Could it have fallen from some other plane, they weren't aware of, that was above their altitude or do the principles of terminal velocity and gravity not support that hypothesis?
I accidentally downvoted you, sorry :-(
Norwegian skydiver nearly struck by meteorite
111–119 of 119 posts
Re: Norwegian skydiver nearly struck by meteorite
#112Earlier quoted context omitted.
>one Yahoo site I ran across suggested they're harder to hit because they're moving fast -- that's also irrelevant, Indeed, it's not as if they're trying to dodge. However, doesn't a faster plane actually have a higher probability of intersecting the same space as a falling rock? Comparable to: http://news.bbc.co.uk/2/hi/uk_news/magazine/4562132.stm ('...So running fast actually makes us wetter according to this anal…
Running makes you wetter than walking over an equivalent time period . The main goal of running in the rain is to get to a shelter -- to minimize that time. Something your link covers, and points out. [1] So it would be with a plane: Flying faster means less time in the air, where meteorite strikes are particularly dangerous (as opposed to strikes while taxiing, or sitting idle). So while a faster-flying plane is mor…
>Flying faster means less time in the air, where meteorite strikes are particularly dangerous (as opposed to strikes while taxiing, or sitting idle).
That's a very good point: for a plane, reaching the ground is the equivalent of a runner reaching shelter from the rain.
But I suppose planes generally spend about the same amount of time in the air, no matter how fast they go. The faster plane just travels further in that time. There's no obvious reason a fast plane would spend more time safely on the ground than a slow plane.
Perhaps flying faster is safer for individual passengers, but more dangerous for the plane?
Re: Norwegian skydiver nearly struck by meteorite
#113Re: Norwegian skydiver nearly struck by meteorite
#114Re: Norwegian skydiver nearly struck by meteorite
#115Earlier quoted context omitted.
Running makes you wetter than walking over an equivalent time period . The main goal of running in the rain is to get to a shelter -- to minimize that time. Something your link covers, and points out. [1] So it would be with a plane: Flying faster means less time in the air, where meteorite strikes are particularly dangerous (as opposed to strikes while taxiing, or sitting idle). So while a faster-flying plane is mor…
>Flying faster means less time in the air, where meteorite strikes are particularly dangerous (as opposed to strikes while taxiing, or sitting idle). That's a very good point: for a plane, reaching the ground is the equivalent of a runner reaching shelter from the rain. But I suppose planes generally spend about the same amount of time in the air, no matter how fast they go. The faster plane just travels further in t…
reaching the ground is the equivalent of a runner reaching shelter from the rain.
A meteorite capable of striking a plane in flight is just as equivalent of striking it on the ground. It's already passed through the ablative portion of its entry, and is falling at terminal velocity. So the probabilities of a strike don't actually change.
The implications for the aircraft, passengers, and crew, are rather different, however, when the plane is at-rest and on the ground.
Re: Norwegian skydiver nearly struck by meteorite
#116Earlier quoted context omitted.
$ If that's a 60fps camera (I think it is?), that's 180 f/s speed or 122mph. That seems really slow for a rock flying into the atmosphere from space, and far slower than a rock would have to be going for it to "cut him in half." A slushie travelling at 120mph into a windshield: http://www.discovery.com/tv-shows/mythbusters/videos/soda-cu... Regarding the speed, the atmosphere will slow the rock down considerably, aer…
The high speed/slowmow internal shot of the slushie at 120mph: http://www.discovery.com/tv-shows/mythbusters/videos/soda-cu...
Er, the actual direct link: http://www.discovery.com/tv-shows/mythbusters/videos/soda-cu...
Re: Norwegian skydiver nearly struck by meteorite
#117Earlier quoted context omitted.
>one Yahoo site I ran across suggested they're harder to hit because they're moving fast -- that's also irrelevant, Indeed, it's not as if they're trying to dodge. However, doesn't a faster plane actually have a higher probability of intersecting the same space as a falling rock? Comparable to: http://news.bbc.co.uk/2/hi/uk_news/magazine/4562132.stm ('...So running fast actually makes us wetter according to this anal…
roc is correct and, additionally, remember that part of the reason that you pick up more moisture per second while running is because while running you lean forward - by changing your orientation from the vertical, your cross section relative to the path of the rain increases as well. whereas with a plane, it's exposing the same cross section to the meteor whether it's flying level at Mach 2 or sitting on a runway.
It's not the leaning forward (which reduces your forward cross-section), but your forward motion (which increases your _effective_ cross-section relative to the rain, which is the relevant factor in the running example.
In the case of an aircraft, since the frontal surface area is smaller than the topside area, the effect of velocity is to reduce the apparent interface.
Re: Norwegian skydiver nearly struck by meteorite
#118Earlier quoted context omitted.
Agreed. When is the last time you saw a bullet videotaped on a normal camera? This is moving 10x faster than a bullet?
Did you actually read the article? The stone/object they filmed was within the atmosphere, thus going around terminal velocity, depending a little on the size of it, which varies a little on the estimations.
> Did you actually read the article? The stone/object they filmed was within the atmosphere
OH! They were parachuting inside the atmosphere!
I read the article, watched the video, and read other content related to it, so the answer is yes. Somewhere i ran into that crazy speed estimate.
Re: Norwegian skydiver nearly struck by meteorite
#119Earlier quoted context omitted.
>Flying faster means less time in the air, where meteorite strikes are particularly dangerous (as opposed to strikes while taxiing, or sitting idle). That's a very good point: for a plane, reaching the ground is the equivalent of a runner reaching shelter from the rain. But I suppose planes generally spend about the same amount of time in the air, no matter how fast they go. The faster plane just travels further in t…
reaching the ground is the equivalent of a runner reaching shelter from the rain. A meteorite capable of striking a plane in flight is just as equivalent of striking it on the ground. It's already passed through the ablative portion of its entry, and is falling at terminal velocity. So the probabilities of a strike don't actually change. The implications for the aircraft, passengers, and crew, are rather different, h…
>The implications for the aircraft, passengers, and crew, are rather different, however, when the plane is at-rest and on the ground.
Yes, that's so. A 300km/h 5kg rock striking any part of a plane in flight must have a very high probability of proving fatal for all aboard. On the ground the risk of injury for each passenger must be much lower - the plane might even be empty.
However, while the plane is in the air, it seems that a faster plane moves through a greater volume of space per unit of time, compared to a slower plane, therefore it is at greater risk of passing through the space occupied by a meteorite in any particular hour. So, assuming that faster planes spend about the amount of time airborne as slower planes, the risk of an accident is higher for faster aircraft.
The risk for an individual passenger is not increased in the same way (I guess it is not much affected by aircraft speed), because the faster aircraft gets them to their destination in less time, so they spend less time vulnerable to meteorite impacts on the aircraft.