Any cat restrained for the purposes of administering a pill has the potential to reach escape velocity. Newton's Law of Concentration of Mass A cat's mass increases in direct proportion to the comfort of the lap she occupies. Newton's Law of Feline Gravity Manipulation Cats have the ability manipulate gravity, forming localised areas of strong gravitational attraction. This gives the impression of a cat growing heavier as it occupies a lap or bed. This is a linear effect with gravity increasing at a steady rate over time.
Cats know that energy can only be stored by a lot of napping.
If the rate of energy uptake exceeds the maximum rate of energy storage, the difference will be emitted in the form of purring. Boyle's Law of Cat Thermodynamics Heat flows from a warmer to a cooler body, except in the case of a cat, in which case all heat flows to the cat. Kirk's Law of Cat Magnetism Dark coloured clothing attracts light coloured cat hair in direct proportion to the darkness of the fabric. The converse is also true. A cat will stretch to a distance proportional to the length of the nap just taken.