[HN Gopher] Balloon detects first signs of a 'sound tunnel' in t...
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Balloon detects first signs of a 'sound tunnel' in the sky
Author : amichail
Score : 141 points
Date : 2022-04-28 13:40 UTC (9 hours ago)
(HTM) web link (www.science.org)
(TXT) w3m dump (www.science.org)
| zackmorris wrote:
| The link in the article about measuring global warming by the
| speed of sound through the SOFAR channel is genius IMHO:
|
| https://www.science.org/content/article/ocean-s-hidden-heat-...
|
| The embedded video shows how much energy in zettajoules the ocean
| has absorbed at the 20 second mark:
|
| https://www.youtube.com/watch?v=kPH1TFgv6m8
|
| This is stuff that just can't be unseen, regardless of how hard
| deniers keep denying.
| dontcare007 wrote:
| Wow, knowingly releasing data that could negatively affect
| National Security.... -
|
| "We didn't tell the Navy that if you published the signal,
| which we did, then you could figure out where the receivers
| were,"
| dontcare007 wrote:
| Negative points and no discussion of why? The quote was in
| the first of the linked articles.
| jiveturkey wrote:
| > regardless of how hard deniers keep denying.
|
| sorry, but lol. We've had very good evidence for some time.
| This is "just" something additional. The deniers aren't
| operating on evidence.
| jkubicek wrote:
| You can't reason people out of a position they didn't reason
| themselves into in the first place
| zmgsabst wrote:
| That chart claims there's 0 ZJ in 1970... which seems unlikely,
| since the planet wasn't at absolute zero then.
|
| I think you'd come across as more credible if the chart showed
| the contextualized change -- rather than clearly being edited
| for dramatic effect.
| ErikVandeWater wrote:
| It's funny how this thread is making fun of people for not
| taking climate change seriously when the thing that "can't be
| unseen" is a chart with no title and no error bars that cuts
| off ~9 years before the video was published.
| dontcare007 wrote:
| Wow, knowingly releasing data that could negatively affect
| National Security.... -
|
| "We didn't tell the Navy that if you published the signal, which
| we did, then you could figure out where the receivers were,"
| JoeDaDude wrote:
| Some people are so nitpicky...
|
| From TFA: "He instigated a top-secret experiment, code-named
| Project Mogul, that sent up hot air balloons equipped..."
|
| I believe this is an error. Per Wikipedia [1]: "...rubber
| meteorological balloons, however, these were quickly replaced by
| enormous balloons made of polyethylene plastic. These were more
| durable, leaked less helium...". So the Project Mogul balloons
| were NOT hot air balloons. Which is not surprising. To fulfill
| the mission, a hot air balloon would have to carry fuel and
| perform controlled burns to maintain altitude. Not that this
| would be impossible, it is just easier IMHO to release ballast.
|
| [1]. https://en.wikipedia.org/wiki/Project_Mogul
| wolverine876 wrote:
| Why do you trust one source and not the other?
| kurthr wrote:
| Because simple hot air balloons (without gas buoyancy) would
| not be very effective at this sort of problem. It makes much
| more sense to use He lift weather balloons (even if they use
| temperature controlled solar power to maintain proper
| buoyancy).
|
| I'm just looking at the pictures, but they don't look/lift
| like simple hot air balloons to me. I'd lean toward the
| science writer simplifying the language.
| JoeDaDude wrote:
| It's not just one source over the other, it is also the
| impracticality of the hot air balloon for this purpose, as I
| stated in my post.
|
| This observation, borne out of my (admittedly brief) exposure
| to both hot air balloons (I know hot air balloon pilots and
| have ridden with them) and weather balloons (I planned, but
| did not execute, a project with my son's boy scout troop to
| launch a weather balloon to the stratosphere), combined with
| my engineering instincts (FWIW), convinced that the Wikipedia
| source was correct.
| grugq wrote:
| Related. Here is a good lecture on project modul, the initial
| work looking at sound propagation in the atmosphere.
|
| https://www.youtube.com/watch?v=k4ygiQHSNDc
| areoform wrote:
| Wasn't this exactly what the Project Mogul, the project thought
| to have sparked off the entire Roswell alien saga, was doing?
|
| https://en.wikipedia.org/wiki/Project_Mogul
|
| Is this the first time that the channel has been publicly
| verified? Or, in other words, has the data for the existence of
| this channel been known for some time and kept classified? Or, is
| there something else going on?
|
| edit - yes, I've read the article. And while the article mentions
| this. It doesn't seem to go into detail about what Mogul actually
| found, and how this diverges. At least not to my understanding of
| the text,
|
| > After geophysicist Maurice Ewing discovered the SOFAR channel
| in 1944, he set out to find an analogous layer in the sky. At an
| altitude of between 10 and 20 kilometers is the tropopause, the
| boundary between the troposphere, the lowest layer of the
| atmosphere (where weather occurs), and the stratosphere. Like the
| marine SOFAR, the tropopause represents a cold region, where
| sound waves should travel slower and farther. An acoustic
| waveguide in the atmosphere, Ewing reasoned, would allow the U.S.
| Air Force to listen for nuclear weapon tests detonated by the
| Soviet Union. He instigated a top-secret experiment, code-named
| Project Mogul, that sent up hot air balloons equipped with
| infrasound microphones.
|
| > The instruments often malfunctioned in the high winds, and in
| 1947, debris from one balloon crashed just outside of Roswell,
| New Mexico; that crash sparked one of the most famous UFO
| conspiracy theories in history. Soon after, the military
| disbanded the project. But the mission wasn't declassified for
| nearly 50 years. By then, Cold War tensions had settled and
| research in atmospheric acoustics had all but died out, says
| Stephen McNutt, a volcanic seismologist at the University of
| South Florida. "All of a sudden, the rug got pulled out, and
| infrasound wasn't funded for 30 or 40 years," he says.
|
| > But Sarah Albert, a geophysicist at Sandia National
| Laboratories in New Mexico, never gave up on the idea. She was
| intrigued by the potential of new solar-powered balloons that can
| float passively at stable altitudes and wireless telemetry that
| can broadcast data continuously over long ranges.
|
| I raised this because the article seems to be a bit incorrect,
| because geophysical MASINT continues to be an important part of
| intelligence gathering.
| https://en.wikipedia.org/wiki/Geophysical_MASINT
|
| The DNI has a public primer on it,
| https://www.dni.gov/files/ODNI/documents/21-113_MASINT_Prime...
|
| Directly after Project Mogul, there was Project Skyhook,
| https://en.wikipedia.org/wiki/Skyhook_balloon , which IIRC
| included a number of sensors including microphones.
|
| I'm struggling to understand whether or not they actually
| verified something that seemingly was known since the 1940s?
| smm11 wrote:
| Then a couple years later we chucked Starfish Prime into space
| to see what might happen.
| ancientworldnow wrote:
| The article discusses this if you read it.
| xeromal wrote:
| Yeah, they mention this in the article.
| [deleted]
| InitialLastName wrote:
| Per the article, the main issue with Project Mogul is that the
| detection equipment wasn't reliable enough to confirm the
| channel (even just getting a weather balloon to stay at a
| constant altitude is difficult); the project fell into the low-
| priority list for military research and (due to being
| classified until recently) wasn't visible to the general
| public.
|
| Even now, researchers have only detected "signs" of an evasive
| channel; it appears to be far more inconsistent than the analog
| in the ocean (which makes intuitive sense, since pressures and
| temperatures in the atmosphere are far more variable than in
| the ocean).
| MentallyRetired wrote:
| Correct me if I'm wrong, but won't this inevitably lead to
| articles with the title "Researchers detect subsonic boom but
| can't identify the source"? What other possible benefits could
| this have? Surely we know about the earthquakes this article says
| the "tunnel" it will detect.
| 8bitsrule wrote:
| Article: "But to their surprise, the scientists also picked up
| other sounds in the channel. "There's infrasound events of
| unknown nature that occur several times per hour," says Daniel
| Bowman, a geophysicist at Sandia and collaborator on the
| project. "And there's no good explanation."
|
| This could help sort out those worldwide "hum" problems ('Taos
| Hum','Windsor Hum'. [https://en.wikipedia.org/wiki/The_Hum]
| revolvingocelot wrote:
| FWIW the now-silent Windsor Hum seems to have been a
| (particularly ill-maintained) steel plant on Zug Island,
| across the Detroit River.
|
| https://windsor.ctvnews.ca/infamous-windsor-hum-finally-
| dies...
| xeromal wrote:
| They're seeking similar benefit to the tunnel in the ocean.
| Sure, they can't figure out what it is now but over time they
| can improve it. Could be very useful to detecting volcanoes for
| instance.
| aaron695 wrote:
| The fact they are using solar balloons is pretty interesting.
|
| Here's how they made it for ~$30 -
| https://journals.ametsoc.org/view/journals/atot/37/6/JTECH-D...
|
| Fun version on Amazon for ~$30 - https://www.amazon.com/TEDCO-
| Tedcotoys-Activity-50-foot-Ball...
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(page generated 2022-04-28 23:00 UTC)