Put empty second bottle on top of the first bottle so that the mouths are together. Connect bottles with masking tape. Vigorously churn bottom bottle as you turn both bottles over and place on a table.
Water forms a tornado funnel as it flows into the bottom bottle.
Mix ingredients with clean bare hands. See it change from liquid state to solid as you add more corn starch, then back to liquid when you add more water. Food Coloring Water Playing Card or Piece of Thin Cardboard Fill one bottle with cold tap water and the other with hot tap water. Drop different colored food coloring into each bottle. Place a playing card or piece of cardboard on the opening of cold water bottle.