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  #1  
Old 04-03-2000, 11:44 AM
crnugent crnugent is offline
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My mother sent me picture printed in a south american magazine of a jet aircraft "breaking the sound barrier". It featured a jet with a conical fog-like envelope surrounding it with the nose and cockpit of the plane poking through the envelope. Pretty good doctoring if that is what it is, can't obviously tell if it is fake. I think it's BS myself.

Now, I know that the "sound barrier" is actually the event of surpassing the speed of sound, but my question is could the event of a "sonic boom" be photographed?

Thanks,
Chris

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  #2  
Old 04-03-2000, 11:50 AM
KarmaComa KarmaComa is offline
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I think that it can be seen in some cases as a kind of vapour hemi-ellipse, simply because of the air pressure buildup around the plane. The plane must be flying through moist air, or some such thing, I think/
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  #3  
Old 04-03-2000, 01:57 PM
Strainger Strainger is offline
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Schlieren photography
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  #4  
Old 04-03-2000, 02:54 PM
Ike Witt Ike Witt is online now
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A couple of weeks ago on The Discovery Channel, they had a show about the Thrust SSC. Some of the pictures had the 'sound barrier' clearly visible.

The sound barrier is about breaking through the build of air infront of a vehicle that is moving at high speeds. If there is any dust in the air it will reflect light and make the 'barrier' visible.
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  #5  
Old 04-03-2000, 03:01 PM
Strainger Strainger is offline
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More details on Schlieren photography
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  #6  
Old 04-03-2000, 03:27 PM
crnugent crnugent is offline
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Thanks. OK, I'm a dork. I should have searched the web a little more. Here's a web page with not only several pictures of the phenomenon I'm now believing in, but it links to an MPEG file as well. Way cool.

Thanks to all. KarmaComa wins the prize.

Chris

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C R Nugent mailto:crnugent@tamu.edu
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Oceanography - TAMU http://www-ocean.tamu.edu/~nugent
Ph409)845-5767
Fax409)845-6331 Lex clavitoris designati rescindenda est!
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  #7  
Old 04-03-2000, 03:28 PM
crnugent crnugent is offline
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Thanks. OK, I'm a dork. I should have searched the web a little more. Here's a web page with not only several pictures of the phenomenon I'm now believing in, but it links to an MPEG file as well. Way cool.

Thanks to all. KarmaComa wins the prize.

Chris

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C R Nugent mailto:crnugent@tamu.edu
Research Assistant
Oceanography - TAMU http://www-ocean.tamu.edu/~nugent
Ph409)845-5767
Fax409)845-6331 Lex clavitoris designati rescindenda est!
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"As far as I'm concerned, there won't be a Beatles reunion as long as John Lennon remains dead." George Harrison
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  #8  
Old 04-03-2000, 07:45 PM
Johnny L.A. Johnny L.A. is online now
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Yes, the photo is real.

FTR, I saw VX-4's black "Playboy Bunny" Phantom (tail # 3783) do the same thing on a damp day at NAS Pt. Mugu.



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  #9  
Old 04-03-2000, 07:52 PM
UncleBeer UncleBeer is offline
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How 'bout this photo of a F/A-18 Hornet from the U.S. Navy archives
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  #10  
Old 04-03-2000, 08:54 PM
the_nuge the_nuge is offline
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Truely a dork... I got home and see I double posted *and* left out the URL:
http://artbell.com/graphics15.html

One movie and three still photos of planes breaking the sound barrier.

Chris (aka crnugent, aka the_nuge) Nugent
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  #11  
Old 04-04-2000, 06:12 AM
Milton De La Warre Milton De La Warre is offline
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The photo is very real. I've seen the phenomena myself quite a few times. Often times when the aircraft would pass the carriers and tap their afterburners to accelerate through Mach 1, this would be seen. The shock wave apparently condenses the moisture in the air to produce the distinct disc-shaped cloud. There are lots of pictures available of it, including posters that you can buy through the various aviation enthusiast shops.

This particular disc cloud is unique to busting Mach. But there are various forms of contrails which form at somewhat lower air velocity which have also been seen and photographed many times. Airliners taking off and landing in humid air will produce brief wingtip contrails, as will heliocopter blade tips. Sometimes aircraft moving at high alpha angles (high angles of attack) will produce breif moments of condensation over the entire upper surface of the wings. You can see this sometimes in films of military aircraft making sharp turns or steep climbs at airshows.
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  #12  
Old 04-04-2000, 08:46 AM
DougC DougC is offline
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- - - Art gets a gold star for putting that movie on his site. Take the time to watch it if you haven't: it is very cool. - MC
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  #13  
Old 04-04-2000, 10:05 AM
Strainger Strainger is offline
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In one of my fluids labs (undergrad aerospace engineering), we took Schlieren photos of wedges in a supersonic wind tunnel. I wasn't aware of the ability to obtain Schlieren photographs of aircraft in flight until I found that site that I linked to in my first posting above. That's because that particular aspect of Schlieren photography wasn't developed (heh) until 1993, after I had graduated. Oh, and, shouldn't it be me who gets the prize?

By the way, avoid the Art Bell links. That tends to screw up the credibility.

(Thanks also to Gas Dynamics by James John for giving me the spelling of Schlieren so that I could get the damn search engine to work properly.)
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  #14  
Old 04-04-2000, 10:29 AM
crnugent crnugent is offline
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In truth you share the prize. The type of photograph I sought was described by KarmaComa and found on the Art Bell site (among others), but you came up with an answer to the question as I worded it as well.

About Art Bell... don't know much about him but yeah I looked at his other stuff and thought "maybe a kook" but he does say some of his stuff (on this particular series of photos) is "faked" and some of the sources for the "sound barrier" material is listed. You've got to admit that video is pretty impressive.

Chris
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  #15  
Old 04-05-2000, 05:33 PM
Irishman Irishman is online now
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But it was on Art Bell - it can't be real!
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  #16  
Old 04-06-2000, 01:27 AM
MrWhy MrWhy is offline
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I've heard that if you are near to an aircraft that is going faster than Mach 1 you can actually suffer serious physical harm (death?) from the shock wave. Also, the shock wave can destroy trees buildings etc.

Is this true? How close do you have to be?

If it is true, how do these pictures/videos get taken?
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  #17  
Old 04-06-2000, 11:51 AM
InutilisVisEst InutilisVisEst is offline
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MrWhy -
Worry not: they're taken by a chase plane, and the cone shape of the shock wave guarantees that the photographer is well out of harm's way. Imagine trying to pan your camera as a Mach 1 plane passed you. For that matter, imagine trying to break Mach exactly beside a stationary cameraman.

It is said that Phantom pilots in Vietnam who ran out of munitions but still had fuel would make supersonic low-level passes over villages to harass, injure or kill inhabitants. I can't confirm or refute this, though. Certainly a deaf VC isn't gonna hear soldiers creeping through the jungle.

Project SLAM (nuclear-powered cruise missle) designers planned for the weapon to do damage after its submunitions were expended. It would fly at Mach 3 at treetop level (aerodynamic heating was a a major design concern) and spew radioactive bits from its unshielded reactor. Deaf, internal hemorrhage victims who lived would later die of radiation sickness. The project was cancelled.

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  #18  
Old 04-07-2000, 12:20 AM
Guy Propski Guy Propski is offline
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MrWhy--I think there's a very good reason why you'd get hurt if you were near a plane going Mach 1. That would mean that you are 50,000 feet or more in the air, and you will shortly fall to your death.
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