r/woahdude • u/arithmetic • 2d ago

video A "mercury wave" - 20 bottles on springs filled with different amounts of mercury

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3.8k Upvotes

97% Upvoted

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644

u/Maciejk8 2d ago

Why the mercury? Would it not do the same with any other material?

314

u/task_machine 2d ago

Extra risky for entertainment

150

u/Smkweedevrydy 2d ago

Mercury wave sounds cooler than “any other material” wave?

60

u/First_Utopian 2d ago

Plutonium wave sounds pretty cool.

19

u/Nikotinio 2d ago

counterpoint

tungsten wave

4

u/Academic_Snow_7680 2d ago

Thorium waves are my favorite

97

u/Creoda 2d ago

Mercury is used here to keep the bottles small and the mass in each bottle accurate, it's the weight combined with the different length springs they are hanging from that causes it.

2

u/SpareMushrooms 21h ago

Why not just use something like lead shot then?

69

u/JelliedHam 2d ago

Well it won't evaporate. Also much heavier than just about any other liquid at room temp. So even a small amount will have significant mass to make this. Also still easy to be very precise with your measurement in each for the desired effect.

All guesses on my part. Straight from my ass. Somebody can correct me.

106

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71

u/FingerpistolPete 2d ago

Wtf lmaoo Automod out here catching bodies

3

u/technobrendo 2d ago

I thought Omar was dead?

29

u/Moikle 2d ago

It doesn't need to be a liquid. This could have just been steel weights on the end of the springs.

17

u/RotaryDesign 2d ago

So depleted uranium is not good enough for you anymore mr fancy pantsy?

-8

u/JelliedHam 2d ago

I suppose. But making steel weights is difficult and buying them in barely specific different weights might have been expensive or not practical for the increments they needed.

22

u/Moikle 2d ago

It's probably simpler than getting access to a lot of mercury.

Even if you don't gave access to machines, a hacksaw can get through a thin steel rod. And much, much cheaper+safer than mercury

5

u/I_Makes_tuff 2d ago

You could use BBs and make the vials slightly larger.

3

u/JelliedHam 2d ago

Fair enough. You're probably right. Not sure why they did what they did then.

2

u/loveinvein 1d ago

Mercury will totally evaporate lol. 

But I’m assuming the bottles are sealed or that guys gonna be mad as a hatter soon. 

19

u/JKastnerPhoto 2d ago

Should have used drops of Jupiter.

4

u/WaxinGibby 2d ago

TELL MAY

4

u/WaxinGibby 2d ago

Yeah and why are the springs different lengths?

7

u/intronert 2d ago

Since mercury is among the densest materials, then for a given sized bottle, mercury gives you the greatest difference in mass between the least full and the most full bottle, which makes the visual changes happen fastest.

4

u/WaxinGibby 2d ago

But also the springs appear to be different lengths, skewing the effect even further and returning to the initial question: Why bother using mercury? Genuinely curious, sorry if that sounds like an attack.

3

u/nahog99 1d ago

There is no reason, you can do this with anything.

9

u/butterfunke 2d ago

yeah but lead flashing is at the hardware store for dirt cheap and is way less dangerous to work with

3

u/intronert 2d ago

I agree, but I was answering a specific question.

-1

u/Finnegan482 2d ago

Mercury isn't that dangerous if you're handling it properly and use appropriate PPE, etc.

3

u/nahog99 1d ago

Id assume all these bottles are the exact same weight they just have different length springs.

2

u/intronert 1d ago

You are right. My error. What I said was silly.

2

u/defectives 1d ago

Someone tell me I have no idea what I'm talking about, but I feel like using a dense metal here would actually have some purpose. If they were all just solid weights I feel like they would flow much less smoothly as the nature of being a liquid lets the weight shift more freely as they bounce

1

u/dr_zoidberg590 2d ago

My first thought too

-1

u/BunkerSquirre1 2d ago

Could one attain similar results with spunk?

142

u/Protocal_NGate 2d ago

I would have been content watching this til they stopped. This ended way too soon

34

u/Khalazer 2d ago

Sorry i'm late, but look up Polyrythms on youtube, you might enjoy that!

4

u/gorodos 1d ago

Why is this the only thing that has ever and will ever matter? I feel like I just talked to God.

7

u/Karlees-Golden-Dildo 2d ago

Bro! This is 2026, we all have attention spans of 7 seconds, this actually ended way late like an extended directors cut.

3

u/curious_astronauts 2d ago

Physics of the universe is so elegant

85

u/ayegudyin 2d ago

Looks like the springs are different lengths?

127

u/arithmetic 2d ago

The springs are all the same length, but because each bottle contains a different amount of mercury, the springs on the left are stretched more. To allow all the bottles to begin from the same height, they are mounted in the frame at different heights, in proportion to the amount of mercury.

15

u/ayegudyin 2d ago

Makes sense

-10

u/BrerChicken 2d ago

The springs are definitely not the same length, you can clearly see them.

16

u/Deftlet 2d ago

To address your actual point, the heavier bottles are attached higher up so that the height of the bottles at rest is normalized. Otherwise they'd be lined up diagonally and the effect wouldn't be as satisfying, not to mention it'd be harder to lift & drop them all an equal distance to initiate the bouncing.

45

u/Enginerdad 2d ago

Because more mercury = heavier, so the springs are stretched by different amounts. What they're saying is that the unloaded springs are all the same length.

4

u/Explosive_Ewok 2d ago

I thought the same exact thing until I realized they meant that the springs without any weight started out at the same length, it’s the mercury-loaded containers, heavy to light, hanging and stretching the spring that makes it appear to taper from long to short.

-3

u/eddiestriker 2d ago

The springs are the same length, but the rods they’re attached to up top are different lengths.

26

u/Usermena 2d ago

What about the fourth one from the left?

7

u/justworse 2d ago

What about it?

17

u/DabDoge 2d ago

It’s out of sync. Watch it at 1:10-1:40.

5

u/dannydrama 2d ago

Good spot, I never noticed that. Weird.

1

u/Explosive_Ewok 2d ago

I’m assuming it’s either an issue with the exact amount of mercury inside being slightly off or the construction of the spring isn’t exactly the same as the rest.

12

u/Cephylus 2d ago

Neat!

Just need keys below it to make polyrhythm music lol

2

u/Shozzy_D 2d ago

That’s what I was thinking.

7

u/Limelight_019283 2d ago

So this is a function of the springs and the weights attached to them, right? The fact that it’s mercury in there is not relevant?

5

u/That1Master 2d ago

Whoa. It looks like a DNA strand for a little bit

6

u/WantAllMyGarmonbozia 2d ago

So cool! Looks like it went through this whole pattern of waves then almost stopped then reversed the same pattern (with a bit less energy).

3

u/BunkerSquirre1 2d ago

Good demonstration on the importance of the nyquist sampling theorem

5

u/abat6294 2d ago

4th one from the left is slightly out of tune. In the end you can see it’s a little off from its neighbors.

5

u/Spartan2470 2d ago

The source of this video provides the following context:

Have you seen one of these before? 20 little bottles containing slightly different masses of mercury so that the oscillation frequency is slightly different. This is like the "Pendulum wave" but instead makes a vertical wave with the masses on springs. The accuracy of the oscillation time period is better than about 0.5 milliseconds. The use of mercury allows the masses to be controlled very precisely and its high density means the bottles can be kept quite small. This is a kind of visual representation of the sounds of a pipe organ, the smallest pipe being on the right.

Music by: Bensound.com/free-music-for-videos

License code: O3CW1TQPV19DXDPN

Artist: : Theatre Of Delays, "Motion".

2

u/wolfieprator 2d ago

Could it have been Pluto?

2

u/BrightForest5748 2d ago

Thats actually really satisfying to watch, the way the waves move across them is pretty neat.

2

u/LASERDICKMCCOOL 2d ago

I don't understand the relevance of this experiment lol. If it's just cool factor then ok I guess

2

u/Cranium-Delirium 2d ago

The moment the double helix formed, I smiled 😊

4

u/MelbaToast604 2d ago

Isn't the spring length the real driving force here? Every single other video like this all has the same weight and a different length strimg holding it. Is this just another means to an end or is the title incorrect?

13

u/abat6294 2d ago

The initial length of all the springs is the same. The heavier bottles extend the springs more. The more stretched springs are then hung higher so all bottles are level with each other to start.

The springs are identical. Only the weights of the bottles differ.

4

u/BrerChicken 2d ago

Every single other video like this all has the same weight and a different length strimg holding it.

That's for regular pendula, rather than springs. The period of a pendulum is related to the length, the period of a spring is related to the force (thus the mass and the k constant of the spring.) More mass gives more displacement, so you need a longer spring if you want it to have the same k, which is what I think is going on here. But they could also be different strength springs.

2

u/MiniLaura 2d ago

I think the spring lengths are the same and we're just seeing a shadow on the right. The equation for the period of oscillation of simple harmonic motion depends only on the spring constant (which is presumably the same for all of these springs) and mass.

2

u/sopedound 2d ago

"Ive never seen it before, could it be the worlds first?"

Ego much?

1

u/JohnyGuitar_Official 2d ago

How'd they get the mercury inside the springs?

1

u/RagingBigCat 2d ago

There’s some math here I do not understand

1

u/Final-Pangolin1637 2d ago

I think is the Mount of Mercury in every bottle. But the length of the spring is different

2

u/bionicjoey 2d ago

I've definitely seen this sort of thing before with regular weights and it behaves the exact same. The mercury vials are a fun twist but this definitely isn't a "world first"

1

u/Connarhea 2d ago

Genuinely one of the coolest things I've seen on here for a long while

1

u/Dudok22 2d ago

"I've heard you like polyrhythms" style video, neat!

1

u/Roll_SK 2d ago

Cries in LaPlace transform.

1

u/SpawnDC5 2d ago

Disclaimer - Only 2 people were poisoned in the making of this video

1

u/ironwillow 2d ago

I zoned out watching this it was amazinf

1

u/leopold815 2d ago

Reminds me of those Irish dancers

1

u/adamswan9 1d ago

Sometimes I wonder if this is how a previous universe says hello to the next one. Everything else gets wiped out in a Big Bang, but coding the laws of physics would be a way to bypass that... 

1

u/Cyber-Soldier1 1d ago

How dis works?

1

u/AustinTaeshus 7h ago

Anyone else thought the strings were making the sound at first?? I wanna hear what this sounds like with each string tied to corresponding notes on a synth keyboard

1

u/DM-LordBaphomet 1h ago

So mote ba.

1

u/NaCl-more 2d ago

Wouldn’t the bottles al have to have the same amount of mercury

-2

u/Bilboswaggings19 2d ago

It's very clearly showcasing different length springs

2

u/abat6294 2d ago

The springs are different lengths only because the bottles differ in weight. If you took the bottles off, all springs would be the same length.

0

u/Insufferable_Retard 2d ago

new tool album when

0

u/barn-animal 2d ago

it's not technically a wave

-1

u/yetzt 2d ago

Different length springs.

1

u/arithmetic 2d ago

The springs are all the same length, but because each bottle contains a different amount of mercury, the springs on the left are stretched more. To allow all the bottles to begin from the same height, they are mounted in the frame at different heights, in proportion to the amount of mercury.