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Skydiving Across the English Channel
loonix_gangsta writes "Felix Baumgartner, an Austrian, has become the first person to skydive 35 km (22 miles) across the English Channel. Wearing a jumpsuit with a large carbon fin strapped to his back he reached speeds of up to 360 km/h. The whole flight took approximately 14 minutes. The newsitem is being covered by the BBC, SkyNews
and CNN."
Exactly! The BBC article mentioned that he was in "free fall"! I've got about 900 skydives, and if you've got wings attached to you, that ain't free fall... at least it wasn't when I was skydiving.
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Since your replies seem to suggest your sincere, I thought I'd give a reply.
Jumping from the height this guy was on, means you have less drag, but the drag increases when you go lower, until he reaches the lower parts of the atmosphere where unpowered flight seems to be limited to about 220kph. Now would he have jumped out at 30km height, he would have broken the sound barrier and then, slowed down to 220kph.
This ofcourse holds untill the density goes (quite abruptly) up to that of solid rock, at which point velocity goes down to zero.
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If this is a troll, I'll bite, but since there are two comments in the same vein, I don't think it is. Unless the trolls are teaming up.. dear god..
Speaking from skydiving experience, if you open your parachute at 360kph, the parachute will be ripped right off your back and probably break a few bones in the process.
Even during a "normal" skydive the diver can accelerate to around 160mph (sorry for the sudden unit switch) by falling vertically. However, before deploying the parachute, the skydiver must slow themselves down by going into the "neutral" position: arched back, hands and legs out. This will slow the diver down to around 120mph, which is safe to deploy the canopy.
Buses stop at a bus station
Trains stop at a train station
On my desk there's a workstation....
Turbulence in from the wind moving around the buildings would be a problem, that would probably make it as bad of an option as jumping.
l oh a/terrain/terrain.html
l if t.htm
Plus a glass desktop cover is going to be heavy and it don't have an airfoil to it so it's going to drop like a piece of glass and get a flutter to it.
http://response.restoration.noaa.gov/cameo/dr_a
"Even if air flow into New York City is relatively steady and the winds predictable, ALOHA's first assumption is not likely to be met within the city itself. Buildings may block and divert the wind. Air flowing past large obstructions such as buildings forms into turbulent eddies, just as eddies form immediately downstream of a boulder or bridge piling in a river. Air flowing across an urban landscape composed of many buildings breaks up into irregular patterns of eddies of various sizes, speeds, and strengths. Winds blowing through city streets can speed up, slow down, and markedly change direction. In fact, wind blowing past an obstruction such as a building sometimes can completely reverse direction. "
"New York City contains many "street canyons" long, straight through streets bordered by tall buildings. A street canyon can funnel the wind at a speed and in a direction different from what a user may have entered into ALOHA. Similarly, it can act to channel a cloud. The cloud, prevented by the walls of buildings from dispersing in the crosswind direction, may travel much farther downwind than ALOHA would predict before diluting below the level of concern."
That link is in relation to computer modeling of NBC weapons release in an urban setting, but it talks about the complexity of winds in a city.
Velocity doesn't make something fly or glide, it's the lift provided from the wing. The basic idea is that a flow over a curved surface has lower pressure than the flow over a flat surface, so you curve the top of a wing and the lower pressure there allows the wing to create lift. The faster the flow is the more lift you get, which is why aircraft need engines to provide foreward movement.
http://www.aa.washington.edu/faculty/eberhardt/
Here is Leo Valentin's 1950s version
BBC says:
.
Think like a man of action, act like a man of thought.
Now would he have jumped out at 30km height, he would have broken the sound barrier and then, slowed down to 220kph.
Mach I at 30 km (18.6 miles) is about 675 mph. He was travelling, at his fastest, at 360 kmh (200 mph), nowhere near the sound barrier at any altitude. The sound barrier increases and decreases even as altitude increases, but it never goes lower than about 660 mph. Here's a chart of Mach 1 at different altitudes.
(On an entirely different note, has anyone besides me noticed that the quality of Slashdot moderation has degraded over the last year or so? I haven't been "assigned" mod points since the great move West, but I know I used to do a better job than what passes for moderation these days. The mod system needs something way much more effective than the current M2 system which does absolutely nothing. I mean, we're talking about something fundamental as the speed of sound.)
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