When a small group of mathematicians created the theory of matrices in the
1850s they did so to solve problems in pure mathematics. From an applied
perspective, matrix theory was very much a ‘solution looking for a problem’. As
so often happens ‘problems’ did arise which needed the nascent theory. An early
application occurred in the 1920s when Werner Heisenberg investigated ‘matrix
mechanics’, a part of quantum theory. Another pioneer was Olga Taussky-Todd,
who worked for a period in aircraft design and used matrix algebra. When asked
how she discovered the subject she replied that it was the other way around,
matrix theory had found her. Such is the mathematical game.

the condensed idea

Combining blocks of numbers