The generation of random numbers has many uses (mostly in statistics, for random sampling, and simulation). Before modern computing, researchers requiring random numbers would either generate them through various means (dice, cards, roulette wheels, etc.) or use existing random number tables.
Yawning, swallowing or chewing helps open the small canal (Eustachian tube) which connects your middle ear in the inner side of the ear drum, and equalizes the pressure with the outer side and causes the sensation of ears popping when swallowing.
Lower pressure can also cause pain or discomfort in your ears, which is made worse by a cold, and some people find that it causes their feet and legs to swell. There is little you can do to combat hypoxia; to avoid DVT see the suggestions below. Swallowing, sucking sweets and yawning all help to pop your ears.