joehills tweets the following link:

New Generation of Supersonic Jets Aims to Get Rid of the Boom

True to its aeronautic roots, NASA is evaluating a new generation of supersonic airplane designs to see whether they can reduce sonic-boom levels.

Boeing and Lockheed Martin have submitted futuristic concepts that look similar to the Concorde, but aim to muffle the annoying and potentially damaging sonic boom problem.

This is where it starts, but who knew it was this early in the 21st Century?