The cartesian diver uses pressure (exerted by you) to make the diver sink and rise based on the amount of pressure applied to the water bottle.
Step 1: Supplies
1) 1/2 inch smoothie strawd
2) permanent marker
6) needle nose pliers
7) ruler or measuring devise
8) water bottle or empty 2 liter bottle
Step 2: Prepare Straw
Step 3: The Build
Full the straw with exactly ten BBS, and then deal the opposite end.
Done! Now drop your diver the bottle full with water, cap it and squeeze!
Step 4: Final Thoughts
Thank you for checking out this instructable, and if you liked this one, you may like my others, so be sure to check those out too.
More to come!