Innovation only happens in the past. The present is only series of small adaptations.
When we speak of things like the automobile, or democracy, there is a general knee-jerk response to when they first came to be: Henry Ford and the model T; George Washington and the signing of the declaration of independence. Yet moments like these are only obvious as history. Neither of these experiments (in politics or industry) were a sure thing at the time they were happening. Nor could any one, at the time, imagine the eventual impact either of these experiments would have.
Innovation is (with the rare exception) a series of modifications that eventually hit a critical mass of change. A current example of this would be the cell phone. When was the cell phone invented?
My personal association of the first was of a StarTac phone from the late 90's. Yet recently I saw a drawing of the possible coverage from cell towers in New York City that were drawn back in the 40's.
So when was the cell phone invented? It wasn't. It was developed through modifications that began when the telephone came in general usage at the beginning of the century; with serious development from the mid-70's onward.
We need to stop thinking of innovation as a series of unrelated events that are caused by tangible definable, eureka, moments.
There is a life cycle to innovation from the time of initial idea through to the acceptance, implementation, integration, re-assesment, adaptation and modification.
The idea of when is an innovation discovered is more a personal question – as in when do we need to discover the specific invention.
