this is bbc news. the headlines: the us house of representatives has approved a series of measures aimed at regulating the sale of guns, including raising the age for purchasing semi—automatic rifles. but the proposals do not have the 60 votes they would need for approval in the senate, and are unlikely to become law. ukraine's second city of kharkiv has come under renewed attack from a number of russian missile strikes. the city of severodonetsk is also under heavy fire. prime minister volodomyr zelenzky says in many respects the fate of the donbas region is being decided in that region. on his first trip to the democratic republic of the congo, king philippe of belgium has returned a priceless kakungu mask, taken out of the country before independence in 1960. this is the first of almost

80,000 artefacts that will be returned for display in museums in the drc. now on bbc news, it's time for click. this week we are live at the hay festival for 100 years of the bbc in 23 minutes. we'll look at the secrets behind the broadcasting technologies that changed the world. a radio legend talks about legendary radio. i used to set my watch by the pips, and my favourite pip is always the last one because it's extended. and artificial intelligence

goes bird spotting and in the quest for greener energy, 0mar discovers a tasteless fluid called water. it goes in your mouth and then disappears? this book was... writing this much... we are back and it's brilliant. after an unbelievable three years, the hay festival is back to its full glory. gathering together authors and thinkers, bookworms and those with the writing bug. it's all the same to me, ijust like writing, can't stop. it's so good to be back and this year especially is a really special year. not only is the queen celebrating 70 years on the throne but the bbc is celebrating 100 years on air. we thought we'd put on a show to talk about some of the technology the bbc has been instrumental in developing. we talked sound and vision

with our brilliant panel. placing sounds around this microphone... 1922, the idea that the bbc had to make programming that would inform, entertain and educate the world. and because it was a public broadcaster, it kind of had quite a lot of freedom to decide what programming could be developed but also it meant they developed their own technologies to be able to make such a wide range of programmes for the biggest audiences. of course, way before television came radio, and what do you need to broadcast a voice to the nation? one of these. and one of the most iconic microphones ever is the bbc marconi type a. trust me when i say it is iconic i mean it is an icon, literally. one of our panellists really likes this microphone, i mean really likes

this microphone. he spent the last few months uncovering its story and here it is. not many are around these days, especially ones that work. it became tradition at the corporation to empty the insides and plate them with gold as leaving presents for announcers. but what a thing to have on your mantelpiece. the good news is here at the bbc we have plenty. you'll notice it looks pretty hefty, and it's actually really big. so it tended to stay in the studios and leave the world travel to its smaller counterparts, but what it missed in adventure it made up for in the circles it socialised in. it played host to film—maker alfred hitchcock, poet ts eliot, legendary author hg wells and that's charlie chaplin. # go downtown. british singer and legend petula clark began her career aged nine in front of a type a. now you are going back a bit.

i was sending a message, to my uncle, i think. now it's time to send along personal messages and greetings to you... it was just to say hello, we are ok, don't worry about us, and give a little bit of home news, and that was it. air raid siren wails during rehearsal, there was the most enormous air raid and the producer asked if one of the kids could come up and sing a song or say a piece of poetry, to calm things down. so i go up on stage and they put a box so i could reach the microphone, it was one of those big bbc microphones. singing petula clark, there. so while setting off singing careers and directing the second world war, the microphone was clearly doing something right

operationally, too. eyes had been on the ground—breaking ribbon microphone invented by rca, the radio corporation of america, but it was a little too expensive so, in true bbc form, they made their own for less than 10% of what rca were charging. nice going. the type a stayed in use by the bbc from 193a until 1959. a whole 25 years. that is a long time when technology was developing so rapidly. so what about inside? the type a is called a ribbon microphone. that's because behind the perforated cover is exactly that, a ribbon of metal. with the help of one of the trusty bbc engineering manuals, we can see that sound waves come in from either the front or the back and hit the ribbon in the middle. so thin that it flexes and wiggles when the noise vibrations in the air hit it, just like your eardrum. the flexing moves the ribbon through a magnetic field created by two magnets on either side. doing this generates a very

small voltage which is unique to the sound it is taking in. the microphone then connects to studio equipment that amplifies this up to level that you can hear. and because the ribbon is a flat piece of metal, it can interpret vibrations from both sides. finally, of course, we want to hear a bit more of how the microphone sounds. we can hear it in use by sirjohn snagge, the bbc voice who made the first announcement of the d—day landings and who went on to become one of the first bbc television news readers. he specially recorded with the microphone for this demo tape. this speech is recorded from a bbc marconi velocity ribbon microphone type ax bt. i'll leave it for you, then, to make up your own mind on how that sounds. for a lack of time it was not possible... interference of course, radio continues to innovate and evolve. podcasts have taken the world

by storm, giving us the chance to listen to what we want, when we want. even this medium is adapting and changing. literally. the future of radio is really exciting because it means it is going to be adaptive. podcasts and programmes will change around people listening to them. the programme would understand some of your preferences, the device you're using, where you are, if you are moving on a journey, and it might change part of the programme to fit around those contexts. if you are listening to a politics programme, it might give you an update in the morning with fresh news and throughout the day it would understand what other news you might have consumed, what you could have read online, and bring you an opinion piece in the evening that fits in with everything else you've learned through the day. if you are a fan of radio, a real fan of radio, you will know what this is.

pips those are the pips, when you hear them it means it's something o'clock. long before they were singing with gladys knight, they were absolutely vital for ships. the pips tell ships what time it is and help them navigate. at the height of the british empire, britain had a lot more ships than anyone else in the world and their maps all needed to follow a strict format so they could figure out where they were. the centre of all british nautical charts was the greenwich meridian, 0 degrees, and each vessel also kept a fancy clock on board that told the local time at the meridian and helped them to calculate their position really precisely. 0ver longjourneys, how could captains keep those clocks accurate to the second? well, to bring in the new year in 1923, the bbc ran an experiment to broadcast the midnight bongs of big ben on the radio. it was a bonging success and the following year

the first fully accessible time signal, the greenwich time signal, started to be broadcast every hour. pips it hasn't stopped since. the pips, as they were known, were generated by a swinging pendulum fitted with electrical contacts. so now you could have accurate greenwich mean time literally anywhere you had a radio. the pips have become legendary, a symbol of bbc radio, and who better to tell us about them than another legend of bbc radio, tony blackburn? welcome to the tony blackburn show this morning on tuesday the 9th of december. my thanks tojohn forswinging us up... the pips have always been a favourite of mine since 1967 when ijoined the bbc and opened up radio 1. good morning, everyone. welcome to the exciting new sound of radio 1. everybody else finds it a bit weird that i like them

but i do, i love them, and on my programmes i used to promote them, particularly as my favourite pip is always the last one because it's slightly extended. but they are very bbc but they were useful at one time because before all these smart watches and things like that, you just had an ordinary watch that used to probably lose a minute a day or something like that, so i used to set my watch by the pips. nowadays of course with smart watches and things like that, you don't need it quite as much, but it is still very bbc and i like it, i wouldn't like to see it disappear. and off we go with the next one. what a lovely sound this is as well. the original clock that kept the time still sits in a museum at the royal 0bservatory. in the 60s, an atomic clock started to do the job, which stayed in use until the 1990s when it transmitted its last pips from the royal 0bservatory. ever since then the bbc has generated its own pips from its atomic clock buried deep inside broadcasting house, which uses gps signals to stay synchronised. so the next time

you hear these... pips ..you know they come from this. time to come right up to date with the the week's tech news now. twitter has been told to pay a $150 million fine after us law enforcement officials accused it of illegally using people's data to help sell targeted adverts. a 22—year—old has just 3—d printed a school in madagascar. welcome to our school. maggie grout started the organisation thinking huts as a teenager with the aim of 3—d printing schools in countries where some children lacked the opportunity to get an education. the benefit of 3—d printing is it allows us to build schools much faster than a traditional construction method and also the opportunities we are able to create with innovation.

sorry to drone on about this but now us supermarket chain walmart is the latest to announce it will be taking to the skies to bring an estimated 4 million customers their products quicker than ever. and in recognition of how far things have come in the last 70 years, here are two platinum jubilee portraits of the queen created by the latest tech. this masterpiece has been painted by the ada robot we may last year and this zoomable mosaic was created using a technology called megafiche and consists of about1 million individual images and a total of a trillion pixels. the hay festival is full of interesting characters talking about their interesting projects. i'm on my way to meet someone who has rebuilt a pretty infamous bit of technology. during the second world war, one of the key german

strategies was to blockade britain by cutting off essential food and raw materials that were being imported by sea. siren it relied heavily on its submarine fleet deployed with communications the german navy was sure couldn't be cracked. at the heart of it was a very sophisticated coding machine. the enigma machine. this is it. correction, this is not it. this is a replica made of wood by this guy, dr reuben binns. sounds like you got very bored during lockdown. that's right, you are, i was pretty bored, staring at a screen, stuck inside my house so i thought i'd build something with my hands. dr binns' machine has been laser cut from mdf and although it doesn't look like the original it is wired in the same way. and after each letter is typed, the wheels, or rotors, on the top are rotated so the next letter is encoded in a different way. what goes on inside each of the rotors is the electrical current from one of these

contact pins underneath is being transferred to another contact pin through these wires. you press a letter here and it gets turned into one letter there, another there, another there and then back out. yes. of course the enigma code was eventually cracked through some slip—ups by the german operators in codes that were sent, but also thanks to the hard work of the codebreakers at bletchley park. including, of course, the father of computing, alan turing and his machine. here at hay we are talking about some of the ways the bbc has shaped the broadcasting industry over the last 100 years, and of course it still does that today and it is still innovating. while we are here, 0mar mehtab is in norfolk with the bbc�*s springwatch team, to find out how their production is being made more sustainable. birdsong and babbling water. listen to that. gorgeous, isn't it? we all love a bit of nature, don't we? and programmes like springwatch, an annual tv show

that watches british wildlife during the changing seasons, offer us a unique insight into these animals' lives. for programmes like springwatch to run, it requires a lot of time, effort and equipment. with over 60 crew and 35 cameras, it is one of the biggest outside broadcasts the bbc offers. so it needs a lot of power. but in an effort to be more green, and protect the wildlife they feature, springwatch has taken a number of measures to cut down their emissions. we turned up to one of their production bases to see what they are. this is the big one — the green hydrogen generator. why is it called green hydrogen? because the process of electrolysis used to separate the hydrogen from water is powered by solar energy. if it was powered by fossil fuels then it would be known as blue or black hydrogen. not so good, kind of

defeats the purpose. but with solar, you are using clean energy to make clean energy. compared to diesel generators, it is a 3.5—tonne reduction based on what we normally do with a couple of weeks use. a couple of weeks? yeah. the only two things that this outputs is heat and brand—new water, the newest water in the universe. this is where it comes out. it is all there is, it is brand new. it's absolutely pure. tastes the weirdest thing, no taste at all. it is all texture. nothing to it. no minerals, no nothing. not keen? no, it's fine, itjust goes in your mouth and disappears. but what are these? these are the canisters that contain the hydrogen we use to power the event. each of these stacks weighs 1.5 tonnes but within that is 7.7kg of hydrogen and each gram is capable of producing 100 kilowatts per second. this machine can produce up to 100 kilowatts an hour.

that's enough to power a laptop for 200 days. at the moment we are doing 22 kilowatts so we still have quite a lot of headroom to go. just basically ticking over here. at the moment is slightly more expensive but like anything this essentially is the cutting—edge of green technology. and over time, the cost will go down. massive operation. this is the site we are working on, 4,000 acres we have access to, which is a huge area to cover. so we have been putting fibre across the whole site and as a way of trying to keep things down, working on c02, we put fibre down once and leave it for the duration. we have nodes up and down the site where we can connect to as we come back and go live. you must have your favourite name here, right? i know what my favourite is. we'll go for that.

they also have solar—powered cameras they have installed on sites such as in this beehive here. so there is a sustained effort across the site to lower emissions, but also off—site a lot of producers are now utilising the work from home way of working so they don't spend unnecessary fuel going to sites. and for the really remote sites, they are using solar panels to power up the recording set—ups. there is also one more special thing about this system. it uses al to flag a clip when an animal appears, and tries to identify it. so this year we have 32 wildlife cameras across the site. all of those need to be monitored and logged for activity 2a hours a day. that is a fairly intensive process when it comes to labour, so bbc r&d have come up with al tools that will help identify different forms of wildlife. they are very accurate. species of birds are often quite distinct, so it's very good at identifying birds of different shapes and colours, so it performs very well.

these changes aren't without cost. as mentioned earlier, the green hydrogen generator isn't normally as cheap as a diesel powered one. and new ways of working always require some adjustment — but the team want to do what they can to set an example. it hasn't been seamless, but they were very determined to take advantage of that new carbon—friendly technology and we pioneered it. using new technologies that have been pioneered in science and bringing them to media is, from my point of view, really exciting. and the guys in the van here, our story developers, we asked them "was that the male, the female, that one, that one"? ai and all that technology we have got is telling us but we are not going to save the world on our own, we won't save the reputation of the media when it comes to environment on our own. we need sport, we need light entertainment, we need drama, everyone has to buy into this. change is never convenient or easy, but the team here at springwatch are taking strides forward to help the bbc

reach its goal of net zero greenhouse gas emissions by 2030. and here's hoping when it comes to powering our devices, this is a sign of things to come. that was 0mar in norfolk. let's rewind from the very latest tv production to the very first. it's 2 november 1936, and some rather beautiful music is drifting out of alexandra palace in london. singing. this is adele dixon performing with the bbc television 0rchestra. she is singing a song called television, which was written specially for the opening night of television. it was broadcast to viewers across london and the home counties through a transmitter on the palace roof, and it marked the beginning of a — quote — "high definition" television service. i know! but before that, television

was just an odd fuzzy experiment to small, selected audiences. and, behind the scenes, there was a bit of a battle going on. see, the bbc had actually opened two studios in alexandra palace. in studio b was a mechanical system made byjohn logie baird, which produced an image like this. and in studio a, an electrical system by emi, captured an image like this. the two studios would be used on different days, and they were being pitted against each other — and emi's electronic images, running at 25 frames per second, were double the quality of the baird system. it had other advantages, too. the baird camera was enormous — the emi one was somewhat more portable. oh, and if you're filming with the baird system, you needed quite a bit of make—up, too. well, this is how it was, playmates, black and white, you see? and a bit of blue down

each side of the nose. very sexy, yeah. the emi system, on the other hand, could capture a well—lit studio perfectly fine, so the winner really wasn't hard to choose. under the lid of the imatron was this, a cathode—ray tube, which is basically an old tv working in reverse. capturing images instead of showing. # is all about us... the imatron stayed in use without much change for many, many years. the coronation of king george vi was the first time the cameras were used outside, and the broadcast was watched by about 50,000 viewers. file footage: we have two of our cameras high up - on the gate itself. however, it was the coronation of his daughter that brought the television into millions and millions of homes. seven decades on, and both institutions — the royal family and the bbc — face mixed opinions, with many questioning their importance and relevance in the modern world.

the bbc has had an incredible impact over the last 100 years, from introducing people to radio which, at the time, was such a kind of an unfamiliar medium, to showing the coronation on television to 20 million people, and now looking at the future of where broadcasting might take us. the question of whether a publicly funded corporation can be a better innovator than either nimble start—ups or massive megacorporations is up for a very public debate. so one of the most interesting things, i think, is for the internet in the future, is thinking about public service internet and models for allowing you to have control and oversight of your personal data. you get to say for how long for, for what purpose, and, in return, you get experiences that understand you better, are good for you and benefit you rather

than corporations and advertisers. after all, these days, when broadcasting is less about transmitters and more about the highly personalised internet, maybe there will be a role for public service broadcasters after all. spencer imitating newsreel: from all of us at the bbc, a very good night. pips good morning. wednesday was certainly a day of contrasting conditions. if you managed to keep the sunshine, you also had some warmth. it was very pleasant out there. in fact, we saw a high of 23.5 celsius in london through wednesday afternoon. but there were some showers,

and if you got caught in one or two of them, you would certainly know about it. they were heavy with hail and thunder at times. in fact, if we take a look back at wednesday, we had some fairly persistent rain throughout the day moving through central and northern scotland and a cluster of showers piling in behind. some of those, as i say, heavy and thundery. those showers tending to fade away as we speak, and we keep some clear skies over the next few hours across central and southern england, a little bit of nuisance cloud further north with an odd isolated shower. but it will be a relatively mild start to thursday morning, temperatures holding up, 10—12 celsius. the best of the sunshine certainly across central and southern parts of england first thing in the morning. we'll see cloud and light, patchy rain gathering in from the west. that's going to drift its way steadily eastwards, so eventually the sunshine being nibbled away with cloud as it moves its way steadily eastwards. we'll keep some light rain and some misty, murky conditions along west—facing coasts, the highest temperatures where we see the best of the sunshine — 22 degrees, 72 fahrenheit. and it's certainly

worth bearing in mind if you are a hay fever sufferer that where we've got that sunshine, grass pollen is now reaching its peak, so very high levels of pollen expected through the course of the afternoon. so, if we move out of thursday into friday, we've got this area of low pressure. it is the ex—tropical storm alex, the remnants of that storm bringing some windy conditions to the far north and west but also some warmth, as it's a south—westerly wind to go with it. so we keep a cluster of showers and winds perhaps gusting in excess of 40—50 mph in exposed coasts. but across much of england and wales, with some sunshine coming through, a breezy afternoon but warm with it. we could see highs of 23 degrees. that low pressure just drifts to the north of scotland, so we still keep the squeeze in the isobars, the strongest of the winds here, but high pressure is starting to build in from the southwest, calming things down quite nicely. so, yes, some showers to the north and west and still a fresh breeze to contend with, but an improving picture as we go through the weekend.

this is bbc news. our top stories: gun control measures are once again approved by the us house of representatives, but they're unlikely to become law. it comes after a harrowing day of testimony. he shot... he shot my friend. renewed bombardment of ukraine's second largest city, kharkiv, as severodonetsk in the donbas region also comes under heavy fire. gymnast simone biles and dozens of other athletes sue the fbi for failing to stop convicted sex abuser larry nassar. and on his first trip to the democratic republic of the congo, king philippe of belgium returns a priceless

kakungu mask, taken out of the country before