# would a high altitude sky diver feel anything as he broke the sound barrier? **URL:** \ **Category:** Factual Questions\ **Created:** [November 28, 2012, 4:38pm UTC](https://boards.straightdope.com/t/would-a-high-altitude-sky-diver-feel-anything-as-he-broke-the-sound-barrier/642381 "2012-11-28T16:38:59Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![blood63](https://avatars.discourse-cdn.com/v4/letter/b/97f17d/32.png) [@blood63](https://boards.straightdope.com/u/blood63)\ **Post date:** [November 28, 2012, 4:38pm UTC](https://boards.straightdope.com/t/would-a-high-altitude-sky-diver-feel-anything-as-he-broke-the-sound-barrier/642381/1 "2012-11-28T16:38:59Z")
Well? ---
**Author:** ![solosam](https://avatars.discourse-cdn.com/v4/letter/s/9d8465/32.png) [@solosam](https://boards.straightdope.com/u/solosam)\ **Post date:** [November 28, 2012, 4:43pm UTC](https://boards.straightdope.com/t/would-a-high-altitude-sky-diver-feel-anything-as-he-broke-the-sound-barrier/642381/2 "2012-11-28T16:43:38Z")
Aircraft experience a rattling from turbulence as they approach the sound barrier, followed by smooth sailing after it is passed. This is called “transonic buffeting.” ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [November 28, 2012, 5:31pm UTC](https://boards.straightdope.com/t/would-a-high-altitude-sky-diver-feel-anything-as-he-broke-the-sound-barrier/642381/3 "2012-11-28T17:31:44Z")
> [@solosam](#): > > Aircraft experience a rattling from turbulence as they approach the sound barrier, followed by smooth sailing after it is passed. This is called “transonic buffeting.” This appears to be true for airfoils that are generating lift; there’s a problem with the interaction between shock waves and the separation of airflow from the top surface of the wing. A induces B which cancels A which cancels B which results in the reformation of A and the repeat of the whole cycle. Something along those lines. It’s not clear to me whether buffeting also occurs on bodies that aren’t generating lift, i.e. situations in which flow separation isn’t happening (or isn’t likely to occur when the flow field changes in response to the development of shock waves). ---
**Author:** ![StrangerThanFiction](https://avatars.discourse-cdn.com/v4/letter/s/f05b48/32.png) [@StrangerThanFiction](https://boards.straightdope.com/u/StrangerThanFiction)\ **Post date:** [November 28, 2012, 6:45pm UTC](https://boards.straightdope.com/t/would-a-high-altitude-sky-diver-feel-anything-as-he-broke-the-sound-barrier/642381/4 "2012-11-28T18:45:18Z")
From the man himself, in an interview with Forbes contributor Ariel Adams: > [@](#): > > AA: On the way down you broke the sound barrier. Did you hear the sonic boom? What was it like doing what mostly jets do with your body? > > FB: I did not hear or feel anything. My suit and helmet were protecting me very well. Though lot of people on the ground near the landing zone meant to have heard the sonic boom. English is not his native language, but I think the jist of that last sentence is that people on the ground heard the boom. Transonic buffeting can occur on any body that experiences flow approaching 1.0 Mach. Typically, the first place this happens on an airplane is on the wings, due to the acceleration of airflow over their upper surfaces. This can happen at relatively low speeds - depending on wing design it can be less than 80% of the local speed of sound. This is often the limiting factor for maximum forward speed in civilian jet aircraft. In cruise flight, the airflow is often accelerated past 1.0M as it passes over the forward portion of the wing. As it slows back to subsonic near the back of the wing, a shockwave is formed. You can see an analog by turning on your kitchen faucet. As the water strikes the sink, it moves away in a thin, high speed layer. This layer is moving faster than the speed of wave propagation, so it is known as a supercritical flow. As the water gets further away, it slows, and a standing wave forms, with a thicker layer of water attempting to move inward. However, this wave is held in place by the supercritical thin layer of outward moving water. Essentially the same thing happens on the upper surface of a wing as an airplane begins to approach the speed of sound. The shockwave the forms on the aft portion of the wing is an area of high pressure, and we all know that air doesn’t like to move from low to high pressure. This is known as an adverse pressure gradient, and it tends to cause the boundary layer of air (immediately next to the wing skin) to separate from the wing, resulting in buffeting and loss of lift. This shock formation can be delayed, weakened, and sometimes prevented through the use of vortex generators, supercritical airfoil design, and wing planform compromises. ---
**Author:** ![Freakenstein](https://avatars.discourse-cdn.com/v4/letter/f/b782af/32.png) [@Freakenstein](https://boards.straightdope.com/u/Freakenstein)\ **Post date:** [November 28, 2012, 7:52pm UTC](https://boards.straightdope.com/t/would-a-high-altitude-sky-diver-feel-anything-as-he-broke-the-sound-barrier/642381/5 "2012-11-28T19:52:13Z")
Yes, I think he would feel well. ---
**Author:** ![EdwardLost](https://avatars.discourse-cdn.com/v4/letter/e/bbe5ce/32.png) [@EdwardLost](https://boards.straightdope.com/u/EdwardLost)\ **Post date:** [November 29, 2012, 1:00am UTC](https://boards.straightdope.com/t/would-a-high-altitude-sky-diver-feel-anything-as-he-broke-the-sound-barrier/642381/6 "2012-11-29T01:00:04Z")
Perhaps the air was still too thin at the point he broke the sound barrier for him to get any sensation from it. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [November 29, 2012, 1:15am UTC](https://boards.straightdope.com/t/would-a-high-altitude-sky-diver-feel-anything-as-he-broke-the-sound-barrier/642381/7 "2012-11-29T01:15:25Z")
Need answer fast? ---
**Author:** ![Capt\_Kirk](https://avatars.discourse-cdn.com/v4/letter/c/779978/32.png) [@Capt\_Kirk](https://boards.straightdope.com/u/Capt_Kirk)\ **Post date:** [November 29, 2012, 2:41am UTC](https://boards.straightdope.com/t/would-a-high-altitude-sky-diver-feel-anything-as-he-broke-the-sound-barrier/642381/8 "2012-11-29T02:41:57Z")
> [@StrangerThanFiction](#): > > From the man himself, in an interview with Forbes contributor Ariel Adams: > > English is not his native language, but I think the jist of that last sentence is that people on the ground heard the boom. > > Transonic buffeting can occur on any body that experiences flow approaching 1.0 Mach. Typically, the first place this happens on an airplane is on the wings, due to the acceleration of airflow over their upper surfaces. This can happen at relatively low speeds - depending on wing design it can be less than 80% of the local speed of sound. This is often the limiting factor for maximum forward speed in civilian jet aircraft. In cruise flight, the airflow is often accelerated past 1.0M as it passes over the forward portion of the wing. As it slows back to subsonic near the back of the wing, a shockwave is formed. You can see an analog by turning on your kitchen faucet. As the water strikes the sink, it moves away in a thin, high speed layer. This layer is moving faster than the speed of wave propagation, so it is known as a supercritical flow. As the water gets further away, it slows, and a standing wave forms, with a thicker layer of water attempting to move inward. However, this wave is held in place by the supercritical thin layer of outward moving water. Essentially the same thing happens on the upper surface of a wing as an airplane begins to approach the speed of sound. The shockwave the forms on the aft portion of the wing is an area of high pressure, and we all know that air doesn’t like to move from low to high pressure. This is known as an adverse pressure gradient, and it tends to cause the boundary layer of air (immediately next to the wing skin) to separate from the wing, resulting in buffeting and loss of lift. This shock formation can be delayed, weakened, and sometimes prevented through the use of vortex generators, supercritical airfoil design, and wing planform compromises. Thank you what a great answer and a nice water analogy. I use water waves to explain audio waves as I say a wave is a wave is a wave, yes I know that is not entirely true but it works for me. **Capt**