I've recently read some odd things and visited some odd websites while Googling to find out about the various aspects of falling. Free-falling in the sky, I mean - not falling out of my chair or down the stairs.The first thing I was trying to find out was how long it would take you to splat into the earth falling from various heights, but I soon came across some other interesting questions from other readers of the various articles.
As to my first question, about how long it takes a person (or object) to fall to the earth from various heights, they started talking about physics right away so that sort of turned me off. All I really wanted to know was how long it would take an object to fall to earth from 20,000 feet, but could I get a straight answer? No. They kept talking about things like mass and resistance and attitude. I will admit to the attitude by then.
I realize that if I jump out of an airplane and go into a diving position I will fall faster than if I fall flat with my arms out like a skydiver. And I realize that a rock tied under an umbrella is probably going to fall a lot slower than a non-umbrellaed cannonball would, but I just wanted a general answer. Not possible, the Googled scientists said - need to know some factors first.
I remember Rocket Scientist telling me one time about terminal velocity, which I assumed referred to a child running through an airport. Anyway, the subject was sudden loss of cabin pressure and whether one would really get sucked out the airplane window like Goldfinger did. I think she said no, because the pressure would be lost too fast and wasn't that great of a differential in the first place, but if you were under several atmospheres of pressure or lack of pressure, like in a diving bell, then your bod would get pushed through the meat grinder pretty grossly.
Back to falling. What prompted this was me reading an old news story about two large airliners crashing over the Grand Canyon at 20,000 feet back in 1956. I was wondering how long it might have taken them to fall from that height to crash into Grand Canyon, and whether or not it would be a long enough fall for the passengers to have time to realize what had happened and what was about to happen to them, if you get my drift. I'm not insensitive to their terror, but inquiring minds want to know and I can't help them anymore by not asking anyway.
So, basically you get back to air resistance of the various parts of the still-intact parts of the airliners which contained the 200-some passengers (it was the largest loss of life of any airline accident up to that time.)
I'm guessing, and only guessing, that it took a least a couple of minutes. Must have seemed like an eternity to them. Neither of the planes were flyable and went straight down, crashing near each other, although one assumes engines or some of them were still running, they were screaming down to earth and not "gliding." The TWA super Connie had it's entire tail torn off, so you assume some passengers in free fall away from the plane, but the United DC-7 had half of one wing ripped off so maybe the pilot was able to keep the shiny side "up" rather than spiraling, but almost straight down. Can anyone improve upon my guess of "a couple minutes?"
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The second question that came up (other than the normal questions of throwing cats and caterpillars out of upstairs windows) was about falling through the center of the earth. The deal was you drill a hole all the way through the earth and jump into it and fall out in China. And the question was how long would it take to make the trip. Everyone came up with between 12 and 14 minutes, which I thought was preposterous. Of course, you had to pretend a lot of things like you could breathe and there was no air friction and it wasn't hot at the center of the earth and things like that.
Nobody, none of the elementary school science teachers, came up with the answer I came up with, so I will present it to you here. They were concerned with mass and terminal velocity and diameter of the earth, and I was concerned with something they didn't even mention, which was gravity. I say, you would fall slower and slower and finally come to a stop at the center of the earth when the gravitational forces equalized. What's wrong with that idea? But nobody else mentioned gravity, so I must be wrong.
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When I left the google thing, my mind kept on going, in free-fall, as it were. Like, what if you dropped two round lead balls out of an airplane, one the size of a marble and one the size of a small cannon ball. Pretend the airplane could come to a stop while you dropped them carefully. Pretend there was no wind to blow the lighter one sideways. Just think about mass. I say they would reach the ground at exactly the same time (if you pretend there was no air resistance. Sigh.) I say that the two objects of different weights (neglecting aerodynamics) would fall at exactly the same speed.
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Speaking of terminal velocity. I think we were at one time. It turns out that an object doesn't just fall faster and faster until it reaches its terminal velocity and then continue at that speed until it hits the ground. Air being denser and denser the closer to the ground you are, the objects slow (slightly) down the closer they get to the ground. That's what they said. So you reach terminal velocity and then (still falling side by side?) you begin to slow down a bit. We are probably talking about less than a second here, but you know how scientists are.
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I have finally convinced myself that if you are trapped in a falling elevator you will still be killed if you jump hard and high a split second before you crash. But I can't explain why. Sounds reasonable to me.
