The Digg Crew wants to hear your thoughts!
Please take our short survey about Digg and potential feature ideas.
Skydiving from 100,000ft / edge of earth & falling at the speed of sound watch!
video.google.com — First man to skydive from the edge of the earth, while free falling, he reaches the speed of sound, falling at 990km/h before deploying his parachute. Amazing video.
absoluteczech- 1481 diggs
- digg it
- Crockpot, on 10/12/2007, -13/+31Absolutely amazing! I'm surprise he didn't just burn up in the atmosphere!
- masgrada, on 10/12/2007, -2/+33He was afraid to jump at lower altitudes until the thought of floating into space crossed his mind...
- nesibus, on 10/12/2007, -5/+38Why would he burn up in the atmosphere?
The only reason the shuttle burns on reentry is cause its hitting the thin air at over 15,000mph.
The man reached a free fall speed of over 700...no where near enough to produce lots of friction. - bryanjones, on 10/12/2007, -1/+39The heat from re-entry is caused from the compression of air, not friction. It's the exact same effect that your refrigerator uses, when it expands freon gas, but in reverse.
- Revadarth, on 10/12/2007, -3/+10I'm more surprised that his parachute didn't rip. Those things must be able to take a lot of punishment. Imagine how much momentum that guy had from going that fast and then stopping suddenly.
- Dimah, on 10/12/2007, -0/+33You know what I'm supprised about? That more people don't do this. The view was amazing and it was probably cheaper than those Virgin Space flights people are going to pay big bucks for.
- rspeed, on 10/12/2007, -1/+6It's worth pointing out that the speed of sound at 100,000 feet would be about 3/4 the speed of sound at sea level. Anybody have the formula for converting mach to kph?
- CorDawg, on 10/12/2007, -2/+8From Google
speed of sound at sea level = 340.29 m / s
1 meters per second = 3.6 kilometers per hour
1225.044 km/h is the speed of sound - ebs16, on 10/12/2007, -2/+5@Revadarth
I'm surprised that his body wasn't torn apart when he deployed the parachute. - bonyicecream, on 10/12/2007, -0/+13I severely want to link that PBF comic, but pbfcomics.com is down! arrrr!
ok, found it on ytmnd and imageshacked it since finding the image link on ytmnd is a pain...
http://img294.imageshack.us/img294/7363/snowflakeci9.jpg - eridius, on 10/12/2007, -0/+21"I'm surprised that his body wasn't torn apart when he deployed the parachute."
You guys do realize that he let the air decelerate himself before he deployed the parachute, right? This means by the time he deployed his parachute, he was falling at about 120mph, which is terminal velocity for a human in normal skydiving free-fall position with a closed parachute.
In other words, when he deployed his parachute, he was just like any other skydiver. - badbrain, on 10/12/2007, -0/+4He used a multistage parachute (I can't recall how many). And, I believe that he broke his leg on landing.
- afghanwhiggle, on 10/12/2007, -0/+28That dude is a serious badass.
On a side note, Boards of Canada uses a lot of this footage in one of their videos. I think it's called Davyan Cowboy.- storm8956, on 10/12/2007, -1/+20yeah. it's a sweet music video. here's a link...
http://video.google.com/videoplay?docid=-7451064378458599055&q=dayvan+cowboy - alex.will, on 10/12/2007, -0/+6I think that video is better than the original link.
- kamikazecow, on 10/12/2007, -0/+1Awesome music video, thx for the link. After watching it a second time though, i noticed that there were no stars...? what gives?
- vagarach, on 10/12/2007, -0/+1wow, brilliant song along with a perfect video, they work so well together!
- voyage34, on 10/12/2007, -0/+4Digg for BoC. Awesome song and video
- deepsub, on 10/12/2007, -0/+3"Digg for BoC. Awesome song and video"
I see there are other BoC fans here.
Anyone who even remotely likes electronic music owes it to themselves to check these guys out! They're my favorite musical artist. :D
http://www.boardsofcanada.com/ - Ryetronics, on 10/12/2007, -0/+1I'm a huge BoC fan, so thanks afghan for giving everyone the link.
@kamikazecow: I think you don't see any stars because the camera has the earth in the frame, making it's light too bright. It's similar to why you don't see stars on the pictures from the Moon... too much glare.
- storm8956, on 10/12/2007, -1/+20yeah. it's a sweet music video. here's a link...
- captinherb, on 10/12/2007, -0/+54I can't imagine the cahoones this guy has. He sat in that damn balloon for 3 hours knowing he was going to jump out over 18.5 miles above the earth, I get woozy looking out the window of a tall building.
- DjOverEZ, on 10/12/2007, -1/+14I was seriously getting nervous watching this video, thinking about how high he was and jumping!
- berfmurret, on 10/12/2007, -14/+2not the best footage i have seen of this.
- HP844182, on 10/12/2007, -0/+46...did something amazing. He jumped.
Guy: oooohhhh shiittttt! - wvannus, on 10/12/2007, -1/+28I met Kittinger last summer. What an absolutely amazing guy.
He is definitely one of the figures history forgot. - dziban303, on 10/12/2007, -0/+11I read about this a few months ago. I think the glove joint on his space suit lost its seal, so his hand decompressed and swoll to twice its size. I think it only took him like 14 minutes from jumping to landing. Incredibly cool.
- Qtip42, on 10/12/2007, -0/+7That would suck (the hand thing) but the view would be awesome.
- JustinMMcKay, on 10/12/2007, -0/+32ONLY 14 MINUTES?
Falling that would be like an eternity lol. - diggdon, on 10/12/2007, -9/+2Simple physics. From a stationary start, distance = 1/2 * acceleration & (time)^2. Using a value of a=10m/s^2, and using distance = 30km (30000m) we solve for t in seconds and we find t is (I'm doing this in my head, so excuse my rounding errors) 77 seconds. That means he fell for 77 seconds (maximum free fall). Of course, if you count all his glide time after he opens his parachute, the amount of time could easily be 10 minutes. If he opened his parachute right at the top (assuming the rate of descent is an IMPOSSIBLY EVEN 10m/s) he would fall for 3000 seconds which is 50 minutes. And if he could catch an updraft like I've seen in the mountains of Hawaii, he could remain stationary in the air with a parachute indefinitely. PS My comments exclude maximum air speed calculations. I welcome someone to improve on these numbers by accounting for air resistance.
- patrickbwells, on 10/12/2007, -0/+3@diggdom
Your "simple physics" is ***** up. He was in free-fall for four and a half minutes. - diggdon, on 10/12/2007, -0/+1I told you what was wrong with my physics, air friction. So I wasn't wrong. My numbers are irrefutable, and nobody attempted to refute them.
- dziban303, on 10/12/2007, -0/+1LOL.
"I told you what was wrong with my physics, air friction. So I wasn't wrong."
Uhm. I bet you lose arguments with yourself all the time.
- iceluigi, on 10/12/2007, -1/+5So was he able to accelerate to that velocity because the air resistance was much less at that altitude right? I did hear her say that once he hit the thicker air he decelerated.
- LiveDirect, on 10/12/2007, -10/+8What about terminal velocity? I'm no physics guy, but I seem to remember the episode of Mythbusters where they couldn't get that coin to fall faster than [x speed].
The speed of sound seems too fast for a human. Someone enlighten me?- iwhitney, on 10/12/2007, -0/+21Terimnal velocity depends on air resistance. Where he jumped from had little to no air resistance.
- mikesty, on 10/12/2007, -0/+9I was just thinking that, but obviously the air is thinner.
- nipterink, on 10/12/2007, -0/+6not to mention the speed of sound is approx. 1200 km/h.
- Tocc, on 10/12/2007, -0/+6The air is lighter so it doesnt produce as much air friction to oppose gravity.
- mc7winkie, on 10/12/2007, -1/+8Terminal velocity is only based on air resistance. He jumped at an altitude where the air was so thin and had relatively little friction. If you listened in the video he didn't open his parachute until he was at the lower altitudes ,with thicker air, when he would be traveling at about 120 miles per hour.
- Barlo_Mung, on 10/12/2007, -0/+5@nipterink
"not to mention the speed of sound is approx. 1200 km/h."
Not at that altitude. It's more like 800 km/h. Sound travels slower in thinner air. - nipterink, on 10/12/2007, -0/+3just to settle this once and for all.
essentially the speed of sound ONLY depends on temperature, because given an ideal gas (air comes close enough for minimal error) given a particular temperature the pressure and density change in sync and cancel out for being needed to calculate it. so anywhere you see equations to calculate the speed of sound you'll only see temperature being used.
just for fun http://bpesoft.com/s/wleizero/xhac/?M=s
put 100,000 feet, and you get a whole bunch of information (including speed of sound at 1100 km/h)
- lucas448, on 10/12/2007, -7/+2i cant watch it... i think my isp hates Google and wont load it 90% of the time... please tell me I'm not alone
- captinherb, on 10/12/2007, -0/+35sorry but you are as alone as a guy in a balloon 30 kilometers above the earth
- Thezeppelin62, on 10/12/2007, -24/+1I'm almost positive this was already posted
- lazlonger, on 10/12/2007, -0/+16Well then I, for one, am REALLY glad it was reposted.
What a guy. I am in awe. Truly astounding guts.
- lazlonger, on 10/12/2007, -0/+16Well then I, for one, am REALLY glad it was reposted.
- iamnotaminor, on 10/12/2007, -0/+5now i want to go skydiving
- rbanffy, on 10/12/2007, -0/+3I think we could call it spacediving.
- ah802, on 10/12/2007, -13/+21960.. Whew, this post is dated and duped.
- macmcrae, on 10/12/2007, -2/+10My god that is the most frightening footage ever. Falling at mach one has to loosen your bowels a little. That man has balls of steel.
- ryan4477, on 10/12/2007, -0/+6kind of makes falling out of a tree and bragging about it seem...stupid.
- jaxxon, on 10/12/2007, -0/+12Where did he land???
- SavageOwnage, on 10/12/2007, -1/+23I think its safe to say he landed on earth.
- mapkinase, on 10/12/2007, -0/+1Thanks, savage. Good to know.
- Wisgary, on 10/12/2007, -0/+4What if he had opened his chute as soon as he jumped? How far off would that have taken him, and how long would it have taken for him to land. That would be awesome if he ended up in like Europe or something.
- nesibus, on 10/12/2007, -0/+6If he would have opened it when he jumped....nothing would have happened....there was no air to help pull it out....it would have probably wrapped around his body, he was in an uncontrollable tumble cause of such thin air.
- aknowles5139, on 10/12/2007, -1/+9shut up about the dupes... we know it was already submitted. It was good then and its still good now.
Even though most of us have already seen it, theres alot of people that haven't seen it. Give them a chance. - giraldus, on 10/12/2007, -0/+4I like the comment at the end about how gravity did him no harm. Of course it didn't. Gravity never does anyone any harm. It is the hard stuff -- like the ground -- you bump into on your way down that do you harm.
Oh by the way, the speed of sound is not a fixed number; it depends on temperature; see the Wikipedia article for details: http://en.wikipedia.org/wiki/Speed_of_sound- Murdats, on 10/12/2007, -0/+2and medium and density and whatnot
however they are probably referencing the speed of sound at sea level which is what is commonly refered to as the speed of sound in general context
- Murdats, on 10/12/2007, -0/+2and medium and density and whatnot
- moronpatrol, on 10/12/2007, -0/+1Balls of steel
though i've read various things on him and there seems to be some confusion on if he did or did not hit the speed of sound..close but didn't actually hit that number.
he blacked out for a few on the way down then regained consciousness, and the chute was rigged with pop automatically at a certain altitude
eitherway they dont make em like him anymore....- Barlo_Mung, on 10/12/2007, -0/+6Blacked out? wow. Can you imagine waking back up.
"wow, I was just having the craziest dream. I dreamed I'd jumped from a weather balloon at the edge of space. hmm, what's that sound of rushing air? Oh yeah, I just jumped from a weather balloon at the edge of space." - kamikazecow, on 10/12/2007, -0/+4 (insert 3 second pause) HHHHOOOOOLLLLLLLYYYYY SSSSSSSSHHHHHHHIIIIIIIIITTTTTT!!!!!!!!!
- Barlo_Mung, on 10/12/2007, -0/+6Blacked out? wow. Can you imagine waking back up.
- schwit, on 10/12/2007, -11/+1Dupes are a pestilence no matter how good the original story. If we don't quickly bury them Digg will become mostly inconsiderate jerks posting the same stories over and over.
If you like a story then bookmark it and watch it at your convenience, but don't trash digg. - mrASSMAN, on 10/12/2007, -1/+3"amazing but, if there isnt no gravity on space why when he "jumped off" u see him.. falling...?"
sigh..- nesibus, on 10/12/2007, -2/+5...
- nesibus, on 10/12/2007, -1/+2agreed with you there......
..you would have to be a long way from the earth or any other planet to truly "float" cause you need to get away from its gravitational pull....the only reason the shuttle and satellites stay in orbit is cause they are being "thrown out" by a perfect speed which keeps them in their orbit....just like a merry go round in perspective.
Same reason why the moon doesn't collide into the earth...its slow orbit around the earth keeps it from crashing into us...its far enough and heavy enough to go that slow...unlike the tiny stuff we send into space that is in tight orbits.
The GEOstationary satellites are far enough out that they rotate with the earth. and they do not need tons of forward momentum to break gravitational pull.
For the things to get in lower or higher orbits in space they either need to slow down or speed up. - Murdats, on 10/12/2007, -7/+1I think that guy is a moron and thinks that gravity is something like water, ie above water you dont get wet, and water just stops suddenly
as I said, moron - MasteRR, on 10/12/2007, -0/+3There had to of still been some air when he jumped. Otherwise the balloon would have been falling with him (thus appear as though he was floating next to it when he jumped), not staying at the same altitutude or climbing. The air may have been very thin, but it wasn't complete space.
- apache2, on 10/12/2007, -2/+1@nesibus, sorry, but the only way to escape gravity is to escape light, which means you would have to go past our known universe, into the unknown. Time and space are fused together, and so are the effects of gravity, there is really no way to escape it, to exactly 0.0000% nothingness.
- Humptydank, on 10/12/2007, -0/+1@nesibus:
Just to add my own clarification -- practically yes, but theoretically you can never truly get "far enough away" from the gravity of any object with mass. Gravity quickly fades to unmeasurable levels with distance according to the inverse square law, but it never goes completely to zero. So no matter where you go you're awash in the gravitational fields of everything around you, even at truly huge distances.
A nitpick, but such is physics.
- Somniis, on 10/12/2007, -0/+2I bet that was an amazing view. I'd love to do that.
- prockcore, on 10/12/2007, -0/+3Back in 2000, Rolf Gibbs dropped a video camera out of an airplane at 30,000 feet. It's a very cool video.. the camera is in the nose of a rocket so it points straight down.
The name of the short film is called "G". - chall2001, on 10/12/2007, -0/+20I love the cowboy attitude they had toward scientific experiments back then. These days they would send up some probe loaded with sensors---YAWN...
I can imagine the conversation they had leading up to this--
We're pretty sure you can't feel gravity in space but we need to be sure. Hey Joe, how about we load you on a tiny platform hung from a weather balloon? After you reach the edge of space we need you to jump off and tell us how it feels. - rbanffy, on 10/12/2007, -0/+2I have no wish to jump from a plane a couple miles up, bu jumping off a balloon, where the sky is black and the Earth is blue is totally different.
And hitting Mach 1 is the icing on the cake.
Wish there was a way to do it these days. - distrbnce, on 10/12/2007, -0/+2I want to see the whole video he shot. Where is that?
- Daiken, on 10/12/2007, -2/+1Been posted bout 5 times now but still, more people need to know who the real first man in space was.
- digitalintrigue, on 10/12/2007, -1/+7Not trying to take anything away from this guy or the feat itself, but jumping from 100,000 feet isn't much different than jumping from 10,000. When you skydive, there isn't a sensation of falling...it's like you are still (except for the rush of wind) and the earth rushes up to meet you. It's not like your stomach is in your mouth during the entire fall.
I don't have a fear of heights when at 10,000 feet looking out the door of a plane, but 100 feet in a tower looking over the edge freaks me out. Anyone else feel the same thing?- Glidedon, on 10/12/2007, -0/+5Yep, I get nervous on my roof, but not so much flying my paraglider off mountain tops.
- Phlag, on 10/12/2007, -0/+9I don't think that's really what people admire Kittinger for. He's not brave because of the sensation of falling he may or may not have had. He's brave because they weren't even that sure that the balloon would carry him to his top altitude safely. He's brave because he was the first person to exit the earth's atmosphere, all whilst wearing a relatively untested prototype space suit, paving the way for the rest of the world's space exploration. He's brave because his glove malfunctioned, but he chose not to notify the team back on land because they'd cancel the mission and he wasn't sure that he'd ever get this opportunity again. And in deciding not to tell them, he thought that he might LOSE that goddamn hand. But he went through with it anyway.
And THEN he jumped. But there were so many praise-worthy things Kittinger did that came before that jump. - anonydigg, on 10/12/2007, -1/+2It probably has an evolutionary basis.
- lswinney, on 10/12/2007, -0/+3"He's brave because his glove malfunctioned, but he chose not to notify the team back on land because they'd cancel the mission and he wasn't sure that he'd ever get this opportunity again."
How would he have aborted this mission? Jump out with a parachute? - dxmzan, on 10/12/2007, -0/+1@digitalintrigue
Yes, I couldn't even stand next to the edge of a 100ft high building, but as my profession (Military C130 Loadmaster), I am required to stand on a platform outside an aircraft at around 10,000ft (hooked to the plane/or with a parachute) and have no problems doing that.
- wyomingred, on 10/12/2007, -0/+0I wonder how many road pizza Xtreme athletes we're going to have in the near future thanks to this?
- GrimReeper, on 10/12/2007, -1/+1What no sonic boom?
- nesibus, on 10/12/2007, -0/+2No..for many reasons...the main one being that there is basically no air...thats why he was traveling so fast...he had no resistance.
Plus...to break the sound barrier at "sea level" is 770mph in perfect conditions for it......as you get higher that speed is different do to lots of factors...but just the thin air..or lack there of...would make him have to go way faster then that. - rootneg2, on 10/12/2007, -1/+3thinner air => slower speed of sound
He definatly broke the sound barrier for that altitude. There probably was a "sonic boom", but the object breaking the sound barrier doesn't hear the boom; it's a conical shockwave extending out *from* the object, you hear the boom as you intersect with that cone.
Although, the thinner atmosphere would likely mean the the boom would be very faint (if anybody could have actually been stationary up there to hear it) - nesibus, on 10/12/2007, -0/+1ok yea your right...I'm thinking temperature...higher temp means higher speed needed.
- nesibus, on 10/12/2007, -0/+2No..for many reasons...the main one being that there is basically no air...thats why he was traveling so fast...he had no resistance.
- JoeCool1986, on 10/12/2007, -1/+6It would've sucked to have jumped out, and then realize that you were neither falling towards the earth or floating away and had in fact gone into orbit. You probably would say "oh, sh**" for about two hours as your air supply ran out.
(I know that's really not even possible, but the idea of it is rather funny to me)- apache2, on 10/12/2007, -0/+2would be even better if you caught a slight breeze on the way up, and ended jumping out over siberia.
- Sharkee, on 10/12/2007, -0/+2"thinner air => slower speed of sound"
FALSE. Colder air lowers the speed of sound. A = sqrt(m*r*T) where T is the temperate in Kelvin. The colder air up there lowers the speed of sound, so it's easier to go have a higher Mach Number. The lower pressure up there reduces the drag, so there isn't as much force resisting you.
At Mach Numbers greater than 0.3, the compressible flow component can't be ignored anymore. When a flow is moving at those Mach Numbers, when a high speed flow is brought to a stop, there is a large temperate increase at the stagnated air.- rootneg2, on 10/12/2007, -1/+1hmm, I'm not sure why you say that's outright FALSE.
thinner air means the molecules are further apart, molecules further apart means the molecules take longer to "bump" into each other, and thus the shockwave propagates slower. That's why sound travels faster in steel and water than in air (get a friend to hit some train tracks with a hammer, stand far away and put your ear on the track; now wait for a train. ok j/k about the train...) even though they are the same temperature.
you aren't wrong about the temperature though. The temperature is less because the air is thinner, each molecule has approximately the same average kinetic energy, they simply don't "bump" the thermometer as often, and so the temperature is less.
PV=T so it seems like it's all a matter of semantics to say which one *causes* the slower speed of sound.
- rootneg2, on 10/12/2007, -1/+1hmm, I'm not sure why you say that's outright FALSE.
- Sharkee, on 10/12/2007, -0/+2The pressure (and therefore density) can be roughly modeled for the Earth's atmosphere as exponential decay from the surface pressure. 2/3 of the Earth's total atmospheric mass is below 25,000 feet.
- Sharkee, on 10/12/2007, -0/+2"The heat from re-entry is caused from the compression of air, not friction. It's the exact same effect that your refrigerator uses, when it expands freon gas, but in reverse."
Both are right actually. The compression of air against flat surfaces that they blow on causes higher temperatures. Also, as air flows past him, the air closet to his body stands perfect still (called a boundary layer). The flow must transition to full speed. This also induces a Thermal Boundary Layer which creates a heat transfer.
So, he's getting viscous flow effects (friction) as well as compressive flow effects (classical thermodynamics). - Sharkee, on 10/12/2007, -0/+3Sorry for all the posts. Here's the way to convert speed into the local speed of sound. You'll need to know the static temperature in degrees Kelvin (what's the temp at that altitude when standing still?)
a = sqrt ( 1.4 * T)
a is the speed of sound in meters per second
T is the temperature in Kevlin. (Kelvin = 273.15 + Celsius)
sqrt is the square root
if you want to convert meters to feet, take the meters and divide by 0.3048. The above formula only works for air.
I got my degree in Aerospace Engineering and had to take lots of fluids classes including a Propulsion class (which covered compressible flow). I just graduated in May.- nesibus, on 10/12/2007, -0/+1@Sharkee
If a jet is doing 600mph...and say for example has a 200mph jetstream blowing against it....will that cause it to break the sound barrier sooner?...or the other way around...if the barrier is at 770....you traveling 800 with a 200mph stream pushing you..making the wind speed only 600....would that increase the speed needed to break it? - patch, on 10/12/2007, -0/+1"what's the temp at that altitude when standing still?"
At that high of an altitude there really is no defined "temperature", the gases are getting too thin and inconsistent. But generally its considered to be several thousand degrees kelvin, although the particles at that temperature really have no affect on large objects passing by. I know this doesn't really help you... - Sharkee, on 10/12/2007, -0/+1@nesibus:
"If a jet is doing 600mph...and say for example has a 200mph jetstream blowing against it....will that cause it to break the sound barrier sooner?...or the other way around...if the barrier is at 770....you traveling 800 with a 200mph stream pushing you..making the wind speed only 600....would that increase the speed needed to break it?"
Typically we separate out the definitions of "air speed" and "ground speed". I'm assuming the 600 mph you're saying is ground speed (how fast it is moving relative to the ground), so it is moving 800 mph air speed (with reference to the air). Jets that fly at those speeds typically fly around 35,000 to 40,000 feet. Since the speed of sound is determined by the local temperature (and NOT pressure), the local temperature is somewhere around -50 degrees Celsius (I think?).
I made a mistake in my formula earlier. Speed of sound = sqrt( 402 * Temp_in_Kelvin)
So that equates to a speed of sound of 300 meters per second (sealevel is 340 m/s). That's about 671 mph. So doing 800 mph in that condition would be doing Mach 1.17. I don't think most passenger jets do the transsonic area since it's really rough and requires changes in design. I've never seen the in-flight map data show us going over 660 mph (trans-pacific flight). I'm guessing they are posting the "air speed", which is more relevant since it determines your drag and lift, and other aerodynamic properties. Most aircraft designers like to stay away from the trans-sonic region (mach 0.99 to 1.1 or so) because it's really nasty to control the plane and a really rough ride. If a fighter jet is going to go supersonic, they typically accelerate as fast as possible through the trans-sonic region to avoid it (like driving quickly through a bad neighborhood).
- nesibus, on 10/12/2007, -0/+1@Sharkee
- bluemansteele, on 10/12/2007, -5/+3I CAN'T BELIEVE NOBODY POSTED "FAKE"!!!!
I'm.. I'm so PROUD of you all. A nearly unbelievable but well documented event happens and no one posts (as of this posting) "FAKE". Talking about terminal velocity and rate of fall... *sniff... I'm.. so so happy this day.
LET'S ALL HUG SHIRTLESS!- cryptoknight, on 10/12/2007, -6/+2FAKE!
- ZenMojo, on 10/12/2007, -1/+1This guy's got balls like cantaloupes.
- lswinney, on 10/12/2007, -0/+4If his suit had decompressed, he would have had balls the size of cantaloupes.
- tastethevenom, on 10/12/2007, -0/+3http://en.wikipedia.org/wiki/Project_Excelsior
- johnvid, on 10/12/2007, -7/+2RESPECT... But wish it was BUSH with no chute.
Oops.
I wonder how long it will be before the thought police come knocking- nesibus, on 10/12/2007, -2/+5Ok..that was just stupid and ignorant to make a comment like that, which has no business or relation to this story.
- Osjpr, on 10/12/2007, -1/+1And he didn't know what would happen so far above the clouds in the dark...whether he would fall asleep and snap-freeze or get injury from the changing gravity...
- nysus, on 10/12/2007, -0/+1Here's a more accurate account of Joe Kittenger and his jump: http://www.centennialofflight.gov/essay/Explorers_Record_Setters_and_Daredevils/Kittinger/EX31.htm
- truck87bp, on 10/12/2007, -1/+1Does this mean that NASA has an alternative to get people off the Space Station if there was an emergency? Special suits and jet packs, tracking device and a parachute? Forget an emergency shuttle launch......
- bolerobell, on 10/12/2007, -0/+1No, because the Space Station is in orbit at ~528,000 feet (100 miles). To stay in orbit requires that it have an extremely high lateral (sideways) velocity. And when I say high, I mean near 17,000 mph. It's that 17,000 mph speed (which the station and the shuttle and all the prior capsules had and have) that cause re-entry heat and flame, not the altitude. Capt. Kittenger never got up to that speed.
Kittenger went up to 100,000 feet and was basically not moving at all when he jumped out of the balloon. He accelerated from 0 to ~600mph (a speed possible for a person outside of a machine because of the thin air) in a matter of seconds. As he continued to fall, the air started getting thicker and he slowed down from ~600mph to about ~120. He then opened his chute at ~18,000 feet (which is above where recreational skydivers typically jumps from).
- bolerobell, on 10/12/2007, -0/+1No, because the Space Station is in orbit at ~528,000 feet (100 miles). To stay in orbit requires that it have an extremely high lateral (sideways) velocity. And when I say high, I mean near 17,000 mph. It's that 17,000 mph speed (which the station and the shuttle and all the prior capsules had and have) that cause re-entry heat and flame, not the altitude. Capt. Kittenger never got up to that speed.
- takehiro12, on 10/12/2007, -0/+2Why is this not a sport for the rich and crazy?
- Sharkee, on 10/12/2007, -0/+1@rootneg2
"thinner air means the molecules are further apart, molecules further apart means the molecules take longer to "bump" into each other, and thus the shockwave propagates slower. That's why sound travels faster in steel and water than in air"
The molecular dynamics of solids, liquids and gases are all quite different. Solids and liquids have forces attracting fellow atoms and molecules to each other. Gases don't have this, so it's like comparing apples to oranges. Liquids have a different law that governs their speed of sound, as solids have even another law. Check wikipedia.
"thinner air means the molecules are further apart" True. But the molecules move faster at higher temperatures, that's what the definition of temperature is (linear momentum of the molecule). If a molecule is moving faster, then they will bump into each other more often.
This was a trick question on my first Propulsion test. The prof had drawings of 2 tanks of propane gas. In both, the temperature was 500 Kelvin. One had a higher pressure than the other. He asked which one had a higher speed of sound. It was a trick question, both had the same speed of sound. 2/3 of the class got the trick-qualitative question wrong, as they tried going the PV=T stuff you're trying.
http://www.ae.utexas.edu/faculty/members/dolling.html . You're welcome to call or email him :-)- diggdon, on 10/12/2007, -0/+1"But the molecules move faster at higher temperatures, that's what the definition of temperature is"
I always thought so too, my friend. But temperature is actually a product of molecule speed times the number of molecules. Rather than tell you why, I'll prove it from another website, as follows. Go here: http://bpesoft.com/s/wleizero/xhac/?M=s and plug in 100,000 feet. Notice that the temperature is much lower than sea level but that the speed of sound is faster, which means the molecules are moving faster. If temperature was defined as the speed of the molecules, as you said it was, then the temperature would go up when the molecules were speeding up. But as you can see from this simple example, it's the reverse. I can give other examples, but this should suffice.
The point you were trying to make about the speed of sound being the same at different pressures is valid. So on that point you were right.
- diggdon, on 10/12/2007, -0/+1"But the molecules move faster at higher temperatures, that's what the definition of temperature is"
- GeneralJoe, on 10/12/2007, -0/+1NOW THATS WHAT A CALL A BALLOON
- GeneralJoe, on 10/12/2007, -0/+1What happens with the balloon?
Check out the new & improved 
© Digg Inc. 2008 — Content posted by Digg users is 