YOU TRY IT! Bottled Black Hole
WHAT YOU NEED
- Two clear plastic bottles with their caps (two-liter size works best)
- A sharp knife or pair of scissors
- Strong tape (black electrical tape is best)
- Water
WHAT TO DO
- Remove the labels from both bottles.
- Using the knife or scissors, carefully cut a hole through each of the plastic caps, including the soft liners on the inside. The holes should be large enough so you can poke your little finger through them.
- Hold the two caps so their tops are touching. Check to see that the holes are lined up so you can put your finger through both of them.
- Wrap the tape tightly around the edges so the two caps are joined (don’t cover the parts that screw into the bottle!). Make sure to wrap the tape around several times to attach the caps tightly.
- Screw the joined caps tightly onto one of the bottles.
- Fill the second bottle three-quarters full of water.
- Screw the empty bottle tightly onto the one filled with water so the two bottles are joined together end to end.
- Carefully pick up the bottle containing the water, making sure you don’t twist or bend the joint between them. Then flip the bottles over so the one filled with water is now on top.
- Swirl the bottles around in a circular motion to get the water spinning, and watch what happens as the water drains from the top bottle to the bottom one. You should see a long silver funnel appear in the water as it drains out. Once the funnel appears, stop swirling—the funnel will remain in place until all of the water is gone from the top bottle.
- Once all the water has flowed into the bottom bottle, turn them over and repeat the action. You will see the same formation again. You can repeat this as often as you like.
You just made a model of a black hole! The funnel shape the water takes as it drains from one bottle to the other is a vortex. And remember: we can see that the water in your black hole model goes from one space into another, but we still don’t know what happens to matter that falls into a black hole.
