During the recent inauguration of President Donald Trump, you can see bullet proof glass all around him. I got to wondering how exactly ballistic glass works. Bullet proof glass is made up of layers of glass and polycarbonate. The two materials are alternated and cannot not stop a bullet by themselves. A piece of glass by its self will shatter and a piece of polycarbonate by its self will be punctured. When the two are layered together, no bullet will get through. The bullet proof glass completely absorbs the impact from the round. Today's bullet proof glass can stop just about anything, from hand grenades to .50 cal rounds, nothing is getting through the glass.