The experiment itself is simple. A cored watermelon sits on a patch of hay, and a man hovers over it with a container, one so hot that he can’t hold it in his hands. With the attached apparatus, he carefully tips it, pouring molten aluminum into the center of the giant fruit below. What happens next? Well, we don’t reckon anyone could have predicted the surprising and yet beautiful results…
You’re probably thinking that such an experiment – one that revolves around molten aluminum – would have to take place in a science lab. But a brave and arguably pathologically curious scientist decided to conduct his test in the backyard of his home. If you have a patch of grass behind your abode – and a certain amount of other technical equipment – you could replicate it yourself.
So, try and imagine what it would look like in that very space. You, standing over a giant watermelon, very carefully wielding a piping-hot container of liquid metal. You tip it forward and pour, expecting something dramatic to happen. You might reasonably assume that such a high-temperature element in any kind of experiment has a high chance of causing an explosion.
And something shocking does happen to your watermelon filled with molten aluminum. But what, exactly? Write down your hypothesis now, because someone has actually tried this. And you’re not going to believe what YouTube’s Backyard Scientist discovered when he performed the experiment in, well, his backyard.
His YouTube followers know Kevin Kohler as The Backyard Scientist, but his experiments didn’t always take place in the grass. It all started while he was studying chemistry at the University of South Florida. There, he started filming his scientific tests in his dormitory.
Kohler’s early videos saw him performing relatively small experiments. In his first-ever upload, he taught viewers the many ways they could use Borax – showing them, in one example, that they could use it to turn fire green. He also demonstrated to YouTubers how they could create their own crystals out of the cleaning product.
But those videos didn’t quite make the same splash – and here the pun is intended – as the first one that incorporated molten aluminum. Kohler dumped the liquid into a swimming pool to see what would happen. Interestingly, the silvery metal cooled into tear-shaped pieces and a blob-like mass at the bottom of the pool.
The aluminum-in-the-pool video racked up more than 10,000 views, at which point Kohler realized that his bigger experiments would turn more heads. So, he acted accordingly, coming up with extreme and extraordinary tests, and he recorded himself at the helm of them all.
On Kohler’s roster of mad-but-true experiments, you’ll find the time he set his pool alight. Still not crazy enough for you? Well, to extinguish the flames, he tossed liquid nitrogen over the blaze. Another time, he heated up salt so that it became molten, then dumped that into an aquarium: that combination produced a big explosion, a shocking end that was caught on camera.
Of course, Kohler’s experiments weren’t just about fire and molten metals and exploding things – he also taught his viewers some lessons along the way. He told magazine SRQ in 2016, “By explaining the science behind it, I make it more than entertainment. I bring something new and teach you something.”
And viewers have made it clear that that combination works for them, too. Eventually, Kohler’s YouTube channel garnered so many followers – and advertisers – that he decided to pause his university studies and convert The Backyard Scientist into his full-time occupation. As of December 2020 his channel has a staggering 4.64 million subscribers.
And, to those millions of people who follow him, Kohler never gives out a warning when he’s about to perform a dangerous experiment on his channel. He told SRQ, “In my videos I don’t say, ‘Don’t try this at home.’ I’d like to see more experimenting and people trying new things in general.”
On his YouTube channel’s landing page, though, Kohler does issue a semi-warning to The Backyard Scientist’s fans, though. He wrote, “Almost everything I do can be considered dangerous! If you insist on trying my videos at home, just remember – if you play with fire, you’re going to get burned.”
To be fair, some of Kohler’s most explosive – and headline-grabbing – experiments have shown that to be true. Perhaps none of them exemplify the try-at-your-own-risk mantra quite like the clip titled Rocket-Powered Fidget Spinner. Now, these handheld devices were initially designed as soothing sensory toys for those with autism, anxiety and ADHD.
But as we all know, fidget spinners became a popular mainstream toy, too, with kids young and old trying to learn how to perform tricks with them. Along the way, Kohler caught sight of the spinning device and came up with an activity of his own – one that ended up being a bit dangerous.
As the title suggests, Kohler filmed a Backyard Scientist installment in which he attached rockets to the fidget spinner, sending the device whizzing to a peak speed of 5,294 rotations per minute. That sounds cool, except his first take saw one of the rockets working itself loose from the toy – and nearly smashing into his girlfriend’s ankle.
But it may just be The Backyard Scientist’s molten metal experiments that are the most intriguing. We’ve already touched on the time he poured scorching-hot aluminum into a swimming pool. He has done the same to a lava lamp and a plugged-in toaster and he has seared a steak with the stuff, too. Yet perhaps his most interesting metallic test came when he poured the silvery liquid into a watermelon.
Watermelon makes a great snack – most of us have chomped into a slice of the pink, seed-filled fruit. But it has also become a great resource for experimenters the world over. Of course, most of them are performing far less dangerous tests than dumping molten metal into the center of the fruit.
For example, a hollowed-out watermelon makes the perfect base for a volcanic simulation – yes, the one you did in elementary school science class. Mixing vinegar with bicarbonate of soda in the fruit’s basin will create a bubbling explosion that looks even cooler when erupting from a watermelon rind.
On top of that, watermelon has become a surprising and beautiful medium for artists the world over. The practice is believed to have originated in Thailand, where fruit carving has been a renowned artform for hundreds of years, locals using the etched-out rinds as décor when setting tables for royalty. Now, other artists have followed suit, creating pieces meant to delight the masses instead.
The Backyard Scientist’s watermelon experiment wasn’t meant to create art, though. After all, Kohler planned to pour incandescent aluminum into the middle of the fruit. And bearing in mind that his previous experiments had caused explosions and smoke and melting, it seemed like this would go the same way.
The premise of the experiment, like many of the others devised by Kohler, was simple: he was going to pour hot aluminum into the watermelon and see what happened. So, the video starts with his girlfriend boring a hole into the middle of the fruit from its crown while he separately heats the metal in a propane-fueled foundry.
Just before The Backyard Scientist pours the metal into the cylindrical opening she created, he asks his co-conspirator what she thinks will happen. His partner responds simply, saying, “It’s going to explode.” Based on Kohler’s previous experience of related experiments, he must’ve expected the same.
But, as the video footage rolls, Kohler narrates what happens – and it’s far from explosive. Instead, he pours the molten aluminum into the watermelon and, while it causes a few pops, nothing major happens. Instead, the former chemistry student explains, a few “little steam explosions” break out.
The Backyard Scientist says, “You can see that I missed it in the first couple of seconds of me pouring it but, once I get it in the hole, it starts reacting with the water inside the watermelon and basically [flings] it all over the yard.” The grass on the ground surrounding it ignites too, but the fruit itself remains intact.
After that, Kohler seems to leave the watermelon to cool before his next step. Since the fruit didn’t explode as expected, he has to crack it open to see what did happen. He reveals that his YouTube followers had predicted a fiery end for the fruit in advance, so they must have been anxious to see what happened, too.
Kohler then says, “I’m really curious to see what the inside of this watermelon looks like, so we’re going to cut it open and see how far the aluminum got.” When he finally slices through the fruit’s rind to reveal the fleshy insides, though, it initially looks pretty much like a normal watermelon.
Once the fruit opens up, The Backyard Scientist makes an instant observation about how it has changed – one that his viewers can’t experience for themselves. He says of the aluminum-filled watermelon, “It does stink.” In the description of his YouTube video, he elaborated, writing, “Those asking what it smelled like: Sickly sweet with base notes of burning hair.”
And yet, that aroma isn’t enough to stop Kohler from digging further into the fruit. It doesn’t take long for him to look more closely at the watermelon and realize where exactly the aluminum has gone. He exclaims in the video, “Oh, it got in all the seeds!”
The Backyard Scientist gets a closer look and admits, “That is so much cooler than I thought.” He then spends a bit of time slicing away the singed-smelling fruit to get to the aluminum core, which has, indeed, filled in all of the slots where you’d normally find the watermelon’s small, black seeds.
Once he has the entire aluminum form out of the fruit, Kohler comes up with a scientific explanation for his experiment’s results. He says, “I guess what happened is the aluminum found little channels throughout the watermelon that connected the seed chambers to each other, and this caused this awesome casting to happen.”
And The Backyard Scientist reiterates that he never expected this outcome from his molten-metal-based experiment. Instead, he explains, “This is totally unintentional, I thought it was just going to be a stupid watermelon-exploding video.” So, to make sure his results weren’t a fluke, he does what any good scientist would.
Yes, The Backyard Scientist can’t perform his aluminum experiment just once. He repeats the same process, but decides to use even more of the molten metal for the second go-round. The results? “The cast came out just as cool as the first did,” he reveals.
And Kohler clearly wasn’t the only one who felt this way about his watermelon experiment. The video has garnered more than 32 million views on YouTube since its April 2015 upload. And nearly 6,000 people have been moved to leave comments beneath the surprising video clip.
Most who viewed it and contributed their own thoughts shared Kohler’s opinion on the aluminum structure created by the watermelon pour. One commenter said, “That got me excited. The sculpture that came out of it is something that seems worth keeping.” Others said they’d buy such creations from The Backyard Scientist, if he ever made an online shop.
And then, of course, there were a few funny comments, too. Some drew comparisons between the aluminum innards of the fruit and, well, a prehistoric skeleton. One commenter joked, “How awesome is it that just the one watermelon he chose to pour molten aluminum in, had a small dinosaur skeleton in it! What are the odds?”
Since his watermelon experiment, The Backyard Scientist has only continued to perform wild experiments – some of which have garnered just as many views as his famous fruit-based test. His January 2019 post clearly struck a chord with YouTubers, garnering nearly 39 million views. Of course, with a title that read Pouring lava in my pool! it was sure to turn some virtual heads.
First, of course, Kohler had to make lava in his backyard. He did so by heating a heap of volcanic rocks inside a crucible nested within a forge. To turn them into a blazing liquid, he had to get them to an incredibly hot 2,400 degrees Fahrenheit. And, once he’d managed this none-too-easy feat, it was time to conduct the experiment.
Of course, Kohler has only a small amount of lava to work with – no active volcano-esque eruption will flow into his backyard pool. But what he does pour into the water puts on a shocking display. In the clip, the molten rock spits and steams as it hits the water, and it quickly becomes a solid.
The cooled lava takes on the consistency of sand – a big let-down to The Backyard Scientist and his teammate, who have it in their heads that the molten rock will turn into a piece of art. Of course, if they do want to create something beautiful to put on display, they need only to source more aluminum and watermelons!