I've always had a fear of heights.

But what strikes me as strange is that it doesn't apply to airplanes. Seriously, I'm never going to get higher from the ground than an airplane, unless spaceflight really does become affordable for the middle-class, which I doubt I'll see in my lifetime.

So, while I hate glass elevators, get nervous over floor to ceiling windows in high rises, and really just get creeped out over being at the top floor of a 50 story building, even if I can't see out, I can fly just fine. I find myself glued to the windows the whole flight looking out.

So what is it that make that possible?

I think of the "Peter Pan effect" from the ride at Disneyland, where you appear to be flying over London and then Neverland, when it's all minitures beneath you. Flying in a plane feels a lot like that. As if it's surreal and not really that your miles above the ground. Even in a shaky, bumpy flight. You're in a narrow, tiny tube, comfortably separated from the feeling that you can fall.

At least for me. I admit, it doesn't make a lot of sense.

But on the other hand, when it's just a thin sheet of glass, or a tiny metal rail separating me and a long drop, I get antsy. The illusion of separation isn't there, and the feeling that I could fall is much more apparent.

Or maybe I've just flown more than being in really tall buildings, so I'm used to it. Maybe if I were just in more tall building next to big windows, I'd get over it.

Hard to say.