Acoustic Standing Waves and the Levitation of Small Objects
ฝัง
- เผยแพร่เมื่อ 22 ก.พ. 2017
- Acoustic levitation meets schlieren imaging: By reflecting a sound wave back onto itself, one can secure a standing wave if the distance between the source of the sound and the reflector is equal to an integral number of half wavelengths. In this demonstration we use 28 kHz ultrasound whose wavelength in air is 1.2 cm. The objects are small Styrofoam spheres, roughly 4 mm in diameter and 1 mg of mass.
Images employing schlieren optics are very sensitive to changes in the density of air, and these changes refract light into the camera. Note that the little spheres settle down where there are bright bands of light. The bright bands of light in the schlieren images are known to be the result of either increasing or decreasing air pressure with respect to vertical position-in other words, the pressure nodes.
For an excellent writeup by David P. Jackson and Ming-Hua Chang on the mechanics of acoustic levitation, see American Journal of Physics 89, 383 (2021); doi.org/10.1119/10.0002764
For more information on our schlieren optics set-up, see
sciencedemonstrations.fas.harv...
Although 28 kHz is beyond the range of human hearing, ear protection should be worn whenever attempting this experiment to avoid damaging vibrations in parts of the ear. The sound you hear in this video is not ultrasound but rather a subharmonic and is not dangerous to your ears.
why do they sit in the high pressure zones? i would have thought they would sit in the low pressure ones
Actually the objects are trapped in the nodes of the standing pressure wave. See doi.org/10.1119/10.0002764
It's really a great job to show a sound wave in real life
It's called schlieren imaging
@@oppy8811 Yeah I recently googled it
@SALINA AJAYKUMAR I 😘 😘 .
i
.:.
I see what you mean.
Put your hand in front of your mouth and scream loud + long.... You can feel the vibration and that is another way too.
I was in the hospital one time many years ago and my roommate snored very loud and one night his snoring hit a resonant frequency and a picture on the wall started vibrating. I'm not kidding either.
😦
Is that even possible?
@@ulysse3254 Yeah, Ive done that with instruments but I guess you can do it vocally too...
@@user-hk8yp7cw1v wow that would be amazing
I never thought i would get to literally see a sound wave! Thank you for this!
th-cam.com/video/wvJAgrUBF4w/w-d-xo.html
Just do psychedelics and you'll be seeing all sorts of wave, sound wave included
the last ball to fall reminded me of tom and jerry when tom realizes he is in the air.
Wile E. Coyote in almost all the Road Runner cartoons 🤪
Lmao 😂
Dude same lmao
even in the deepest regions of Afghanistan, Iraq, Iran, Syria, Somalia, North Korea, Cuba, only this cartoon can make them laugh 😂🤣
That Schlieren optics shot was beautiful. That strange, ghostly glow around the objects and the mirror looking like a window that looks out into space. Wow.
Ya it was cool
This guy: "Even though I can't hear it I'm still going to use ear protection."
Our generation: "Even though I'm bleeding from my ears I'm gonna turn up that bass."
ok boomer
Ok boomer
Ok boomer
ok Boomer
Huu
Crystal clear explanation, demonstration and overall presentation. Doesn't get much better than this :)
awesome to see someone doing this with schlieren imaging, I haven't seen anyone else on youtube doing that before, and it's really cool to be able to actually 'see' what's happening!
I didn't hear anything but my dog is deaf now.
Does the mic get up to 28khz?
I didn’t hear anything either... which means i’m now deaf too
😂😂😂
The audio codec used by youtube has a low-pass filter at around 17 kHz. The dynamic range is also very limited, so nothing harmful could get through.
Videos that scare headphone users tend to have an extremely low overall audio level. The user then turns up the volume (which also increases the noise, which should be a warning) and then someone bumps the microphone. Imagine the opening scene from "Back to the Future": th-cam.com/video/3isQI0nXQRE/w-d-xo.htmlm20s
No worries, I still liked the joke with the dog. I actually imagined the dogs in his neighborhood starting to howl and everybody is confused why they are doing this. ;)
@@zvpunry1971 *confused barking*
"Scientist dangles his balls in the air with close up"
Haha porn science
Dangles his "little balls"
😅😂
Clickbait level 8/10 unlocked!
“Old man plays with his balls”
experiments with the Schlieren method are very revealing !!! awesome !!!
Wow! I LOVE the Schlieren optics idea for visualizing the effect!!
Don't let him fool ya with all the science jargon, this guy is an actual wizard!
He he he yeah baby
I agree with Mr. Solve Everything. To make it funny you should have said: “a wizard level 27”
I bet you don’t vaccinate your children
@@sumguy01 He's probably just making a joke. A bit of a poor delivery is all.
Please don’t make these jokes, most scientist take high respect for science (that’s why their scientists). And to call them magicians is like saying everything they are doing is just a small little party magic trick.
My alien says this is so 6 thousand years old
Are you using the alien toilet messenger on area 51 ?
Aliens are not property and do not belong to any human and I don’t care if Alf or Mork does live with you.
Gut Eater the flush? Yeah
You have a pet Alien? From which planet?
Millions
Thanks for the explanation. And the your response. Time is soooo precious to us all. .
This is an excellent demonstration! Thank you!
Am I the only one who is more interested by this weird magical mirror than those levitating balls?
I was waiting to see something else in the background of it. Im gonna find one of those. Lol
@@lucienberl th-cam.com/video/K7pQsR8WFSo/w-d-xo.html
@@overloader7900
"Schlieren Imaging in Color!"
Thank you! Very interesting video.
I wish it was a bit easier to setup...
lol.. you will be pleased to know the human eye is capable of seeing what that "mirrior" is showing ;) when you see the "heat waves" coming off the road in the distance while driving on a hot day. thats it. just focus differently on things like your finger tips and you will see those same heat looks coming off your hands like came off his in the video
Congratulations no, there are other, stupid people!
Probably the most useful video I ever saw on youtube.... Amazing...
amazing?y interesting?y useful?n
@@iphgfqweio As a matter of fact, it will be very useful for me. I'm a game developer and we will use that mechanic in our upcoming game. We will tweak it to fit our gameplay necessities, but it will be exactly that, on a very large scale. For one of the puzzle in the game at least.
@@fl260 i will buy the game and help you get rich
@@fl260 you can get fat and buy drugs
I am an engineer... And wave physics was always a part of study... We have to apply it in real life... Did You know that even the springs of the coaches of Indian Railways have a frequency near 128Hz so that everybody can sleep pleacefully despite all that noises in a train
That's freaking badass! What a great idea to use a schlieren projector. I've known about this phenomenon for years but it never occurred to me to visualize it like this. Absolutely f****** awesome! So happy. 😁
Fascinating, loved this presentation.
The comments are fresh for a 2 year old video.
*THIS JUST MEANS TH-camS ALGORITHM STRIKES AGAIN*
It started appearing in my home feeds for every refresh and I was ignoring it after watching its upload date.
peenguinne pengguinne *UP VOTE!!!*
True
Yes it is
Like the video.. let the algorithm understand our preference
3:03 it looks like a portal to another world where thunder and lightning is going on !
Doom Eternal
Dead Space
Its hell
You have 69 likes not gonna destroy that.
@@AlexOjideagu2 It does look like the color hues used in the game
Already knew this, but theoritically only. Glad to now see it practically!
Perfect demonstration of standing waves .👍👍you did a great job👍👍
I don't get it. The title says "Ultrasonic Levitation" and the video demonstrates ultrasonic levitation, but still 264 people disliked the video. What were they expecting?!
UFO´s
Clear exemple of: you shouldn't really always give a fuck of what people think
Great point. I noticed this phenomenon as well.
he dint give little balls a chance to stay up
you gotta look at it from little balls perspective. he could of made it
its not limited to little styrofoam balls lol. this is just a glimpse at whats possible. look into the ancient traditions of sound moving rocks and boulders. ancient cataclysm and pre deluvian civilisations
I've seen multiple videos about Acoustic Levitation, though this is the first one I've seen made with a reflector instead of a second speaker. I've also seen multiple videos about Schlieren optical photography, most notably looking at the shockwaves produced by a bullet breaking the sound barrier.
This is, however, the first video I've seen that combines the two, and I quite like it. Well done.
Awesome explanation and demonstration.
Our choir in school once managed to hit the resonant frequence of a window perfectly so it started vibrating. Our teacher then explained us what happened. I wish he would have shown us your video, it would have been perfect to visualize the effect!
It's always a good day when I learned something new. Thank you.
A superb demonstration. Thanks for sharing it!
Loved it ,
A really nice physical visualization of standing waves
Thank you for the visual evidence.
Great demo, proves the potential of levitation by these means, now all we need is a few hundred years to perfect the technique that our very ancient predecessors used thousands of years ago !! We have a LOT to learn !!
What the hell did you smoke?
Sergeant Sharkseant Really good smoke, opened my eyes and my mind to many things I was not yet aware of, ya otta try it sometime‼️
Excellent. Very clearly demonstrated. I noticed that the glass reflector is quite thick.
maybe I'm being obvious, but thin glass would break there =)
* T H I C C *
Saken Kenzhegulov nope😂 it wouldn't..if he doesn't exactly hit that resonance frequency it will just vibrate with the other frequency but with a way lower amplitude..and that's the problem. thinner glass is easier to get to vibrate so it takes more energy up.
I guess thicker glass just reflects it better.
Great ! black hole science Lab.
@@_I_am_a_liar What do you mean? Could this cause black holes?
This is a really great presentation showing the sound wave
Absolutely astounding ! Now we're getting somewhere :)
That's amazing! I'd love to hear more about this!
Already knows the concept but seeing in practical was just awesome .
Feel like my question that I asked my physics professor he should have shown me this instead of just saying yes that can happen.
TH-cam why don't you always these awesome videos to me
What?
this kind of work done by this sir, one day will make all civilization moves forward
what an amazing, beautiful experiment.
I worked in the field video, internet, and VOIP installation and repair and loved this demonstration! I had to learn about wavelengths and fm antennas are built in increments of the wavelengths you're trying to tune into. Older cars were 42" (1/2 of the wavelength) and then they were shortened to 21" (1/4 of the wavelength). Cable installers don't measure the distance between cable clips because, if you space them at the same exact distance apart (i.e. 14", 21", etc), there's a good chance of canceling out the frequency that travels at that wavelength. In the current digital cable world, they can fit 6 digital channels in that one band so, if you're having problems with just 6 channels, something is wrong with that one frequency and that could be one of a few culprits. Cool stuff and much more technical than I originally expected. Love it though!
One of the coolest demonstrations..loved it!!!
We have to perform such demonstrations in schools for young students especially in counties like India(my country) where a lot of rote learning is going on... Many would become 'truely' curious and develop scientific temper.
What a neat demo, thank you.
Thank you. Very nice clear job. More experiments please
its really great to see an information that ı learned in my physics class used in a real life application thanks for uploading
Concept of wave-particle duality demonstrated very clearly.
How does this represents wave-particle duality? This is just simple example of transverse wave experiencing resonance (constructive interference). Wave particle duality was at first just plain and simple hypothesis given by de Broglie's own thought experiments.
He's putting particles on standing waves, the waves are not coming from the particles.
Wait what? I am afraid you have no idea what you are talking about.
This is a concept of ultrasonic levatation, the "waves" you are seeing is the waveform generated from the ultrasonic sound creating gaps of high and low pressure that can suspend ultra light objects.
Literally the transducer or speaker at the bottom generated high frequency sound that creates pockets of high pressure capable of suspending light small objects.
Wave-particle duality has to do with quantum particles. The best demonstration would be the double slit experiment. Again the difference is one thing deals with small macro objects being suspended by macro sound waves that have nothing to do with the objects. The other(wave particle duality) has to do with quantum particles(that for all intents and purposes you can't see) and those quantum particles in some cases act completely like particles and in other act as a distribution of possibilities represented as a possibility wave distribution. Quantum objects and ultrasonic levatation have nothing to do with each other
This experiment is just amazing 👏🏻👏🏻👏🏻👏🏻
Thank you so much for posting this Video, you have inspired me, and explained a subject in a very succinct way.
While using my power saw sometimes it would hit a certain frequency that made me feel like I was levitating. I always thought what you are doing was possible through my experience while sawing that wood!
when my wife screams (sound), the cat lifts off the ground (levitation) ... simple science 101
Scream moaning to coma almost i think be better
Soon as he put the second ball in I felt the frequency change in my ears !
just awesome. thank you for sharing this!
Nice video and wonderful demonstration.
thank you
Incredible demonstration. I would like to see other configurations like three ultrasonic horns/reflectors configured with a computer controlling the amplitude and frequency, or three horns/reflectors to manipulate a lens or a drop of glue suspended in the standing waves.
This is one of the best thing i have ever seen. Superb ❤️❤️❤️
That was pretty fly, thanks Grampa, love ya.
we are now 99% closer to figuring out what the Egyptians built the pyramids
Sure is. They used tech very similar to this levitation. That's why they had cubits measurements in the blocks, they had to be a certain size.
Wait till people also find out that it only took a couple of hours to build them, AAAAAND they were built from the top down :).
Now off you all go down a rabbit ole :D
The sound resonans, great just like in a laser cavity.
Brilliant! Thank you.
really loved the part where you overlayed the schlieren optics with the regular footage, very artistic and pleasing to look at.
thank you
This is what Alfred does while Batman go outside mining the Kryptonite...
I saw the same thing using microwaves back in the mid-1980s. Objects could be held static with specific frequencies of microwaves. It was an 8 mm film that was quite interesting to watch.
Im really glad that there is a vid this cool
Belle démonstration! Merci
thanks for an informative 'no bullshit' video!
I need to get my hands on such a large concave mirror... But they're impossible to find anywhere!
I've been looking for ages as well. I even tried a cheap one from amazon but the tolerance was terrible.
look for a used reflector telescope and use that mirror
Experimentboy just buy girls make up mirror worked for me
Newtonian telescope
Experimentboy make your own simple
Thanks for sharing this in detail
The fumbling at 1:45-1:58, trying to complete the set. Anyone else find that satisfyingly wholesome?
2:30 My man's absorbing the magic aura from the ancient tech loud speaker
U r such a good demonstrater
1st time hearing this and its awesome. Consider the possibilities of applied to today and scaled up. Wow!
Awesome! During the first half of the video, I had this idea that the balls would rest in the low density regions, sitting atop the high density planes of air, so I'm glad for the schlieren setup. It took a fair bit of thought to (maybe) understand what is going on.
It's not that easy, though. The reason why the balls fluctuate is because there's a non-linear term on the sound pressure equation that doesn't cancel out (generating a net force upwards). It's not straightforward!
If you think, since the waves generate pressure both positive and negative in the anti-nodes, the average resulting force should be zero, as the sound is oscillating much more rapidly than the ball can respond. It's fascinating, I myself don't understand that well but if you're interested you can look it up.
My balls always rest at low frequency 😂
Thanks for explaining it properly. The explanation given in the video didn't make sense to me, but your explanation is much better.
glenm99 ball be resting on your bitches face
I am too young to get this.. Aren’t the balls suppoused to sit in the low-pressure point, since everything is naturally going from the high-pressured points to the low pressured points? Just like in a balloon, air moves out, because there is more pressure within the balloon.
Why this kind of videos are underrated 😕 😐🤔🤔
Yeah, that is amazing. Mind blown.
Great demo!
I wish my science class look exactly like this
First off, thank you. This is one of the best acoustic levitation demonstrations on the web. As is the schlieren optics portion in this and in Daniel's video. The amplitude of the pressure waves shown with the schlieren setup was impressive. This was not covered on in the presentations section on Harvard's site so I was hoping you could give a brief description of the amplifier used and the matching transformer in the back ground that appears to be a self wound ferrite core.
The amplifier is a Samson Servo 120 audio power amp. A home-made impedance matching transformer couples the 8-ohm output to the ultrasonic transducer.
The core of the transformer consists of two C-shaped pieces of ferrite which, when put together make a square. Ferrite is better than iron at high frequencies. The primary is 10 turns of #18 wire and the secondary is 100 turns of #22 wire. The inductance of the primary is 230 microH w/ secondary open and 16 microH w/ secondary shorted. It's operational inductance is such that its impedance is well matched to the 8-ohm output of the amp. The inductance of the secondary is 18.8 mH w/ pri open and 1.8 mH w/ pri shorted. It's operational inductance is around 10 mH. The static capacitance of the transducer is 3550 pF. To resonate at 28 kHz, we want an inductance of 9.1 mH. The inductance of the secondary is a close match for that.
The "speaker" is an ultra-sonic power transducer (designed for ultra-sonic cleaning baths) such as one of these: www.americanpiezo.com/standard-products/ultrasonic-power-transducers.html The one I'm using is the 50-watt version (but I'm only operating it at around 8 watts).
Hope that helps. Thank you for your kind words about the video.
Thank you for the quick reply and detailed information. I was heading down the path of implementing some type of impedance matching and your example helps a lot. I wanted it mainly to get the most power at resonance but also to prevent resonance at a frequency other than what the transducer is expecting which is an issue with this amplifier (Pyle PT210) using the 70V output. My setup (for a demonstration in my daughters 6th grade science class) was inspired by yours except I am using an iPhone on an XY translation stage. Thanks again and happy sciencing! :)
www.thingiverse.com/make:382484
Your set-up looks very nice! Good luck with your transformer.
Thank you for your help! www.instructables.com/id/Phone-Camera-Schlieren-Optical-Setup/
you are very welcome
wow this is amazing experiment
Thank you! for showing such type of experiment
Loved the video! Great job!
We learn those things at high school, jeez. Nice presentation
Wow what happened to the education system this was taught in middle school
@@mannyman1012 Really? That early?
Wonderful
thank you
likewise, thank you
shubham singh thank you very much.
Pretty great demonstration man good video
Very beautiful and informative video thank you!!!
Perfect illustrate how zushi zushi no mi (issou - one piece) works
But doesn't that fruit actually allow the user manipulate gravity?
1:11 Does this mean someone can purposefully damage my ears without me even noticing it until it's too late?
Yes
Yep. There is some well deserved controversy over this recently. There are some parks in Philly that are playing loud high pitched noises in the park all night. It's supposed to be inaudible to everyone except kids and young adults, so it's basically used to keep kids away from the park at night. But that just means an adult could walk by and have their ears fucked up without having a clue. It's literally sonic warfare against its own citizens to keep kids out of parks at night... the device is called the mosquito and they need to be removed and/or destroyed. And whoever's idea that shit was should be removed from their position and sued
Scary shit, lets make it happen.
@@Jesse-cw5pv Most animals can hear that high as well, I could imagine they wouldn't be too fond of mosquitos either.
Thats it - getting rid of all the ultrasonic mouse repellers i have plugged in around the house
Amazing! thanks for sharing!
being able to see a waveform was amazing by itself . Three times wow!
I need to go back to studying what I really like, telecommunications
If we learn the Physics in that practical way i am sure there will be more productivity.
i'd be curious to see if it's possible to levitate glitter powder and if it is, what kind of patterns take shape
Yeah ...I'd like to see that too ! 3D patterns "WOW"
WAW...! Amazing.
Great demonstration
That mirror is like opening a portal to other dimension
Yo I thought the same thing
Nice. I never heard about something similar. If you put another Ultrasonic-Loudspeaker to the side, is it possible to move the balls along the highpressurezone?
Longitudinal waves? Tesla?
@@michaelschild8289 i dont think tesla worked with ultrasound.
Yes, that could be done
@@scherenschnitt6333 Tesla was working with longitudinal waves, aka sound waves and actually was famous for it. Ultrasound is sound waves with frequencies higher than the upper audible limit of human hearing. Even more he is known for its experiments of propulsion based on longitudinal (sound waves). Therefore this seems nothing new but recycled Tesla work.
@@michaelschild8289 ah okay. This was new for me. I only knew about his work with electricity and these teslacoils to use the ether for communication.
Its so amazing, well explained
Thanks for your knowledge, sir
Nicely explained, thanks. PS I think I saw my dead relative in that mirror.
wouldn´t the bright lines be the low pressure area? Your explanation did make sense, but my thinking is this:
the ball would be "sucked" into lower pressure areas and the high pressure above and below the ball would prevent it from going anywhere.
since I assume, that i am in the wrong here :D , i would love, if you could take the time to further explain where my thinking is flawed!
regards from germany!
Yeah it made more sense to me too that the ball would settle in one of the low pressure areas. An explanation (from anyone who knows how this works) would be great.
I might be wrong but when he says high and low pressure it means high and low pressure variation. So at a spot of high pressure, pressure oscillate a lot between a pressure above atmospheric pressure and below atmospheric pressure. Whereas on a spot of low pressure, pressure hardly change over time.
@@arseneferriere5151 That basically correct, but the balls will gather at the points where there is no change over time (wave nodes).
A comment to follow the thread
There are 2 different descriptions for sound. One is a pressure wave, that is literally the variation of the physical quantity pressure. And the other is a displacement wave, that is the actual movement of the air. These two waves are out of phase with each other. The nodes of one wave (the zero points) coincide with the anti nodes (points of maximum amplitude) of the other wave. So the regions of highest pressure variation are actually regions of least air movement. It is at these displacement nodes that the beads settle down.
Mind blowing!!
Excellent presentation!