"What you're about to see could be downright dangerous, so, a word of advice..." "Leave the myth busting to us." "Narrator:" "On this episode of "MythBusters"..." "Adam:" "With good reason, we've spent 10 years telling you to not try this at home." "But in this episode, we've compiled a bunch of things that we think you might be able to try at home." "Like this." "Narrator:" "Well, not exactly like that, but after 200 episodes of saying..." "Don't try this at home!" "Whoa!" "...the MythBusters are apparently changing their tune... to deliver a DIY science special." "Your results may vary." "So prepare your safety glasses..." "Whoo-hoo-hoo-hoo!" "...your pocket protectors..." "Oh!" "Holy crap!" "Narrator: ..." "And your clipboard..." "Wow!" "...because for this episode, they're finding myths you can maybe try at home..." "Or maybe not." "Who are the MythBusters?" " Adam Savage..." " It's scientific!" "Narrator: ..." "And Jamie Hyneman." "Bye-bye!" "Between them, more than 30 years of special-effects experience." "Together with Kari Byron..." "The golden dragon!" "...Tory Belleci..." "We're gonna die!" "...and Grant Imahara." "Who wants some?" "!" "Narrator:" "They don't just tell the myths." "They put them to the test." "MythBusters 13x05" " DO Try This At Home Original air date February 1, 2014" "Okay, so, the "DO Try This At Home" Special." "Exactly." "Our lawyers are actually okay with this?" "They are, but here's the thrust of this episode." "We are gonna be testing a bunch of zany experiments and viral videos and assessing, one, whether or not they're true, but, two, whether or not they're actually okay to try at home." "So some of this may be actually too dangerous to try?" "Yes." "The first one, though, I think is gonna be pretty easy to try at home, and it's a classic... microwaved water." "Oh, yeah." "Microwaved water will kill plants if you water them with it." "I don't think it's true at all, and I think we should test it." "It's an Internet myth that has spread worldwide." "Supposedly, these pictures are evidence that water boiled in a microwave is toxic to plants, but could that be true, or is this myth in hot water?" "Well, if it turns out you can try this at home, you'll need the following..." "And down in the shop," "Adam's green thumb is prepping his test of the waters." "So, the question we're gonna answer is, does microwave-boiled water kill plants?" "Ohh." "Very nice." "To determine that, we are going to expose some plants to microwave-boiled water, of course." "Beautiful." "We're also gonna compare that to some other controls." "One will be water boiled on the stove, one will be just regular tap water, one will be no water at all." "Narrator:" "And now for the supposedly toxic ingredient... the microwave-boiled water." "Obviously, conduct this experiment, you're gonna need a bunch of water that's been boiled in a microwave, bombarded by those evil microwaves." "Put it in." "Push the button." "Start." "There we go." "Run it for five minutes of full power, see if that works." "[ Bell dings ]" "There we go." "All right." "Now, as a point of clarity, I want to point out the myth isn't that plants don't like boiling water." "For gosh sake, don't pour boiling water on your plants." "You'll kill them immediately, like most other living things." "No, let this water cool down to room temperature before using it on a living thing." "Narrator:" "Well, with his three types of H2O inside the rig, he's ready to get his thumbs green." "Adam:" "There we go." "We've used eight romaine lettuce in four groups, and we're subjecting those four groups to four distinctly different conditions of water." "Now, that water is coming from these buckets up here, through these water timers, and they're all set to water the plants for exactly the same amount of time and exactly the same amount of water every single day." ""But wait," you say, "what about sunlight?"" "Ah, we thought of that." "Ta-da!" "That's the light." "These are actual grow lights." "We're gonna subject our plants to these grow lights for about 16 hours a day, a really nice vibrant sunlight, and we'll log their growth on this chart here." "After a week, I swear we should see a difference." "After a couple of weeks," "I think this test is gonna be pretty definitive." "Narrator:" "But as exciting as it is to watch lettuce grow, let's fast-forward one week into the future." "All right, let's see how everyone's been doing." "[ Laughs ]" "Look at that." "9.25"." "The microwave-boiled water is outgrowing everything else." "It was around 51/2 inches, and now it's over 9 inches tall." "Right now, it's not looking very good for the myth." "Narrator:" "So, after two weeks of growth," "Adam is let loose amongst the lettuce for the last time." "What we wanted to determine was whether microwave water was dangerous, and I think, definitively, we've proved that it's not." "Look at this." "This is the healthiest plant in here." "Both of these, they're higher than any of the others, and they got the microwave-boiled water." "They're totally fine." "Oh, and we also determined that no water is really, really crappy for plants, so note that, you brown thumbs." "Narrator:" "It may be busted, but don't take our word for it." "Try this at home." "Next up, some emergency firefighting." "All right, so, first up is a viral video." "The fans want to know if it's possible and if they can try it at home." "Check it out." "Narrator:" "With a runabout ablaze, it's jet boat to the rescue, fighting fire with speed." "Man:" "Wow, he's doing it." "This guy's crazy." "But in a crisis, could an extreme 180 really extinguish a fire?" "Dude, that is awesome." "But you know what?" "There's something a little fishy about that video." "It does look like there could be some kind of visual effects going on there." "We need to find out if this thing is repeatable." "Yay, let's go boating!" "Motorboating." "You old sailor, you." "Narrator:" "So to find out if this works, over at Big Break Marina, they're re-creating all the elements of this emergency situation." "Tory:" "So, the boat we're gonna be using to put out the fire is this." "It's a 1978 charger jet boat." "It's got a 350 Oldsmobile engine." "[ Horn beeping ] Come aboard, matey." "All right, safety first, my friends, safety first." "Not only that, but it shoots a rooster tail up to 120 feet." "We should be able to put out the fire with this." "I wish we had dorkier life preservers." "Sorry, man." "These are the dorkiest ones we could possibly find." "What are you talking about?" "They match the boat." "They are in this season's color of safety." "[ Laughter ] It's hot." "Tory:" "And the best part is, they're letting me drive, except the owner has one stipulation." "He wants to be on the boat with us, which doesn't make any sense 'cause this is probably the most dangerous place you can be." "I think we need to practice." "See some stunt driving!" "Whoo!" "Narrator:" "Precision driving is key to this myth, so, first, Tory needs to get the boat up to speed, then just before he crashes into the pylon, pull off that 180 turn so that the boat sends up that dousing rooster tail." "That's nice." "That was amazing practice, but I think it's time to light a fire." "Let's do it." "Yeah, I think you got it, man." "Narrator:" "The second element of this emergency is the flaming boat, and for that, they're taking precautions." "Grant:" "Oh, hay." "So, this fine watercraft is our fireboat." "We're going to set a bale of hay and a pallet on fire and let it burn." "Kari:" "You got the air underneath so that it can light all of this hay and actually get a good burn." "This thing should flame up nicely." "Now, if things go well, we'll be able to put it out using the boat." "And if not, the fire department is on hand to put it out." "Kari:" "Time to set the fire, but before we do that, we're going to wet down all of the lands right behind where the boat's gonna be." "We don't want any stray embers to cause any unnecessary fire." "Narrator:" "The boat is now set to go up just like the video." "Great." "Some vacation, Kari." "But will the speedboat's rooster tail quench the blaze?" "All right, boat's tied." "Tory's all ready to go." "All we got to do is set the fire now." "Yeah, let's do this." "Tory:" "Now, I'm not gonna lie." "I am a little nervous." "I mean, this isn't my boat." "All right, proceed with lighting the fire." "We're gonna be flying at 50 miles an hour, straight towards a flaming boat, and at the last minute, I need to crank on the wheel so that I don't crash into the boat but spray water onto it." "All right, boys." "We have a raging fire." "Bring it on in." "And not only that, I'm gonna have Grant and the owner of the boat in the boat with me so if I crash, I'm not just hurting myself," "I'm hurting two other people." "I'm scared @#$%less." "All right, man, there it is." "Just so I understand what we're doing, we're heading straight towards a flaming boat, right?" " Exactly." " Okay." "And then, at the last minute, we're gonna turn out." "I hope this works." "Now." "Narrator:" "After 10 years of impossible, dangerous, and downright crazy myths that you shouldn't..." "Something just touched me!" "Narrator: ..." "Or couldn't try at home, this episode is all about finding things maybe you can." "So, next, Adam and Jamie get into a rhythm with one, two, five... 216 metronomes." "Adam: [ Laughing ]" "Keep going, keep going." "Well, that escalated quickly, but how did they end up here?" "There are a bunch of videos out there that show these things getting into sync if you let them run for a while." "Come on, guys." "Get with it." "Narrator:" "It all looks so easy online." "Although they start out syncopated, these metronomes eventually tick over into a synchronized symphony." "[ Ticking ]" "But can you make metronomes dance to the same beat at home?" "[ Ticking ]" "There is one thing that I keep noticing in all the videos of the metronomes syncing up, and it is that they always seem to be sitting on a platform that moves slightly, that's got a little shake or shimmy to it." "Let me show you why I think that's important." "If I move this metronome while it's ticking even small movements have a significant effect on the periodicity of its ticking." "I've got a couple of soda cans." "This is my platform with shimmy." "Got a metronome, and I just want to see what happens when I put one on here." "Do you see it?" "It's totally moving." "This is very cool." "This little metronome is definitely having an appreciable effect on my platform, and I think it'll have even more of an effect if the platform's lighter." "And I've got just the thing." "All right, this is working great." "It's definitely having more of an appreciable effect." "Just got a nice bearing surface platform, light aluminum pipes, and a very light platform for it to sit on." "I'm taking away as much friction and momentum as I can so that only the metronome is having the effect." "Now let's try two." "Narrator:" "Adam doubles his trouble with two metronomes set to the same tick mark." "Look at the movement on this platform." "Narrator:" "And after two minutes, the shimmy takes over." "Adam:" "Stay with it, boys." "It just took them a little while to find each other's rhythm." "Narrator:" "So, if two will sync, will five march to the beat?" "This pink one is messing with my mellow here." "Narrator:" "Well, three minutes in and something has come unsunk." "This pink one is way out of phase with the other four." "The other four seem to want to get into phase with each other, but the pink one's not playing along nicely." "[ Italian accent ] Why can't you get along like your brothers?" "[ Normal voice ] All right, here we go." "Let's try." "Narrator:" "Amazingly, it seems that Adam has tickled the pink just the right amount." "There it is." "Okay." "[ Laughs ]" "We got it working." "[ Ticking ]" "Yep, they're in sync." "That's awesome." "Okay." "Everyone be quiet, everyone be quiet." "Stop, stop, stop." "All right." "Let me explain what happened here." "This pink one was not playing well with the others, and I noticed when I was watching it that it was just consistently a little too slow." "So, on the theory that the manufacturing tolerances on these metronomes are loose," "I sped it up by dropping it a tiny amount below its lowest tick mark, which is what all the others are set at." "And that turned out to be the magic bullet that helped this all get in sync." "It's awesome to know." "These are tunable." "Narrator:" "And now that he's got his tickers tweaked, just how many can he make dance to his tune?" "Adam:" "Got it!" "I can't fit any more on here." "1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11." "Dude, it's really kind of amazing." "They go way out of sync, then they come back into sync, and eventually they find this." "And if one of them's out..." "They kind of get him back in line." "They all just want to be friends." "They all want to be friends, they all want to do the same thing." "Adam's taken this to 11." "I sense a serious escalation about to start." "[ Ticking ]" "Narrator:" "Down at Big Break Marina..." "Oh, you got a good, raging fire." "Blast it." "Copy that." "We're on the way." "...Tory is zooming full speed ahead..." "Here he comes." "Straight for the pylon." "...to test an emergency firefighting trick." "I hope this works." "Rip it." "Whoo!" "Whoo-hoo-hoo-hoo!" "Tory's rooster tail certainly seems to have doused the boat, but there's no smoke without fire, so the guys reset." "Reset so we can do it again with one more pass, just to make sure it's out." "I think it's looking good, though." "Skipper Belleci takes another turn at fighting fire with speed." "Here we go!" "Whoo-hoo!" "Yeah!" "I think you got it, man." "I think we put it out." "Whoo-hoo!" "Kari:" "They've just got to be smolders." "There's no way that's still on fire." "I think it went out with the first pass." "The second pass is insurance." "I think the third time's just for fun." "Narrator:" "Clearly, you can extinguish a fire with an emergency U-turn." "Kari:" "Whoa!" "Yeah!" "Wow, they got so close to the boat this time!" "That was amazing." "Narrator:" "But now that they know this firefighting feat is no myth, the question is, should you try this at home?" "Tory:" "That was crazy." "Going at full throttle, 50 miles an hour, straight towards a flaming boat." "Whoo-hoo-hoo!" "And then, right before I hit it, I had to crank the wheel to spray the water onto the flaming boat." "Kari:" "Whoo!" "It worked!" "It worked!" "You put out the fire." "Dude, I totally can't believe it worked, but you know what?" "I don't think I'd try this at home." "Yes, we were able to pull this off despite not being professional firefighters, despite not being professional boat drivers." "But here's the thing." "In order to do this, you need to overcome your fear of driving directly at a flaming boat, and be able to turn at the last second." "Not to mention, you need a jet boat." "Unfortunately, this is not something that just anybody can do." "Narrator:" "Yep, it's always best to leave the firefighting to the professionals." "I wonder if Jess will let me borrow his boat again." "Anytime." "[ Clicks tongue ]" "Adam:" "Well, the myth that metronomes, if placed on a proper surface and activated together, will eventually sync themselves up seems to be on pretty solid footing." "Got it to work with a couple, got it to work with a handful, but now it's time to go for broke." "In front of me here is an air-hockey table, and Jamie has set out, carefully, 216 metronomes." "This is more than we have ever seen in any of the videos demonstrating this phenomenon." "In a few minutes, we are hoping that we'll be setting an unofficial world's record." "Why are we using an air-hockey table?" "Air hockey is a game in which the puck floats on a cushion of air." "It's definitely floating." "And now our metronomes will float on a cushion of air." "That should allow them the low-friction environment that makes them shimmy their way to synchronization." "So, how do you want to do this?" "I'll start at this corner." "Why don't you start at that corner, and we'll just go for it?" "All right, you want to count it in?" "[ Chuckles ] All right." "Three, two, one, go." "[ Ticking ]" "Narrator:" "It's a painstaking task to start all the metronomes one by one." "Done with my half." "But now that they're ticking at the same tempo, in theory, they should start that shimmy." "Now they're all going." "They're all going, and they're floating on the cushion of air." "I'm really..." "I'm totally hypnotized by the sound." "I know." "But with 216 metronomes, almost 20 times the amount of their last attempt, can they break a world record, or will the metronomes march to a different tune?" "Narrator:" "It's the "DO Try This At Home" special, and next up, Adam and Jamie are investigating the old ball chain." "We all know what this stuff is... regular chrome ball chain." "Keys, IDs, and dog tags have been hanging from it for decades, but we've got a viral video that seems to show this stuff, under the right conditions, behaving almost against the force of gravity." "Narrator:" "So, supposedly, this gravity-defying feat is achieved without any special-effects wizardry, but are they yanking your chain, or could you really re-create it with just a ball chain, a beaker, and, if you have one, a high-speed camera?" "Check this out." "Let's check out the high-speed." "Hey, Adam." "No!" "It's like it's going all the way across the room." "Wow." "It doesn't look like it should be able to do that, does it?" "No." "It's like magic." "That is frickin' gorgeous." "That is so frickin' cool." "Narrator:" "Cool and surprising, as the ball chain seems to levitate out and over the lip of the cup, and this strange behavior has gotten Jamie thinking." "Jamie:" "Now we've got some bigger chain." "Let's see if it goes further." "Narrator:" "It does seem, the bigger the ball, the greater the effect, but is this gravity-defying act also related to the distance you are from the ground?" "Okay, let's see what this does from 8 feet up." "That made a difference." "It's clear from our testing that there are two key forces that are causing this effect." "And the first is that mass moving in a particular direction wants to continue moving in that direction." "So when we're yanking the chain up out of the pot, it wants to continue moving upward." "But shortly after, gravity starts to pull it down, and so that's where we get this arc." "If one of these forces is out of balance, like, as in if gravity starts to pull down too hard, then we don't get as large of an arc." "But when these two forces are perfectly balanced, coupled with the unique symmetrical and slick design of this chain, it all converges to create an arc that seems like it should be impossible." "But whatever the explanation, it's a really cool effect." "Narrator:" "It's cool, and to take it to the max," "Adam's got this one all chained up." "Wow." "The biggest ball chain I could possibly buy." "Whenever you're ready." "Here we go." "[ Laughs ] Wow!" "That was amazing!" "That worked really well." "Adam:" "It's almost magical watching the chain flow, seemingly defying gravity, out of the cup." "My favorite part about it, though, is that is seems to be proportional to the size of the ball chain, so you get a little loop with stuff like this, and you get a nice giant loop with stuff like this." "I didn't even know they made stuff this big until this story." "This is awesome." "Narrator:" "Yep, this chain reaction is surprisingly DIY." "So, break out the beakers and the ball chain, and make sure that you do try this at home." "Next, the team is on a chemistry safari." "All right, these next chemical experiments, fans want us to test, one, if they're genuine and two, if it's something that they can try at home." "What are they?" "Elephant toothpaste and exploding snakes." "Elephants and exploding things?" "Are we sure that this is something that people can do at home?" "Narrator:" "Well, with an ingredients list made up of household items, elephant toothpaste is the first DIY science to try." "All you need is a little hydrogen peroxide, the kind you would get for dyeing your hair, liquid dish soap, a little food coloring for pizzazz." "Ooh." "And, finally, the catalyst, which is plain old yeast." "Are you about to blow our minds?" "I am." "Stand back." "Whoa." "Whoa." "It's like a volcano from science fair." "Look at that." "It's minty fresh." "Narrator:" "It's easy to see why this super-sized foam is called elephant toothpaste." "Now, in its basic form, hydrogen peroxide is extremely stable, but what's happening here is when you add the yeast, it's decomposing the hydrogen peroxide very rapidly, and releasing oxygen." "The oxygen is getting captured inside the liquid dish soap, which is creating bubbles and this big, foamy, awesome mess." "Narrator:" "And although it passes the "try this at home" test, it's just a frothy fountain." "So how about an only-on-"MythBusters" twist?" "Don't try this at home." "[ Siren wailing ]" "All right, to take this experiment from "go ahead, try it at home" to "MythBusters" danger, we're gonna use some lab-grade components here." "We have a higher concentration of hydrogen peroxide, and for our catalyst, potassium iodide." "Now, these are much more caustic chemicals here, and the reaction is a lot more energetic." "Narrator:" "Okay, so, take two, but this is definitely a "do not try at home."" " One step back." " Is it gonna get crazy?" "Yeah?" "You about to drop some science on us?" " You ready?" " Do it." "Whoa." "Holy crap." "What the heck?" "Much more energetic experiment." "Look how hot it is." "You can see the steam coming off." "Narrator:" "Yep, that's the kind of toothpaste an elephant would be proud of." "But now we've seen the toothpaste, didn't someone mention an exploding snake?" "Grant:" "Now, for the most part, elephant toothpaste is the sort of experiment you can do at home." "This next one is a little bit different." "It's called "explosive snake."" "Now, the first part of it involves sugar, which, by itself, is innocuous." "The part that makes it different is the other half, which is this... sulfuric acid." "Tory:" "Look at that!" "Wow!" "Sulfuric acid is corrosive." "It's caustic, and if you splash it on your skin, you could get severe burns so, unfortunately, not the sort of thing you want to try at home." "And to do this experiment," "I think I'm gonna need a slightly different wardrobe." "Ah, that's better." "So, I've got an apron to protect my clothing." "Acid gloves should protect my hands, and a face shield for my face." "Now it's time to mix up the elements." "Narrator:" "It's another "do not try this at home,"" "but will it be explosive?" "Grant:" "Okay, so, it's coming." "Narrator:" "Eh, actually, no." "[ Coughing ]" "Okay, so, what happened here?" "Well, the acid interacts with the sugar and breaks it down into its components, releases water in the form of steam, and it leaves behind carbon, which is what the snake is." "Now, it's a very cool reaction, but not necessarily all that explosive." "I think, in order to be explosive, it should be faster and more violent, and I think I can find a reaction that does that." "Narrator:" "So lab raider Imahara swaps out the sugar for a classified organic compound, adds the sulfuric acid, then brings a little heat to the equation." "But will this result in that explosive snake?" "Grant:" "Watch it." "Okay, don't blink, 'cause this can happen really fast." "Okay." "This is it." " No way!" " That's amazing." "Narrator:" "It's an instantaneous process called de-ammonization." "Grant: [ Coughing ]" "Narrator:" "The sulfuric acid dehydrated the compound, leaving in its wake a flaky carbon snake." "Grant:" "So, conclusion... two explosive snakes by different means, but, unfortunately, because of the sulfuric acid, you can't try either of them at home." "Narrator:" "So, while both myths are confirmed, unless you've got access to a lab tech and lab-grade materials, you can't try these at home." "Meanwhile, back at metronome HQ..." "Adam:" "Every now and then, it sounds like they're getting together." "Yeah." "I do think that they cross phases somehow, but I think they may be in sequence, but not in the correct position." "If you look down the line, there's no rhythm or reason to this." "It's a case of "so far, not so good."" "What you're about to see could be dangerous." "We're trained professionals, so, please, leave the myth busting to us." "Narrator:" "Next, could this soda stunt do you harm?" "Next up is a story that should definitely never be tried at home or anywhere else for that matter, given that it's illegal in a bunch of states." "What's that?" "Dry-ice bombs." "Yep, well, exploding things is never a good idea to try, so why is it we're tackling it on this show?" "Because, like it or not, people do try this at home." "These things put out a tremendous bang." "I think they also put out a tremendous bite." "That's what we want to look at." "So we want to find out just how dangerous they really are?" "Exactly." "We're gonna look precisely at why you should not try dry-ice bombs at home." "Narrator:" "This DIY device works on that old trapped-pressure principle, which the MythBusters know can be both spectacular and lethal." "Oh!" "But just how lethal will these dry-ice bombs turn out to be?" "To find out, Adam's got to set his cap first." "The capping it and getting away is where the real danger is." "I've seen these things go off as quickly as a few seconds, so I don't want to be anywhere near these things when we're trying to film them on high-speed camera and assess their damage." "That might work." "Now, we're gonna be conducting this test with bottles as different as this one and this one, but I need to put the caps on all of them, and my method is gonna be using this thing" "because it has a handy turning part out the front." "[ Drill whirs ]" "[ Laughs ]" "That's how we're gonna do it." "Narrator:" "Adam sorted the hands-free capping." "Put your forearm into that hole." "But now Jamie needs to give this dry-ice combo a hand." "Jamie:" "We want to find out exactly how dangerous this is to somebody that might be holding on to it." "Obviously, we're not gonna use our own hands for that, so we're gonna need some artificial hands." "Beauty." "That came out perfect." "So, we've got our complete set of hand molds now." "All we have to do is put these skeletons in them and then put the tops on them, strap them together, fill them with rubber, and we're good to go." "Since we're anticipating a little bit of physical damage to the hand, we might as well make it look good." "Oh, yeah." "Oh, it's so pretty." "Nice." "It's gonna be perfect for the test." "Yeah." "Narrator:" "So, now they can get hands-on with their dry-ice device." "I'm not running for my own recreation." "Who would do that?" "No, I'm running because this is our location for detonating the dry-ice bombs." "That's right." "We've come to the bomb range because that's how seriously we take the danger of these things." "Narrator:" "It's serious, because although soda bottles are designed to resist the pressure of their carbonized contents, expanding dry ice is a whole nother ballgame." "Perfect." "So, what are we doing?" "Well, we're putting frozen CO2..." "Yep, this stuff, known commonly as dry ice." "...Inside a sealed container, along with a little bit of water." "The water converts the frozen CO2 to gaseous CO2, expanding to between 500 and 800 times its original volume." "Which will increase the pressure inside the container to in excess of 100 P.S.I., at which point it'll rupture violently, releasing all of that gas, not unlike what happens when you set off an explosive." "Boom." "Narrator:" "Yep, so, now it's time to bring some data to the equation and find out just how damaging those booms can be." "Back at the shop..." "What is your problem?" "...things are starting to wind down." "Ah!" "[ Laughs ]" "Keep going, keep going." "So Adam and Jamie are winding them up again." "Remember, kids, this is something you can do with that extra 200 metronomes you've got around the house." "After 30 minutes of ticking, Adam tries a last-ditch attempt to nudge the metronomes into sync." "[ Ticking ]" "Oh, look at that." "But as soon as he stops, they come out of phase." "They're starting to run out." "Ohh!" "[ Both laugh ]" "And it's clear this game is up." "Adam:" "Jamie and I, starting them one at a time, were able to get them all going in a couple of minutes, but they never quite got synced up." "You could hear them going in phase and out of phase." "That one's out, that one's out." "And certainly, looking down the aisles and through the columns, they looked awesome and they sounded amazing, but they never quite got all in sync together." "I love the sound, but this is not a successful world-record attempt." "Every now and then, you could hear them sort of... it sounded like they were marching in step, and then they'd march right back out of step again." "This just totally didn't work." "Narrator:" "Despite the high-tech, low-friction air-hockey table, the metronomes just didn't want to synchronize." "Adam:" "So, clearly, while these metronomes work fine individually, there is enough variation in the manufacturing tolerance that to get them all ticking in perfect sync, you would have to calibrate each one individually." "Now, if you want to cross-calibrate 216 metronomes, by all means go ahead and give it a try." "[ Ticking ]" "This one's still going." "Shut up." "This is the biggest fail we have ever achieved." "All that work." "Yeah, you can try this at home." "Your results may vary." "See you next time." "Now, we found this one on the Internet." "A man made a video of water coming out of a hose, and he made the water freeze in space." "I did exactly what he said to do." "I got a speaker." "I taped a hose with running water to it, and then I attached it to a tone generator." "Now, there's one last piece to this puzzle, and that's a video camera." "You ready to have your minds blown?" "Look!" "Grant:" "Whoa!" "[ Laughs ]" "Now, watch this." "I can make it go backwards." "I'm gonna take it to 22 hertz." "It goes backwards!" " What?" " What?" "Now, the whole reason this optical illusion works is 'cause you are shooting 24 frames per second." "If you set the hertz around 24, it vibrates the water so that the water's in the same place every single time the camera takes a picture, which makes it look like the water is frozen in space." "And if you play around with the hertz, you can actually make it look like the water is going in reverse." "It's not really, but it looks like it." "Kind of cool." "[ Siren wailing ]" "Wow." "Look at that." "That is the biggest test tube I've ever seen." "Now, you've seen elephant toothpaste." "What I'm gearing up for now is something you've never seen on television before and definitely shouldn't try at home." "That is monster toothpaste." "We're supersizing it." "Go ahead." "Take me up." "Narrator:" "With over 200 times the raw ingredients, this will be monster toothpaste." "You guys ready?" "I think the question is, are you ready?" "She looks ready." "Do it." "Okay." "Here we go." "This is monster toothpaste." "Oh, all right, go." "Back me up." "Whoa!" "Oh, my God." "Holy..." " Nice." " Anybody want a brush?" "Oh, my God." "That's cool." "That's insane." "Tory:" "That was crazy." "Kari had this giant test tube." "She poured in the potassium iodide and then the thing erupted." "I didn't think it was gonna go very high, but it did, and look at the mess we created." "So definitely don't try this at home." "Sure, monster toothpaste." "Sounded like a good idea at the time." "Who has to clean it up, huh?" "Narrator:" "Just how hazardous is a dry-ice device to your health?" "Well, now it's time to tune in to the data and find out." "So, David Harding and his equipment, which is in the form of some pressure-sensing PCBs placed strategically around the explosion, is gonna tell us exactly how powerful they are." "David, you ready?" " Ready." " All right." "Ice is in the bottle, sensors are in place, cameras are rolling." "It's time to add water." "[ Chuckles ]" "Just add water." "You better get to a safe place." "Oh, it's getting bulgy." "Jamie:" "You know, it's funny." "CO2 is what's normally in those soda bottles." "This is sort of extreme soda, isn't it?" "I think this one is gonna go a little quick." "I hope so." " Yeah." " Nice!" "[ Laughs ]" "The piece just fell down after, like, five seconds." "Narrator:" "The dry ice blitzed the bottle, but just how bad was it?" "What did we get?" "Harding: 3 P.S.I. from that explosion." " That's it?" " That's all." "However, it looked like it blew out the bottom, where we don't have any direct sensors." "So that might be a falsely low rating?" "That's right." "And as it happens, we've got some more data." "Check this out." "[ Laughs ]" "Whoa!" "No way!" "That's steel, and it's steel with an angle on it so imagine what that'd do to your hand." "I mean, that's got to hurt." "And that was just a little bottle." " Let's try the big one." " Okay." "Narrator:" "So, the 350-mil explosion was steel-bendingly strong, but as the 2-liter bottle distends and elongates with the expansion of the gases, will it prove even more dangerous?" "Jamie:" "It's changing shape at the bottom." "Adam:" "Look at that." "It's gonna be a good one." "Wow!" " Getting longer." " Oh!" "Oh!" " That was good." " That was intense." "Intense, just like the data from the PCB sensors." "Jamie:" "The sensor results from the big bottle going off are in, and they're more than double what the little bottle put out." "They were 7 P.S.I." "Now, that's enough to cause permanent hearing damage." "As to what other kind of injury it could cause, the sensors may not be telling the full story." "Show of hands, who wants to ramp it up?" "Narrator:" "The numbers alone say you should never try this, but there's still the damage test to go." "Adam:" "Yeah, I've got a prediction." "I don't think the explosion we're gonna see is gonna be as big as this crater that Jamie made when he arrived at work this morning..." " You happy?" " Yeah." "Let's do it." "...but I do think that after watching what it does to the hands on either side of the bottle, you're not gonna want to try this at home." "Frankly, I've always wanted to do this particular experiment." "Narrator:" "From the start, the expansion of the CO2 pushes the hands apart." "It's moving." "It won't be long now." "Oh!" "[ Laughs ]" " That was loud." " Yeah." "That violent rupture sent the arms akimbo, but although they seemed to flail away from the pressure, surely they're not undamaged by all that P.S.I." "[ Laughing ] Oh!" "I got a broken wrist right here, Jamie." "Yeah, I'd..." "I'd say so." "Look on... it whipped it around, both of these." "Yeah, yeah, yeah." "We got some lacerations here." " Maybe some broken fingers." " Yeah." "We got a compound fracture in the finger." "Oh, and check this out." "There's a... there's plastic embedded in the flesh." "Right." "That's gonna be part of what ruined your day, although you won't be able to hear anyone tell you about how stupid you just were, 'cause you'll have permanent hearing damage." "Yep, not only was the force enough to force bones through flesh, a halo of plastic shrapnel was embedded into the hands." "Look, we called this episode "do try this at home"" "because we've spent more than a decade doing all sorts of random dangerous things that you should totally not try yourself." "Aaahh!" "But we had to end it here with something we hear about a lot of people doing, and we wanted to make it crystal clear for you... and we think we have... that putting dry ice and water in a soda bottle" "is no laughing matter." "You can be permanently damaged by "playing around" with something this dangerous." "Don't do it." "So, we have microwaved, speedboated, synchronized, levitated, frothed, suspended, and exploded, and out of all of that, four are definitely too dangerous to try at home." "Now, when it comes to the others, please make sure you're with a responsible adult, and use your common sense."