Bwah?
This. If you could hear a ceremonial cannon shot at ten miles, then everyone in the immediate vicinity of the cannon would be coughing up blood and suffering from shattered eardrums.
Ten miles isn’t really all that long a distance. Granted, it’s a ceremonial shot, so we should be wary of comparing it to anything, but rifle fire is easily heard at a distance of 5 miles. An ordinary handgun can be heard at 2.
Doesn’t seem that big a deal for a cannon to be heard at 10 miles. Prevailing conditions, intervening terrain etc are going to me a difference, obviously.
I never go anywhere without a solid diamond rod extending between my ear and Big Ben. It’s OK when moving towards the clock, the real hassle is when I have to fuse on ever more diamonds, like when I go swimming.
I would guess that if you were hearing the actual cannon, then it went through the ground and was then amplified by some “antenna” structure like a building or something.
There’s also the wind. If you’re downwind, you can add the wind velocity to your speed of sound. That’s only going to be 20, tops, at the surface, though.
For the same SPL at twice the distance, you need four times the power at the source. Four times as loud as a rifle shot? That’s going to be a very loud cannon shot.
Ceremonial cannon shot as well let’s not forget, not we need to hurl this 155mm shell 25 kilometres down range kind of boom.
But some of us want our ceremonial artillery salutes to use live ammo!
Yes. I wouldn’t be terribly surprised if the report from an Iowa-class battleship firing a broadside could be heard ten miles away. But a ceremonial shot? Doubtful. BBC reports the cannon shots as “deafening,” but I would think that’s an exaggeration; knowing that thousands are in attendance who aren’t wearing hearing protection, I have to believe the shots were rather tame.
Video of event. First cannon shot at 0:54.
Perhaps the sound was conducted via neutrinos and tunneled through an alternate dimension?
Well it seems that the laws of physics were wrong about nothing being able to go faster then the speed of light.
Maybe the laws of acoustics suffer from a fundamental flaw aswell ?
A cannon four times as loud as a rifle doesn’t seem like an extraordinary thing to my (admittedly unqualified) imagination - it is not a linear scale?
Anyway, the above is assuming an ideal scenario - any number of prevailing factors could have focused or channeled the sound waves.
It probably wasn’t a cannon ten miles away, because of the timings, but I’m pretty sure there are fairly reliable accounts of cannon being heard *hundreds *of miles distant.
For an operational piece of military hardware that’s trying to launch a heavy projectile across a useful distance while soldiers nearby turn their heads and cover their ears? No, not particularly loud. But for a ceremonial one that’s merely being used to mark a particular instant in time while civilians gather nearby without ear protection, that’s very loud.
In a busy city? I can understand hearing gunshots at a few miles away in the countryside, but in central London?
The sound would also be blocked by intervening buildings.
It could take days to travel ten miles if the sound was boxed and sent by Royal Mail. Did you check the postmark date?
No, that would be when they finally get that sea wall up.
Well did the “BOOM” sound rather high pitched and squeaky?
I imagine the city was significantly less busy than usual at that precise moment in time, given the occasion, but why not? The presence of many hard surfaces near the origin of the sound might actually help it carry further in certain directions. I’d expect quicker attenuation in a forest than a city.
But as I said above, It seems unlikely on the basis of timing alone that the sound heard by the OP was the directly-transmitted sound of the cannon in the city centre. Assuming 10 miles North of the city means somewhere around Enfield or Potters Bar, there are a number of large green spaces in which some local version of the salute may have happened.
The denser the medium, the faster sound travels through it. In a dense enough medium my understanding is that sound could quite easily travel ten miles in ten seconds.
In fact, and going a little off-topic, I got the impression a few years back that the mass of a neutron star (?) was limited at around the density where the speed of sound approached the speed of light. I’m pretty sure I’m probably wrong about that, but I’d like to hear why.