Physics of Sound Propagation

[@Higgsinophysics]

> my mates said you would love to know about light propagation in materials. Well no problem friend: kzbin.info/www/bejne/d2nPhmWkoL1spsU

[@alans172]

Nope, not thinking about light propagation.... just pressure waves in materials, i.e. sound waves.

[@mrnarason]

Great job on animations and insights on the applications of the topic. Imo, don't shy away from showing equations and formulas.

[@Higgsinophysics]

I'll never shy away from showing equations - but i din't notice i didn't use any equations for this video... whops.. Apart from 2:28 off course

[@fettyprime8780]

Not Dead just listening

[@texmex9721]

Great video. But the best way to make sure a train is not coming is to stay the hell off the train bridge. That would not make for a great movie scene, but just don't go onto it. Stay out of train tunnels and off the tracks in general.

[@Higgsinophysics]

This !

[@ATorres0821]

I really enjoyed the domino demonstration!

[@Higgsinophysics]

Thanks for letting me know !

[@jetsparks17]

VERY well illustrated and wonderful analogies to help me understand how sound (pressure waves) travel through various mediums. This makes me wonder about technologies that give sound through contact, I'm thinking bone conduction headphones. Perhaps a technology exists that's able to transmit sound through contact with another body part and is somehow linked to the brain to interpret that pressure on the contact area as sound. I have no idea but it's interesting to think about.

[@JesusNails8518]

Very nice video. Good job. Keep it up

[@Higgsinophysics]

Thank you !

[@benjamingo111]

Fantastic video! How do you make these animations? Thank you

[@Higgsinophysics]

I did these in cinema 4d, but today I would done them in blender.. all 3d programs will do!

[@akshinbarathi8914]

but wait what type of vibrations does the train realy cauze in the steel tracks, it will be very mild, and also ANY CRACKS IN THE STEEL WILL RUIN THE WHOLE SOUND TRAVEL, BUT MAN YOU NAILEDIT, I LOVED THAT DIFFEREMT DEMOSTRATION

[@richtorelli8648]

this was the best. thanks

[@ChiPhyLy]

Hi, the animation is amazing. can you explain with what you are doing such animations. i am interested for pedagogical reasons !

[@Higgsinophysics]

Thanks I appreciate that. The animations are made with Cinema 4D. But today I would rather recommend Blender or Godot. All free, open source and extremely capable.

[@sethpanagapka9934]

@Higgsion physics would you kindly, as to post a GIF of the Particle wave comparison of Air, Water and Steel, time stamp 1:19.5 - 1:34.9. I would be using it to educate Miners on how hearing conservation is important. I ask this because i can not use the video in my Power Point.

[@Higgsinophysics]

Nice! I don't have time to do it for you sorry, but there are multiple sites where you can post a youtube video and get a gif in a timeslot.. for example gifrun.

[@andrejrockshox]

yeah but the tracks are not one long piece of metal, they have breaks every 20 meters or so to allow for thermal expansion :)

[@dominicestebanrice7460]

High sped rail tracks are usually continuously welded and even where the rails are laid down in sections e.g., on old lines, the sections are bolted together using STEEL fishplates (aka joint bars).

[@kolibril4265]

Wow, that was interesting, and the animations look very cool!

[@Higgsinophysics]

thank you

[@zervzerv1214]

I thought the sound of the train would be instant. This requires experimentation to prove. What is the speed of sound in between tuning forks?

[@alans172]

Your description of a "pressure wave that's kinda pushing its neighbouring atoms" is technically incorrect and, by describing it thus, obscures the vital difference between a wave on a string or a water wave, which are transverse waves, with its true nature as a longitudinal wave. By starting out with this difference obscured, the student has to unlearn the incorrect analogies before learning the true nature of the propagation of pressure disturbances through solids, liquids and gases. I know it's difficult to present a pressure wave graphically, but that's no excuse for getting it so wrong. The detail that is most confusing is that the amplitude of a pressure wave is illustrated by a displacement of particles in the same dimension (the X-Axis) as the movement of the wave.

[@tt_tinytunes]

Great Video and Animation.Can I use the domino animation for our educational video in our college?

[@Higgsinophysics]

Yes if you provide a source link

[@tt_tinytunes]

Higgsino physics thank you. Sure I will

[@leemilica]

I used to feel the tracks with my hand, and if I feel vibrations, i know that a train is a kilometer away.

[@heryardiansyah7997]

i would like to know

[@Kabatification]

In what software are you creating all those beautiful animations?

[@Higgsinophysics]

Cinema 4d :)

[@Frir10]

I mean the animations are really good. But the statement that "there is less molecules in liquids than in solids" is just dead wrong. Take ice as an example. The density of water molecules in ice is smaller than in water (ice has slightly fewer molecules pr. cubic inch). Yet even so, sound travels much faster in ice than it does in water.

[@Higgsinophysics]

Try to take another example than water. Water is the only molecule that does this density flip. But you are right my statement isn't something i would post in a physical paper.

[@박종선-v8i]

I'ts Amazing!

[@komradfrostie]

OMG So epic 2:09

[@alext8828]

Question: You mentioned the "dampening" of the sound. Isn't the term "damping"?

[@jameskane9265]

NOT SCHOOL APPROPRIATE

[@Anterbok]

*losing, not loosing

[@podop529]

Ayyy I got it right

[@Higgsinophysics]

Well done

[@alans172]

0:58 The argument that the speed of sound is dependent on the density of the medium is patently false: speed of sound in ice is 2 1/2 times that in water and ice is LESS dense than water. The argument is false and misleading. This whole "educational" video should be withdrawn.

[@dominicestebanrice7460]

Water/ice is notorious for being an exception to many 'rules' in physics/chemistry. If density does not play some explanatory role, what does? Can you give other examples where the speed of sound in the medium increases with decreasing density? And no, the video should not be 'withdrawn'; even if the density proposition has many exceptions to the rule, the explanation of intensity drop in 3D vs 2D vs 1D was superb and justifies the video. How about you have a go at explaining sound propagation and send us all a link to your video?

[@anonymousbird-4]

Its true that speed of sound is dependent on density, but also on other factor like elasticity as well, the elasticity of ice is much higher than of water. means the molecules of ice returns to their equilibrium position faster than water which allows for faster propagation of sound.