Skip to main content
Loading Explore guides…
Elephant Toothpaste Experiments · Acedra
Home
Explore
Chemistry
Elephant Toothpaste Experiments
Sign in to save
Chat
If YouTube asks you to sign in, open the video on YouTube.
Watch on YouTube
Reload player
Transcript
79 segments
Copy
Hide video
0:00
- Two, one. (structure explodes) (people shouting) - This is me reclaiming my title for the world's largest and tallest elephant toothpaste experiment, and this is a totally different kind of reaction we discovered in all our experimentation called Devil's Toothpaste, which is insanely reactive and super dangerous. I'll explain why in a minute, but for now, here's a hint. (loud explosion) (glass shattering) Wow. And if you look closely in both shots, I'm not holding the trigger. This kid is.
0:32
In fact, that kid was the whole reason we were there at all because this was a culmination of eight months of planning to throw him the most epic birthday party ever. And all of this started inadvertently from a single surprise phone call. (phone ringing)
0:49
What's up, Fletcher?
0:52
- Oh my God. (Mark laughs)
0:59
- What's going on, buddy?
1:04
- What? (Mark laughs) - How are things, man? - They just got better. - This is Fletcher, and this is also Fletcher a year before this call. But unbeknownst to everyone at the time, also pictured here under all that amazing hair, was a fast-growing brain tumor. They eventually realized something was wrong and discovered it was a dangerous form of brain cancer so rare he was only the sixth kid ever known to have had it. So his family uprooted their lives for a year
1:31
and moved almost a thousand miles to be closer to St. Jude where they removed the tumor and would try and fix his brain. In fact, our call was the night before he was going back in for another brutal week of chemo. He's such a funny kid, and I was so inspired by his hopeful attitude that after talking for an hour, I secretly vowed that if he made it to 13 years old, I would fly him and his family out and surprise him with just the dopest birthday party ever.
1:55
And not long after, I texted Fletcher this picture. So he knew we had closely matching hairstyles, but what he didn't know is that plans were already underway for him and I to take back the record for the world's largest elephant toothpaste. And as a quick refresher, last summer, my buddy Science Bob and I set the world record for elephant toothpaste by filling up an empty swimming pool. I wanted to be able to swim in the foam afterwards. So we figured out how to use yeast as the catalyst,
2:19
which is in fact safer, but it doesn't react very fast, and our video seemed to inspire some folks because two months later, this happened in David Dobrik's backyard where they didn't bother with the yeast and just took the normal reaction and scaled it up a bunch. But then a few weeks later, these guys in Brazil did the largest experiment yet, and they are the current Guinness World record holders. And so even though Fletcher's birthday was still eight months out,
2:41
we started our testing right away because I knew blasting a world record amount of foam straight up into the sky wasn't as easy as it might sound, and the part that concerned me the most was picking the right nozzle size, and here's what I mean. These three containers are identical except for the diameter of their outlets. If that diameter is too large, it looks kind of cool, but it doesn't really go that high, Too small, and it will go high, but it just looks like confetti,
3:08
and it doesn't look that impressive. But for every container, there is a Goldilocks size diameter opening that gives you that cool laminar-looking flow while still going pretty high. And you might think, "Well, why don't you just take a typical flask that works so well and just scale all the dimensions up?" And we tried that on our first five foot scale test. (contraption whooshes) And just as I feared, it went all confetti on us, and the problem is illustrated here. If you wanna scale up
3:34
and double all the dimensions of the block, you get this. That's perfect. All these dimensions increased exactly by a factor of two. But wait a sec, the volume increased by a factor of eight. This is called the squared-cube law and its effects are everywhere in nature, such as putting a hard limit on just how big land animals can be because how heavy you are is a function of your volume, but the strength of your muscles and bones is a function of their cross-sectional area.
4:01
So since animals evolved to get heavier by the power of three, but stronger by only the power of two, at some point it's just too much. So on the next five foot test, we increase the top diameter by a mere three and a half inches. But now the pendulum swung too far the other way because while the column looked smooth, it didn't really go that high. And so finally for the third test, we let the pendulum swing back just a tad, and shaved down that diameter by just over an inch
4:26
to try and dial in that Goldilocks outlet size. And sure enough, the column went really high and looked great, but this test uncovered another issue. With such a high volume of foam, the pressure was creating some really high forces in the flask. I mean, that's a lotta damage, which quite frankly, left us with only one option. (upbeat dramatic music)
4:51
And so with the Power Flex Tape, we scale things up even further to a 10 foot test, and did our best to interpolate that Goldilocks outlet size. Oh my God! (contraption explodes)
5:08
So once again, the outlet size worked great, but our joint construction wasn't prepared for the further scaled up forces. In fact, score a fat W for the Flex Tape where you could see it single handedly held the thing together even as the screws and wood busted through. And we were realizing we just had to make the structure so over-engineered and indestructible, so the only option for the foam to escape the high pressure would be going out the top. And so while that wasn't a perfect result,
5:34
I felt like we'd learned enough from all of our failures to design it strong enough for the final 20 foot world record version. In the end, we ran over 150 tests, not only to determine the right scaled up flask dimensions, but things like does neck length have an effect? What happens if you vary the soap amounts? What effect do different brands of food coloring have? All of these tests were really insightful, but perhaps the most interesting finding was stumbling upon something
6:00
I've affectionately named Devil's Toothpaste. Now you might be thinking, "Devil's Toothpaste? That seems a bit extreme, Mark." But allow me to demonstrate. This is a shoebox full of the standard formula of hydrogen peroxide, sodium iodide, and soap that pretty much everyone uses to make elephant toothpaste. Now here's the same volume of reactants, only this time using Devil's Toothpaste. Now see if you could spot the difference in real time.
6:26
(Mark chuckles)
6:30
Not only is it hyper reactive, but the reaction is much hotter so you get these really cool bubble formations. Here's one more. Once again, this is normal elephant's toothpaste in an Erlenmeyer flask. No big deal, people have been doing this for years. But once again, here's the same volume of reactants, now only with Devil's Toothpaste. (glass shattering) (Devil's Toothpaste explodes) And given how explosive this is, this may be irresponsible of me, but while we watch the replay,
6:56
I'll tell you exactly how to make it. You start with (beep).
7:00
Once that mixes, you're gonna (beep).
7:03
Oprah Winfrey. (beep) Torch on the leftover rabbit fur, and you're good to go. And so by taking some rigorous safety precautions, we also intended to set the first and therefore, only world record for the world's largest Devil's Toothpaste experiment by filling six 55 gallon drums with 400 times the amount that broke the flask here. And so after 150 tests and eight months of work, feeling much more confident about our build plans and chemistry, we packed everything up and made our way
7:32
to the small farming town of Gridley, California. We chose Gridley because our family friend, Dale, graciously agreed to let us use his land, which is full of hundreds of acres of walnut trees. No, don't even think about it, fat Gus. He also had a great backyard we could make use of, and so with only four days left 'til Fletcher was flying out for the party, we got to work on a 20 second build montage.
7:55
(upbeat bright music)
8:14
And it took four consecutive 14 hour backbreaking days of labor in the hot sun because with so much time to plan the most epic birthday party ever, I just kept adding more and more ideas to the list we would need to pull off. So in addition to building the indestructible 20 foot flask and the Devil's Toothpaste dumping mechanism, we also needed to make a methane bubble fountain, a 3D bubble printer, a fire tornado, a slip and slide into a pool, and an epic bubble pit.
8:37
And even though I brought my buddies, it was cool to see this turn into a modern day, small town USA barn raising. If we needed extra hands or a piece of equipment, 10 neighbors were there like instantly to help us out. And so the morning of the big day, there was still a lot of last minute scrambling, but things were looking pretty good. I'm seriously so nervous right now. I love pranks, and a surprise is like, the most wholesome type of prank. So I haven't been able to sleep for days
9:00
just thinking about this, like every last detail to how this will go down. And so with only one hour left, we did one final test run on everything. First, the Devil's Toothpaste.
9:11
A perfecto. And then the 20 foot flask.
9:15
For the real reaction, the peroxide would fill the whole bottom pool where John was standing, and then the troughs would dump over all the catalyst at once sort of like this. And I should mention, Guinness only lets you choose one world record category per event. So we're going for the tallest, but when we did the math to scale up the flask to the arbitrary height I picked of 20 feet, and this is a true story, it was exactly one gallon less than the folks in Brazil
9:37
who set the world record for the largest. And so don't mind me while I set these two gallon containers right here. And so as people started gathering for the surprise, I hit the hardened streets of Gridley, California to look for some kind of last minute disguise.
9:54
And so after a bit of a warmup, 'cause these are all moves I can for sure do, and that's definitely me in the costume, the moment I had spent the last eight months planning for had finally arrived.
10:04
And the cover story for the kids is they were coming to tour a walnut farm of a distant relative.
10:10
- [People] Surprise! - And to provide a good juxtaposition, I wanted him to feel as awkward as possible for this part.
10:23
And then when we gathered for the picture, I snuck up right behind him and took off my mask. All right. Cool. What do you guys wanna do next? What should we do?
10:37
His sister, Aila, also had no idea any of this was gonna happen. - [Fletcher] Oh my gosh. - You're kidding. - What up, buddy? - You're kidding me. - How are you? Get in here.
10:56
What's up, dude?
10:58
- You are kidding me. - When I'm not making videos, I'm the Gridley mascot. - Mascot? To really stretch out the surprise, I wanted to think I was only there to drop in and say hi. So I had Dale suggest that I take the kids for a ride in his dune buggy, to which I reluctantly agreed 'cause, you know, I'm a busy guy. I could do it. Like, 15 minutes. You guys wanna go for a Razor ride? Is that cool? Lets get the whole crew, your sister. I had about like a half an hour.
11:23
So it's good to meet you in real life. - Yeah. - Yeah, let's go! (upbeat bright music)
11:33
Don't tell mom! - Not a word! - Not a word, okay! Watch out for walnuts.
11:42
A single walnut grows in one of these, which is crazy to me. All of those are just a single walnut.
11:53
As we pulled up the driveway, I stopped the dune buggy in a precisely predetermined location where the view of the 20 foot flask was obscured by the truck. I heard it was your birthday, so I got you something simple. - [Fletcher] Well, tomorrow's my real birthday. - Oh yeah, tomorrow. I'm one day off.
12:08
So Fletch, I've gotta come clean, buddy. You and I today are gonna set a Guinness World record for the world's tallest elephant toothpaste. - Wait, what? - Are you kidding me? - You are currently in a YouTube video. I want you to wave to 20 million of your newest friends. - Hello. - We're gonna put all the elephant toothpaste in, and just blast it in the air. - Yeah, I got 15 minutes.
12:39
- I actually fully cleared my schedule. - Oh my God.
12:44
- With the surprise fully and successfully executed, my heart rate finally lowered a bit, and I gave them a preview of all the cool stuff we had lined up for the party. Then we headed to the backyard where he saw the setup, and his mom. - You are devious. - Because at this point it had sunk in there would be no Walnut farm tour, and that her and I had been conspiring for months.
13:07
For now though, it was time to party. (upbeat modern music)
13:25
(upbeat modern music continues)
13:43
- Nice bubble party, Mark Rober. (upbeat modern music)
14:19
- Before we busted out the flaming bubbles or the bubble pit, we headed across the street to check out the world's first, and therefore largest, Devil's toothpaste experiment.
14:30
Here we go, Fletcher! Three, two, one! (Devil's Toothpaste explodes)
14:53
- [Fletcher] It worked! I didn't screw it up.
14:58
- Science Bob came over and hooked us up with the slow-mo shot. Whoa!
15:27
This shot was from a GoPro on rails, and we weren't quite fast enough with the pole. And for some reason I found this like Wall-E level pathetically sad. You can see even in slow-mo, the reaction happened so incredibly fast.
15:46
And I apologize for the gratuitous amount of slow-mo, but this has got to be the coolest thing I've ever filmed.
16:08
And afterwards, it kept oozing this rainbow Play-Doh extrusion thing.
16:12
(upbeat music)
16:25
It just looked like some kind of whimsical alien landscape.
16:30
And as you can see, over time, it just sort of deflates itself. And after that, we went back and ate some dinner and had some amazing, and not at all creepy army of Fletcher face cupcakes, while the crew started prepping for the big world record finale. And in the vein of cool stuff I would need to have at my birthday party if I was turning 13 years old, I, of course, had to bust out the Elon Musk flamethrower to light some fire bubbles. And finally, it was back to the front yard
16:52
to top things off with the most amazing bubble pit ever. It was like belly flopping on a cloud.
16:59
(upbeat music)
17:08
And at this point, we realized it was taking way longer to fill up than we had calculated. So it was all hands on deck to try and pull this off before the sun went down. Oh, and this is cool. The bubble pit was dual purpose because once emptied, it served as the bunker to give a completely safe front row seat to whatever was about to happen. And so with the flask really close to being filled, Fletcher asked to take a very quick last minute ride in the Tesla 'cause he'd never been in one.
17:32
- This one. This is in like, every video. - You guys are in a Mark Rober video. For the request, I gave them a quick ride. (passengers scream)
17:48
- Look out! - Autopilot.
17:52
- Oh my God! - The weird part is like it said, and I have a conversation with you, Fletcher, and this feels very freaky, but you trust. (screams) Remember our story, all right? 10 miles an hour tops. And so with the official measurement drone in the air, our timing was perfect because we made it back just as they were sealing up the door for the big moment. Okay, Fletcher, I'm handing this to you officially. To think you should have been touring a walnut farm right now.
18:15
And so after eight months of planning and so much work by so many people, the coolest birthday present I've ever given anybody came down to this moment. Here we go. Three, two, one.
18:28
(people shouting) (Devil's Toothpaste explodes)
19:07
- It worked! - It went from the bottom.
19:12
- Came up the bottom, and lifted it up! Look at my truck! Let's go. - Oh my God. - What you guys think? - So cool. - That floated from the bottom. - Look at the truck, it's like buried next to it.
19:27
(upbeat music)
19:36
Boom!
19:39
(Devil's toothpaste gurgling)
19:52
(soft gentle music)
20:00
And I'd just like to point out how great that flowing column looks with a perfectly selected outlet diameter. That is, until things got chaotic once the pressure changed drastically from the big rupture. (soft gentle music)
20:23
We literally made a rocket ship. I mean, fundamentally, this is how rockets propel themselves. And the actual failure mode wasn't really a floor strength issue, as much as it was a stiffness issue. I knew our structure weighed over a ton, so I just didn't consider that the reaction could lift the whole thing five feet into the freaking air. And in NASA, that's what we refer to as a critical oversight. But honestly, this result was way more spectacular. Plus, it leaves room for improvement,
20:47
and I should also note, even with all that, we still crushed the previous world record by more than double. And so as the sun went down, Science Bob lit up the fire tornado as a fitting end to the party.
21:00
I also told Fletcher there was one more thing, which is that with a little help from Dale, he could use some heavy equipment to destroy our beautiful creation.
21:14
And so with that, the party was all over.
21:18
That was epic. I'll never forget this. - [Mom] Thank you. Thank you, Mark. - [Mark] As they drove away, I thought about everything they'd been through for the past year, and all the people that came together from all across the country to donate their time and energy for a kid they've never even met. And I might not vote the exact same as all of them, but for like five inspiring days, none of that stuff mattered. Whenever I find myself short on hope, I find it helps to put my phone down
21:44
and choose to see the good parts in my fellow humans, and be one of the good parts for my fellow humans to see. And so to Fletcher, thank you for being such a good example of holding onto hope amidst really lame circumstances. Happy birthday, buddy, and congrats on your new world record.
Here to help you learn
Sign in to keep a private conversation with your course tutor.
Ask me anything about the material…
Sign in to chat