But Sound does propagate differently in materials with different density… 
I’m utterly confused.
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Troll said that sound is lower because mean pressure is lower, but that is not true.
Propagation damping is a different thing.
It’s more complicated than just looking at density.
If you only changed the elevation but not the temperature, speed of sound would not change across altitudes. That is because speed of sound in a gas depends on the ratio of pressure and density.
Humidity plays a large factor in propagation damping. So do material parameters of the ground (freshly fallen snow is a very good absorber, e.g.).
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Uhm, that is food for thought.
Sorry, not sorry… 
Did I…?
But humidity affects air density…?
You’re not weasling your way out of this one.
Yes, humidity is also not a direct function of altitude.
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Not trying to. But please explain the phenomenon so that a weaseling pilot can understand it…
Sound is air pressure, no?
AFAIK it’s affected by the density of the air.
But please explain instead of saying it’s a different thing.
I mean that! I’m eager to learn more…
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Yeah I am trying to learn more too…
EDIT: I found this that manages to make some clarity. Temperature means something in sound transmission, but not pressure.
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You have to distinguish between atmospheric pressure and sound pressure. Those are completely different things.
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Ok. But both are airpressure…? Pressure differences of the surrounding air…
Please continue.
Later, lunch break is over and I have to get some work done.
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So, to split hairs… sound is a vibration transmitted through a medium. It can be a gas, liquid or solid. This is why, in space, no one can hear you scream… 
).
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Another picture from the small meadow in the backyard. I really like the variety of colors and shapes. Though I consider to cut the bramble (sp?) back that’s growing in from the left side. Also pondering if to remove some of the concrete tiles to give the meadow more place next year…
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Absolutely stunning.
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Yearly shifting of the unit to cornwall.
Grown up looking pictures are for grown ups.
In other news, i really don’t like my new truck (first world problem) after spending 6 hours driving here. So I’m taking back the blue one when we get home and the wife is having the new one… she doesnt know this yet
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You guys are so cute…
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Yes! Out with the grey, in with the green!
And yes, do fight the brambles. They are invasive imperialist bastards and should not be allowed to colonize that absolutely gorgeous bit of meadow you got there.
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This morning a water company showed up to start some road works outside my station …to this end they have installed a three way temporary traffic light junction and narrowed the road to one lane. This is all quite normal … but they are not working in the road, they have dug up the pavement about four feet from the curb …
The only thing actually blocking the road is the spare pieces of barrier they are not using …and this is causing a mile of traffic
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Lovely, gotta follow standard safety protocols innit?
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Happens all the time here, lane blocked and speed restrictions for kilometres (usually 40km/h) because there are workers at least two or three metres from the edge of the road… Because safety, yet the workers are out in the blazing Australian Sun (extreme UV index) without sunscreen & wearing shorts and T-Shirts and/or operation high Db equipment without hearing protection.
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