hello, this is bbc news with martine croxall. the headlines. 160 people have been killed, and hundreds more injured after a wave of explosions at churches and hotels in sri lanka.

christian worshippers in three churches were targetted as they celebrated easter. there were blasts at four hotels — the uk's high commissioner says some britons are believed to have been caught up in the attacks. a number of arrests have been made after a large fire took hold on ilkley moor in west yorkshire yesterday, more than 70 fireighters are still tackling the blaze. police say they've arrested 831 people protesting in london over climate change. 42 have been charged. the protest organised by group extinction rebellion is now in its seventh day. now it's time for click. this week: the war on fake news. when robots paint the...moon. flipping out over this. and how to make a shooting star.

the world's largest election is under way in india. overfive weeks, 900 million eligible voters in 20 states are casting their ballots to decide who will rule this vast country for the next five years. and this is no small decision — because in that time, india's population is set to overtake china's. and its economy is likely to become bigger than the uk's. the size of this democratic exercise is like no other, but the issues that it brings up are all too familiar. social media, once again,

is playing a part in swaying political opinions. and once again, misinformation, so—called "fake news" is attempting to cloud voters‘ judgment. and the problem is, last year, bbc—led research revealed that ordinary citizens in india are less concerned with the facts of a story, and they are more likely to share it if it bolsters their national identity. the problem is now as acute on whatsapp as it is on facebook. and when messages come from family and friends, the receivers are more likely to believe it and to share it. india's election commission has been working with social media giants to try and stop the toxic overspill. and david reid has been finding out if they have been successful. fake news foxes the best of us. in india it has a particular potency.

i got information from social media, like whatsapp, facebook, news channels... facebook, whatsapp, instagram. last year more than 30 people died after false social media rumours triggered mob violence. this ngo stepped in to counter its effects. the explosion of mobile internet here has been a cultural earthquake. people easily believe fiery fake news, and underestimate the effect of sharing it. india is certainly a country which comes under this four things like follow, share, forward, like. misinformation is catchy, misinformation is alarming, misinformation is like negative news, which is very attractive. we don't feel, you know, bad about forwarding it without realising how a forward can impact people. follow, share, forward, like.

at election time, fiery rhetoric linked to identity does all of these things, and there are politicians here who are happy to foment communal tensions. it's why the election commission has been so worried about fake news hijacking the democratic process, and is asking social media giants to clamp down. whatsapp introduced rationing, limiting to five the number of contacts users can share content with. as for facebook, it is smarting from a number of fake news and data scandals. india's election is the big test. it pulled hundreds of fake accounts and announced a war room, to crisis manage the election. we asked to see it, and were eventually told it was not in india, where the election is, but in san francisco,

where facebook is. our reporter who visited it said the war room had a "cobbled together" feel to it. the fact that we set up these operations centres, that we had the right capabilities in this room, where we have threat investigates, engineers, data scientists, meant that we had the appropriate expertise sp we could respond rapidly when it mattered the most. back in india, facebook has recruited an army of independent fact checkers. the startup news mobile employs a new breed ofjourno. they are certified by the international fact checking network. their job, to review flagged stories, rate their accuracy, and push out a corrective. this is a global epidemic and requires a global response. for every social media company globally, the fake news problem creates a crisis of credibility as well. so for them it is incumbent upon them as well to work

more deeply, especially with independent media companies. by all accounts the fact checkers are doing a terrificjob. the problem is, there is just so much fake news for them to deal with. added to that, fact checking is real journalism — it takes time. for all the time that it takes, the false story is online, doing its damage. by the time a fact checker, you know, pushes out an article, fact checks something, it is already 24—48 hours since the misinformation has been posted on the platform. and the misinformation by that time has more or less reached the intended audience. and facebook has no way of informing the people who have viewed the misinformation, that there is a fact checker responding to that. once a story is found to be fake it does not then disappear. sure it is contextualised by the fact checker‘s work and is made less prominent, its viral wings are clipped,

but it remains up there. there is however a category of misinformation that facebook does take down. in particular cases, where we see that misinformation violates our community standards and essentially co—ordinates harm — a good example of this just to anchor the conversation is misinformation that misleads people about the process of how to vote and logistics of when to vote, that aspect from our platform. for all the drawbacks to fact checking, it does seem to be educating people to be more sceptical. did you just forward it? ijust received it on some random group... 84 million new voters have come of age since the last election, so is the social media generation wising up to the wiles of of the fake newsers?

i think first we need to check it all and we have to decide whether it is fake or not. my idea is if you are not informative about something, it is better not to spread rumours and all that. fake news is imagined to have the most impact in knife edge constituencies where the vote is close. after the elections will be the reckoning, where we will see how well social media outlets have done at curving activists and their desire to trick unwitting voters. that was david reid in india. with me is will moy from full facts, an independent fact checking charity here in the uk. and, will, you have started working with facebook to fact check their articles recently, haven't you? that's right, they came to us last year, we spent a few months talking about how that would work, how we would maintain our independence. when we talk about democratic votes like the one going on in india right now, i can see a future where whoever loses the election will now be able to blame fake news

as much as maybe more than anything else. is that the future we are destined for? it is the past we have already lived in. people have always complained that the election was rigged and it wasn't fair for one reason or another, the newspapers are biased, whatever it might be. there has always been those complaints. what's true now that didn't used to be true, is that a small group of people who control communications to millions of other people, that their opponents can't see. so with targeted online advertising now, it is possible to advertise to millions of people, but only a select group of people, you can advertise just to men with one message orjust to women with another message, or in even more, sometimes quite sinister, targeted groups of people. that needs to be made transparent we will really have a problem with an election, where people can say this all happened surreptitiously, in the dark without scrutiny. and if election is not a shared experience it ceases to be a truly democratic experience. in india especially,

there is a lot of sharing going on on whatsapp. that is not public, everything happens inside private, encrypted groups. how on earth can you fact check whatsapp groups and what they are sharing? we don't know yet, and that is something that people in my line of work talk to each other about, and it is a concern. we were pleased that whatsapp made the move to reduce how easy it is to forward information on whatsapp, because that can make to millions of people, but only a select group of people, you can advertise just to men with one message orjust to women with another message, or in even more, sometimes quite sinister, targeted groups of people. that needs to be made transparent we will really have a problem with an election, where people can say this all happened surreptitiously, in the dark without scrutiny. and if election is not a shared experience it ceases to be a truly democratic experience. in india especially, there is a lot of sharing going on on whatsapp.

that is not public, everything happens inside private, encrypted groups. how on earth can you fact check whatsapp groups and what they are sharing? we don't know yet, and that is something that people in my line of work talk to each other about, and it is a concern. we were pleased that whatsapp made the move to reduce how easy it is to forward information on whatsapp, because that can make dangerous information go viral with too little scrutiny. but actually it is going to come down to individual users of whatsapp and every other messaging platform saying, "i don't want to share things with my friends that i think may not be true". because no—one actually wants to mislead their friends. but it seems to me human nature that we want to share sensational sounding information, and that has been true before social media as well. that is not going to stop, is it? it is not going to stop, no. but equally, pub conversations for the last hundred years have not all been completely accurate, people have told nonsense at the market, nonsense at the pub, nonsense around the kitchen table for generations. it is not necessary to create a world in which nobody says anything that is inaccurate or sensationalised. what we need to do is spot where it is causing harm and ask people to think twice. if you are sharing information

about how to vote and you are not sure if it is right, that is the point where you need to stop and think before you share. do you think facebook and other social media platforms are doing enough to counter... no, we don't. we think they have now started to take some serious and useful steps forward, but actually they need to do more. they need to be changing the product so that it makes it easier for people to work out what they can and cannot trust. we need to see more research, more independent research into where problems are, what harms really arise from them. we need more data sharing. and with the programme facebook came to us with recently, they started for the first time to give outsiders an insight into what is going on the platform, they started to integrate fact checking into the product. that is a decent first step but it is not the last. thank you for your time, will. hello and welcome to the week in tech. this week apple settled its chip royalty dispute with qualcomm, sending the chip—maker's stock rocketing up. twitter ceo jack dorsey said it is time to fundamentally rethink how his service is used, comparing himself to the captain of the titanic. and after nearly five years of development, playstation announced plans for its next generation console. it will be backwards compatible with the ps4 and have 8k resolution. an investigation by the consumer

magazing which has found the amazon online store has been flooded with thousands of products with fake five star reviews. which looked at 14 popular tech items including headphones and smart watches, finding unknown brands also appearing in the top of the search. amazon says it is using automated technology to weed out false reviews. uber launched a feature in saudi arabia that allows female drivers to block male passengers from hailing their cab. uber discovered that up to 75% of female drivers didn't want to pick up male passengers. women have only been allowed to drive in saudi arabia since last summer. aliababa ceo jack ma has defended the culture of working long hours at tech companies, saying it is a blessing for workers to put in a 72 hour work week. the so called 9—9—6 work culture, working nine till nine, six days a week, was highlighted by chinese tech workers online. and finally in the latest sign of the impending robot takeover, boston dynamics showed off its robo dogs pulling a truck across a parking lot. the 30 kilogram robot dogs will go on sale later this year. art this london gallery, art created by a robot using artificial intelligence is on show.

these images are a very modern take on the traditional chinese ink landscape paintings. they are created by using a combination of data from nasa, images collected by the chinese rover on the moon and a human who was taught the al to create brush strokes that look like this. ai genesis will never create the same image twice and its inventor, who calls the robot his soulmate, sees that as one of the joys. when you look at the picture do you feel pleased with it? do you question how it has come out? how do you feel when you first see it? i feel amazed. wow, that is my expression. oh, wow. if i draw myself like this, i will be punished by my ink painting master because that is not the way that a trained traditional ink painting. what's wrong with it? they will not draw that that way.

that is not a traditional technique of chinese ink painting. but the new art ink paintings, what we want to do is put some new things in traditional paintings, to renew it. you have certainly done that. who is the better painter, you or the robot? i would say it is a collaboration between us. and sometimes it is embarrassing because do i say look at my paintings... or look at our paintings? but if the creation of an image comes down to data, numbers, algorithms, is it maybe missing something? each piece of art that is created normally has a person's emotions, persons thought and vision put into it. when you are leaving the al to do a lot of that, is it still art? firstly, what is emotions? emotion is our response to the environment. like on a rainy day you will feel blue.

on a sunny day you may feel the future is so bright. if i put data to stimulate gemini's work, to stimulate it, —— to alter it with extra stimulation, less surrounding, for example i put in humidity and temperature, every time it comes out different. i would say there is emotion and relations at this moment but no—one can say that ai will not have emotion or imagination in the future. and the idea does seem to be gaining ground. a piece of ai art was, for the first time, sold at auction last month at london's sotheby‘s. artist mario klingemann‘s memories of passersby one was created using what is known as generative adversarial networks, or gans. these break down the data

from traditional oil portraits, rebuilding it into a series of unique images. what you see there, i built myself. but like a painter does not build the brush themselves or, let's say, they go in the store to purchase paint or canvas, i am working with materials that are standing on the shoulders of a generation of researchers. but the intention here was deliberately neither to achieve perfection nor photorealism. selling now for £32,000. it was actually the code that was bought here with a couple of screens and a wooden unit thrown in to enjoy it on. so maybe the future of appreciation of art is one of appreciation of technology as well. that was lara. now let's talk phones. and as a gee—ee—ee—ee—eek,

i have been waiting a long time to be able to do this. the idea of a flexible display has been around for years and on click we have watched this story, ahem, unfold. but these things have been an awfully long time coming. we have had to wait for oled technology that allows for flexible electronics to get to a point where it is cheap and reliable enough to survive being bent, flexed and mistreated in the real world. and this year, finally, several companies have been able to, ahem, roll them out. the highest profile flexible phone has to be samsung's galaxy fold which becomes available at the beginning of next month. whispering: for £1,800.

now, the front screen is smaller and narrower than you might be used to but this device is really all about a 7.3 inch tablet screen hiding inside. you can just about see that crease down the centre, although it is less obvious when the screen is bright. on opening or closing, any apps running on one screen will switch immediately to the other in an adjusted size. that bigger screen does allow for three apps to be open at once which you can reposition or pop out into floating windows. now, this is the first time that journalists have been allowed to touch the thing and i came down here today expecting it to weigh a tonne but it does not. it is heavier than the s10+ but it is lighter than an ipad mini, so it depends on your perspective, really. now, about the screen. it does not fold completely flat which has caused some to worry that

a stray coin in the pocket would sneak into the gap and cause all sorts of screen damage. and despite samsung's claims that it can take up to 200,000 folds, some reviewers have already experienced unexplained faults with the screen. samsung says it is looking into it but it's not exactly the best start for what is supposed to be a whole new type of device. now then. i wonder if you have ever seen a shooting star. if you are lucky, you might see a few of them in your lifetime but what if you could control where and when they happen? that would be pretty spectacular, wouldn't it? kate russell has been to japan to meet the scientists who are trying to take control of the night sky. three, two, one, go. it's not often you can get this

close to a shooting star. ooh, that one is green. this simulation of a meteor being burned up in earth's atmosphere is part of an ambitious plan to create cosmic grade fireworks that can be seen from up to 200 kilometres away. since we last visited the company back in 2016, they have been perfecting the technology to make it compact enough to allow it to be sent into space. hitching a ride on a rocket is not cheap, so every gram counts. many shooting stars ordinarily... basically... it is like a sesame seed size and this is bigger than the natural shooting stars.

this is completely burned out in the upper atmosphere. so it becomes very bright and lasts longer. it will take a year before the satellite descends to an orbit where they have been cleared by the world space agencies to eject the pellets. so the particles sit inside this cylinder and they get rotated one at a time into this chamber here. down inside here in the central chamber. then we put pressure behind them right here and we release them and they get shot out of here. 0k. so puff, puff? yes. one at a time. because the release velocity is the number one critical factor in ensuring accuracy of the particles, there is no system on earth currently accurate enough. the company is being secretive about the date for the first

shooting star display. but it does not take a genius to work out that the timing sets things up nicely for the 2020 olympics. in future, they hope to offer multicoloured displays as well. so this is one of the materials that will be tested today, just mounted on the tip of the stick. we're not quite sure how it will burn, what colour it will be, or the brightness but that is the point of these tests. it promises to look spectacular. but there is real science at stake here as well. right now, meteor science is not well known. it is a wide field of research and especially scientists they don't know the mass, the brightness, the composition of meteors and we don't know if it led to the spread of life on earth. because we have such an accurate system we can tell people, scientists and our own crews exactly where to point cameras so that they can record and get data. it is not so surprising to connect fireworks to scientific breakthroughs. around 2000 years ago, alchemists seeking a recipe for eternal life accidentally created firecrackers. this led to our first

fundamental understanding of the forces of nature. so this could mark the beginning of a new chapter of scientific study. it's also going to look very pretty. brilliant. that was kate injapan and that is it from us for this week. you can follow us on social media throughout the week. we are on youtube, instagram, facebook and twitter. thank you for watching and we will see you soon.

hello there. the glorious weather is set to continue for part two of the weekend and for easter monday looking sunny and very warm. perhaps more sunshine across the border tomorrow. today has been a bit of a chilly start one or two places were a mist and fog. most of that is cleared and it is working fine —— most of that is cleared and it is looking fine in the afternoon to be very warm once again. but we have had a bit more cloud across the north—west corner of the country thanks to this weather front. a little bit of rain which has started to retreat back out atlantic to the atlantic so by easter monday all of us will be in the sunshine. atlantic to the atlantic so by easter monday all of us will be in the sunshine. it has been a fairly cool start in places. mist and fog is gone now. widespread sunshine,

a little but he's across the north and west of scotland and parts of northern ireland. some spots of rain there for the outer hebrides that really is about it. everyone else will be fine and dry into the afternoon. widespread sunshine. very warm again. temperatures reaching the low to mid 20s celsius but always a bit cooler around some southern and eastern coasts. the downside to the sunny weather today will be the pollen levels. tree pollen will be very high across most of the country. it is a fine end to the day. some glorious sunsets to be had up and down the country and then overnight most places will be dry and again clear. most places will be dry and again a little bit of mist and fog developing and we see that cloud and rain pushing away from the outer hebrides. so much of western scotland will become drier by the end of the night. enter easter monday, it is a fine start. by the end of the night. mist and fog will clear very quickly and then we are looking at widespread sunshine including scotland and northern ireland. the breeze quite fresh coming up from the south and south—east. a little bit cooler around some coastal areas but otherwise a very warm and sunny day.

temperature is low to mid 20s celsius. just an outside chance of showers developing across the channel islands to the south—west of england. from tuesday night onwards, conditions will turn more and more unsettled as this area of low pressure pushes in off the atlantic and with more moisture pushing and we will start to see increasing showers. some of which could be heavy , maybe thundery, and merged together to produce longer spells of rain. that is wednesday onwards. and it will slowly be telling cooler as well. temperatures dropping out of the low to mid 20s celsius and towards the end of next week we are back to where we should be for the time of year.

a let's get more now on our top story today, the series of suicide bomb attacks in sri lanka which have left at least 160 people dead