Oct. 9, 1962: First Visible LED Is Demonstrated | This Day In Tech | Wired.com

[Robert E. Seastrom]

"Karl W4KRL" <W4KRL at arrl.net> writes:

> It is unusual to consider that it took half a century to go from the red LED
> to a practical replacement of the incandescent bulb. Think of how much
> faster other inventions developed like the airplane or personal computer.

First manned flight [*]:  1783
DC-3:  1936
Elapsed time:  153 years

Hollerith Tabulator [**]:  1889
TRS-80 Model III:  1980
Elapsed time:  91 years

[*] Hot air balloon - Daedalus and Icarus missed the mark.
[**] Babbage difference engine doesn't count; it was a paper design...

LED technology development looks pretty good in that context.

-r