Today, my mom planned a “family adventure” that took us to iFly at Universal City Walk.  I had never heard of “indoor skydiving” before, but I guess there are several facilities around the country (see this WSJ article).   iFly is a vertical wind tunnel that simulates the free fall experience.  I’ve gone actual skydiving once.  It was tandem, and for me, the biggest thrill was jumping out of the airplane and backflipping through the initial acceleration.  That’s when your stomach flips and you have the “oh geez, am I actually doing this??” moment. Once you hit terminal velocity, you feel …