this is bbc world news. the headlines... donald trump has spent a second night in hospital, being treated for coronavirus. he said in a video message that he had made "substantial progress" but was "not out of the woods yet." 18 people are missing in france, and at least two people have been killed in italy, following the worst storm for more than 60 years. the equivalent of six months of rain fell in just a few hours. britain's prime minister boris johnson has warned the coronavirus pandemic could make things ‘bumpy‘ in the uk, up to and beyond christmas. he called on the public to act "fearlessly but with common sense." saudi arabia says it has allowed the umrah pilgrimage to resume, after pausing it in march because of the coronavirus pandemic. now on bbc news,

it's time for click. this week: "water" show we've got for you. we are on the water... under the water... radio static. and... what was that? i have no idea. ..0ops, there's been a spillage. hey, welcome to click, hope you are doing 0k. lara's here too, how are you doing, mate? i'm good thanks, this week i started talking to friends about how the winter was likely to be. would we head back to doing zoom get—togethers? what you think? there was a novelty for a couple of months of meeting friends on video

chat, but then to be honest i got fed up with them. even a antisocial geek like me realises that things are better in the flesh. so true. but the idea of heading back to video calls doesn't seem to have been missed by fashion designers. all you need to do is take a look at some of what was on show at milan and london fashion weeks, and there seems to be a bit of a theme of waist—up fashion, all about big collars and logos around the necklines. i mean, for a while now it hasn't seemed so important how we dress our bottom halves. dunno know what you're talking about. but listen, this week, i have actually been out and about meeting real people! and wearing proper trousers. these people are going to do something incredible. they are trying to make the fastest sailing boat that they can, to compete in one of the toughest ocean races that there is. and for one day only, they let me in to see how they're doing it. the america's cup is like the formula 1 of boat racing. fast, ultra—competitive, with all of the power coming from the wind.

and the boats don't so much sail as fly. relatively small foils underneath the vessels act like wings that help to lift the entire hull out of the water and massively reduce drag. i learned to sail, god, you know, 35 years ago or something. i take myself back to that eight—year—old kid thinking about the boats that we're sailing in now, doing speeds over 50 knots, 65 miles an hour. i just think that's absolutely nuts. here in portsmouth, olympic champion sir ben ainslie‘s team is designing one of the 5 boats that will race next march. now the america's cup has a weird rule — and that is that whoever wins the event gets to decide all of the rules for the next one. now i am notjust talking about the location and the date,

or even how many heats there are — they get to dictate the type of boat that's used and the number of sailors you can have on board. so basically, every america's cup requires teams to design a new boat from scratch. in this case, the previous winners, oracle new zealand, have chosen, guess where, new zealand as the location. they've switched from two—hulled catamaran to a single hulled boat and made a host of other rule changes. one of the big changes in this cup with regards to the rules was we're not allowed to do any physical testing. so we can't test in the wind tunnel or the tow tank. all the testing has been done in the simulated world, in computationalfluid dynamics on machines. max starr is part of the team who've tested many, many virtual boat designs, repeatedly building and rebuilding them in software to try and improve the performance in the water and in the air. so ineos team uk have a big mathematical problem to solve

which is simulating all the air conditions and the hydrodynamic conditions on the yacht as it sails through the water under an insane number of different scenarios. to simulate what happens when water strikes the hull of a yacht, or when air hits the sail of a yacht, we pixelate those surfaces. we put little square pixels all over that yacht. at each one of those pixels we do a little bit of math, we understand what the temperature pressure and forces are that are acting there, then we can work out what's going to happen next and then how that cascades all the way down the line to the next pixel and the next pixel and the next pixel. and suddenly we have got an idea of what a real, living boat will look like when it is in the water in race conditions. and the more detailed your simulation is, the more pixels you can break your boat into, the more accurate your model becomes. but every single pixel is simulated by a different computer processor, which means you need a massive amount of computing. basically, you need to harness the power not of the wind,

but of the cloud. now, the crew do get to test how the virtual designs handle. this simulator knows exactly how the current design will behave when under the control of a master sailor. so let's see how it does with me. now i am sailing! wow, one of the foils has gone into the water... and then, once we're round there, if you go hard right and down... a little bit slow out of the tack in the front of the foils. oops, we seem to have sunk. i'm going to guess, though, that that's user error and not a problem with the boat. it's not all about design, of course. the sailors are at the top of their game. all of them need to be in peak physical form, and that's the job of head of human performance ben williams, who also uses

data, this time captured by garmin watches to monitor the fitness regime and try and find the best mix of training and rest. what i'm interested in is how much training they have done, how their body's adapting to the training and how much recovery they need to harvest that training stimulus. people think you get fit from training — you don't, you get fit from recovering from training. so the training is the stress, once you put stress on the body your body will adapt to be able to cope with that stress, but only when we recover from that stress. you might be wondering, how fit do you need to be to be a sailor? well... now, here's something i didn't know about sailing. it used to be the case that if you wanted to move the sail or an appendage on a boat, you would turn the winch as and when you needed to. but modern boats are so powerful that the only way you can move something like the sail is using hydraulics or batteries. but here's the thing — the only way you are allowed

to recharge the battery is by doing that. it's called grinding. and eight sailors, all built like brick ship—houses, do this for the whole of each race to keep those batteries charged. yes, of course i'm going to have a go, and of course it's going to go well... so we'll be doing this for the duration of the race, hopefully a few more watts than that. all right, alright. do you want to turn that up then? go all the way to what you do, yep. so we will be... argh! wargh! how can you do this, at all, ever? what is fascinating with the sport is that it's not like formula i. here, every boat can be really, really different, it's a massive unknown and there's no tried and tested

formula for success. how quickly do you think you'll be able to tell whether you've got it right or whether someone else has got the better boat? we'll know within the first five minutes. we've got a race in december, a christmas race which is kind of a warm—up to the series itself, and pretty quickly in that we'll know whether we got it right or wrong. hello and welcome to another week in tech. this week, nokia struck a deal to become the largest equipment provider to bt, following the government's decision to block huawei from the uk's sg networks. amazon confirmed it would be joining google, microsoft and nvidia in the cloud gaming market with the reveal of a new streaming service called luna. and it's an end of the era for the original incarnation of farmville after facebook announced it would be closing in december after over 11 years, due to the end

of support for flash. the uk's first driverless car lab has been launched by telecoms company 02. backed by the government and the uk space agency, the darwin satcom lab will trial driverless cars that use 56 and satellite technology. amazon has announced a new payment service that uses a customer's hand to authorise transactions. its amazon one scanner registers an image of the user's palm and is initially being trialled at two stores in seattle. and finally, if a device on your head for vr isn't enough, how about robot boots? these new creations from ekto vr are what they call the world's first robotic vr movement solution. they allow the wearer to walk through the virtual space without actually moving. virtual insanity? you decide. around this time of year the big tech companies

do their annual hardware showcase, where they show off everything that will be going on sale just in time for christmas. last week it was amazon — they have turned their echo speaker into a sphere, and they had a flying home security camera, nothing creepy about that. this week is google‘s turn, with an online event, of course, so let's see what they announced. first up is google tv. it looks a lot like apple tv and amazon fire tv, it brings in recommendations and gives you a lot to choose from. and there's a new chromecast which has a voice remote control, just like the apple tv and amazon fire tv. we actually knew this was coming because it went on sale early in some american retail stores by accident. we are moving on to smart speakers, the newest one is the nest audio which is designed for people who like to listen to music on their smart speakers. and to make it sound

good, they've embedded a high—frequency tweeter — not donald trump! laughs. moving on to the phones, and it's our first look at the new pixel phones. so just a few months ago they brought out the pixel 4a, a cheaper version of the pixel 4, and they've updated it now with the pixel 4a 56, there's a 56 version. and here is the pixel 5, which has wireless charging and reverse wireless charging, so you can charge your headphones on the back of the phone. it's interesting because they've actually got rid of a lot of the flagship features of the pixel four, so the face unlock camera is gone, they have replaced that with a fingerprint reader, and that soli radar has gone, that was supposed to let you control the phone without touching it, though in reality the most you could do was skip through songs by waving your hands over the phone. but that is all gone. but it will let them sell the pixel 5 at a lower cost which is going to be quite important given the global situation we're in. but there are some impressive new software features. it can now take those blurry background portrait shots,

while in nightsight mode, in low light conditions, that's quite cool. you can also now artificially illuminate a portrait with an artificial light by dragging your finger around in portrait mode, that is very cool. and that's it. i tell you what, these events go by much quicker when they're just pre—recorded and you are not watching presenters fumble through things on stage. that might have been the most low—key launch for a flagship phone i've ever watched, but i have to admit the pixel cameras usually are really good, every year google brings new innovation to the pixel camera, and i can't wait to try those new features. now, as entertainment venues have been struggling to reopen safely, one company hopes to bring an experience to your kitchen table via a smartphone. this is an audio only experience, so the idea is that you close your eyes and listen to the strange things that start happening around you. and they really do sound like they are happening in 3d space because they have been recorded using binaural sound.

this is something we have heard before in the programme, and it is incredible. so with no idea what to expect, spencer and i put it to the test. and if you want a taster of the experience from home, you're going to need some headphones too. radio feedback. is everybody here ? yes. now get yourself a glass and fill it with water. we are all in our different rooms. many couples in this same configuration, sitting at a table across from each other. now close your eyes. close your eyes and keep them closed. if you open your eyes before the session is complete, you might experience a tormenting mismatch or a renting of the thin membrane that separates this world from the other competing worlds next door. i so want to open my eyes! with your eyes closed,

try to form an image in your mind of the person sitting opposite you. don't look. don't check if they have closed their eyes. ok, this performance is aimed at couples but ignoring that minor issue, it's all about placing yourself in the story. double is the latest show from darkfield radio. its recent sound—only productions took place in pitch black shipping containers. now, though, it is possible via an app and a pair of headphones. so when we were working with creating these experiences at home, we still wanted it to feel like a live experience. so one of the important elements of that is that it is a timed show — something that happens at a certain time — so there is some feeling of community about it, even though people are sat in their different homes. the main reasons that i think that there is a lot more interest in binaural sound now because of vr and of this increasing interest

in immersive experiences that placing at the centre of a narrative. —— place you. i'm kind of on edge because i wonder whether something... something that will make us jump. chuckles. male voice: two people who have known each other for however many years sit on either the side of a table. one of them has been replaced by a demon whose intentions are unclear and unlikely to be benign, and the other is planning a murder. planning a murder? is that you? i don't know! one of us has turned into a demon and the other is planning the murder. we both sound a bit dodgy. plate smashes. what was that? i have no idea. much like the binaural sound recordings we've seen on the show before, it's recorded using a binaural sound head, shaped like a human. in both ears are microphones. you treat this head as if it were the audience members who is going to be then listening to the performance, so every — everything that the head hears is —

will be from the perspective of the future audience member listening with headphones. and one of the things that analogue binaural recordings do better than any real—time audio spacialisation is proximity, so we are also developing some other tech elements to include live microphones with the audio of the microphone spacialised, speech recognition and a few other things that will allow us to increase this interactivity. male continues speakingzw didn't take long for the right moment to come. footsteps. because opposite me, the demon has its eyes closed. and so, i stabbed it. oh, god. cutlery clangs on a plate. and now that the demonic copy is disposed of... oh god! lara laughs. ..our real partner can come back. # i love you with my heart.

this is pretty freaky! # i love you with my mind. it's whispering in my ear! no! i don't like it! # i can't love you... robotic woman's voice: thank you. you can remove your headphones. thank you. # ..anymore than i do. door closes. oh! and open our eyes. goodness, that was quite bizarre! oh, that was a bit of fun! conceptually, i thought it was brilliant, but i wasn't sure about the storyline because i didn't actually want to murder you. and even though it sounded good, i think we probably would have both benefited from over—ear headphones. true. what's interesting though is that because they asked the two people to face each other, they really can make things sound like they come from a specific place in the room because they can send one person a sound in their right ear and they send the other person a different feed where the sound is in their left ear, so you can both agree that the sound happened over there. really interesting concept, i have to say.

now onto the great barrier reef, wonder of the world, the largest living structure on the planet. at over moo miles long, it's so big that you can see it from space! but as you probably know, it is under threat. rising water temperatures and a changing environment cause the coral to go white, to bleach, and the reef has just undergone its third mass bleaching event in the past five years. this time, for the first time, white, stressed coral has stretched from one end all the way to the other. while cyclones and climate change pose huge threats to the reef, there are other factors, too. so nick kwek‘s been finding out the great barriers to the reefs survival. sugar, a billion—dollar business to australia. almost all of its cane is grown here in queensland, with the great barrier reef right on its doorstep.

when it comes to conserving the reef, a lot of work is being done out at sea, but there is also stuff happening right here at sugarcane farms like these, which are dotted all around the tropical coast. it is the run—off from these sugarcane farms, the pesticides, the herbicides, that are posing to be a huge threat to the future health of the great barrier reef. chris and belinda have developed smart water sensors that remotely measure nitrate levels in farm lagoons. nitrate can lead to more algae build—up and less coral diversity out on the reef. that's where the light shines through and that's where you get your reading from. their system, including a bunch of sensors and a computer in a waterproof box, helps them remotely secure more accurate readings around the clock and, crucially, gauge the effects of specific rain events. we might not have a lot of nitrogen leaving every paddock on every farm, but all it really needs is a little bit over a large area of land. those marine systems,

they have not evolved with high nitrogen levels, so once that changes a little bit, you change the balance. robotic voice: enable spraying. one solution could be this herbicide—spraying drone that zones in from above and targets hard—to—reach weeds, thus greatly reducing the amount of chemical spread across a field. often here, especially in the wet tropics, you actually cannot get back onto the paddock, so it is too wet to be able to get onto. or, as we have with sugarcane, it becomes too large, so the only way to get any product back onto it is to do it with an aircraft of some kind. the dgi drone has four radar sensors on board so it can get close enough to crops without crashing, and the nozzles have been specifically designed to form just the right amount of liquid so droplets don't blow off into the wind. airborne contraptions are helping the reef in other ways. these three little bumps just there? yeah. that means that this is live coral. right.

so you can inferjust from the shape of the wave? yeah. doctor karenjoyce uses drones equipped with sensors, like spectrometers, to capture detailed information unseen by the human eye. it measures the way light is reflected or absorbed. so, for example, we see trees as green because they reflect green light. different things on the reef reflect light differently as well. that helps us to understand the types of things we have on the reef, but also how healthy they are. you just realise how small an area the drone can capture. so that would be like 15 minutes' work to do just that little bit there. and this only represents one of 3,000 of the reefs of the great barrier reef. to better understand the scale and complex ecosystem of the reef, i have come to the epicentre of tropical marine research — the australian institute for marine science. behold, the seasim!

one of the most advanced reef replicators on the planet. 33 tanks, more than 140 pumps, and over 42 kilometres of piping, all controlled with custom tech. and of course, ijust had to have a nosy behind the scenes. the bits and pieces you see along the back wall here, they're what control our ph. they provide dynamic active control of the processes occurring in the tank. and that means we get much, much better control, much tighter control of our seawater, so the conditions are more like what we actually see out on the reef. they've have got taps, tubes, a orange snake! musical sting. this enables us to control our temperature within plus or minus 0.1 of a degree. we can create profiles, where they be seasonal or daily. we can control salinity, so replicating freshwater plumes. we can replicate contaminants, whether they be nutrients or pesticides, insecticides — a whole range of different parameters.

the seasim's able to precisely replicate the conditions of the great barrier reef as it's found in nature, but it's also able to look into the future. what will the reef look like in, say, 50 or 100 years from now? we're looking at those mechanisms that make corals more thermally resilient. this is not a solution. the solution is dealing with climate change and the carbonisation of the economy. we're just looking at ways of assisting this to enable those corals to survive, until we find a solution to that bigger issue. scientific facilities, drones, monitoring sensors — these are just some of the many efforts to importantly buy time for the reef. while seismic shifts are required to truly preserve this natural phenomenon, small actions can lead to big change. fascinating stuff! that was nick in australia, and that's it from us for this week.

as ever, you can keep up with the team on social media throughout the week on youtube, instagram, facebook and twitter at @bbcclick. thanks for watching and we'll see you soon. bye— bye. hello there. we have already seen a lot of rainfall this weekend. more wet weather to come through the day today for a number of areas. those rainfall totals have been really mounting up. over the last three days, winchcombe in gloucestershire has had more than a month's worth of rain. more than a months worth in parts of aberdeenshire and parts of hampshire and berkshire as well. the weather has been particularly wet, all down to this slow moving area of low pressure with a stuck weather front right over the british isles, bringing rain

for many of us through saturday, overnight, and it is still raining at the moment as well. that said, we are starting to see something of an improvement in eastern areas but with the met office amber weather warning still in force right the way to the middle part of the day, across wales, the west midlands and south—west england, we could see further issues building in here. as well as his persistent band of rain, it will be windy particularly around coastal areas. the rain pivoting away from the south and east of scotland with brighter weather here and we should see sunshine for northern england across north wales, into parts of the midlands, maybe norfolk, but with sunny skies, we are also seeing some heavy showers. the rainfall has been mounting up with the accumulations of rain building we now have a number of flood warnings in force across parts of scotland and england. once you have factored in today's rain, we could see the number of warnings increase for a time.

overnight tonight, the rain will tend to clear away for most areas, with the exception of south—west england where it will continue to rain through much of the night. otherwise, clear spells and heavy showers, particularly for northern england and scotland as well. low pressure then, this is the low that has been bringing rain through the weekend. that is still on the chancery monday, tuesday and into wednesday as well. —— on the charts through monday. a particularly slow—moving area of low pressure. weather—wise, it means we are staying on the unsettled side but it is turning a little bit less grim for some of us. scotland, england and wales brighter skies, sunshine but some potentially heavy, thundery showers, particularly in the east. outbreaks of persistent rain return to northern ireland during the day. tuesday, another showery day but at this time the showers across england and wales could merge together to bring longer spells of rain for a time. further showers at times for northern ireland and scotland. temperatures continue to be below par but the rain is cause for concern, we could see further flooding today.

good afternoon. president trump has issued a video from the hospital where he's being treated for covid—19, saying he is feeling much better, but that the "real test" will come in the next few days. mr trump — who was given oxygen before being taken to hospital — admitted he had not been feeling well when he arrived on friday.