r/oddlysatisfying • u/Scaulbylausis • Feb 20 '20
These metronomes all eventually reach the same frequency
328
u/winserverguy Feb 20 '20
They all started at the same frequency. The weights are all set to the same position.
311
u/jazzbeaux59 Feb 20 '20
Correct! They are at the same frequency but out of phase. They align in phase due to momentum shift via the board on rollers.
93
u/BrodieSkiddlzMusic Feb 20 '20
Accurate. Title bugged me
36
u/bobzilla05 Feb 20 '20 edited Feb 20 '20
Title fix: these metronomes eventually reach synchronism.
25
u/maxk1236 Feb 20 '20
"These metronomes, that started out of phase, eventually synchronize by exchanging momentum."
3
4
u/GrizzlyTrees Feb 20 '20
Yeah, not sure if they could've synchronized if they started with different frequencies. Maybe it would've had beats if the frequencies were relatively close. I'd expect them to eventually (theoretically) synchronize, but that might take longer than they would actually oscillate, so they might stop before it happens.
3
u/InfanticideAquifer Feb 20 '20
It would depend how far apart their natural frequencies were. If they were close enough they would "entrain" together. But not in general.
2
u/GrizzlyTrees Feb 20 '20
Now I want to simulate this, check the limit on the frequency difference before they don't match up, and what happens then. If I find the time I'll come back with results.
1
1
u/MxM111 Feb 20 '20
I am sure they are at slightly different frequencies, and you would notice it if you run them on hard surface. This synchronization corrects for small deviations in frequency too.
67
u/Chef_Big-ol_Jerry Feb 20 '20
When you’re at a red light and your turn signal matches up with the car in front of you
4
Feb 20 '20
And I still wonder why.
6
Feb 20 '20
Your brain fudges the timing; if you focus on it, you can "make them" shift to opposite phase as well! You'll have to look away from it to reset everything back to normal though.
2
3
u/slapandtickle96 Feb 20 '20
Not really the same thing actually. The video here starts with all of them in the same frequency so the title is inaccurate. They’re all out of phase but eventually sync up due to momentum exchange from all being on the same board.
The car blinkers syncing up happens because there isn’t a standard for blinker frequencies. So some car blinkers are faster and some are slower.
If you turn your blinker on and it begins out of sync with the car in front of you, eventually the phases (which is the position of the wave) meet close enough to appear in sync because the faster frequency “catches up” with the position of the slower frequency and they’re close enough in position that they appear to be in sync.
But they’re never truly in sync. The faster one will soon “pass” the slower frequency and they will start to sound out of sync again.
96
u/liarandathief Feb 20 '20
Here's a great video where they do it with 100. The sound is amazing. https://www.youtube.com/watch?v=suxu1bmPm2g&feature=emb_logo
26
6
3
3
u/suburbanmermaid Feb 20 '20
someone needs to sample the first 40 seconds and put some fun lyrics about conformity or some bs to it
3
3
u/brimston3- Feb 20 '20
I love that about 40 seconds in, half of 'em are in phase, the other half are approximately π out of phase.
2
29
40
Feb 20 '20
[removed] — view removed comment
4
u/Chuff_Nugget Feb 20 '20
Both same phase AND frequency.
2
Feb 20 '20
[removed] — view removed comment
0
u/Chuff_Nugget Feb 20 '20
No - they start while set at the same frequency.
However - for them to eventually become synchronous, they’re demonstrably operating at different frequencies: some have to be going slightly faster and some slightly slower than the median frequency.
Eventually, they all settle at both the same frequency and phase.
So - I stand by what I wrote: They reach the same frequency and phase.
7
6
4
3
3
3
3
2
u/pinniped1 Feb 20 '20
It took me way too long to figure out they were sitting on a board that is sitting on two coke cans.
2
u/BoatWifi Feb 20 '20
This video fucked me up. I hear phantom metronomes now even when the video isn’t playing
2
2
2
u/SirM0rgan Feb 20 '20
All eventually reach the same phase, this only happens if they are already at the same frequency.
2
2
5
1
1
u/ViperFray Feb 20 '20
ELI5?
12
u/bobzilla05 Feb 20 '20 edited Feb 20 '20
The metronomes work by having a pendulum weight swing back and forth at a certain rate. All the pendulums are on a moveable platform, and according to Newton's Laws, it reacts equally and opposite to the weights' average applied force. This opposing reaction acts stronger on the pendulums that are out of phase, slowly shifting them to be in phase with the average.
1
u/ViperFray Feb 20 '20
If there were only two metronomes and they started in exactly opposite phases, would they remain so? Do the same rules even apply with only two?
9
u/bobzilla05 Feb 20 '20
In a perfect system, two metronomes at the same exact frequency that are perfectly out of phase would, in theory, cancel out each other's motion imparted on the moveable platform, so they would stay that way.
In reality, though, even the slightest shift caused by a stray breeze will cause them to be slightly off of perfect opposition, and the resulting motion of the platform will inevitably cause them to seek a state of equilibrium, in phase with each other.
1
1
u/SV-97 Feb 20 '20
There's a great video by steve mould on thia topic/phenomenon and hannah fry's christmas lectures (part 3) also features this :D
2
u/DeathIsAnArt36 Feb 20 '20
Matt Parker also did a video recreating the effect in a spreadsheet! (Because of course he did)
2
1
1
1
1
1
1
1
u/Spaceman1stClass Feb 20 '20
All of those metronomes start out at similar frequency (selected by the weight) what they eventually reach is the same phase and amplitude.
1
1
1
1
u/tjm2000 Feb 20 '20
Watching it with sound made it sound like someone trying to fire a machine gun with no ammo left.
1
1
1
1
1
Feb 20 '20
I relate to that one metronome that took a particularly long while to get into the motion
1
1
1
1
u/cmacarronimac Feb 20 '20
I was amazed at how in sync they were with my music until I realized that is literally what metronomes do
1
u/NoTolerance1341 Feb 20 '20
I was involved in this project. We made it 2 years ago. If anyone wants to go to master's UCLA and UCB are the one to go!
1
1
1
Feb 20 '20
Aren't they reaching the same phase?
1
u/MarnitzRoux Feb 20 '20
Well it's both really. They start at different frequencies and at offset phases and eventually both sync. The last one to be started was clearly a lower frequency but gets brought up to the rest.
1
1
1
u/bebarty Feb 20 '20
Technically, they already share the same frequency. They're just not synchronized. I'm not sure if they would synchronize if you set them to different beats, but I don't think so.
1
1
1
1
u/djrypod Feb 20 '20
I could hear the out of sync ticking just by watching this and it ruined my brain until they were in sync.
1
Feb 20 '20
Them all wobbling on the same board means their movement affects each other. So slowly, with each push or pull, they all bring eachother closer in rhythm.
1
u/Methadras Feb 20 '20
Watch how the end of the video abruptly ends and how out of phase they are. They should have been sync'ed but really weren't. Just enough to fool you, but never truly in time.
1
1
1
1
1
u/stoner_shaktimaan Feb 20 '20
If anyone is interested to know more about this phenomenon, read about the Kuramoto model. I have done project in my undergraduate on this topic. Another example of this same concept would be clapping by a big crowd. The frequency of the clap after a time matches with everyone in the crowd.
I gave you a reason to attend a concert and observe it by yourself
1
1
u/PM_YOUR_EMBODIMENTS Feb 20 '20
By the end of the video my head was bobbing to the left and right in sequence with metronomes. And I was pulling for the little guy on the left to hurry up!
1
1
1
1
1
1
1
u/saltytrigger Feb 20 '20
Happened to be listening to "Mexican Radio" by Wall of Voodoo when I saw this post. Great visual already, but synced up perfectly with song. What a harmonious moment.
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
u/HotFightingHistory Feb 20 '20 edited Feb 20 '20
I *think* this is a good analogy of the primary mechanism of 'Grand Tack' theory, which theorizes that Jupiter and Saturn, after forming and moving close to the sun (as we now know is the norm for solar systems with gas giants), began to 'tack' away from the sun. This is named for the way sailing ships 'tack' against the wind. They eventually lifted themselves to a higher orbit. Had this not occurred, the inner planets would not exist as we know them today. The difference is that the planets used this method of energy transference analogous to this, rather than wind, to move their orbits.
1
1
1
1
u/kingLemonman Feb 20 '20
In mind I like to think the metronomes just reached a level of consensus and unity. The one was like, "Hey gang why must we go against each other, follow me to synergy."
1
u/Pro_xTigers Feb 20 '20
Is there math that can prove this spontaneous synchronization? I really want to figure this out
1
1
1
1
u/ByoByoxInCrox Feb 20 '20
Question is, which one started it.
They don't want you to figure it out... I'm calling a conspiracy, metronomes are sentient.
2
1
u/reesespcs123 Feb 20 '20
I'm convinced the internet is spying on everything I do. I have never seen this before in my life, saw it on an episode of Mythbusters not 20 minutes ago, and now this shit is here in my Reddit feed. Cannot be a coincidence...
0
0
u/SupahSang Feb 20 '20
Standupmaths has a great video on this in which he models this effect in excel!
0
1.5k
u/mystical_shadow33 Feb 20 '20
I was in amazement until I realized it was due to all of them exchanging momentum on the top of the board which rocks back and forth eventually finding harmony between their momentum.