There are certain stories that force us to stop and reconsider what we believe is possible, and the story of Etched may be one of them. Three Harvard dropouts, all only 24 years old, have built a semiconductor company that is now being valued at approximately $21 billion, and what makes the story particularly remarkable is that in a matter of 4 months they moved from an idea on paper to working silicon, a fully integrated computing system, a maj…