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> It’s not to say that trees don’t crack—but rather that spooky noises long attributed to trees may emerge from the night sky itself. Well, it seems like he de
by karaterobot 2y ago
> It’s not to say that trees don’t crack—but rather that spooky noises long attributed to trees may emerge from the night sky itself.
Well, it seems like he demonstrated that the night sky itself can make sounds under certain conditions, not that these sounds are always the night sky.
By the way, I don't recall ever hearing the supposed tree cracking sound in an area where there were no trees. If it's always just the sky, you'd expect to hear it at least occasionally on the plains, or coming from 250' in the air above you when you're on a frozen lake.
- rini17 2y agoDepends whether the landscape is prone to inversions. They happen most often in wide and enclosed valleys.
- dylan604 2y ago> or coming from 250' in the air above you when you're on a frozen lake. If you're on a frozen lake, you much prefer the crack coming from above than below.
- deleted 2y ago[deleted]
- greenbit 2y agoAnd then of course, there are the "ice making" sounds that do come from below. And different lakes and ponds even seem to have somewhat different voices in that way.
- idatum 2y agoAnd something equally chilling -- the sound of a glacier cracking (more of a deep thud sound).
- deleted 2y ago[deleted]
- maxbond 2y agoI think that framing comes from the article rather than the Aurora researchers (I skimmed some of their papers & didn't see it mentioned), but the article claims: > Indeed, these loud cracking sounds are often attributed to large pressure splits in tree trunks, caused by sap freezing and expanding inside the tree’s interior. But while freezing sap in trees has been found to produce sounds at ultrasonic frequencies, outside of the range of human hearing, scientists have found no evidence this phenomenon might make sounds that are audible to the human ear. Though if you told me you'd heard a tree make a groan or a crack, I'd be inclined to believe it, it doesn't strike me as outlandish.
- RHSeeger 2y agoThat quote seems odd to me. Specifically, 1. The sound is attributed to trees cracking 2. The cracking is caused by sap freezing and expanding 3. Sap freezing produces sound in the ultrasonic range 4. So it's not the trees Point 4 is not a valid conclusion from 1-3, because it was never stated that the sap freezing is what is being heard. Rather, it's the trees cracking, which is _caused_ by the sap freezing... but its own thing with its own sound.
- nardi 2y agoI think you missed the last bit: > scientists have found no evidence this phenomenon might make sounds that are audible to the human ear. Which I take to mean they’ve measured ultrasounds but no audible sounds.
- bmicraft 2y ago"Found no evidence" and "didn't even try to measure" isn't really the same, is it?
- RHSeeger 2y agoI'm not sure why you say I missed that. I didn't. Can you expand on what you meant by your reply. To me, your reply actually highlights what I was talking about; because your use of "this phenomenon" is _somewhat_ ambiguous. 1. "this phenomenon" can be the sound of "large pressure splits in tree trunks, caused by sap freezing and expanding" (presumably audible to humans) 2. "this phenomenon" can be the sound of "freezing sap in trees" (presumably not audible to humans)
- slashtab 2y agoMaybe trees are affecting the rate and intensity of Inversion.
- nuc1e0n 2y agoWell thunder and lightning comes from the sky and lightning is caused by static effects of ice crystals in thunder clouds. So maybe it's something similar.