Skydiver's iPhone survives 14,000-foot fall from a plane

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  • Reply 21 of 28
    sdw2001sdw2001 Posts: 18,020member
    sdw2001 said:
    tshapi said:
    Survivability also depends on how the iPhone landed, I think it has a better chance of surviving such a fall if it hit the ground on a corner or a side. Also your not taking into account wind factor. The phone will have a better chance of surviving if there was wind to slow down velocity. 
    A horizontal wind would slow down a vertical drop? That's a new one. And then you say that the faster the wind the slower the velocity when it hits the ground - that's also a new one. I won't actually argue with you because I don't believe any argument is required here. I'll just let you reconsider.

     
    I'm a Part 107 Unmanned Aircraft pilot and commercial drone pilot.  I also fly fixed wing electric ducted fan jets.  Based on the above, I don't think you should be criticizing anyone.  You clearly have little understanding of how the principles of airflow work.   



    1. Wind is not "horizontal."  It comes from a cardinal and intercardinal (sometimes called "ordinal") direction, but is never "horizontal" (at least for long) due to all sorts of factors, including thermals, gusts, etc.  

    2. Almost any object dropped from a plane is not going to be "vertical" in its fall, either.  Even if you are dealing with a high mass, high density object with minimal wind resistance, you'll have some variation in the fall.  

    3.  Putting the above aside, yes, wind will absolutely affect a falling object, particularly an iPhone.  This will happen because of the velocity of the object and the wind resistance as it gains speed and hits terminal velocity.  Like any airframe, speed increase resistance.  It also will generate some degree of lift as the object flips about.  

    4.  Yes, in reality, increased wind would slow down the object's descent (assuming there wasn't a downdraft).  Such slowing could be significant if there was a thermal, gusting or rotational winds, etc.  It's not hard to understand why.  If moved "off course" laterally by wind, the object would no longer be taking a straight path to the ground.  Even if it only was blown in one direction consistently...any horizontal movement would lengthen the path to the ground.  Of course the chances of that one direction "push" are not good...it would obviously move back and forth with the wind.  

    Let me put it this way...do you think the rate of descent would be slowed if it was dropped into a hurricane? A tornado? What about just a WNW 45Kn wind?  

    I specifically did not argue with him - I asked him a question and I asked him to reconsider. Then you put a huge effort into arguing with me and you asked me some questions. Hurricanes and tornados are out of scope because I was talking about "horizontal winds." So tornados and hurricanes are irrelevant. But they do have vertical components so they will affect vertical speeds of falling objects. In that sense, you win the argument, but that's because you changed the explicit parameters of the argument which was a horizontal wind. If you consider that a win, good for you.

    A falling object doesn't even know if there's a horizontal (or vertical) wind component or not. There is no physical mechanism you can carry with you (other than a GPS device) which can tell you when you are falling if there is a horizontal wind component or not. It's like Einstein's relativity - you can't tell if you are in an accelerating elevator in space or standing in a stationary elevator on a planet. If the wind is zero or perfectly steady, the falling object will have no way of knowing the wind speed. That's the only condition I was talking about. I was not talking about tornados or hurricanes or tidal waves or earthquakes or any other conditions you care to talk about.
    Oh stop.  You know what you were doing, as so does everyone else.  As for you looking at one variable in a situation while ignoring all others that occur in the real world, that's up to you.  I suppose you're more interested in arguing than discussing.  Did wind affect the iPhone dropping or not?  That's all that matters.  
    watto_cobra
  • Reply 22 of 28
    chutzpahchutzpah Posts: 392member
    chutzpah said:
    22july2013 said:

    In that sense, you win the argument, but that's because you changed the
    explicit parameters of the argument which was a horizontal wind.
    You are the only one who mentioned horizontal wind, something that basically doesn't exist in nature.  And you also said you weren't making an argument either, because apparently you were so confident in your correctness it wasn't necessary.  You've made yourself look a right tit here.
    When the falling object approaches the last hundred feet above the ground there is no vertical wind. I'm sure the original poster will realize that when he reflects on my question to him. And notice that I have refrained from calling people offensive names who disagree with me.
    Why are you introducing a new criteria of the last hundred feet above the ground?  Did you really think no one would pull you up on another change of goalposts in your supposed non-argument?  I doubt it's even true, wind simply doesn't work in a uniformly horizontal fashion, at least for any length of time.

    You done goofed man, just admit it and move on.  This faux politeness as a veneer over passive aggressive superiority and pompousness is doing nothing for anyone.
    watto_cobra
  • Reply 23 of 28
    anonymouseanonymouse Posts: 6,922member
    sdw2001 said:
    sdw2001 said:
    4.  Yes, in reality, increased wind would slow down the object's descent (assuming there wasn't a downdraft).  [...]  If moved "off course" laterally by wind, the object would no longer be taking a straight path to the ground.  Even if it only was blown in one direction consistently...any horizontal movement would lengthen the path to the ground.
    Hmmm, I think this part is wrong. If the phone reaches terminal velocity it will continue falling at x m/s until it hits the ground. The time it takes to do this is simply distance / speed — e.g. at 30 m/s  from 3000 ft it will take 3000/30 seconds = 100 seconds to reach the ground. Since the vertical speed is unaffected by any perpendicular (horizontal) forces, no amount of horizontal wind (if we are ignoring lift) will change the rate at which it falls or how long it takes it to reach the ground — i.e., even if the wind were driving it horizontally at 30 m/s, it will still reach the ground in 100 seconds, ignoring outlandish factors such as the curvature of the earth. The path traveled (the hypotenuse) may become longer, but the distance traveled vertically (the side), the speed it travels that distance, and thus the time required, remains the same; it's a simple vector problem.

    Meanwhile, based on the accompanying picture, did the phone really "survive" this fall?

    I am not a physicist, so I'm not sure.  You may be correct, at least scientifically speaking.  In reality, wind (among other things) absolutely does affect a falling object.  It depends on the cross section and flat surface area, as well as mass...of course.  Because if what you're saying is true, then a "horizontal" wind wouldn't affect the rate of descent of a hot air balloon.  
    The main point is that the lengthening of "the path to the ground," would not affect the time it takes to travel to the ground because that distance and the speed in that direction remains constant in the scenario of your original point 4. Your other points, and the fact that winds will generate lift or otherwise slow the descent because of an upward component in their motion, are correct.
    watto_cobra
  • Reply 24 of 28
    22july201322july2013 Posts: 3,636member
    chutzpah said:
    chutzpah said:
    22july2013 said:

    In that sense, you win the argument, but that's because you changed the
    explicit parameters of the argument which was a horizontal wind.
    You are the only one who mentioned horizontal wind, something that basically doesn't exist in nature.  And you also said you weren't making an argument either, because apparently you were so confident in your correctness it wasn't necessary.  You've made yourself look a right tit here.
    When the falling object approaches the last hundred feet above the ground there is no vertical wind. I'm sure the original poster will realize that when he reflects on my question to him. And notice that I have refrained from calling people offensive names who disagree with me.
    Why are you introducing a new criteria of the last hundred feet above the ground?  Did you really think no one would pull you up on another change of goalposts in your supposed non-argument?  I doubt it's even true, wind simply doesn't work in a uniformly horizontal fashion, at least for any length of time.

    You done goofed man, just admit it and move on.  This faux politeness as a veneer over passive aggressive superiority and pompousness is doing nothing for anyone.
    Name calling still doesn't help you, except in your own mind.

    Vertical winds can't exist at ground level. You haven't disputed that.
  • Reply 25 of 28
    anonymouseanonymouse Posts: 6,922member
    chutzpah said:
    chutzpah said:
    22july2013 said:

    In that sense, you win the argument, but that's because you changed the
    explicit parameters of the argument which was a horizontal wind.
    You are the only one who mentioned horizontal wind, something that basically doesn't exist in nature.  And you also said you weren't making an argument either, because apparently you were so confident in your correctness it wasn't necessary.  You've made yourself look a right tit here.
    When the falling object approaches the last hundred feet above the ground there is no vertical wind. I'm sure the original poster will realize that when he reflects on my question to him. And notice that I have refrained from calling people offensive names who disagree with me.
    Why are you introducing a new criteria of the last hundred feet above the ground?  Did you really think no one would pull you up on another change of goalposts in your supposed non-argument?  I doubt it's even true, wind simply doesn't work in a uniformly horizontal fashion, at least for any length of time.

    You done goofed man, just admit it and move on.  This faux politeness as a veneer over passive aggressive superiority and pompousness is doing nothing for anyone.
    Name calling still doesn't help you, except in your own mind.

    Vertical winds can't exist at ground level. You haven't disputed that.
    Well, you know, once you get below the atmosphere there is very little wind in any direction.
  • Reply 26 of 28
    chutzpahchutzpah Posts: 392member
    chutzpah said:
    chutzpah said:
    22july2013 said:

    In that sense, you win the argument, but that's because you changed the
    explicit parameters of the argument which was a horizontal wind.
    You are the only one who mentioned horizontal wind, something that basically doesn't exist in nature.  And you also said you weren't making an argument either, because apparently you were so confident in your correctness it wasn't necessary.  You've made yourself look a right tit here.
    When the falling object approaches the last hundred feet above the ground there is no vertical wind. I'm sure the original poster will realize that when he reflects on my question to him. And notice that I have refrained from calling people offensive names who disagree with me.
    Why are you introducing a new criteria of the last hundred feet above the ground?  Did you really think no one would pull you up on another change of goalposts in your supposed non-argument?  I doubt it's even true, wind simply doesn't work in a uniformly horizontal fashion, at least for any length of time.

    You done goofed man, just admit it and move on.  This faux politeness as a veneer over passive aggressive superiority and pompousness is doing nothing for anyone.
    Name calling still doesn't help you, except in your own mind.

    Vertical winds can't exist at ground level. You haven't disputed that.
    We're down to ground level now, not a hundred feet above the ground?  There's no wind at all at ground level, because there's a little thing called the ground in the way.  If you don't actually mean the silly thing you just said and are still talking about the hundred feet above ground then I said I doubt it's true, and I very much do.  It doesn't make any sense to me, wind only operating in a totally horizontal direction.  Wind hits things and has eddies, just like water. It goes left, it goes right, it goes up, it goes down.  It forms cyclones, it has updraft, it has downdraft.  It exists in three dimensional space.  So not just horizontal. Why on earth would it just be horizontal? Am I imagining it when I see leaves dancing on the wind, up and down, here, there and everywhere?

    But I don't claim to be an expert at all, wind is not an area I have an excess of knowledge about.  You're the one making the ludicrous sounding claim, with zero reference to any science, why don't you try offering some proof or substantive argument instead of clutching your pearls that I called you a tit?

    Or don't, I really don't care much, I just think you're being a bit of a tit.
    edited May 2023 muthuk_vanalingam
  • Reply 27 of 28
    anonymouseanonymouse Posts: 6,922member
    chutzpah said:
    chutzpah said:
    22july2013 said:

    In that sense, you win the argument, but that's because you changed the
    explicit parameters of the argument which was a horizontal wind.
    You are the only one who mentioned horizontal wind, something that basically doesn't exist in nature.  And you also said you weren't making an argument either, because apparently you were so confident in your correctness it wasn't necessary.  You've made yourself look a right tit here.
    When the falling object approaches the last hundred feet above the ground there is no vertical wind. I'm sure the original poster will realize that when he reflects on my question to him. And notice that I have refrained from calling people offensive names who disagree with me.
    Why are you introducing a new criteria of the last hundred feet above the ground?  Did you really think no one would pull you up on another change of goalposts in your supposed non-argument?  I doubt it's even true, wind simply doesn't work in a uniformly horizontal fashion, at least for any length of time.

    You done goofed man, just admit it and move on.  This faux politeness as a veneer over passive aggressive superiority and pompousness is doing nothing for anyone.
    Name calling still doesn't help you, except in your own mind.

    Vertical winds can't exist at ground level. You haven't disputed that.
    BTW, @techstud, is that you?

    edited May 2023
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