[nine_k]

Regarding technology taking time: look at LEDs.

- The effect first discovered: 1907.

- First prototype device built: 1927.

- First commercially viable parts shipping: early 1960s.

- Ubiquitous and cheap as an indicator device: 1980s.

- Highly efficient, used for lighting: 2010s.

The principle never changed along the way. The specific materials changed quite a bit.

[bcrl]

And we only have blue LEDs due to the sheer stubbornness of Shuji Nakamura. If you haven't already heard the tale of its development, head over here and enjoy: https://www.youtube.com/watch?v=AF8d72mA41M