We may here note the explanation of Kepler's second law: when the planet is near the sun it moves faster, and the radius vector changes its direction more rapidly than when the planet is remote from the sun on account of the greater force with which it is attracted, and the exact relation between the rates at which the radius vector turns in different parts of the orbit, as given by the second law, depends upon the changes in this force.
"A Text-Book of Astronomy"
George C. Comstock
If there's an animal vector to the disease, we've never discovered it.
"The Planet Savers"
Marion Zimmer Bradley
Mass, which used to be regarded as the most indubitable of physical quantities, is now generally believed to vary according to velocity, and to be, in fact, a vector quantity which at a given moment is different in different directions.
"Mysticism and Logic and Other Essays"
Bertrand Russell