Doesn't the speed of sound change with air pressure, as well as temperature? I would guess that Mach 1.0 is much lower at altitude than at sea level due to the increased mean free path between air molecules.
A couple of worrying moments when he was asked to give a countdown and just gave a thumbs up and when asked to detaqch the umbilicals he just sat there and had to be asked again, seemed like he wasn't quite with it perhaps the effects of the pure oxygen?
Then the tumbling which seemed to go on for an eternity! He mentioned passing out as he descended?
Great achievement! Just wondering if he pulled his chute early on purpose in honour of Kittenger so as to not break all his records? He was only a few seconds away from breaking the longest freeefall one.
I think there was some mention of blacking out on his last (76,000?) jump. It may go with the territory.
I also wonder about the early chute deployment. He had enough altitude for a few more seconds.
A couple of worrying moments when he was asked to give a countdown and just gave a thumbs up and when asked to detaqch the umbilicals he just sat there and had to be asked again, seemed like he wasn't quite with it perhaps the effects of the pure oxygen?
the rising temperature is caused by the ultravioliet light. The UV-light heats up the air.
This is the reason why the temperature rises in a certain altidude.
here's a picture of the temperature gradient http://www.klimedia.ch/kap1/a5.html
@Ken: did you see the advertising for the propeller while he was free falling? :-)
Doesn't the speed of sound change with air pressure, as well as temperature? I would guess that Mach 1.0 is much lower at altitude than at sea level due to the increased mean free path between air molecules.
-Phil
For an ideal gas the speed of sound depends only on the temperature - the square root of absolute temperature. Low density gases approach ideal gas behaviour. However the composition of the gas matters, I don't know how much that changes with altitude.
[edit: thinking about it we already 'know' this: the lower pressure of an aircraft cabin doesn't make our voices change pitch.]
On this very day, in 1947, Chuck Yeager first broke the "sound barrier" under powered flight. It's taken exactly 65 years to the day to do the same with unpowered "flight." Although Chuck Yeager was a Real Pilot and deserves the lion's share of applause for his accomplishment, rescuing oneself from a flat spin in free-fall is no mean feat and also deserves some recognition.
On this very day, in 1947, Chuck Yeager first broke the "sound barrier" under powered flight. It's taken exactly 65 years to the day to do the same with unpowered "flight." l
Every report I've read today states that Felix is the first, while acknowledging Joe's 1960 "attempt."
This from Joe Kittenger's Wikipedia entry:
"On August 16, 1960, he made the final jump, from the Excelsior III, at 102,800 feet (31,300 m). Towing a small drogue parachute for initial stabilization, he fell for 4 minutes and 36 seconds, reaching a maximum speed of 614 miles per hour (988 km/h) before opening his parachute at 18,000 feet (5,500 m)."
I noticed that too. Even checking wikipidea makes no mention of Joe breaking the speed of sound. However, for decades I have known of Joe Kittinger's balloon jump and it was widely reported that he broke the sound barrier.
Here is just one source from http://www.af.mil/; "In freefall for four and a half minutes, Kittinger fell at speeds up to 714 mph, exceeding the speed of sound."
Other places report his max speed at 614mph, and this newsreel says 450mph!
It appears that, somewhere along the line, somebody meant to hit the "6" key on their Underwood, and hit "7" by mistake. Then someone else recognized that -- wow! -- 714 is greater than the speed of sound. And the rest is history -- sort of.
It appears that, somewhere along the line, somebody meant to hit the "6" key on their Underwood, and hit "7" by mistake. Then someone else recognized that -- wow! -- 714 is greater than the speed of sound. And the rest is history -- sort of.
Yup, I agree. So can I get a pass on eating crow this time then?
It's a great accomplishment to go up 24 miles and free fall back to Earth. Someday astronauts may leap overboard and return from orbital space (99-1,200 miles) but currently this raises a lot of questions. Very good web site citing discrepancies and showing "Colonel Joe Kittinger and Felix Baumgartner at their first press conference after the historic jump. After his journey, it looks like Felix just stepped out of a washing machine.
On the other hand, the Big Brain Space Program has used DIY and common resources as seen in this chart to explore seven regions of space which currently has achieved biological space flight up to 7.2 miles and machine injection down to 10-nanometers.
Hey, it just occurred to me that there have been quite a few people to fly supersonic without a vehicle. There are many instances of pilots ejecting above Mach 1 and even Mach 2. There's even one case of a Blackbird disintegrating at Mach 3 where the pilot survived.
Passenger planes can average fast subsonic fights of 600 miles per hour and with a tail wind monitors have reported an excess of 729 miles per hour during flights when the plane is traveling above the ocean. Though to go supersonic requires an average speed of 768 miles per hour.
Hey, it just occurred to me that there have been quite a few people to fly supersonic without a vehicle. There are many instances of pilots ejecting above Mach 1 and even Mach 2. There's even one case of a Blackbird disintegrating at Mach 3 where the pilot survived.
So I suppose that we have to divide this into those that have been dumped out of a vehicle going faster than Mach 1 and those that have physically crossed the barrier without the aid and protection of a vehicle.
This all sounds very 'lawyer-like'. I am not exactly sure what he did other than go higher. After all, how fast does sound travel in the stratosphere, or does it travel at all? And the longest free fall record may have not been broken.
About the only thing I know for sure is that I don't know where to buy Red Bull in Taiwan.
"In the Earth's atmosphere, the chief factor affecting the speed of sound is the temperature. For a given ideal gas with constant heat capacity and composition, sound speed is dependent solelyupon temperature; see Details below. In such an ideal case, the effects of decreased density and decreased pressure of altitude cancel each other out, save for the residual effect of temperature.Since temperature (and thus the speed of sound) decreases with increasing altitude up to 11 km, sound is refracted upward, away from listeners on the ground, creating an acoustic shadow at some distance from the source.[2] The decrease of the sound speed with height is referred to as a negative sound speed gradient. However, there are variations in this trend above 11 km. In particular, in the stratosphere above about 20 km, the speed of sound increases with height, due to an increase in temperature from heating within the ozone layer. This produces a positive sound speed gradient in this region. Still another region of positive gradient occurs at very high altitudes, in the aptly-named thermosphereabove 90 km." From Wikipedia about the Speed of Sound
So I suppose that we have to divide this into those that have been dumped out of a vehicle going faster than Mach 1 and those that have physically crossed the barrier without the aid and protection of a vehicle.
Passenger planes can average fast subsonic fights of 600 miles per hour and with a tail wind monitors have reported an excess of 729 miles per hour during flights when the plane is traveling above the ocean. Though to go supersonic requires an average speed of 768 miles per hour.
Comments
-Phil
I think there was some mention of blacking out on his last (76,000?) jump. It may go with the territory.
I also wonder about the early chute deployment. He had enough altitude for a few more seconds.
I was surprised today to see the temperature going up as he traveled up though the statosphere.
He hadn't finished praying yet.
1.1°C?
This is the reason why the temperature rises in a certain altidude.
here's a picture of the temperature gradient
http://www.klimedia.ch/kap1/a5.html
@Ken: did you see the advertising for the propeller while he was free falling? :-)
best regards
Stefan
Although he did do a 90,000 foot jump this year also.
[edit: thinking about it we already 'know' this: the lower pressure of an aircraft cabin doesn't make our voices change pitch.]
-browz
Do you put the butter on your belly or your back?
-Phil
More like 13 years. Joe Kittinger did it in 1960.
-Phil
There are many sources that state that he did, why do you say he didn't?
This from Joe Kittenger's Wikipedia entry:
614 mph is below Mach 1.0.
-Phil
Here is just one source from http://www.af.mil/; "In freefall for four and a half minutes, Kittinger fell at speeds up to 714 mph, exceeding the speed of sound."
Other places report his max speed at 614mph, and this newsreel says 450mph!
If you can't trust the Beeb, whom can you trust?
(I'm assuming the af.mil report was written by an E4 corporal transferred to Stars and Stripes from the catering corps.)
-Phil
-Phil
Yup, I agree. So can I get a pass on eating crow this time then?
-browz
The Browz has spoken!
-Phil
http://hypertextbook.com/facts/2012/2012-10-14_4.44.08_pm_edt.png
On the other hand, the Big Brain Space Program has used DIY and common resources as seen in this chart to explore seven regions of space which currently has achieved biological space flight up to 7.2 miles and machine injection down to 10-nanometers.
So I suppose that we have to divide this into those that have been dumped out of a vehicle going faster than Mach 1 and those that have physically crossed the barrier without the aid and protection of a vehicle.
This all sounds very 'lawyer-like'. I am not exactly sure what he did other than go higher. After all, how fast does sound travel in the stratosphere, or does it travel at all? And the longest free fall record may have not been broken.
About the only thing I know for sure is that I don't know where to buy Red Bull in Taiwan.
"In the Earth's atmosphere, the chief factor affecting the speed of sound is the temperature. For a given ideal gas with constant heat capacity and composition, sound speed is dependent solelyupon temperature; see Details below. In such an ideal case, the effects of decreased density and decreased pressure of altitude cancel each other out, save for the residual effect of temperature.Since temperature (and thus the speed of sound) decreases with increasing altitude up to 11 km, sound is refracted upward, away from listeners on the ground, creating an acoustic shadow at some distance from the source.[2] The decrease of the sound speed with height is referred to as a negative sound speed gradient.
However, there are variations in this trend above 11 km. In particular, in the stratosphere above about 20 km, the speed of sound increases with height, due to an increase in temperature from heating within the ozone layer. This produces a positive sound speed gradient in this region. Still another region of positive gradient occurs at very high altitudes, in the aptly-named thermosphereabove 90 km." From Wikipedia about the Speed of Sound
Or perhaps intentional vs unitentional.
Ground speeds don't count for Mach numbers. In the jet stream 100mph tail wind isn't that unusual... And at typical airliner altitudes the speed of sound is more like 660mph due to the lower temperatures: http://en.wikipedia.org/w/index.php?title=File:Comparison_US_standard_atmosphere_1962.svg&page=1