In 1843, William Rowan Hamilton had a four-dimensional flash of insight that still shapes our three-dimensional world. When you purchase through links on our site, we may earn an affiliate commission.

Robyn Arianrhod does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond ...

(In contrast a scalar quantity has magnitude only - eg, the numbers 1, 2, 3, 4...) The diagram above represents a vector. The arrow displays its direction, hence this ...