Is NON-BUOYANT WATER Deadly?

what are three things everyone knows about water everyone knows that you can drink it it's chemical composition and that a lot of stuff floats in it but what if one of these facts suddenly changed what if you couldn't float in water anymore couldn't swim in it no matter how hard you tried well this is the liquid nightmare that i want to explore today what is non-buoyant water and why is it in these tanks now entering the facility now if you know me you know i'm a fan of scary warning signs we've done episodes about them here at the facility before and heck i even sell some as merchandise which is why when i saw these signs warning of non-buoyant or negative buoyancy water you know i had to investigate non-buoyant water just sound so sinister and weird like hard air or burning ice or unmaintained hair could you imagine i know right it's so weird sounding that even hideo kojima himself used non-buoyant water as a death plane in a boss fight in metal gear solid 2 and that actually stuck with me through all these years now make no mistake these signs are very real as are unfortunately the fatalities reported in and around the tanks that these signs are posted on but here's where it gets really interesting it's actually controversial whether or not these warning signs are warning about the right thing the actual harm so let's dig into it first if we want to know what non-buoyant water is we must fully understand what buoyancy is so grab your best pair of swimming pants and follow me what you don't have a pair of swimming pants peasant when we say that something is buoyant or not we're actually saying many things everywhere all at once we are describing a relationship between the object to be floated and the fluid doing the floating or not put simply an object will be buoyant it will float if the weight of fluid it displaces with its volume weighs more than it does so for example a rock is quite small in its volume but it is very heavy and so the displaced water is likely to be less heavy than this rock and so the buoyant force isn't enough to make it float on the other hand if you have something like a water bottle it's mostly air throughout its volume and so any fluid it displaces probably weighs more than the entire water bottle itself and so and so it floats put more mathematically an object will flow if the ratio of the densities is less than one wanna see me derive that sure density is also why i'm in this hot tub the density of this very bubbly water can't be the same as normal water can it it might be a very slight difference but all these bubbles are taking up some volume within the water and they weigh almost nothing let's see if we can prove that so what i'm gonna do is fill this bottle with mostly water and then see how far the water line comes up to as a judge of its buoyancy i'm gonna mark that right about there now what we're gonna do is bring it over to the hot tub i'm now gonna put the same water bottle into this more bubbly water to see if there really is a difference in buoyancy created by these michael bubles the difference here is quite slight but i think you can tell that on average the water bottle falls just a little bit lower in the water in theory then a fluid like water could get bubbly enough such that nothing no one could ever float in it nothing could ever swim in it and this brings us back to our scary warning signs the signs in question today are all found posted against so-called aeration tanks found in nearly every waste water treatment plant in the world inside these tanks is bubbling human sewage why do we need tanks like this well without these tanks we wouldn't be able to use bugs to eat our poop well someone's someone's got to do it wastewater treatment is a critical piece of modern society's infrastructure allowing for water reclamation and recycling and preventing waste from polluting the cities societies and environment the separation and treatment of our waste is literally one of the most important advancements in human history and today our techniques are surprisingly sophisticated but the basic treatment method that most plants use is biological treatment via these aeration tanks inside these tanks there is circulating human sewage yes but intentionally mixed in with it are microorganisms or what civil engineers like to call bugs that naturally eat our carbon containing material like your poop yes arya but more importantly when these bugs get to feeding they tend to clump together or flocculate this allows engineers to create a multi-stage treatment process where sewage is first cleaned by the bugs those bugs settle out of the mixture in another tank naturally and then clean water is reclaimed biological wastewater treatment is a simple effective and very clever way to treat our waste and take advantage of what nature already does best but like you or i these bugs need some input they need oxygen to live and so this is why these aeration tanks that we've been talking about look like the worst hot tubs you could possibly imagine the bugs need many cubic meters of air circulated around them for proper respiration oxidation of materials and so they can eat your poop yes arya sorry she just loves wastewater humor and it's all this air circulating in these tanks that makes civil engineers believe this water is non-buoyant and therefore extremely dangerous however unlike another engineering hazard known as a drowning machine where the mechanism of harm is very clear it's actually controversial whether or not aerated water in the context of these tanks is dangerous in the first place is there a difference between the theoretical and the practical though people have unfortunately died inside of an aeration tank there doesn't seem to be an actual consensus as to the cause could it have been super bubbly water that you'll immediately sink to the bottom of or could it have been just accidental drownings which can happen in any body of water yes you can find dire warnings about sinking like a stone in dnr documents and on the blogs of wastewater treatment plants but is this a difference between theoretical and practical yes bubbly water is less buoyant but is it less buoyant as to be dangerous inside of an aeration tank specifically you see inside of an aeration tank unlike a hot tub the bubbles come straight up from the bottom this creates a flow and a force which can act to counteract any loss of buoyancy in fact a study looking into how an object's buoyancy would change inside of a real aeration tank found that the total loss of buoyancy was less than two percent but engineers wanting to know what it's actually like for a human to fall into one of these tanks did not stop there in 1985 witnesses watched as one midwestern engineer tossed himself into an active aeration tank don't worry he tied a rope around himself and his wife held it the result of this test was that he was totally fine he experienced nothing like what we see on the warning signs more recently just last year sewage treatment plant specialist philip can't pronounce your last name decided to freaking swan dive into an aeration tank filled with drinking water when it was being cleaned he's an amateur diver and as you can see a bit of a show off finally a facebook post reads one of the big unanswered questions in engineering is answered no you don't sink although you are not quite as buoyant philip explained these two in-situ tests also confirm what maker daddy adam savage found in a 2011 episode of mythbusters that bubble generated flows seemed to be enough to either partially or fully counteract any loss of buoyancy due to density change were you to fall into a narration tank when i texted adam about name drop much calm down when i texted adam about this about the guy who dove headfirst into a working aeration tank he definitely gave his nerdy blessing as to the results look despite what these signs say on their faces as professor richard feynman once famously quipped if it disagrees with experiment it's wrong that's right though in theory non-buoyant water sounds dangerous in practice inside of wastewater treatment plants it doesn't seem to be so does that mean that these scary signs that we started off with are wrong well no i think it's more complicated than that though non-buoyant water or less buoyant water inside these tanks doesn't seem to be dangerous falling into a giant vat of water in full clothing when you're not expecting to getting pulled to the edge of one of these tanks where the downward circulating flow force from the bubbles can counteract the buoyancy from a typical life jacket studies found that yeah that could absolutely be dangerous and that's probably why those unfortunate souls drowned these signs are probably scarier than they need to be but that's totally fine when your ultimate concern is someone's safety until next time now exiting the facility thank you so much to the vera nerdy staff at the facility for their direct and substantial support in the creation of this here video if you want to join the facility if you want to drape on a sold out white lab coat if you want to see episodes early get bloopers videos have private monthly members only live streams with me not like that you can go to patreon.com kyle hill and join the facility today and if you support us just enough ho you get your name on arya each and every week and as you can see there's literally hundreds and hundreds over a thou i have no idea how to pass the time thank you to adam savage for once again answering my weird text messages in the middle of the night and fun fact my degree is actually in civil and environmental engineering so this video was pretty close to what i've studied throughout my life so it was quite interesting and what gets even more interesting than this aerobic biological wastewater treatment there's also anaerobic biological wastewater treatment which uses bugs that don't need oxygen and when they do that they produce a lot of methane when they're eating you know your excrement and they produce a lot of uh natural gas and methane that you can then refine on site into clean natural gas which many wastewater treatment plants do and one time i was working in a lab as a scientist and i was working on a container that was pressurized full of these things and i didn't open it right and all the bugs and some of the wastewater poop splashed all over my face and hands okay that's why you wear a lab coat for watching i can still i can still remember what it smelled like

Channel: Kyle Hill

Views: 2,778,014

Keywords: because science, engineering, kyle hill, learning, math, physics, science, stem, the facility, chernobyl, what is buoyant force, buoyancy, wastewater treatment, wastewater treatment plant, wastewater treatment process, aeration tank, swim, warning sign, science experiment

Id: ey06E4iEXzg

Length: 12min 34sec (754 seconds)

Published: Sat Apr 23 2022