?

I don't know how common this affectation is, but it happens to me--and I'd like to know some things about it.

I'm blue-eyed and had brown hair (though as a child it was even lighter-colored); I'm gray now. Anyway, the affectation that I have (I won't call it a disease since I don't see any disability arising from it) is that, if I have been in a room or setting of average brightness and step out into brilliant sunshine, within 30 seconds I sneeze--usually once, maybe twice, but no more. I don't have a "sun allergy"; I can stay outside and tan or burn as easily as average people and feel no ill effects. Is there a name for this phenomenon? Does anyone with eye colors other than blue have this as well?

Any and all information about this would be appreciated; again, I'm not suffering, I'm just curious since this has happened throughout my life, and as far as I know, I'm the only one affected by it.

First, my apologies to Steve C; I thought that I awarded you the Best Answer for the question on complex numbers in aerospace engineering, but an email said otherwise. Yours was truly great; I'm new at this, but I'll work on it.

Now, the question. I've taught precalculus and shown the relation between acceleration, velocity and displacement. I know that gravity is constant, so it makes sense that acceleration due to gravity is constant, the change in velocity is linear, and the displacement is a quadratic function...

Until...one considers the impact of Newton's Law of Gravitation. This is what throws me. We all know that F = ma, but that F is Gm1m2/d^2 in planetary terms. It's that d^2 that gets me. Using Earth as being 6373 km in radius, if I dropped Baumgartner-style to Earth from that altitude, wouldn't the acceleration be 1/4 what it is on the surface? Shouldn't it be about -2.45 m/sec^2? If that's the case, then don't we have to rethink our model? It's no longer quadratic, but what is it? Is the acceleration model really (gulp) a differential equation, since acceleration would depend on distance from Earth, but distance depends on which way we're moving, and that on how we're accelerating?

See the quandary I'm in? I may be missing something, but I know someone can clarify this. Who's got it in them to help me out?

I have read about complex numbers in alternating-current circuits in physics where resistance is specified using a number in the form a+bj ("j" used instead of "i"), and that the imaginary part increases as the Hertz of the current flow increases. (I don't understand it but may study it later.) How, though, are complex numbers used in aerospace? Are they used in both subsonic and supersonic design, or only one or the other? I'm guessing that it has to do with the vortices that form over a delta wing to increase lift, but I don't know. Could someone please explain?