Settling physics arguments

[Eclipse]

Your next AE argument discussion.

Much like the infamous Mythbusters "Plane on a conveyor belt", people continue to
debate things which have been proven by practical demonstration.

And in regards to Adam's comment about "a jet next time"...
I think the demo at 4:32 of a prop "screwing itself into the air is particularly effective".

[NIN]

Many, many, years ago,  I was but a young pup and learning all there was to know about jumping out of airplanes. Internet discussions on the subject were held on USENET's rec.skydiving. Being the wild-wild West of the Internet in those days, some of these "discussions" were pretty interesting. Suddenly, discussions held around the firepit with an adult beverage in hand among a small group of jumpers at a DZ were coastal.

One oft-debated subject that came up was the order jumpers should get out of the plane.  Somewhat counterintuitively, jumpers fall thru the air at different rates of speed. Mostly depending on their "orientation" to the relative wind or type of jumping (formation flying on the belly vs all-aspect free-flying) Along with those rates of speed and orientation to the relative wind comes some degree of distance traveled horizontally across the ground due to the forward throw of the airplane before the jumpers are falling straight down (and the changes in that forward throw due to the effects of aicraft ground speed).

The discussions always tended to devolve in to crazy (textual/verbal) mental gymnastics regarding  of the effects of ground speed, the wind, using a balloon (tethered or otherwise), and often "imagine if you hooked a tractor to the DZ and were pulling it in an opposite direction of the line of flight...." One dude even brought up the Coriolis Effect. (Dude, really?)

Spoiler alert: it took a long time to puzzle this out, but some people who are way smarter than the rest of us figured out that a) the general exit order should always be belly-flyers before freeflyers; b) within those larger classifications, bigger groups of jumpers first, smaller groups last; and c) the key determining factor of safe horizontal separation between individual groups of jumpers is aircraft ground speed.

One fellow went so far as to build a web-based application (might have been in Flash) that let you input variables (exit order, the time between groups, freefall speed, aircraft ground speed, mostly) and watch an animated trace of each type of jumper's path thru the sky. Very quickly it was apparent what the correct order of exit would be, and how to provide safe horizontal separation, and how everybody else was all wet.   That was what really pushed the discussion over the top: the ability to take real world, GPS-derived fall rate and horizontal throw data and apply it in a graphical way that even a 10-year-old could probably get.

For the record: Since I was pretty new to it and didn't have much knowledge, when the discussion came up I always volunteered to drive the tractor towing the DZ.  It was really the safest spot.