Just you wait: all the whackadoodle conspiracy theories about stealth bombers having "plasma stealth" or "active camouflage" or "cloaking devices" will of course turn out to be bunk, but we'll eventually find out that the B-21 is the first aircraft to be fitted with a Perspective Muddler, and the sweepback is actually 47 degrees.That's pretty conclusive that it isn't 40 degrees though.