Yellow fever vaccine should be administered 10 to 12 days before exposure to the vector.
— The United States Dispensatory (1978)
Vectors are the formal mathematical entities we use to do 2D and 3D math. The word vector has two distinct but related meanings. Mathematics books, especially those on linear algebra, tend to focus on a rather abstract definition, caring about the numbers in a vector but not necessarily about the context or actual meaning of those numbers. Physics books, on the other hand, tend towards an interpretation that treats a vector as a geometric entity to the extent that they avoid any mention of the coordinates used to measure the vector, when possible. It’s no wonder that you can sometimes find people from these ...