How To Hear Halfway Around The World

Thanks to CTBTO for sponsoring this video: www.ctbto.org
Sounds in the ocean can travel more than 10,000 miles - that's halfway around the world! Here's how.
LEARN MORE
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To learn more about this topic, start your googling with these keywords:
Refraction: the bending of a sound wave based on changes in the wave's speed
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CREDITS
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This video was produced by:
Kate Yoshida | Script Writer, Narrator and Director
Arcadi Garcia Rius | Illustration, Video Editing and Animation
Nathaniel Schroeder | Music
MinuteEarth is produced by Neptune Studios LLC
neptunestudios.info
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Sarah Berman • Arcadi Garcia Rius
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REFERENCES
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Heaney, K.D., Kuperman, W.A., and McDonald, B. E. (1960). Perth-Bermuda sound propagation: Adiabatic mode interpretation. Journal of the Acoustical Society of America, 90, 2586-2594, 1991. asa.scitation.org/doi/10.1121...
Munk, W.H, Spindel, R.C., Baggeroer, A., Birdsall, T. G. (1994). The Heard Island Feasibility Test, Journal of the Acoustical Society of America, 96, 2330-2342. asa.scitation.org/doi/10.1121...
Payne, R. S., and Webb, D. (1971). Orientation by means of long range acoustic signaling in baleen whales. Annals of the New York Academy of Sciences 188:110-141. www.thecre.com/sefReports/wp-...
Shockley, R. C., Northrop, J., Hansen, P. G. Hartdegen, C. (1982) SOFAR propagation paths from Australia to Bermuda: Comparision of signal speed algorithms and experiments, Journal of the Acoustical Society of America, 71, 51-60. asa.scitation.org/doi/10.1121...

[@MinuteEarth]

We're always glad to hear your support, no matter where you are in the world! Want to become our Patreon or member on KZbin? Just visit www.patreon.com/MinuteEarth or click "JOIN". Thanks!

[@abinothayyilsanoj4182]

Is it because you made it private ?

[@Henry-zk9sy]

MinuteEarth love ur vids

[@arnavsharma8914]

This is like Total internal reflection (in fibre optics) but with sound.

[@jonasarnesen6825]

To hear so far is easy. Be a wale.

[@alto7183]

Aun hay muchas cosas que desconocen del océano, así como océanos de otros planetas, si estuviera marte terraformado 0.55g g con una luna y atmósfera respirable con océanos planeados y trazados por ingeniería verían un nuevo océano y otro tipo de comportamiento del agua, se asombrarse como cambios en salinidad, presión del agua y gravedad afectan todo, teniendo una variabilidad que permite varios océanos, criaturas y planetas, sin dejar de ser realista. Observación.

[@icrisologo]

Like fiber optics but for sounds!

[@icebox6240]

oMg 19 HoUrS aGo HoW!!!!???

[@burkiwa]

That's what I was thinkin'

[@Scudzzorz15]

Time traveler confirmed.

[@abinothayyilsanoj4182]

This video wasn't a premier right ? Then how ?

[@abinothayyilsanoj4182]

Is it because it was private video?

[@traskforge]

Imagine being a whale trying to go to sleep and you suddenly hear your best friend talking crap about you from a thousand miles away

[@hamiltonianpathondodecahed5236]

ngl that's literally me and my brain

[@justaviewer5150]

@@hamiltonianpathondodecahed5236 yes ur brain and ur you from miles away short.

[@cheezergaming]

@@justaviewer5150 r/woosh

[@pizzatime4024]

GEORGE I THOUGHT WE WERE FRIENDS

[@FelipeFigueroaG]

In WWII (way before GPS was a thing), sofar bombs of spheres where used by downed planes and navy ships as a way to transmit their position. It was basically a bomb design to be thrown overboard and it would explode at the correct depth of the sofar channel. With at least 3 listening stations on shore, you could triangulate the position of the detonation with pretty good accuracy.

[@kjhcvfggrrgh327]

cool

[@ananas_anna]

The pun at the end of this one was actually pretty good.

[@nickkayfabe6147]

It sounds pretty good

[@Shon_-]

'Always have been'

[@luthfimuhammad3068]

I've already expected it when she said SOFAR at first, sounded pretty punny..

[@NatetheNerdy]

This water channel is responsible for Roswell. The scientist who discovered it wondered if there was a similar channel in the air (there is), so he got the US government to fund research into it. The government wanted to be able to hear if Russia did anything with nukes in the air without them knowing we were listening, so the whole operation was hush hush. When one of their listening balloons fell onto a New Mexico ranch, the military moved in to make sure Soviets couldn't get there first, but also weren't 100% what they should say as to why they were there. So yes, Roswell was a cover-up, but not in the way most conspiracy theories say.

[@jackcr2477]

NateTheNerdy Do you have a source for this? Be really interested to read more about it

[@NatetheNerdy]

@@jackcr2477 The Internet Historian on KZbin is the only one I can identify. I know I've seen at least one other video talking about this, and read a quick article or two, but I'm not sure who wrote those. Also, Project Blue Book was basically the same thing, covering the evidence of government experiments misidentified as aliens by claiming they're swamp gas. Quinton Reviews has a video going more in depth on that.

[@user-dh8tu8jz1x]

kzbin.info/www/bejne/oWXcmJyHfbiBesU That should help! It's a lecture by Robert A Muller regarding the true nature of events that led up to the Roswell alien conspiracy

[@SimonClarkstone]

Intriguing; I had thought it was a secret radar-reflector technology being tested on a balloon that was covered up.

[@werh227]

This is what was developed into sonar, correct?

[@husaynbootwala1729]

You just explained total internal reflection of waves in the most interesting way possible.

[@advanceringnewholder]

Hey, that sounds bouncing off, that sounds familiar. It's kinda like the total internal reflection

[@abinothayyilsanoj4182]

Yep like a optical fibre.

[@jasonreed7522]

That is exactly what happened, the equations for waves don't care if its sound, light, or voltage. With only a little fudging the sofar channel and fiber optics are the same type of waveguide.

[@cylo5264]

Hey i just replied to you on xizuma's channel what are the chances of us seeing each other on two different videos so quickly

[@piotrgradkowski6810]

The analogy doesn't stop there. The speed of light in the fiber is smaller than in air or vacuum.

[@cylo5264]

@@piotrgradkowski6810 nothing can exceed speed of light it is the maximum speed anything can have in the universe speed of lights is technically not slower in fiber optic cables they just have to travel a longer distance in them as they don't go in a straight line in fiber optic cables and they are also absorbed by some particles and then rereleased

[@Samuftie]

Did whales got startled and confused like like "what the hell was that???"

[@EmilyRose-op1gd]

probably yeah

[@frankwu4747]

Search for underwater noise pollution.

[@moonrazk]

"What the heck, that was Joe's voice for sure, but he's supposed to be on the other side of the world!"

[@letter_o_hyphen_letter_o]

When you say hi to the guy on the other side of the world and hear him reply 8 hours later

[@Samuftie]

@@frankwu4747 what does it affect?

[@Saxshoe]

I can't believe Internet Historian got to this topic before MinuteEarth

[@BitterTast3]

Which video?

[@abdullaalsulaiti1803]

Interesting

[@flowerwithamachinegun2692]

For anyone interested, it's the video on the Roswell Incident kzbin.info/www/bejne/jIWUY2t7oaeKoa8

[@anthonyanth8368]

@@flowerwithamachinegun2692 will check it out. Thanks. Have a great day

[@ericyt7589]

when you hear references to "the layer" in submarine books/movies, this is what they're talking about. it's rather important in submarine warfare due to the sound trapping qualities.

[@zuthalsoraniz6764]

That's not quite correct - military submarines cannot dive down to the SOFAR channel. The layer, as well as a related phenomenon, the surface duct, occur when the temperature of the water, and thus the speed of sound, changes rapidly with depth. This causes sound waves that hit this layer at a shallow enough angle to reflect off of it, and so for example a submarine that is sitting just below the layer can be extremely hard to detect for sufficiently far away surface ships. The duct occurs when sound waves are repeatedly reflected between the layer and the ocean surface, which can otoh greatly increase the range of sonar detection for objects that are within the duct.

[@xxOmponxx]

Jive Turkey, retired submariner, made a good video about the layer. I recommend anyone interested check it out.

[@AverytheCubanAmerican]

Using a Bomb-omb to represent explosives? Nice touch for Mario’s 35th

[@olek0]

i spotted that too

[@phosphorus4]

It's called a Bob-omb. Took me a while too.

[@Villanotrh]

Scientits : *creates explosion at the sofar channel Grandpa whales : *get war flashback

[@theMxiden6fF7re]

Minuteearth: A sound wave has traveled from Perth to Bermuda. Me: *Water* you talking about? I can't *sea* how that's possible. Wow, that's a lot of likes. Thanks!

[@Deinobi]

*posseable

[@theMxiden6fF7re]

@@Deinobi lol

[@KuruGDI]

You should write their puns

[@theMxiden6fF7re]

@@KuruGDI How? The closest one to me is Ever, and he's in Venezuela (probably). But sure, why not. As long as I don't get *pun* -ished by the mayor of pun city.

[@alba2162]

Water you doing, clam it

[@SupremeLeaderKimJong-un]

Pretty cool you can hear sounds from halfway around the world. I want the world to fear me when I launch missiles

[@GassWitNoG]

I know ur gonna be top comment and blow my head off so im commenting so im on your good side

[@Bruh1]

@@GassWitNoG fax

[@orion6983]

Is Is... Is the supreme leader

[@bobby_greene]

@@orion6983 he is Dear Leader! you go to re-education camp.

[@pranit_33xa91]

Who is better Kim Jong - Un or Kim Kardashian ?

[@nosferathu258]

Minute earth is the best pun channel on YT. The science content is a nice bonus.

[@alexf9480]

When you're too early: You have no idea what to write When you're too late: All the good ideas are taken

[@gabizavrski3898]

this is the most accurate thing on the planet

[@abinothayyilsanoj4182]

Yet you got it 🙂

[@sailor5853]

How about only write when you have something to say? That way you won't care if you are late.

[@QuestionEverythingButWHY]

“The man who asks a question is a fool for a minute, the man who does not ask is a fool for life.” --Confucius

[@KonradofKrakow]

Can I ask you for your source of this quote?

[@alphaprime1871]

@MinuteEarth, your videos are beautiful. Please keep coming. 🙂

[@heitorprevitalli3182]

2:22 Derpish face on earth.

[@juliorebelo6475]

I was just looking for someone that had mentiond that hahahhahaha

[@ngiorgos]

Was about to comment that too

[@Sineri-rj6nw]

• -> •

[@jaketheperson8495]

Minute Earth is the best and cutest educational channel!

[@krizhiaasuncion1093]

i love your videos MinuteEarth keep up the good work!!!!

[@canadianchemist5052]

That skiing metaphor is the best explanation of refraction I think I’ve ever heard

[@KartTheExplorer]

Hi, minuteEarth! This is amazing! I love the way you explain concepts! SOFAR is cool! Thank you!

[@techiescience474]

Minute Earth U solve great mysteries👍👍 🙌U have motivated ME & MOST to establish their youtube brand👍🙏

[@Jeeeliiiziiizzz]

I love the style of their drawing!!

[@ananyasahoo5161]

That is so amazing. Breakthrough!!!

[@appa609]

I've never thought about this. This is cool.

[@seojayu]

i was sonar operator in navy! submarines are use that slow layer for hide and listening surface ships sound well. we call it 'shadow zone' cuz while sounds wave suddenly drop down and bouncing up, it makes huge whole of undetectioning area

[@Jackson-pu7gd]

I could listen to that beautiful voice all day.

[@flyflyflycrawl]

Boom! What an explosion of knowledge!

[@user-ht3tp3uj4v]

:p

[@octopusesarecool8719]

_squids peacefully swimming_ "hey inkster what was that?" "no idea bro"

[@iamnotaustraliangaming8617]

Love your guys videos

[@aditya95sriram]

Beautifully explained! Love it when videos just make you click

[@kiwiabcdefghijklmnopqrstuvw]

I'm amazed by how well made this is

[@leCauchemarXY]

Beautiful

[@ACivillage]

I didn't have any idea about it Or even knew that it was possible in oceans Good content 👍

[@jasonwalker9471]

I didn't know anything about this. Interesting stuff!

[@ExoHugh]

Australia to the Caribbean is also almost exactly half the world away (~20000km is almost half the circumference of Earth) which means the microphone may have also been helped by the lensing effect that happens at the antipodal point - waves that are divergent at one point on the surface of a sphere must converge at the far side of that point. Sound & seismic energy from Krakatoa's 1883 eruption were famously focused at a point in South America this way too.

[@370Location]

I have been exploring antipodal seismic focusing as a means for detecting the impact of flight MH370 in the Indian Ocean. I find faint evidence for the effect in the mid-Atlantic AF447 accident. I've also spent quite some effort trying to use multipath SOFAR channel delays as virtual sound sources for triangulation. So, it's an intriguing question but I see two counterpoints. SOFAR channel sounds have little horizontal refraction. The effect is there, but mainly due to changes in water temperature. It's not a focusing effect, more like looking through a prism. The other point is that any focusing from multiple paths would cause the signal arrival to be smeared out over time. That also happens with the antipodal amplification of seismic signals, especially with multiple arrivals since the odds of finding a seismometer directly opposite the origin are small. The antipodal paths range from the major to minor arcs distances. For some reports on antipodal focusing for MH370, I invite you to search: 370Location.org

[@gnochhuos645]

Is the part where sound is stuck in the sofar region related to how waves reflect instead of refract through different medium?

[@dascientist8443]

I think you might have them the wrong way around. Refraction is the one that bends waves and I think that'll be what's going on here, as there's nothing for the sound to actually reflect off.

[@tonydai782]

It's when the angle of refraction is big enough that the wave stays inside, the same way fiber optic cables work.

[@gardenhead92]

Refraction and reflection are two aspects of the same phenomena. It just depends on the index of refractions

[@Goldendroid]

The idea is that the sound refracts initially as it enters the SOFAR area but then when it reaches the boundary between the SOFAR and regular water at an angle beyond its “critical angle” (based on the refractive index of the different waters) it will totally internally reflect. This is important because TOTAL internal reflection means all of the energy of the sound wave is reflected, none of it makes it out. This is why the sound doesn’t lose much energy over the distance.

[@eliscerebralrecyclingbin7812]

Cool!

[@vadipp]

I've been enjoying your videos sofar

[@dankemo3169]

Great video.

[@Roxor128]

It's like the sound counterpart of an optical fibre! Doubly-nifty that it's naturally-occurring without anyone needing to make it.

[@cheating_lemon]

Awesome

[@Bonhomme7h]

I learnded! ❤️

[@russneho]

I live in Perth and I have never heard anything about this. So interesting!

[@_kc5892]

I especially find this method of communication and detection very useful for both animals and humans.

[@alexanderdall6923]

love the vids

[@ShortsByHaaziq]

Wow that was cool

[@GeographyWorld]

Very interesting.

[@gilgabro420]

fascinating

[@sharpiemanyepyeah3892]

*this video starts with a bang*

[@rossplendent]

This is also how optic fibers work for light! I just finished teaching my students about this today!

[@RocioDiazS]

Finally you made s new episode

[@AcousticalSocietyofAmerica]

Thanks for sharing! Acoustics is great, right?

[@JoseVasquez-pg6or]

Wow ^^

[@kanishakvaidya6686]

It's total internal reflection. Equation of waves give so many similar phenomena in very different settings.

[@rustypwn]

The CTBTO also helped in the search of the Argentinian Submarine "ARA San Juan" using his network of microphones a few years ago

[@youngcoopus1430]

Able to hear sound halfway from earth: Exists Dads snoring: Are you challenging me

[@gamefreak974]

I truly believe almost everything can be studied better using the physics of water. Like the way those sound waves bounce off of the higher pressure water looks similar to the way water ripples hitting a solid wall.

[@Permafrost107]

Cool :)))

[@avivore2864]

Nice

[@coolchannel44]

COOL

[@rextanglr4056]

Total internal reflection!

[@asfakjamilshanto252]

Her voice😍

[@FelipeKana1]

Cool

[@manooxi327]

tnx

[@avathesus3197]

Yay im 3rd and i love your guys videos! 🤩💖

[@hongqiangwu6695]

keep going with the vidos

[@RedBuit02]

The channel is almost like a huge optical cable, keeping the sound waves inside by total internal reflection

[@ketoonkratom]

Love is the answer God Bless Everyone

[@Alasarey]

Isn't this the same principle that a obtical fiber-cable is using? But in that case it's different refraction-indexes that enables this.

[@kor_cinnamon]

I love ur voice

[@belgarath91]

ok, this is so cool it cant be real xD

[@dissonanceparadiddle]

Gotta love refraction 😋

[@nathanokun8801]

NOTE: Radars and communication radios use a similar air-channel "mirage" effect called "ducting" (when present due to proper temperature/pressure conditions, especially in hot regions of the world) to channel and funnel the radio waves to greatly enhance the range the signals travel. If expected, this can be a major benefit, though if it happens when not expected, this can cause some problems with radio signals from a distance scrambling short-range signals. Expertise in such things is needed for proper operation of such devices in the real world...

[@yuxin7440]

It's basically total internal reflection, for sound. Not so much different from optical fiber for light. I am kind of curious about how the frequency of sound wave affect this.

[@usama57926]

*Its like total internal reflection of light in Optical fiber cables*

[@aidynsbestyoutubemoments]

how to hear halfway across the world: use discord

[@RileyzStudioz]

Lol

[@antimatterg]

Lol

[@SaucerJess]

♥️♥️♥️

[@megaboss0719]

Wow

[@kevinbihari]

Is it total internal reflection? Not partial? And how much energy did the wave lose? Seeing that water is still a fluid, so there will be losses through motion at the borders right.

[@kevinkim5817]

That's crazy, i just learned this from lemmino cuz of the roswell incident n how it's the same in the air

[@werh227]

I watched about it on the Internet Historian :D

[@jasonhernandez619]

I learned all this in sonar school when I was in the Navy.

[@PanduBintang]

that total internal reflection is the basic concept of fiber optic cable

[@Rodoadrenalina]

Theres a video here on youtube called the Sound Channel by Richard A. Muller, it was discovered and used in the cold war, watch the video for a great class about it.

[@judgeomega]

i heard about it from prof sadoway of MIT.

[@EntergeticalakaBot]

sound waves making waves... smart

[@C_Boomwuw]

Can you make a video about force field's?

[@quahntasy]

*Umm use Discord?* And that derp faced earth lol 2:22

[@stevenclark2188]

I'm guessing the signal losses are effectively inverse-linear? Like ionosphere bouncing of AM radio.

[@370Location]

Yes, a point source distributed into a circular plane, rather than the inverse-square reduction of a point onto a sphere. The biggest losses come when seafloor topography intrudes or disrupts the SOFAR channel. Still, for an unblocked path, even a faint source can stay above noise level for a long distance. Search 370Location dot org for references to a report on a small lithium battery pack that exploded in an ocean bottom seismometer off the coast of New Jersey, and it was strongly picked up in the middle of the Atlantic at the Ascension Island hydrophone array.

[@sosheeanand3537]

Interesting

[@HolyFuckinSex]

Total internal audiofraction 😁

[@abilashbrian4997]

wow

[@hamz5791]

Everybody gangsta till the sofar channel goes dead silent.

[@RarelyAChump]

:O what other waves can travel in the SOFAR channel??? Can wifi for example? This opens up a pretty cool potential for a fantasy universe where instead of satellites, we used these channels for technology.

[@Nilguiri]

Total internal Reflection for sound instead of light.

[@pradyunsharma2903]

Basically Total internal refraction of sound wave

[@Sirenhound]

Hey, I live in Perth.

[@ParadoxV5]

Total internal reflection, but for sound wave instead of light wave