Complex numbers are numbers that consist of two parts — a real number and an imaginary number. They are the building blocks of more intricate math, such as algebra.

Even mathematical giants found complex numbers difficult to swallow. For one, calling -√1 “imaginary” isn’t doing it any favors in helping people understand that it’s not fantastical.

Real and imaginary: The time-dependent Schrödinger equation formulated using complex numbers. (Courtesy: iStock/piranka) Complex numbers are essential to achieve the most accurate quantum-mechanical ...

Our February Insights puzzle sent readers on a treasure hunt based on complex numbers. First we provided a bit of a primer, demonstrating that complex numbers (expressions of the form a + bi, where ...

And in fact, before quantum theory, Newton’s mechanics or Maxwell’s electromagnetism used real numbers to describe, say, how objects move, as well as how electro-magnetic fields propagate.

Imaginary numbers are what you get when you take the square root of a negative number, and they have long been used in the most important equations of quantum mechanics, the branch of physics that ...