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?
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/
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.
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. 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.
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.
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.)
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.
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?
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.
I lead a boring life of relative unimportance. Really.
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.
