John Huntington and his friends decided to test the reported phenomenon of infrasound (very low-frequency sounds) causing people to feel spooky chills and thrills, a phenomenon blamed for ghost sightings and reports of hauntings. They created a spook-house with a double-blind randomized infrasound generator and used surveys to check for a correlation between infrasound and creepy feelings. John exhaustively documented the experimental setup (and the setbacks encountered in getting things up and running), and the results. Spoiler alert: they didn't find a correlation.
We picked a 19 Hertz (Hz, or cycles per second) sine wave as our infrasound source, since that's the frequency Tandy and Lawrence had found in their initial investigation of a "haunted" space (see Part I of this series for details). For our initial tests last spring, we used an Audio Toolbox as our signal generator, and connected it up to our ancient Apogee P-10 subwoofer processor and a Crown K2 amp, which drove an Apogee AE-10 double 18" subwoofer (these units work just fine, but haven't been made in years.) We got the sound going, but after a minute or so, it would cut out. I figured out that the processor was apparently protecting the subs against the "bad" infrasound, and was cutting out. So, I bypassed the processor and its protection circuits, and (carefully) drove the subwoofers directly from the amp. This worked just fine, but I was a bit concerned about damaging the speakers themselves. Fortuitously, over the summer I managed to get for our department a massive, modern Meyer Sound 650-P powered subwoofer. And after some tests in late summer we determined that the unit could generate quite a bit of 19Hz without clipping, and we figured the level was pretty good because by the time we pushed the 650-P up to its limits, the effects of the infrasound would be obvious to anyone in the room, which wouldn't have been acceptable for our purposes.
Artists Jeff Louviere and Vanessa Brown explore cymatics, the study of wave phenomena and how they are represented visually. Using black-colored water, a laptop computer, and a modified guitar amp, they captured “portraits” of the 12 notes in the chromatic scale. From my sister-in-law Heather Sparks’s profile of their project in Nautilus: In each (“portrait”), […]
Yesterday’s science-by-press-release announcement that a research team had made a “breakthrough” in treating ALS thanks to funds raised in last year’s viral ice-bucket challenge turns out to be vaporware: the gene identified was already known to be implicated in ALS, but only affects 3% of cases, and the new refinement in the research suggests some […]
New research on trends in adult human height over the last century confirm that, no surprise, humans are getting taller overall due to better nutrition and disease control. However according to the health science group Non-Communicable Diseases Risk Factor Collaboration (NCD-RisC), the gain in adult height varies dramatically by country. From their paper, published in […]
Looks like all of your potential employers are hiring candidates with programming skills (which you don’t have). With all of the languages out there today, it’s tough to know where to start.With the Complete Front-End to Back-End Coding Bundle, you can beef your resume up in all the right places, no confusion necessary. This package of […]
Those of us who love music wish we could listen to it 24/7. But it’s impossible when we’re trying to converse with our friends, or when are swimming in the local pool.That is, until now. The KOAR Bone Conduction Bluetooth Headset, now 48% off, has changed the audio game.Made with lightweight titanium memory metal, this headset boasts patented bone conduction technology to transport sound […]
It’s one thing to enjoy dinner at home and a nice glass of Cabernet Sauvignon with your best friend, Netflix, but it’s another thing entirely to make that meal from scratch and get that wine delivered right to your doorstep.But what if we told you there’s a way to make this possible? To keep your social life, […]