> Mouritsen thinks, that the reason those warblers left Tennessee was not because they heard wisps of a distant superstorm but because of changes in atmospheric pressure.
Sound is changes in atmospheric pressure, and we're talking about infrasound which is really low frequency, so there's not exactly a sharp distinction here.
There's still a pretty good distinction here. The baseline pressure actually changing vs. the pressure rising and falling every 4 seconds over and over.
TLDR - the pigeon problem coincided with high-decibel infrasound from sonic booms from the Concorde SST. That suggests they were temporarily deafened in that frequency band. (At 11 octaves below middle C, they're sensitive to anything over 0.1 Hertz.)
Is it actually possible to be specifically deafened at such a low frequency? There's no resonance down there, and it would be so much lower energy. I would expect all other hearing to be severely and possibly permanently impacted before infrasound could be deafened.
I'd like something that keeps pigeons off my balcony. Surprisingly little works. I have a motion detecting sonic alarm that doesn't work - maybe it's in the wrong frequency for pigeons. I wonder if a motion detecting laser frightener would work better. Kickstarter anyone?
I've got a feeling in a couple decades the military will declassify how they used some kind of new ULF device to talk to submarines and it had a power level equal to nuclear weapons.
And that as a side effect it screwed up all kinds of wildlife.
For sure this is interesting, but it's curious that articles of this sort are appearing on HN with increasing frequency. There used to be purely tech news, now it seems that anything interesting qualifies for an up vote.
The first page alone includes articles on the migration of monarch butterflies, boardinghouses, income taxes by US counties, doodles by medieval kids, health benefits of eating nuts, and more.
Two people have posted the guidelines. Here's the guidelines from 2008, which shows that this intellectually curious thing has been there for many years.
> On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity.
"On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity."
A post like the parent and a reply of the guidelines happens multiple times per weekend. I wonder when the complainers will notice the pattern and accept it.
For what it's worth, I love reading HN, compared to other news sites.
It's a refreshing change from say, Reddit's technology subreddits, which are a continuous regurgitation of the same old Comcast, Google, Apple and Microsoft opinions every single day; a thinly-veiled political and astroturfing soapbox at best, where anything remotely interesting in regards to what we're learning about this universe and how our technology applies to it, barely gets above 50 points.
Sound is changes in atmospheric pressure, and we're talking about infrasound which is really low frequency, so there's not exactly a sharp distinction here.