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The Ministry of Defence is investigating reports of a loud bang that has been heard across a large part of England.
Warwickshire Fire and Rescue Service also said they were looking into what caused the mysterious noise heard at about 18:10 BST.
Reports have come from across the West Midlands, Warwickshire and Oxfordshire.
Originally posted by thefamiliar
reply to post by PurpleDog UK
Thats a highly speculative subject with talk of meteors exploding, surely this should be the correct thread as it is at present news that is breaking?
Independent claim MOD admit it was a super sonic jet with permission to fly over land but no explanation of why as yet.
usually heard as a deep double "boom" as the aircraft is usually some distance away. However, as those who have witnessed landings of space shuttles have heard, when the aircraft is nearby the sonic boom is a sharper "bang" or "crack". The sound is much like the "aerial bombs" used at firework displays.
It is a common misconception that only "one" boom is generated during the subsonic to supersonic transition, rather, the boom is continuous along the boom carpet for the entire supersonic flight. As a former Concorde pilot puts it, "You don't actually hear anything on board. All we see is the pressure wave moving down the aeroplane - it gives an indication on the instruments. And that's what we see around Mach 1. But we don't hear the sonic boom or anything like that. That's rather like the wake of ship - it's behind us.".
In 1964, NASA and the Federal Aviation Administration began the Oklahoma City sonic boom tests, which caused eight sonic booms per day over a period of six months. Valuable data was gathered from the experiment, but 15,000 complaints were generated and ultimately entangled the government in a class action lawsuit, which it lost on appeal in 1969. Sonic booms were also a nuisance in North Cornwall and North Devon as these areas were underneath the flight path of Concorde. Windows would rattle and in some cases the "torching" (pointing underneath roof slates) would be dislodged with the vibration. There has been recent work in this area, notably under DARPA's Quiet Supersonic Platform studies. Research by acoustics experts under this program began looking more closely at the composition of sonic booms, including the frequency content.
Several characteristics of the traditional sonic boom "N" wave can influence how loud and irritating it can be perceived by listeners on the ground. Even strong N-waves such as those generated by Concorde or military aircraft can be far less objectionable if the rise time of the overpressure is sufficiently long. A new metric has emerged, known as perceived loudness, measured in PLdB. This takes into account the frequency content, rise time, etc. A well known example is the snapping of your fingers in which the "perceived" sound is nothing more than an annoyance.
a Typhoon responding to an emergency call. A Coventry resident said: "I thought somebody had thrown a brick through the window." The Ministry of Defence initially said it was investigating what was behind a loud noise in Oxfordshire but a spokesman later confirmed it was from one of two RAF Typhoons that had been launched following an emergency call from a helicopter.
The helicopter had transmitted on the wrong frequency, he said. Warwickshire Fire and Rescue Service had also said it was looking into what caused the noise, after a flood of calls.
Some of those who heard it said the sound lasted a few seconds. The British Geological Survey had also said it was investigating the incident. There were reports of the noise being heard in Bath, Swindon, Coventry, Rugby and Oxford.
Originally posted by thefamiliar
Normally I'd aggree PDUK but felt in this case that discussing it instantly as a conspiracy as opposed to an unknown event was going to get pretty silly pretty quick. went to the other thread and it was indeed "Highly speculative". Given that it happened over my own head I'd like to know what it was or could plausably have been
Boom intensity is greatest directly under the flight path, progressively weakening with greater horizontal distance away from the aircraft flight track. Ground width of the boom exposure area is approximately 1 statute mile (1.6 km) for each 1,000 feet (300 m) of altitude (5 m/m); that is, an aircraft flying supersonic at 30,000 feet (9,100 m) will create a lateral boom spread of about 30 miles (48 km), or at 10,000 meters a spread of 50 kilometers. For steady supersonic flight, the boom is described as a carpet boom since it moves with the aircraft as it maintains supersonic speed and altitude.
Some maneuvers, diving, acceleration or turning, can cause focusing of the boom. Other maneuvers, such as deceleration and climbing, can reduce the strength of the shock. In some instances weather conditions can distort sonic booms. Depending on the aircraft's altitude, sonic booms reach the ground two to 60 seconds after flyover. However, not all booms are heard at ground level. The speed of sound at any altitude is a function of air temperature. A decrease or increase in temperature results in a corresponding decrease or increase in sound speed.
Under standard atmospheric conditions, air temperature decreases with increased altitude. For example, when sea-level temperature is 59 degrees Fahrenheit (15 °C), the temperature at 30,000 feet (9,100 m) drops to minus 49 degrees Fahrenheit (−45 °C). This temperature gradient helps bend the sound waves upward. Therefore, for a boom to reach the ground, the aircraft speed relative to the ground must be greater than the speed of sound at the ground. For example, the speed of sound at 30,000 feet (9,100 m) is about 670 miles (1,080 km) per hour, but an aircraft must travel at least 750 miles (1,210 km) per hour (Mach 1.12, where Mach 1 equals the speed of sound) for a boom to be heard on the ground.