250,000 DOMINOES! - The American Domino Record - Smarter Every Day 178

It was so great to have you here at the Incredible Science Machine!! You brought so much energy to the team! Thanks for highlighting our event and doing this study - it was super fascinating to watch :)

This is exactly what I would have predicted: the bottom of the domino slips backwards more on surfaces with less friction and the domino line topples faster. I did my AP physics project on a similar concept and found that a smaller spacing on sandpaper (frictional surface) was SLOWER than a large spacing on sandpaper. What's interesting is that my original hypothesis was the exact opposite. From experience, usually a larger spacing is slightly slower on a normal wooden floor, but I didn't account for the floor surface when I made my hypothesis. A slippery floor surface (and also domino material, hence the color to speed variation) such as glass makes the dominoes fall faster.

You're right though that this is more complicated than we think, and having an unexplored area of domino physics is super exciting :) Can't wait to see what you discover in the next experiment!

Also a suggestion for starting the dominoes... I feel like we need some sort of motorized toppler that very, very slowly moves forward hitting the center of the first domino near the top. If you use a small spacing, the first domino may just lean against the next domino and not topple right away, but this would allow the bare minimum force required to topple the line. You're also right that a longer line is necessary so that the speed of the dominoes can reach terminal velocity. I'm not 100% sure how many dominoes that is (this could also vary with spacing), but I'd recommend maybe 50 in the line to be safe. Thanks again for coming! And now to watch the behind the scenes :D

Use a motor to move the dominos

Imagine if the earth was actually spinning, those dominoes would fly all over the place.

What happens if an earthquake hits before they get to set it all off though?

Rc servo to trigger?

If the dominos are on a grippy surface, the moment of inertia is ML^2/3, if it is rotating about its center it is ML^2/12, roughly. So the center of masses fall the same height regardless so the PE->KE has the PE per block as the same value, whereas the KE=1/2*I*w^2, so for a domino that rotates about its center of mass would expect omega to be greater at any point in time, making the domino contact the next one quicker.

The overall picture is certainly more complicated, but this would be the simplest explanation that pops into my mind.

pinball on a pendulum dropped from consistent height

Attach a hammer on a pivot point like a pendulum and release it from the same height because gravity is a constant force

I love your videos man. You make learning new things so interesting! I like falling asleep to them haha

I watched this video 2 years ago. Last weekend, my family traveled to Michigan for a wedding. My 11 year old daughter had never flown before, so it was a whole new experience for her. We were hustling through the Detroit airport on the way to the baggage claim. Out the blue, my daughter says "hey Dad, isn't that the fountain with laminar flow." How awesome is that?



Thanks Destin for your great videos. They're always informative and fun.

I haven't read all the comments, but I'm guessing that it was the late night that made the back row going faster difficult to understand.

Why don’t you do a collaboration with mark rober and he will build a robot that tips the dominos the exact same way every time so you guys can do a in depth video of the science and math of domino fallings

Alone the manufacturing costs of those useless dominos could feed some hungry chlildren elsewhere on this world - for years.

So... essentially apply the Griswold "sled wax" from Christmas Vacation onto glass and set the dominoes up in a vacuum to break the sound barrier
*In before everyone says you can't break the sound barrier in a vacuum. It's humor ;)

Youneedtogetaproperjobman.

The most soothing sound 7:30

To get a better average speed for the dominoes falling, I think you need a longer "fall" to let them get "up to speed". Your fall is so short, it's barely getting started. You may get a more accurate result measuring a fall over a longer distance (or at least a longer "lead-in").

Using some actuator like a piston that can be regulated seems like it would deliver the same force every time..

You could have a marble roll on a ramp to a stick that pushes the domino with constant force and speed

You shouldn't stand on the right. Stand in the middle, unless someone is trying to pass you. While polite, standing on the right side of a conveyor or escalator creates uneven wear on the bearings and tracks underneath, leading to more frequent failure and maintenance needs of the system.

pff... American record... we have the world record with 4.8 million domino's 😂

but it's still totally awesome, I couldn't do even 1k without messing everything up.

Go to bed. sheesh.

Okay! Nobody leaves until all these dominoes are picked up !

I have seen the Domino Day world record in Europe 20 years ago and i think they said that stop to accelerate after 1,5m but im not sure and can't find any
TV recording.

OMG I just saw hevesh5!!!!

Hey destin, have you thought of trying this under water perhaps a different fluid medium would help you undress the friction/motion change happening?

I think if you can trigger it without touching it with anything that's what missing. So why not put two small magnets facing in different direction on both the first Domino and attached to the stick. So that you have a constant repelling force that doesn't require you to add any initial forces.

Drop a wedge for your trigger.

ok to get the same speed and not have the dominoes accelerating you would first have to find how many it takes to reach full speed and measure segments of when its going at top speed. That could be a lot of work but you can do it!!

Use an electromagnet to trigger it. Set the first domino in the same place every time.

Im going to make a domino field that takes 5 years to sit through. It will only take 157,680,000 dominos.

I think that you should make a simple machine to regulate the push of the dominos. I also think that the surfaces with more friction cause the dominos to take longer to get to max speed. I think when the bottom slips due to low friction, gravity and the weight of the dominos increases the forward velocity faster than the dominos on a higher friction surface. Perhaps you can also set something up at the end of the dominos so you can better gauge start-end points of your measurement.

Nevermind. I found it.

Is there a follow up to this video?

Alias....

OMGosh! I am flabbergasted!

A mark rober colab?!

You can trigger it by using a rod attached to the servo.
Using this, you can adjust height, speed of pushing, friction (you can use different materials for the rod.) etc.

Search for "Servo motor push rod" on the net.
It's mostly used in RC aircrafts and rarely on cars.

Why not make a competition and race groups of domino's between two competitors over a distance?

This is amazing yall can stop bragging about this domino day thing and enjoy the video uwu

250k is the us record?! "Domino Day" laughs at that number...

I can’t do 5 dominoes in a row

Use a solenoid to trigger the fall, should yield consistency I would think

Awesome Domino video! Watched it yesterday. I think you should revisit the oscillating/twisting effect as they topple. Just to see if it wasn't causal to the initial uneven push, which seemed biased towards one side, possibly starting the chained oscillation? Or whether the oscillation is intrinsic to the wave-like energy propagation from an overall even push. If it's not an artifact introduced by the uneven push, then the oscillation is eerily similar to a descriptive electromagnetic propagation. Give it a more controlled environment!

Well the acceleration at the beginning can be explained by the fact that when you push the first domino with the stick, that gives less energy than the dominoes falling onto the next ones further on. So at the beginning its building up energy until it somehow gets consistent

I know why the heavier dominos move faster. If the force it is pushed at is the same. The mass affects it because Force= Mass *Acceleration. If the Acceleration is the same ( the force of which the domino is being pushed at ), mass is the only variable, so if the mass is greater, the force will greater as well so the speed at which the Lego moves is greater.

Use some sort of piston to topple the dominoes at the top speed of the dominoes.

3:50 1512 hours is 63 days.
7 days (24 hours) times 12 hours is 288 hours
7 times 12 hours is 84 hours which is pretty cool.