The elaborate records kept by the US Patent Office since 1790 are allowing researchers to study the nature of invention and how it has changed in 200 years.
One way to think about invention is as a process that combines technologies to fulfil some human need or purpose. In other words, inventions never come out of nowhere. They always build on earlier advances to create something new.
So, for example, the incandescent light bulb uses electricity, a heated filament, inert gas and a glass bulb; an inkjet printer relies on the ability to position matter with extreme precision and to pump ink in very small droplets; and the laser is based on the ability to make highly reflective optical cavities and so on. All these inventions stand on the shoulders of previous advances.
That’s why many technologists think about invention as a combinatorial process—a walk through the entire space of technological permutations. To find a new invention, simply combine various old technologies in a new way.