this is bbc news, the headlines: huge crowds gathered in front of buckingham palace for a spectacular open—air concert, marking a high point of the celebrations for queen elizabeth's 70 years on the british throne. in a tribute to his mother, prince charles, praised what he called "a lifetime of selfless service". russia says ukrainian troops in the eastern city of severodonetsk have suffered critical losses and are retreating. ukraine insists it's still pushing back russian forces, despite the city remaining the main goal of russia's offensive. soldiers from both sides are locked in fierce street battles. mercedes—benz has recalled nearly one million older vehicles worldwide, due to a potential problem with the braking system. the german manufacturer says corrosion in some cars, built between 2004 and 2015, could lead to the connection

between the brake pedal and the braking system failing. 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 cold 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 as the bbc marconi type a. trust me when i say it as 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 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 is 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 sd printed a school in madagascar. welcome to our school. maggie grout started the organisation thinking huts as a teenager with the aim of sd printing schools in countries where some children lacked the opportunity to get an education. the benefit of sd 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 is in norfolk with the bbc�*s springwatch team, to find out how their production is being made more sustainable. birdsong 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 this to run it requires a lot of time, effort and equipment. with over 60 crew and s5 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 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 s.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 7.7 kilograms 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, 4000 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 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 setups. 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 s2 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 instantaneously. 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 19s6, 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 ema'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. 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 as this, a cathode—ray tube, which was 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. 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. imitating newsreel: from all of us at the bbc, a very good night. pips hello there, heavy rain with thunder and lightning has continued to spread northwards across central and southern england, and wales. it means for part two of the weekend we will have a north — south divide again, with much of scotland and northern ireland staying dry with some sunshine.

more cloud and rain across england and wales. a very wet start to wales, the midlands and eastern england through the morning. and then that rain slows as it comes down as it moves northwards. it will stay rather grey and damp. any sunshine that comes out across southern areas may spark off a heavy shower or thunderstorm into the afternoon. temperatures reaching highs of around 18 or 19. much cooler under the rain, low teens, cool along the north sea coast, the better sunshine and warmth across central—northern scotland. 21 degrees or so. 0vernight, cloudy, further pulses of rain across northern, central and eastern england. some of the ranges getting into southern scotland. double—figure values to start the day on monday in the south. single figures in the north under clear skies. for monday, the pressure chart showers the low pressure pulling out into the north sea, taking the rain with it. remember, in between weather systems for monday afternoon so many places should be dry with more sunshine around. rather cloudier start for monday, through central england. rain and strong winds pull away

from the east coast. more sunshine in the south. plenty of sunshine again across large parts of scotland where we can see the high teens there, maybe 20 degrees in warmer in the spots in the south. we'll have to watch that area of rain moving into southwest england and the channel islands during monday night. into tuesday, the rain should clear away from southern areas, and then because we are in between weather systems again it looks largely quiet. maybe an odd shower here and there, but good sunshine around. more sunshine in the south. we could see highs of 21 degrees in the capital. 19 also through the central belt of scotland. more unsettled on wednesday onwards. areas of low pressure moving in off the atlantic. 0ne system will bring in outbreaks of rain followed by sunshine and showers. this next system through thursday and friday could bring a spell of windy weather with outbreaks of rain followed by sunshine and showers. it is much more unsettled to end the new week, with sunshine and showers, fairly strong winds. these temperatures around the seasonal average.