18

I have heard that a man can fall faster than the speed of sound, and survive, by jumping from 36,000 meters; a free fall that, it seems, lasts ten minutes after the jump. Is it true?

32

Can a man fall faster than the speed of sound?


Update (15 Oct 2012): Definitely, yes - 372.8 m/s, or Mach 1.24,


Yes, almost certainly, though none have yet (7 Oct 2012) in any well-published verified account.

on Aug. 16, 1960, Capt. Kittinger jumped from a height of 102,800 feet, almost 20 miles above the earth. With only the small stabilizing chute deployed, Capt. Kittinger fell for 4 minutes, 36 seconds. He experienced temperatures as low as minus 94 degrees Fahrenheit (-70 degrees Celsius) and a maximum speed of 614 miles per hour. … The 28-foot main parachute did not open until Capt. Kittinger reached the much thicker atmosphere at 17,500 feet.

From http://www.nationalmuseum.af.mil/factsheets/factsheet.asp?id=562

That is 274 m/s at some point during a descent from 31333 m to 5333 m altitude.


Speed of sound graph

From http://en.wikipedia.org/wiki/Speed_of_sound

From this graph we can see that if you start at 36000 metres, when you have fallen 16000 metres to 20000 metres height, the speed of sound is 295 m/s. Kittinger's maximum speed was 274 m/s at unstated altitude. It seems plausible that someone might be able to travel 7.6% faster oriented head down with no stabilising chute.


There are reports that say Kittinger in 1960 reached supersonic speeds - e.g. Airforce Magazine - but in a BBC video (at 02:10) Kittinger says he was "very nearly supersonic").

  • 4
    Fixed units - please use metric units in the future. Most users of this site are not familiar with uncommon units of measure such as imperial. – Sklivvz Oct 7 '12 at 12:46
  • 2
    @Skliwz, I changed to SI units (the universal language of science) except where needed to preserve the integrity of quotations. The units are not important to my answer, it is the smallness of the required percentage improvement I am trying to show. – RedGrittyBrick Oct 7 '12 at 13:41
  • We already have a faq-level policy (meta.skeptics.stackexchange.com/q/1001) on meta. You may want to move your "note on units" over there :-) – Sklivvz Oct 7 '12 at 14:26
15

Yes!

BBC News reports:

Austrian Felix Baumgartner has become the first skydiver to go faster than the speed of sound, reaching a maximum velocity of 833.9mph (1,342km/h).

In jumping out of a balloon 128,100ft (24 miles; 39km) above New Mexico, the 43-year-old also smashed the record for the highest ever freefall.

The whole thing is part of Red Bull Stratos project. Highlights video is available on YouTube, there will be the National Geographic documentary "Space Dive" released later on.

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