On the way home from a thoroughly enjoyable trip to Scotland with an old college friend, the following incident happened. We were in good spirits and had time to spare. At airport security, the couple in front are a bit miffed. They have 6 mini pots of souvenir confiture that security want to confiscate as the weight is given at 110g. Said couple thought this included the glass jar. An enquiry of their plight lead to the following: Turns out the 110g was net weight, i.e. contents only. Mr. Airport Security Manager arrives, as the couple has requested his presence to state their case. Cue flashing the science-card! “Excuse me Mr. Airport Security Manager, but 110g equates to less than 100ml, as 100g of water = 100ml. 110g of jam, being relatively more dense than the water, will actually occupy a volume of less than 100g (Mass = density/volume).” Jam survives unharmed and Science wins!