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kleinbl00  ·  355 days ago  ·  link  ·    ·  parent  ·  post: How do you combat noise and light pollution?

Ordinary consumers can't create much in the way of either light or sound pollution.

Sound is logarithmic. A doubling of power increases the sound level by 3dB. 1-2dB is basically the minimum detectable; in other words, doubling the amount of power you put into something noisy will give you a "....myeah I think I can tell the difference" level of increase. A 10dB increase is perceived as a doubling of loudness, which requires about 6.7x the power.

More than that, point-source sound radiation decreases 6dB per doubling of distance. If you are standing next to a blender making a smoothie, you're experiencing about 88dBA (if you're standing in an Abercrombie & Fitch you're experiencing 84.5 dBA but that's another story). If you take two steps away from the blender you're experiencing 82dB. Four steps away and you're at 76dB. Eight steps away and you're at 70. Sixteen steps away and you're at 64. From the end of your yard the squirrels aren't even bothered. There's nothing in your life that can really make that much noise; your threshold of pain is 120dBA and once you get 50 yards away from that it's "annoyingly loud" and another 50 yards and it's just loud.

The principle contributor of noise pollution is air travel, and it's gone down a whole bunch. An old-school 727 or 747 is legit 40dB louder getting around than a modern 787 or Embraer. Remember - 3dB is a doubling of power. So the amount of energy lost to "loud" has gone down precipitously in the past 50 years.

Light is similarly logarithmic. But more importantly, the efficiency is also related to leakage. Used to be a streetlight was a 400W metal halide fixture blasting in all directions with a mirror behind it. Now it's a 100W array of LEDs. More than that, those LEDs provide light in one direction and pass through a lens that limits it. They're also notchy from a color perspective. I know people hate 'em but they need to STFU because if your choice is "400W of blobulous spraying everywhere"

Or "100W of gimme light"

...go with the low impact.

Frankly? There's a lot to not be optimistic about but we're at a place in history where noise and light pollution have nowhere to go but down.