The example Carl Sagan gives is Maxwell's equations. They seemed pretty abstract at the time, but well ... Radio. Television. Fibre optics. Satellite communications.
That said -- these didn't happen all at once. And every technological upheaval, no matter how large it has been in itself, has still appeared in the larger context to be only an incremental improvement.
That said -- these didn't happen all at once. And every technological upheaval, no matter how large it has been in itself, has still appeared in the larger context to be only an incremental improvement.