This final note today: A helpful tip as you get those holiday packages ready to ship off to relatives. Whatever you do, don’t mark it “fragile.” The good people at Popular Mechanics did some actual science on this. They packaged up identical bunches of vibration sensors, sent them via FedEx, UPS and the US Postal Service and tried to figure out which was gentlest. The Post Office won.

But here’s the thing: The sensors inside packages that were marked “Fragile” or “This Side Up” show they got the roughest treatment.