Extreme Water Science With Richard Hammond | Richard Hammond's Wild Weather | Spark

whether one of the most astonishing forces on earth capable of both devastating power and spectacular beauty wherever you live on the planet whether shapes or world yet for most of us how it works is a mystery to really understand whether you have to get inside it so I'm going to strip weather back to basics science uncovering its secrets in a series of training ambitious and sometimes just plain unlikely experiments to show you whether like you've never seen it before water lies at the heart of our weather but not just as rain because water can transform itself redefining its powers in the process creating the fastest the slowest the softest and the hardest weather on earth often changing from one to another with alarming speed and striking consequences in this program I'll reveal water in all its shapes I'll capture a cloud okay little ad let's see what you got to see just how much it weighs discover why hailstones are able to do so much damage find out what would happen if rain fell in one big lump it's amazing isn't it and I'll experience water and its most voraciously powerful form as an avalanche speechless genuinely speechless all our everyday weather appears to come from the clouds they're the best clues most of us have as to what the weather is likely to do next they dictate if it's sunny or dull and there where all our watery weather seems to come from but how what exactly is a cloud come on you've done it if not you should gazing at clouds dreaming up shapes and the next time you do two things you should know about plans that might just change the way you think number one clouds are really heavy even that fluffy little cumulus could weigh as much as two elephants and secondly because of that weight all clouds are falling slowly steadily down to earth I know both those things sound pretty unlikely which is why I'm going to put them to the test and I'm going to start by trying to discover just how much a small cloud really does weigh there I know I'm not the only one who when presented with a sign on a bench saying wet paint has to touch the bench just to check it really is so when I heard that a cloud can weigh as much as two elephants but I'd to check it out the only thing is it turns out that weighing a cloud is a bit more of a faff than checking to see if paint is wet obviously you can't just hang your cloud of a spring balance or pop it on a set of scales but you could measure the moisture in it and work it out from that so I thought what if we could fly a giant ball of cotton wool into the cloud to gather the moisture as an idea it needs a bit of finessing yes so I've got an engineering mate of mine to win out some of the wrinkles and he came up with this okay so it's not actually cotton wool it's an industrial version ceramic wool and it's not one solid ball either my friend reckoned that by making the center hollow it would double the amount of wall that came into contact with the cloud he calls it his sky sponge and then we've got that to put it in the cloud it's all fairly standard stuff so first off let's check how much this sky sponge weighs dry that's 37 kilos which for a sponge is already pretty heavy but we need that weight to be able to fly it accurately especially when the pilot it's someone not that used to carrying Freight I know it's not a good start [Applause] but as nobody is ever done anything like this before I'm as good a choice as anybody in the end it was deemed not a job for an amateur no matter how enthusiastic so I took a co-pilot Andrew with me to keep an eye on things mostly on me [Music] [Applause] so helicopter check basket full of highly absorbent ceramic wool check all I need now is a nice that LeClair to dip it into and that's not as easy as you might think because when you get close to them clouds are well very Norma's you look at it from the ground they all look perfect and fluffy and spawn get up and they're looking Tyler different I'm gonna find a nice individual one drop in it and see how much water it brings out of it the shimmy won't soak up the entire Claire that we'll be left with underslung the weight of two elephants that'll be bad a full-grown African elephant weighs on average four and a half tonnes a quarter of that would pull my helicopter straight out of the air but if I just weigh a fraction of a cloud then multiply my results it should give us some idea how much a whole cloud actually weighs a convicted about the one in front up here yes a nicer bright cloud has been sourced it is quite important the helicopter itself doesn't go in the cloud you have to remain visual with well pretty much everything I need to fly low enough to dip the sky sponge into the cloud but high enough to keep the chopper above which is trickier than it sounds well for me right well that's all ran bad first time around I miss the cloud altogether this is a fairly unusual exercise plan connected that's my excuse anyway this hole will do a treat okay little cloud let's see what you got [Music] close up the cloud seems so wispy it's hard to imagine we're going to soak any water on the tour [Music] okay we dipped it let's get this thing down and see what we've got well it's wet that's a start but how wet have we managed to collect enough moisture to make a difference on the scales we have 10 whole kilograms of difference I know that doesn't sound like much but look at the size of the cloud then look how much of it the sky sponge flew through just that small section had 10 kilos of water in him if every section that size weighs the same then that little cloud must be getting on for well not quite 9 tonnes lot [Music] and a good-sized thundercloud might be ten kilometers tall and ten kilometers wide which would make its total weight more like a million elephants Dorothy prefer about 60,000 jumbo jets so how on earth does all that weight stay up there to find that out we're going to have to build a cloud of our own [Music] right what I've asked to achieve here is an indoor cloud what I've got is a cattle trough full of water and I don't know what these things are fortunately what I've also got is Jim who is an atmospheric scientist and can hopefully help I don't what is this how's it gonna work so this is how we're going to make something akin to clouds rice is not a it's not a cloud but it's a closest we've got to a cloud making machine right so what we've got in here are some ultrasonic humidifiers so you quite often see these sorts of things at garden centers and things like that then just they just produce very very fine mist garden centres sounding less high-tech now I'll be honest they're masquerading as nice ornamental devices but secretly they're cloud making devices well there we go well come on then make it work so what we need to do is turn this on don't man up there you go suddenly miniature clouds appear and that's just by breaking the water molecules down into smaller bits of breaking the liquid water yeah into just very very tiny droplets of water these garden pond devices turn the water into tiny droplets and that is exactly how a cloud works clouds float because the water drops inside them are so small and so light what's the difference in size how big is a droplet of this competitor a droplet of that is 5 microns but that means absolutely nothing too small okay so but the rain droplet you can you can get your head around the size of raindrop the raindrop it's about two millimeters so the difference in size between these and the rain droplet is the same as if you've got a sugar cube and a caravan and on which is the caravan so the caravan it's the rain droplet right and the sugar cube is these tiny little droplets right well that is working the humidifiers have split all our caravans up into billions of sugar cubes okay let goes on okay but to really complete the effect we want to see if we can get those tiny moisture droplets to float in the air what's in the funnel now and we'll see clouds emerge there it is weirdly it feels dry hard to believe our sky sponge managed to soak this stuff up so this isn't just something that looks a bit like a cloud this is pretty close to again these are just droplets of water very very small droplets of water and nuts that's what a cloud is is that Jim not being critical of your cloud but it looks a lot more frantic I think clouds is just solid state really just drifting what you're seeing here is what's happening around the edge of cloud it's constantly changing so you get up close to a cloud and it's really quite busy yes so whilst I'm very impressed with your homemade cloud here it's kind of not [Music] [Applause] now this might look like overkill but actually our cattle trough is surprisingly heavy just like the water in a real cloud and I do need to get all that water off the ground to check that second fact are all clouds really falling back to earth [Music] Jim and I wait with bated breath we might have made the water droplets small enough to float but it's true once they're up in the air they drift back towards the ground so this effect where I can see it rolling over the top and then some falling that's accurate yes our cloud is dropping out so if you look at clouds with binoculars or something like that you'll see you'll see bits of streams of cloud so because this is small it all looks faster but if this were as big as a real cloud this effect this exact effect is what's going on all the time yes just continuously all the time around the edges of cloud around the periphery of clouds with all this this process going on all the time so there you have it clouds are heavy and they are all falling slowly down to earth [Music] it's just the most evaporate before they ever get there in fact the typical lifespan of a small cumulus cloud is only 10 to 15 minutes but while they're up there they act as a sort of public transport system for water carrying it from one place to another until either the service goes off duty or they dump all their passengers at as rain there are about 13 trillion tons of water being moved around in the atmosphere and every day about 1/10 of that comes crashing back down to earth sometimes these storms are incredibly intense the quickest on record dumped 12 centimeters of water in just eight minutes the heaviest managed nearly a meter and a half of rain in under 10 hours and so to my home territory where on average it rains one day out of every three this is my favorite place in the entire world it's in the Lake District Hollister pass running down to Lake butterman I've been coming here for 27 years it has one of these best views in the world I've seen it once that's because this specific place is the wettest in England on average four meters of rain falls here every year specifically to talk to you about rain it's not actually raining yes sprinklers in the wettest place in England however this will suffice perfectly to allow me to show you what I wanted to show you puddles puddles hold the key to seeing how those tiny cloud droplets turn into raindrops we can't look into a cloud to see how raindrops form but we can get an idea of what's going on by looking in a puddle [Music] as the raindrop hits part of it is attracted to the water what bounces back up is a smaller droplet about half the size when that droplet is the same thing happens again around half of it stays in the puddle [Music] now imagine that in Reverse and upside down the puddle is declared a water droplet doubles in size by attracting other water droplets please stick on in a process scientist called coalescence it increases again and again until it's so heavy it falls away and that is roughly how rain is formed [Music] it feels right like this this is how it feels here which is just as well because I've got one more thing I want to tell you before I get them to turn these sprinklers off and it's about the official difference between rain and drizzle not closely at a puddle surface if the drops are splashing like here then it is rain but if there are no splashes there it only qualifies as drizzle officially clever isn't it splashes rain no splashes drizzle but what they've both got in common is that they're just too heavy to be held and loved we talk about heavy rain but water is heavy very heavy give us an idea of just how heavy we are about to see what would happen if all of four adele's four meters of water fell in one go now obviously we can't get a bigger the size of the Lake District so we're just going to recreate what it's like when four meters of water hits one small area so we have four cubic meters of water in the bucket which amounts to four tons at height then beneath it you'll see we've found a car for scientific purposes let's see just how much damage that amount of water can do hmm looks like rain [Music] yeah pretty brutal but I shouldn't be surprised because the water actually weighed four times more than the car and the needed every minute of every day 900 million tons of rain land on our planet that's about the same amount of water as in all 16 lakes of the Lake District [Music] or they're going to notice but it does prove the point water is really heavy that is just the annual rainfall for Borradaile we're up in go on holiday all of my life explains something about it it's amazing isn't it luckily this could never happen with real rain not even in a tropical storm where sometimes it feels that the heavens have literally opened partly because as we saw earlier raindrops fall the moment they get heavy enough and partly because of what happens to rain as it falls [Music] to show you what I mean I'm hard at work building a sandcastle and professor jane Rickson from Cranfield University is filling a plastic bucket there are always kids like you on the beach one ok so what's all this about well pour water on a sand castle and you completely flatten no surprises there but rain doesn't fall from waist height it falls from clouds that are at least 300 meters above the ground and that makes all the difference let me show you by building another sandcastle and throwing the water off something just a little bit higher [Music] they're obviously this isn't as high as a real cloud they start at around 300 meters is Terry's 30 but it's tall enough for what we want to do okay Richard yeah wrong side how was I to know let's try it again and so another bucketful leaves the tower but what arrives they love is rain and there it is it's still standing so why why is it if I throw the water from up there you'd think it would smash it to bits even more but it's still standing what's the difference well what happens is you were throwing that water down air resistance the turbulence in the air is overcoming the surface tension of that lump of water breaking it into smaller drops you want to go and see that you do it again yes I'll get the bag of the water [Music] as the water falls it meets air resistance and the larger the lump of water the more resistance it experiences that friction breaks the water up into smaller pieces sometimes inflating the drops like parachutes before blowing them apart the further they fall the smaller those drops become until finally they're so small that the air has little effect on them and they land as rain so that's why the water landed in drops and didn't smash it rather than a big bucket shape lump that's right and in fact you can actually see the point at which that lump starts to break up into those smaller drops well you can if I climb the tower again [Music] it actually happens surprisingly quickly within 10 meters there's enough air blowing on our bucket full of water to break it down into drops if our digger had been just a few meters higher then the cup might well have survived so even if it was possible for water to fall out of the sky in one big lump by the time it got to the ground it would still be rain because they break down like this the average raindrop ends up about two millimeters across but there is a way the water can fall out of the air in bigger more dangerous pieces by shape-shifting into ice now most of us think that when we see ice falling out of the sky its hail so what if I told you this wasn't hail at all sure it looks like hail but it can't be hail you can't get hail in winter that only happens in summer I know you think you've seen hail in winter but trust me you haven't what you've seen is this ice penny ice pellets have formed when a snowflake partially melts on the way down losing all its pretty branches and then refreezes forming a small ball before it hits the ground just to make things even more confusing in North America they call this sleet which over here means a slushy mix of rain and snow either way this is not hail hail is something entirely different [Music] Charles Knight has been studying hailstones for the last 50 years and in his refrigerated laboratory in Boulder Colorado he offers to show me exactly how hailstones are different by sawing one in half it's very simple we just use a hobby bandsaw like he's just gonna slice in half yes I know if you had that has done Oh about 10 years actually but it's worth it as soon as Charles opens it up the difference is revealed Heil is made of layers and there you can see one layer there anyway so when is that the circle yes but in the bigger hailstones there's much more obvious layering this is an example of a really what we would call it a giant hail it's enormous its enormous yeah yeah but that's obviously not gonna stop him cutting it in half even though this one is 15 years old this time the layers are crystal clear if you make a thin section then you can really see the layering that's a slice right through that's absolutely beautiful that's really telling his own stories just like the rings of a tree these layers chart the story of how this hailstone groom it's a story that starts with a thunderstorm and thunderstorms only tend to happen in summer because of the height of thunder clouds some of the water droplets inside them freeze but the powerful updrafts created by the warm weather keep the droplets supported in the cloud where they collect more water with new layers freezing on in a separate shell until finally there are so many layers that they're too heavy to be supported and they fall to the ground which got me thinking because it's made in layers does that mean hail is stronger than a single solid ball of ice you make wood stronger by laminating it you make glass stronger by laminating it so does laminating ice make it stronger certainly hail is powerful it causes over a billion pounds worth of damage a year but is it any harder than conventional ice [Music] to find out we're gonna have to go into uncharted territory with an experiment that hasn't been done before using that yeah I know it looks like and lent the plastic pipe on some tables in a field and to some extent well it is but you should see what it's about to do to that table tennis bat its inventors Purdue University's Jim Stratton and Craig's Eric wanted to see just how fast they could get an ordinary ping-pong ball to fly [Music] and the answer using this contraption turns out to be very fast indeed [Music] it's astonishing this projectile is moving when it comes out of there oh yeah about 919 miles an hour so you brought along your device which is if you think about it a sort of nightmarish automatic serving machine and you've agreed to help us yeah okay right so here's the plan we're gonna see which is harder ice or hail but first of all we're going to make some hailstones we've already seen how much of a faff that is and even for Mother Nature but luckily Jim and Kraig have a plan a plan that starts with dry ice the greatest pop video a pop video starring a bead on a bit of stream the dry ice makes the bead really really cold to rolls well before it's dropped into cold water if you'll notice every time he puts it in there you can hear just a little bit of a crack you can hear a little bit of fizz and that's the water instantaneously freezing to the outside so that's one layer of ice ran that little seemingly very small air how long does this take about 10 minutes oh god please do we need quite a few and they need to be the size of ping pong balls to fire them from Jim and Craig's gun can I go yeah right dip it in here very quickly into there that's it it's already the size of a pea I'm just I'm just suggesting we'd probably need to find a way of mass-producing these I mean this is the land of Henry Ford right one is good we can try three and now you've tripled your efficiency haven't I half a night sometimes on TV we don't do things in actual time this is one of those occasions [Music] you gonna do anything I'm reading this there's no words you just looking at the pictures it's my turn again yes oh you've been busy [Music] Hales ready they're done they are done magnificent they are as well look at that okay they might need a little bit of rounding off to get them down the barrel of the gun but the size is good say goodbye one excellent three of 30 we're gonna throw some more away so we have something to compare them with we've also frozen some water into ordinary ice using a few of Craig and Jim's spare ping-pong balls as remodels so we've got solid ice and we've got Hale which is ice in layers time to put them up against each other to see if there really is a difference and we can't resist starting with one of our homemade hailstones I'll give you the honors again something see quite dramatic yeah believe it or not we're breaking new scientific ground here so to make sure we capture any differences between the ice and the hail we're recording everything at ultra-high speed and sure enough our cameras capture every detail from the plastic seal topping off the tube to a hurtling hailstone punching through the talk is it worth experimenting now with just seeing how much more resilient one is than the other yeah we brought plenty of materials we can shoot out so we can actually shoot - I'm at the same thing and see well want to go through one won't go through and the type of force that we have and that's exactly what I was gonna do that all right so here's the setup we've got lots of different sorts of wood and we're going to take two shots at each piece first with plain ice then with our homemade Hale first up chipboard right three two one ice straight through Hey straight through okay slightly thicker piece of chipboard same result plywood [Music] the ice barely dented come on hail three two one well there is a difference the hail splintered the back of the plywood let's try a slightly thinner piece this time the ice barely makes it through the hole it makes is far smaller than the projectile itself right fingers crossed [Music] awesome did it work what happened - and there's your impact yeah that's why the way through yeah you fellas completely different same piece of wood same shooting speed different results in slow-mo you can clearly see how much of the ice ball never makes it through the board well it might be crude but that is on a hoped would see this mark here that's from the straight ice barely getting through that is our homemade Hale with its laminated layers around it clearly a more fearsome projector [Music] both balls are made of frozen water so you wouldn't expect any difference in how hard they are but the layers inhale do appear to make it stronger so summer hail does seem to be harder than winter ice but water can shape-shift into something even more dangerous naturally quicker than hail with a mightier punch than hail and what it is might well surprise [Music] this is how most of us are used to seeing snow move delicate flakes floating gently down to earth floating so gently that a snowflake can take nearly an hour before it finally reaches the ground [Music] traveling at just four miles an hour little more than walking speed and yet snow can be the fastest form of water that there is [Music] because when it's in an avalanche it can hit 80 miles an hour in six seconds flat and then well it just keeps on accelerating the fastest one ever recorded on max and Helens in America taught a staggering 250 miles an hour so how can snow move down a mountain faster than water can Walter Stein Coppola of the Institute for snow and Avalanche research is trying to find out how that incredible speed is possible by starting an avalanche every zone Walter yes is this where it's gonna happen that's absolutely you can see it quite nicely now it's the whole slope you see to spontaneous avalanches already and we're gonna try to release the avalanches from the very top well tell those to our launch is made it's already happened this is all over see there's plenty of snow still on the slope ok and I - this is a really good indicator for us that there is the potential to produce noise Evelyn and then when that's going on you're going to be conducting experiments and learning I mean this is part of an ongoing piece of work for you isn't it it is it is actually my part of my PhD thesis and this data is really essential from my work yes right there are several different types of avalanche but the fastest by far is what's known as a dry powder avalanche and that's the type we're hoping to get if he can trigger a dry powder avalanche Walter can find out more about how they moved so fast and we've offered to help by putting a barrage of slow-motion cameras on the slope we're not gonna mess up your PhD I will tell you afterwards but I would appreciate if you don't do that if I do send him the bill oh let's hope it doesn't come to that but I would like to add an extra element into his experiment so Walter can I place these on the slope if there are known distance apart I thought I could time when the front day head we call it the front that the front of ever lunch pass is one of these yes I can time it over that distance and I can work out how fast it's going sure sure that's a nice approach you can do that yeah thank you very much right well do I just need a helicopter [Music] okay well that's that sorted but now we need to work out how to fly our fences into precise positions without triggering an avalanche ourselves our safety team have been thinking long and hard about the best way to do it and what they've come up with is dangling someone on a bit of rope this someone in fact who apparently enjoys this kind of thing [Music] [Music] if you single coolest thing I have ever witnessed that man is without a doubt the best helicopter pilot ever seen in action I mean that sky sponge was difficult enough I'm just leaf lying that close to mantids and sheer rock faces in this gusty wind each angel weather just that let alone with another bloke Daniels with a piece of road below you and then below that a huge belt basically wooden sail speechless genuinely speechless Walter has told us where he expects the avinash to fall so we position the first fence slap-bang in its path but the conditions up here are very changeable as we discover when we try to fly the second fence suddenly the winds quicken and start to gust alarming at any moment the whole fence could be dashed into the side of the mountain taking that load with it not to mention the helicopter and the fence needs to be exactly 100 meters from the first one never have the words rather him than me be more directly applicable it's death so everything is now in place my two boards I know where 100 meters are parked when the front of the ambulance passes the first one I'll start the stopwatch on my phone stop it when it passes the second and we'll get an idea of the speed and I do know we're gonna be surprised has something that a little snowflake can take an hour to drift down out of the sky can suddenly be part of something so fast and so powerful all we have to do now is wait for them to trigger it [Music] okay they're off thanks one thanks I missed it but I suppose it does prove in a way just how fast an avalanche can be and luckily for me slow motion cameras captured everything so let's take a look at that Avalanche again this is the moment that dynamite is dropped from the helicopter causing this explosion at the top of the mountain immediately it's surrounded by a powder cloud made up of 1% snow than 99% air this is a dry powder avalanche the Avalanche accelerates down the steep incline until it reaches our first fence they're not exactly at the angle we expected the leading edge passes the first one now and that particular bit of snow reaches the second fence now almost exactly the same time the first fence is destroyed no wonder I had trouble timing it Avalanche was actually only traveling at 25 miles an hour just 1/10 of the speed of the fastest one ever measured but still faster than if we just pushed that snow over a cliff I want to know how that's possible let's imagine if there's a chunk of snow at the top and then it starts to move what's happening to that snow from the moment it starts to move down well first it will break into pieces and it gets rounded a bit and it also gets compressed and these are the pieces which you can see up there they look like snowballs technically most of them are snowballs yes these snowballs are the secret of what's going on underneath that powder cloud voltar offers to show me how okay Walter this is like an avalanche how well you imagine an avalanche that's moving down a slope it's gonna pick up snow like you are doing now and it's gonna put it in motion as in our tumbler here it seems you losing your motivation come on keep on going one more you can do it perfect I think we're good there you can see already it's compacting that it's breaking apart again then it's compacting again and at some point you will end up with fall shape features it is magically making of course in an avalanche this is happening much faster and it's much more violent process going on there but this is a slowed down version at exactly the same process and you can see that sort of grinding rolling motion you can imagine happening perfectly that's exactly the case - so understanding this will allow you to understand more about how fast it might go where it might go how it will behave absolutely I would say they're quite down yeah yeah tonio perfect yeah turn it off please yeah so in here it's Nobel's perfect snowballs right don't date me I mean that's seriously packed it's quite hard right I mean it would be not that nice to throw it on it personally guess this one is everything he's looking over there and thinking targets cuz I was the old ed tech cross-country runners he was scared for a second did you see Walter wants to excavate the Avalanche to see how much snow it contained and I follow him into well a big hole because I want to be sure whether it's these snowballs then make the Avalanche move so fast this is not answer because still going on ongoing research but for sure it defines the motion of the Everland yes so you can't say for definitely yet as scientists and I love it when you guys can't give a definitive answer yes I can because it's my research and if I say it now I mean I need to publish this stuff first so would you ever end up with your Avalanche effectively rolling along on like ball bearings or like when they used to build you know they got a huge stone and move it to place to put it up it's a monument they roll along on logs wouldn't they is it like that I think it's you can kind of say it like that yeah I'm I'm from a scientific point of view I'm not a hundred percent sure that's rubbish don't you know that there are studies that say that really it's the ratio between the bigger cranes or the bigger balls to the smaller poles that can significantly influence the speed and emotion of the events so you're not that far off actually if your comparison is just jealous because it's my own day yes I know but ya know you you can publish that back to me that would be something for I have to write it out yeah but you can't go to recent decades put something on wheels and it can accelerate quicker than if you simply drop it and these snowballs maybe the wheels of a dry powder avalanche [Music] snow is the softest lightest way that water can fall to earth but an avalanche can move faster than any other type of water four times faster than the fastest flash flood ever measured and it seems snowballs might well be the secret [Music] of all the water on our blue planet only a tiny fraction is actually in the atmosphere yet waters incredible powers of transformation that mean that that's enough to bring us all our clouds rain hail and snow and with it all the everyday weather on earth [Music]

Channel: Spark

Views: 1,026,633

Rating: 4.854187 out of 5

Keywords: Spark, Science, Technology, Engineering, science documentary, science photography, science explained, science experiment

Id: WorxCpQb-yY

Length: 56min 45sec (3405 seconds)

Published: Fri Feb 28 2020