Ingrid found science experiments on the internet. The one in the front is water (with food colouring) and oil. With some salt it behaved like a lava lamp. (Description here.)

The two glasses at the back were an attempt to make a two-coloured flower. (Split the stem, put one half in one glass and the other in the other.) The experiment description called for a carnation but we didn’t have any. A white Aquilegia was the best I could find in the garden but it did not take up much colour at all.