Medical and Hospital News  
IRON AND ICE
Origin of spooky meteor noises reappraised by Sandia researchers
by Staff Writers
Albuquerque NM (SPX) Feb 22, 2017


Sounds concurrent with a meteor's arrival "must be associated with some form of electromagnetic energy generated by the meteor, propagated to the vicinity of the observer and transduced into acoustic waves," according to the article. "A succession of light-pulse-produced pressure waves can then manifest as sound to a nearby observer."

When a meteor is about to conk your neighborhood and gives fair warning by emitting sizzling, rustling and hissing sounds as it descends, you might think that the universe is being sporting.

But these auditory warnings, which do occur, seem contrary to the laws of physics if they are caused by the friction of the fast-moving meteor or asteroid plunging into Earth's atmosphere. Because sound travels far slower than light, the sounds should arrive several minutes after the meteor hits, rather than accompany or even precede it.

So maybe atmospheric shock waves from the meteors are not the cause of the spooky noises.

Another theory is that the sounds are created by radio frequency emissions. That seems unlikely without designated receivers.

But what if the sounds are caused by the brilliant, pulsating light emitted by the asteroid as it burns up in Earth's atmosphere?

In an article published in the journal Scientific Reports, the late Sandia National Laboratories researcher Richard Spalding reasoned that such intense light could suddenly heat the surface of objects many miles away, which in turn heats the surrounding air. This could create sounds near the observer. Colleagues John Tencer, William Sweatt, Ben Conley, Roy Hogan, Mark Boslough and Gigi Gonzales, along with Pavel Spurny from the Astronomical Institute of the Czech Republic, experimentally demonstrated and analyzed that effect.

They found that objects with low conductivity, such as leaves, grass, dark paint and even hair, could rapidly warm and transmit heat into nearby air and generate pressure waves by subtle oscillations that create a variety of sounds. The process is called photoacoustic coupling.

Sounds concurrent with a meteor's arrival "must be associated with some form of electromagnetic energy generated by the meteor, propagated to the vicinity of the observer and transduced into acoustic waves," according to the article. "A succession of light-pulse-produced pressure waves can then manifest as sound to a nearby observer."

The experimenters exposed several materials, including dark cloths and a wig, to intense pulsing light akin to that produced by a fireball. The process produced faint sounds similar to rustling leaves or faint whispers. Computer models bear out the results.

A less extreme version of the photoacoustic effect had been observed in 1880 by Alexander Graham Bell when, testing the possibilities of light for long-distance phone transmissions, he intermittently interrupted sunlight shining on a variety of materials and noted the sounds produced.


Comment on this article using your Disqus, Facebook, Google or Twitter login.


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.
SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only


.


Related Links
Sandia National Laboratories
Asteroid and Comet Mission News, Science and Technology






Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
IRON AND ICE
Russian scientists find 13kg of meteorites in Iranian Desert
Moscow (Sputnik) Feb 14, 2017
A team of Russian geologists from Ural Federal University recently returned from an expedition in the Lut desert in the east of Iran. The team found 13 kilograms of meteorite-like material. Sputnik Persian spoke with Viktor Grokhovsky a member of the Committee on Meteorites at the Academy of Sciences. "We planned to send an expedition to the Iranian desert Lut, intending to find a concentration ... read more


IRON AND ICE
Bringing satellites to users can improve public health and safety

DR Congo snubs calls for inquiry of massacre video

British Museum training Iraqi experts to save Mosul heritage

'Scorpion' robot mission inside Fukushima reactor aborted

IRON AND ICE
GLONASS station in India to expedite 'space centric' warfare command

Australia and Lockheed field 2nd-Gen sat-based augmentation system

UK may lose access to EU Galileo GPS system after Brexit

Falsifying Galileo satellite signals will become more difficult

IRON AND ICE
Flat-footed fighters

Advances in imaging could deepen knowledge of brain

Study: The human brain always has a backup plan

Study links working remotely to more stress, insomnia

IRON AND ICE
Decline of grass threatens world's most endangered antelope

Gabon's forest elephants slain for ivory at alarming rate

How ants find their way in the desert

Indonesian orangutan brutally killed and eaten

IRON AND ICE
Bird-flu deaths rise in China, shutting poultry markets

Test can detect HIV within a week of infection: researchers

At least five infected with HIV at Chinese traditional medicine hospital

West Nile virus epidemics made worse by drought: study

IRON AND ICE
Villagers glorify their children in China festival

Hong Kong police jailed over attack on democracy protester

Struggle against evil sparks China ritual

Ex-VP of China's top court jailed for life over graft

IRON AND ICE
Philippines seeks US, China help to combat sea pirates

IRON AND ICE








The content herein, unless otherwise known to be public domain, are Copyright 1995-2024 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. General Data Protection Regulation (GDPR) Statement Our advertisers use various cookies and the like to deliver the best ad banner available at one time. All network advertising suppliers have GDPR policies (Legitimate Interest) that conform with EU regulations for data collection. By using our websites you consent to cookie based advertising. If you do not agree with this then you must stop using the websites from May 25, 2018. Privacy Statement. Additional information can be found here at About Us.