A soap bubble is an extraordinarily beautiful thing and yet it requires virtually no skill to produce. This is because surface tension does all the work for you, making sure that a perfect spherical liquid membrane is produced every time. In fact it is impossible to blow imperfect bubbles. Even if you try to blow the bubble through a noncircular orifice you may at first achieve a temporary nonequilibrium shape (see Figure 3-1), but the end result is always a perfect sphere.
FIGURE 3-1 A soap bubble in an intermediate state, before becoming a perfect sphere.
In this chapter we will ...