Sonic Boom

[fjmeat]

That's an old Sukhoi SU-24M "Fencer". Between 0:17 and 0:19 you can hear the man exclaim "Sukhoi". It's definitely subsonic as it looks to be traveling about 300-350mph. The sound is created by air being drawn into the large rectangular engine intakes at very high velocity, which for the relatively low speed he's traveling at would be extremely loud for several hundred yards in front of the aircraft.

So you're saying the boom was audible before the jet arrived? Or no..? :\

 

[boochi]

The video and audio are not in sync. That is quite easy to discern.

 

[el-Capitan]

Came for this. Not disappointed!

 

[Train]

It's not easy for any aircraft to get over M1 at 200'. Were they over it for the whole flyby, by how much?

Booms will vary a bit according to weather, type, size, speed of the aircraft. The window's susceptibility will vary depending on its properties as well as it's orientation to the boom, the surrounding land, etc.

I don't trust mythbusters at all.

Are you saying they didn't break the sound barrier? Given the booms in the videos, as well as the instrumentation inside an F-18, I'm at least going to assume they actually broke it and didn't lie to us about that part.

 

[Minerva]

Fuck mythbusters (most reality shows).
That video looks fake as shit, it may be legit with the sound off but these days people will go all kinds of stupid ways to screw the pooch to get views. They shouldn't do that, it's probably illegal, the dog isn't going to like it, and you will get dog shit on your fuck stick.

 

[phucheneh]

Mythbuster did not really 'bust' anything. IIRC they proved that the concussion is enough to knock windows out of their frames; just not enough to break modern windows that are still firmly attached to their mountings. I'm sure they were wearing hearing protection when the jet flew over, either way.

And 'modern windows' is a key thing. Heck, I had a fairly old pane of glass out of a screen door in my garage for years. Finally got around to chucking it a few weeks ago. Wouldnt fit in the garbage bin very well, so I put it in a trash bag, braced it between a brick wall and the concrete drive, and smacked it repeatedly with a ho (lol, smacking something with a ho). Pointed edge, long handle, pretty big swings. Couldn't break the damned thing.

 

[Train]

Mythbuster did not really 'bust' anything. IIRC they proved that the concussion is enough to knock windows out of their frames; just not enough to break modern windows that are still firmly attached to their mountings. I'm sure they were wearing hearing protection when the jet flew over, either way.

And 'modern windows' is a key thing. Heck, I had a fairly old pane of glass out of a screen door in my garage for years. Finally got around to chucking it a few weeks ago. Wouldnt fit in the garbage bin very well, so I put it in a trash bag, braced it between a brick wall and the concrete drive, and smacked it repeatedly with a ho (lol, smacking something with a ho). Pointed edge, long handle, pretty big swings. Couldn't break the damned thing.

Regardless of how thorough the Myth Busters were, using the math I posted above, there is simply not enough decibels, even within 50 feet, to break auto glass, or make ears bleed, not even close.

 

[MixMasterTang]

Regardless of how thorough the Myth Busters were, using the math I posted above, there is simply not enough decibels, even within 50 feet, to break auto glass, or make ears bleed, not even close.

You'd think this was a P&N thread with so many people ignoring facts

 

[Bubbaleone]

So you're saying the boom was audible before the jet arrived? Or no..? :\

No, I said the sound (pressure wave) is produced by the Sukhoi's two very large jet engines sucking air into the intakes, below each side of the canopy, at very high velocity. That high-pressure sound wave is emanating from the front of the aircraft at the speed of sound (761.2 mph@sea level), probably twice as fast as the aircraft's speed, and at his altitude would be deafeningly loud at several hundred yards in front of the aircraft. That's what the cars occupants recorded. If you happened to be standing a quarter mile away as you observed the Sukhoi travelling at that altitude, from your left to right, you would have heard a continuous deafening roar. There was no boom.

 

[phucheneh]

Regardless of how thorough the Myth Busters were, using the math I posted above, there is simply not enough decibels, even within 50 feet, to break auto glass, or make ears bleed, not even close.

So you only consider hearing protection important if something makes your ears bleed?

And I didn't say it would break glass. I said I recalled windows being knocked from their frames in their test.

 

[Train]

So you only consider hearing protection important if something makes your ears bleed?

And I didn't say it would break glass. I said I recalled windows being knocked from their frames in their test.

Who said anything about hearing protection?

I was responding to this ridiculous assertion: http://forums.anandtech.com/showpost.php?p=35101928&postcount=4

 

[LurkerPrime]

Seems like lots of people have never heard a sonic boom in thier life in this thread. I work and live near an AFB and sonic booms are usually heard multiple times a day. It sounds like an explosion and will rattle the walls/windows of your home or office. The strength of the pressure wave associated with the sonic boom is mostly determined by the profile of the object exceeding the speed of sound.

and for reference

Sonic booms produced by aircraft flying supersonic at altitudes of less than 100 feet, creating between 20 and 144 pounds overpressure, have been experienced by humans without injury.
Damage to eardrums can be expected when overpressures reach 720 pounds. Overpressures of 2160 pounds would have to be generated to produce lung damage.
Typical overpressure of aircraft types are:

• SR-71: 0.9 pounds, speed of Mach 3, 80,000 feet
• Concorde SST: 1.94 pounds, speed of Mach 2, 52,000 feet
• F-104: 0.8 pounds, speed of Mach 1.93, 48,000 feet
• Space Shuttle: 1.25 pounds, speed of Mach 1.5, 60,000 feet, landing approach

http://www.nasa.gov/centers/dryden/news/FactSheets/FS-016-DFRC.html

 

[Gibsons]

I guess this is relevant - I don't think it's a boom, but a plenty of glass breaking.
http://www.youtube.com/watch?feature=player_detailpage&v=Xv2tal66Edw#t=10s

 

[unokitty]

I was in Coco once or twice when a Shuttle landed.

Shuttle always came in with a pair of sonic booms.

Video of Cars Reacting to Double Shuttle Sonic Boom.

Uno