This is an incomplete list of investigations in-process at the wiki. If you want to contribute to bubble knowledge, you could help perform these investigations.
Bubble Juice[]
Japanese PVA Laundry Starch[]
Hisao Oono's recipe seems incompatible with baking powder as noted in some blog entries. Is the problem the baking powder itself, or is it simply that the PVA Starch is ruined when the juice has its pH lower. Mix some of Mr. Oon's recipe with about half the normal amount of detergent. Use citric acid to lower the pH to 7.4 and compare with "normal" mix of the recipe.
Wicks and Loops[]
Single vs Double Strand Twine Bottom Very Large Loop[]
With a very large top-string loop (i.e. 100" or so), compare the performance of single-strand and double-strand twine bottom strings (using soda-washed twine). Previous explorations have indicated that the single strand (surprisingly) outperformed the higher-capacity double-strand both in ability to close bubbles but also size potential of closed bubbles and tubes. This last result was surprising. The result was the same in two sessions but further repetitions need to be performed.