executes it.
I always try to bring in some quick demos for days we will be reading from the book to get the kids excited. I am glad I found this website, because there are so many wonderful experiments to do with your students.
I always try to bring in some quick demos for days we will be reading from the book to get the kids excited. I am glad I found this website, because there are so many wonderful experiments to do with your students.
Assessment
Students will be formally assessed at the end of the unit using the test from our MacMillan-MacGraw Hill textbook. I will also have them journal or do an exit card in their science notebooks about what they noticed and why it happened?
Standards
2. Interdepen-dence Within the Earth System 3. Water circulates through the Earth's crust, oceans and atmosphere in what is known as the water cycle. 4.3.2.3.1 Identify where water collects on Earth, including atmosphere, ground and surface water, and describe how water moves through the Earth system using the processes of evaporation, condensation and precipitation.
4. Human Interactions with Earth Systems 1. In order to improve their existence, humans interact with and influence Earth systems. 4.3.4.1.1 Describe how the methods people utilize to obtain and use water in their homes and communities can affect water supply and quality.
This is not a complete standards match, but I have found that need some quick water demos to go with our water unit to give students a little more background about some of the unique properties of water, but also to "wow" them a little.
4. Human Interactions with Earth Systems 1. In order to improve their existence, humans interact with and influence Earth systems. 4.3.4.1.1 Describe how the methods people utilize to obtain and use water in their homes and communities can affect water supply and quality.
This is not a complete standards match, but I have found that need some quick water demos to go with our water unit to give students a little more background about some of the unique properties of water, but also to "wow" them a little.