> Modern physics would have been impossible to develop without the useless math concepts invented throughout the 19th century. Case in point: imaginary numbers

> Modern physics would have been impossible to develop without the useless math concepts invented throughout the 19th century. Case in point: imaginary numbers were "discovered" in the 16th century and were widely considered to be "useless" by contemporary mathematicians and scientists. However, in the 19th century it was realized that complex arithmetic is perfect for analyzing steady state alternating current circuits.