丁香园AV

What you need

• Flubber 鈥� mix 戮 cup of warm water with 1 cup of white glue until smooth. In a separate dish, mix 1 tbsp of Borax (from the laundry aisle in the grocery store) with to 2/3 cup cold water. Carefully mix the borax mixture into the glue mixture until all of the liquid is absorbed.
• PVC pipe, cut length wise
• Toothpicks
• Sandpaper
• Aluminum foil
• Protractor

What to do

1. Mix the flubber and with your hands mould it into a ball. Put this on one end of the pvc pipe (flat on the table). Put a line of toothpicks across the lower edge of the flubber.
2. Tilt the pvc pipe with the flubber at the top end, to 45degrees (use the protractor for this) and watch what happens to the flubber and the toothpicks. Which part of the flubber 鈥榞lacier鈥� moves fastest? Slowest?
3. Now try the same thing with a sheet of sandpaper under the flubber. How long does it take to get to the same place on the pvc pipe. What about with a piece of silver foil covering the bottom of the pipe?
4. Now try putting the flubber in the fridge for 30 minutes and then doing the same activity. What do you notice?
5. Try it with steeper and gentler slopes of the PVC pipe. 

What鈥檚 going on?

The Flubber acts a little like glacier ice. When the flubber or glacier flows, the ice in the middle moves fastest down the pipe or valley and the edges more slowly because of the friction with the sides of the pipe. The sandpaper and tin foil mimic rough surfaces and wet surfaces that a glacier might flow over. Ice will flow faster over wet (tinfoil) surfaces than over rough (sandpaper) surfaces. As climate warms the ice at the bottom of glaciers begins to melt. From your experiment, will a glacier in a warmer setting flow faster or slower?

Look at photos of glaciers, or if you can go and see one. Where is the nearest glacier to you? Look on Google Earth to find out. How steep do you think the slopes are under different parts of the glacier? Which part of the glacier would you predict to be flowing the fastest?