Okay, let's just get this out there right now, I know This is weird you probably watch this channel because you want to see slow motion phenomenon of like bullets hitting stuff and fracture mechanics and water drops bouncing and animals squirting things Whatever you're into But this is crazy. Most people think "Oh look, the cute little nerds set up the dominoes, and they knock them down, and everyone claps and it's great." No. This is different than that. I was naive enough to think that I was gonna set up a high-speed camera, point 'em at dominoes, I was gonna set 'em up knock 'em down, vary the spacing and the type of floor it was on and I was going to transcend the knowledge of dominoes instantly, you were gonna get smarter every day, and we were gonna go about our merry way. But no. Look me in the eyes. This has broken me. I do not understand dominoes. The reason this's broken me is because I've been sitting here doing all this math to determine the gap Necessary in order for this red Domino's weight to always knock over the blue one, but when I set up with my calipers It doesn't work, and if you think about it the same people that taught me how to do this math Also told me if I needed to I could assume a cow is a sphere in a vacuum Paper physics can only get you so far. If there's anything I've learned from my job as an engineer. It's that There's no replacement for actual real-world testing if we want to make observations of the exact times these Dominoes hit down to the millisecond It's really hard to do it from a camera like this the reason is look over here You can see the inside of this Domino, and then the inside of this one and somewhere in the middle it changes So if we want to get a shot where we get all this data We have to have a moving camera not only that but a moving camera that is Perfectly timed right here in the middle so we can see when this edge hits this edge Which means we're gonna have to time it perfectly With the wave of Dominoes as it runs along the track do I want to keep making videos on smarter every day about Dominoes Yeah, if that's what it takes to find the answer. Yes, that's what I want to do This is about not quitting so now we're gonna give Domino's the respect they deserve and we're going hardcore mode We're at fifteen millimeters The second one over here Welcome to hardcore mode... It's the same as before only I try harder so here we go we're gonna build stuff And we're gonna do experiments, and we're not gonna quit, and there's a twist at the end of this video. Let's do it Okay, this is Trent. He is the contraption fabricator that I talk about on the patreon page, and this is my cousin Hayden, hey Hayden okay, so this is a high speed camera on a skid and Trent made this, good job Trent and we are about to try to pace These dominoes so that we can tell the difference between a hardwood floor, and you know a surface that's grippy. Okay ready ? That looked awesome, oh it outran us it moves a lot faster than the wood floor, and I'm so used to the wood floor He's frustrated. I know well enough to know when he's frustrated. He's frustrated. You miss that one Are you frustrated Trent? No all right we're going to figure out exactly how to nail this we're gonna get all the dominoes in frame as they fall So we can gather the timing data and figure out what steady state velocity is it took some practice because sometimes the dominoes would outrun us And sometimes we outran them So I keep messing up the high speed which means Hayden has to keep set up dominoes Which means up if we're gonna my half-court shot We got it. It'll work, it'll work this data This is the first good run we got on felt Watch closely and you can see that the bottoms are trying to slide out from under the Domino But it digs into the felt and stops I think we got it do that one more time I feel really good about that. Oh, we did pretty good Hayden Hayden We got it, that's the one right This is the best run we got on hardwood if you look at the bottom you can see that It's slipping out from under the Domino makes it rotate around its center of gravity and also if you look at the top you can See that they're not hitting square on So which one is faster We've got hardwood on the bottom that slips and we got filth up top that doesn't slip and Trent and I both felt felt Was faster so how do we know we have to like quantify this? The answer is brute force science to figure this out We did a ton of runs mostly filmed at 5,000 frames per second the goal is to figure out exactly What millisecond each individual impact occurs which made for over a hundred and twenty thousand frames of data to reduce? Your boy here has too many kids and too many jobs to reduce that much data So I blasted out a spreadsheet template to everywhere that smartereveryday touches the Internet I compared you guys against each other Twitter Got it done fastest people follow me on Instagram and snapchat got it done quickly Facebook helped surprisingly the physics subreddit wasn't interested in doing physics that day the smartereveryday subreddit was great and accurate but Patreon was by far and away the most accurate source, which makes sense because these are the best people in the world There's a reason I gave each social media outlet its own spreadsheet. It's called the wisdom of the crowd here You can see exactly what frame each individual chose at the impact point and the average of those selections These averages were then graphed for each individual video file and there you have it if you average all the runs together it appears that The non slipping felt is faster than the slipping hardwood before I go into why I think it's faster I'm gonna let grant from the YouTube channel three blue one brown take a crack at it because this dude is fantastic at reducing super complex mathematical systems down to quick little YouTube bytes It's amazing you should check his channel out anyway go for it grant Hey, Destin its grant, so I wouldn't haven't looked at some of the data that you sent and here I'm just gonna pull up two examples one of them with Domino's on felt the other on hardwood and these are just the plots of the average velocity of each individual Domino as they fall and Obviously the first thing that stands out is just how chaotic this is right they're super jaggedy and I think some of that might just be that the Distances between each Domino were probably a little bit variable right that's probably not perfect But the way that we were computing those velocities kind of assumed that that distance was a constant So one pretty simple thing I did to just kind of smooth out this data is rather than graphing each Individual velocity point take a look at the previous 20 different velocities And then average all of those and that way if we look at the moving average It should hopefully kind of smooth out any of the small variations and things like distances between dominoes so when you do that It does look like that in general filth is a little bit faster than hardwood, right? But that's not always consistently true like here if we look at the last few Falls It seems like the hardwood sort of catches up with it, and this is just two examples But I saw this in a lot of the other ones so if you just look at the overall average Velocity felt definitely does look faster, but it wouldn't be comfortable saying that it's consistently faster I think there's probably a lot of other variables at play here that sometimes might pull hardwood ahead grants Channel is amazing you should really go check it out, but you gotta skimmed over the chaotic part of the graph and for me that's the most fun part when you track a rocket with a radar you get a general idea of the Acceleration profile by looking at the distance versus time plot But the magic is over here in the noise When a rocket makes a correction usually that shows up as a perturbation in the raw data And I'm seeing perturbations in this data and there seems to be an actual pattern here a Natural undulation of the curve initially I didn't have enough Domino setup to determine a steady state velocity But now I'm wondering if there. Even is a steady state velocity because if you look at the data It goes faster and slower over and over again. I think this might be happening for two reasons number one You can see little twists You can see that the Domino's aren't hitting each other Square and in fact the twist gets worse and worse and slower and slower until it gets so slow that the pushers behind it fall Down and straighten them back out this slam down is that velocity spike that we're seeing watch this twist Things are stacking up and Slam see that spike. It's a natural cycle in the graph there's a twist a twist Twist Twist They're starting to stack up and slam The twist is energy lost in the system And the slam is the positive correction the second thing I'm seeing becomes more clear when we spread out the Domino's where each Domino hits the next one seems to determine how much it rotates versus how much it's pushed watch this When a Domino is hit down close to the center of gravity the impact will tend to? Translate the Domino forward instead of rotating it because this Translation calls it to still be upright when it hits the next one it hits it up high which makes the next one rotate faster the next one gets hit down low and you see that a back-and-forth pattern emerges I'm not really sure how this plays in but it's clear to me that where a Domino's hit on its back determines How it falls forward when you spread the Domino's out farther the effects of these phenomena are amplified even more for example watch this case one Domino in the entire chain Doesn't fall all right, so This is curious, so we see how that happen Check this case out where the chain stops altogether due to the twist error building up past the point of recovery Okay, here's the twist to all this this video is not about dominoes this video is about creating an experiment To understand what seems like a simple system at a very very Complex level now that you know what to look for you're able to see very Intricate interactions in this Domino chain right now right in front of you. There's no real direct Application so why do we do this, this is what we call basic research, and it's very very important It's not like Applied Science where you're inventing things using some technology It's about being able to understand and predict Natural phenomenon humans weren't able to go to the moon because they suddenly felt like it it started by wanting to understand how birds fly Someone had to first answer that Question before we could ever start on our way Cancer won't be cured because we walk into a lab with a lot of money and want it to go away It's gonna involve basic research like how cells work these complex Building blocks to understand the world are right there in front of us all the time But we have to make that first little push into the unknown to start the chain reaction So here's the point ask The simple questions keep an eye out for those little things that end up being building blocks that lead to the bigger stuff At work my favorite people are the ones that ask questions in meetings that might sound silly but they're not because for every 10 they ask there's one that they'll ask that'll start this chain of discovery and Pull us all towards the profound So that's the take away ask the simple questions and dare to try to answer them I'm Destin you're getting smarter every day. Have a good one all right I'm gonna travel for my day job, so sorry for the weird transition here This is the hotel room that I'm staying in I want to say. Thank you to everyone who worked on the data That was a big deal It would've taken dozens of hours So thank you everyone that did that especially the patrons who helped me fun things like Trent making the little high-speed camera cart I also want to say. Thanks to the sponsor, which is 23andme 23andme is a personal DNA service They send you this kit And then you send off a sample and you get all kinds of info And back about your DNA in about six to eight weeks now I wanted to know what happened in that six to eight weeks so in another video on smarter every day I went to the labs where they actually process the samples and I got to see exactly what happens there It was awesome, and I feel really good about the process I personally enjoyed doing the service because I got to share my DNA family history with my dad And so we got to connect over that it was really cool And I'm totally gonna give it as a gift if you want to check this out and learn more about your DNA then go to 23andme comm slash smarter you can get yourself a kit do it yourself. It's really a fun thing to do again That's 23andme comm slash smarter doing that support smarter every day And you get to learn more about yourself in the process alright. That's it Thank you to everyone who follows me on all the social media yet reddit Twitter Instagram obviously I'm not like an Instagram model, but I try to do intelligent stuff or at least things I'm thinking about which is normally kind of abnormal stuff, so thank you for following me on that and also Thank you for answering the call when I have that data problem if you're new here And you like the idea of crowd science feel free to consider subscribing to smarter every day To help me do stuff like this when I blast that out on social media or whatever I really appreciate the consideration for subscriptions and follows on all that stuff I'm just a dad that works for a living so whatever. Thank you anyway. I'm Destin. Thank you again. Have a good one Okay, you can do it! Trigger!
This video perfectly sums up why Smarter Every Day is so awesome. The simplest things turn out to be amazingly complicated when given the proper attention. I feel like there’s a lesson in there somewhere...
Great video Destin! Are you planning on doing more with dominoes?
I think one of the things that inspires me the most from Destin is his confidence. No way I'd ever feel comfortable enough to willingly toss out different theories about random, complex physics and mechanics to millions of people. The anxiety from an infinitesimally amount of shouting how I'm wrong about xyz or whatever would be enough to overwhelm the f*ck out of me. And I design "live concrete structure" supports for a living.
The private obsession of trying to figure out the math, though. Yeah I can relate.
I don't understand. He went through all that effort to get new data and his method of triggering the dominoes is still a handheld ruler? Why didn't he use a reliable source like I don't know, a pendulum dropped from a fixed height or something to trigger it? Now there is an error in the data because of the variation in the force of the triggering mechanism.
Hey Destin! Have you considered setting up a system to try to eliminate that rotation? To me, it seems obvious that it starts with the initial push being a bit off.
“Ask the simple questions.”
You hear that, Reddit? Now stop making fun of me for asking dumb questions!
Here's a thing I learned: for sometime now I've been restraining myself in asking the silly questions because it feels like either it's a waste of time, or science already knows the answer. But I'm more confident that I should investigate those questions. Thanks for that!
I was looking forward to a domino followup, and that was great. Cheers and happy holidays!
Thank you so much for this.
Destin,
Seeing videos like this is so awesome, been following you for years and this one really blew my mind. I've been teetering on an idea for a bit and now that I'm at a place where I can finally do this: I want to open up my company for use on Smarter Every Day, in whatever means you may need. I do 3d printing, rapid prototyping, and laser cutting (soon adding short run injection molding). If there is anything you can think of needing for the channel, or even for the family, let me know. I'm happy to put my skills to use to help others get Smarter Every Day. My company is in Tampa, FL but I'm happy to ship parts as well. Would love to help any way we can. Not sure of the best way to reach out, but I know you check your Reddit so this only seemed appropriate! Thanks for all the amazing videos that I get to share with people any time I can!
-Grant (not the one from the latest video unfortunately ha ha)