You fly in a 747 across the Atlantic from Amsterdam to Detroit at about 900 km/hr. Effects of the Theory of Relativity are of course unnoticeable at such speeds, but just as a thought experiment—which of the following are true? 1. The walk from your seat to the restroom actually becomes shorter. 2. If you don’t adjust your clock at all and fly back a few days later, your clock is again going to be exactly synched with the Amsterdam time. 3. From your window you see another 747 traveling in the opposite direction. The other747 is shorter than yours. 4. You are crossing six time zones, but your clock is actually going to be off by less than six hours. 5. You really want Frequent Flier miles calculated from a reference frame on the ground, not from one attached to the airplane.