h a l f b a k e r y
Is it soup yet?
add, search, annotate, link, view, overview, recent, by name, random
news, help, about, links, report a problem
or get an account
It is possible to buy such a thing as a bat detector.
This device has a microphone to pick up ultrasonic sound
(actually, all sound), and
a circuit that heterodynes it against a (selectable) high
outputting it to a speaker. The net result is that
ultrasonic sound gets
the audio range, and hence becomes hearable.
The results are really quite surprising, even in the
absence of bats. You would not
believe how much high-frequency noise there is in the
world. The jangling coins in
your pocket become cacophanous; a mechanical
wristwatch sounds like a maniacal
gong; a crisp fiver, when crumpled, becomes an artillery
barrage. All in all,
£39.99 well spent.
Howevertheless, what about infrasonics? We are assured
communicate through the ground using low-frequency
sound, and that the Earth
itself rings like a huge bell at every minor earthquake.
But can we hear this? No,
Proposed, thenceherewith, is the Infrasonic Upshifter.
Its front end is a simple
microphone, but with a relatively large mass attached to
the diaphragm. Placed
on the ground/floor/table, it will respond well to
vibrations down to a few tenths
of a Hertz.
These low-frequency vibrations are up-shifted by some
slightly clever circuitry,
into the audio range. Naturally, there will be some lag
(a 1Hz vibration will take
at least a few seconds to be registered, analyzed, and
reproduced as audio), but
that's OK - elephants say very few things that require an
What, you may ask, is the point? What if you have no
elephants nearby? Well,
who knows? The world is rich in ultrasonics that we
usually don't hear, so who
knows what variety of infrasonics are out there waiting
to be heard? That
earthquake in Eastern Pangal? The pile-driver thirty
miles away? The hitherto-
unknown infrasonic chit-chat of cows? The possibilities
female ROAR SIDESHIFTING ?
dECODER RING BETWEEN FEMALE AND MALE ELEPHANTS? [popbottle, Jan 28 2016]
||A boundary mic would be a better choice (Ive got a
Clockaudio CS4-RF boundary mic somewhere here).
||Excellent. And I have learned a new thing.
||An accelerometer would work too. The Freescale
MMA8451/8452 goes up to 800 Hz in sample rate (which
Nyquists down to 400 Hz signal).
||// The possibilities are unlimitless //
||There are certain road intersections in London where you can feel the vibration of tube trains passing underneath. This is experienced by cyclists putting one foot on the road while waiting at traffic lights because metal cycling cleats transfer these vibrations to the foot, whereas they might be absorbed by rubber-soled shoes.
||//There are certain road intersections in London where you
can feel the vibration of tube trains passing underneath.//
||We have a subway running right in front of our building,
consequently, we have to have a timetable on the wall of
the fancy microscope room. You can't do nanometre-scale
imaging if the building's wobbling by micrometers.
||I would just like to go on record as heartily endorsing this idea.
||Come the revolution, [2fries], you shall have a seat
on the council.
||You say what if we have no elephants nearby, but
using your tool it may be found that there are in fact
elephants nearby, only nobody noticed them!
||Like it. I would love to hear and see the inaudible and invisible parts of the entire frequency spectrum, light as well as sound. Nothing a little gene splicing won't take care of. (+)
||Hmm, with practice you might not only be able to detect
earthquakes but actually predict them. Hence moving the
entire cost into the 'safety budget' and more likely to get
||//elephants say very few things that require an urgent
||"Stand aside please, we're coming through."?
||Joining the two shifters together would allow the first
bat/elephant conversation since they diverged on the
evolution pathway. The elephants would say "I remember
your great, great...(2 days later), grand-father". Fortunately
the batteries would run out before the resultant squeak could