r/oddlysatisfying • u/Key_Performer_3645 • 3d ago
A mesmerizing demonstration of a vertical wave
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u/Sir-Kyle-Of-Reddit 3d ago
Why the fuck is this video at a 45° angle
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u/HairlessHoudini 3d ago
These videos would have been appreciated in the 90s when we were all on acid
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u/Yequestingadventurer 2d ago
Wait, we stopped taking acid?
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u/HairlessHoudini 2d ago
Not all of use butt I'd be scared of it these days LoL.
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u/Yequestingadventurer 2d ago
Something about being older for me means the lessons are so much harder
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u/grateparm 3d ago
I mean The Wizard Oz to Dark Side of the Moon was pretty cool. Mr. Resistor or Plymptoons were a fun trip. There was always something cool on the Winamp Shoutcast streams and StupidVideos started in 2001.
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u/DamnitDom 3d ago
Kinda fun to see the limit of human brains as you slowly stop being able to predict the patterns until a certain point when you can distinguish the two oscillations (that is at least where I'm able to pick it out lol)
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u/hunt4some71 3d ago
reminds me of those old winamp visualizers from back in the day. super trippy and nostalgic.
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u/Different-Bet8069 3d ago
Was pleasantly surprised by the DNA creeping in like that.
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u/PhantomAngel042 3d ago
Seriously, the double helix was my favorite part. The whole thing was beautiful.
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u/antrubler 3d ago
Fuck, I thought the music was played by silly small cylinders. Hope they remain unharmed
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u/tinydeepvalue 2d ago
Technically those are a bunch of individual oscillators.
A wave have to be on coupled carriers
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u/AltruO3 2d ago
Ok I think I get most of this.
But is there a reason for it being Mercury, or could it have been water for all anyone cares?
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u/Cruffe 23h ago
I guess so it can keep going for much longer given the small size, since mercury is a whole lot denser/heavier than the same volume of water.
Cylinders made of tungsten would be a safer choice and even denser than mercury, I don't think it's critical for the effect that the contents is a liquid. I'm speculating it might be because it's easier or cheaper to measure out a precise amount of mercury than to precisely cut a bunch of tungsten cylinders to each correct mass. Tungsten is fairly expensive.
Lead could also be used, it's not that much less dense than mercury.
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u/rhino_moss 3d ago
This is not a wave.
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u/elliot200255 3d ago
The bottles are just showing the wave motion. The actual wave travels along the strings while the strings move perpendicular to that direction
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u/xnuh 3d ago edited 3d ago
There is no wave motion. These are completely independent oscillators with slightly different frequencies. Nothing propagates. They each are a different weight on an elastic. They are not coupled.
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u/PyroDragn 3d ago
They don't need to be coupled to be a demonstration of a wave. If I draw a 'wave' on a piece of paper then I can still measure the wave's properties despite the fact that the piece of graphite are not coupled together.
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u/xnuh 3d ago edited 3d ago
That's not a wave either imo. A drawing of wave maybew but not a wave in a physics sense. Waves are pretty hard to define, but wikipedia defines them as delayed changes of a physical property that result from changes in adjacent regions. Most definition have this idea of delayed reponse from adjacent changes. Here, if you mess with one oscillator only, all the other ones will remain static. I'd say that cannot count as waves
You can call that a wave, but it's not a physical wave. My point is that the video is a bit misleading, because it shows you a physical system that, when primed in the correct looks like it produces physical waves, ie one part of the system affects the adjacent ones. But actually, it just produces the representation of a wave/a wave in a more mathematical sense.
It makes you think you're looking at nice physics of propagating stuff, but it's actually obscuring what's physically going on.2
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u/xnuh 3d ago
It's not a wave because the oscillators are independent. The movement of one oscillator is not caused by the previous one. They just have slightly different frequencies, so they gradually come out of sync creating the illusion of a wave. But nothing actually propagates from one oscillator to the next, they are not coupled.
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u/HaMMeReD 3d ago
I wouldn't say they have to by physically coupled. They are mathematically coupled via each strings set period.
Like you could likely look at that wave, measure it, do a fourier transform and then break out it's constintuent waves. It's an aggregate wave. I.e. perlin noise (but with some randomness stripped).
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u/MuscaMurum 3d ago
There's actually NO information on this post about how or if they're coupled. There is no real information here at all except "isn't this pretty". Lots of assumptions can be made, but this isn't a demonstration of anything because nothing is asserted.
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u/xnuh 3d ago
Waves are hard to define, but for example wikipedia's definition is that they are delayed changes in a physical property resulting from changes in adjacent regions. Here, if you pick different initial conditions, like start with only one of them moving, they will still be "mathematically coupled by their frequencies" and yet only one will move and it won't look very wavy.
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u/Destructopoo 3d ago
surely the fact that they're all connected to the same frame would mean they are not independent
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u/xnuh 3d ago
The elastics are attached to wires that look pretty much static. They're definitely not 100% completely independent, but they have very very little I fluence on each other. You get this exact behaviour of the wave splitting and recombining etc with independent oscillators that have different frequencies
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u/trwawy05312015 3d ago
but their behavior is well described by the wave equation... so... they may not be coupled, but they are correlated
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u/Jetison333 3d ago
Their behavior is not described by the wave equation. A wave doesn't split apart into two separate waves, or change frequency like it does in the post. It doesn't make sense to analyze this as a wave, because it isn't. Its a bunch of separate synced oscillators.
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u/CatL1f3 3d ago
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u/ocelocelot 2d ago
came here to see if someone would post this!
edit: see also this visualisation of it
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u/MakingWaves24_7 3d ago
Still makes no sense how they don’t all move at the same time in uniform.
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u/Maaniker 3d ago
They are different weights.
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u/Available_Ad9345 3d ago
Thanks Galileo. 🤦♂️
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u/3forward2back 3d ago
Different weights as in each one weighs a different amount. The greater the mass, the slower the oscillation.
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u/3forward2back 3d ago
Each of the capsules has a different level of mercury metal and therefore a different mass. The formula for the period of an oscillating spring is: T=2π*sqrt(m/k)
As the mass of the weight (m) increases so too does the period of oscillation (T). The heavier the weight, the slower the oscillation.2
u/MakingWaves24_7 3d ago
Thank you. Your math makes me think I need to go back to school. 🤓 I appreciate you.
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u/CoffeeWith2MuchCream 3d ago
They would need to be coupled in some way to be a wave. This is just a cool demonstration of fun patterns you can get by setting up a bunch of slightly different springs with different weights on them. Make them in an interesting order like this and you have need moments where they come in and out of phase.
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u/jugstopper 3d ago
Not a wave. It is a bunch of mass-spring systems with very similar natural frequencies of oscillation (same spring constants = k and slightly different masses = m), where frequency = [1/(2xpi)] x sqrt(k/m). The point of phase of each in its cycle relative to the others is changing due to their different natural frequencies. With a consistent difference of mass (apparently, mercury in glass cylinder) from one cylinder to the next, you get this pleasing result of the progression of phase differences.
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u/CardiologistOk2704 3d ago
also demonstrates the discretization / sampling limit. Why you cannot record wavelengths smaller than 2dx
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u/Mapicar1 3d ago
Me all the video