Bubble sphere

If we knew the spherical half-lens equation (dioptria) we could calculate the size of air bubbles inside a glass or gelatine sphere (or in scent gelatine candles).

For example, a bubble inside a sphere of a diameter of 20 cm (say, 15 cm from the 'front' surface of the sphere) in which case R = -10 cm in the dioptric power equation, seems to be 1.6 time bigger, if it floats in wat (n = 1,33)and twice the original size, if it is submerged in glass (n = 1,5).

If we place the bubble closer, for example 5 cm from the front surface, the enlargement is reduced to 1.2 times. In the critical point on the other side of the diameter, the object is enlarged n/(n - 2) times, for glass it is 3 times, regardless of the radius.