hello. this is bbc news. the headlines at 3.30pm: the canadian pharmaceutical billionaire barry sherman and his wife honey have been found dead at their home in toronto. police have described the deaths as suspicious. the south african president jacob zuma says the country and the governing anc face enormous challenges as the party gathers to vote for a new leader. a leading supporter of brexit has said the uk cannot become a "colony" of the eu during the expected two year transition period after britain's withdrawal in march 2019. and the renowned scientist and television presenter heinz wolff has died at the age of 89. he became known to british tv audiences in the 70s and 80s on the great egg race. now on bbc news, click. this week, the wide world of 360 video.

the artistic world of marina abramovic. and the strange world of quantum computers. imagine a computer that could crack the world's most secure codes in minutes, design extraordinary new medicines, even pave the way to intelligent machines. big tech companies like google, ibm and microsoft are all trying to be the first to achieve a breakthrough in the field of quantum computing, but we're not quite there yet. at the moment, if you want a quantum computer, you need all of this.

you need your ionising lasers, your cooling lasers, and your processor. you need all of this, and currently all this can do is add a zero and a one. but it does do it in a really cool way. quantum computers harness weird and wonderful phenomena seen only at very small scales. the data in an ordinary computer is represented as bits, each of which can either be zero or one. a quantum computer, instead, uses quantum bits, or qubits. now, these qubits can be both zero and one at the same time. this is called superposition and it's a key feature of a quantum computer's unique powers. so, when a quantum computer adds

a zero and one, it's also adding one and zero, and one and one, and a zero and zero, all at the same time. so numbercrunching could in theory be done much faster on a quantum computer. there are a few really important things that we know they will be to do, if we can ever build them. so one thing is searching through a data base. let's say you have a list of a million items, say, and you want to find a particular item on that list. well, all an ordinary computer can do is look computer can do is through look that list one at a time, the first item, the second item, and the third item, until eventually you find the item that you're looking for. a quantum computer can in some sense look at all of those items simultaneously. we know that quantum computers will be able to help artificial intelligence learn better, and learn faster. optimising things in designing things — if you're trying to design, let's say, the shape of a car

so that air will flow over it in exactly the right way, that's an optimisation problem. it looks like quantum computers are going to be extremely good at that. and then there is code—breaking. if you give an ordinary computer a code to break, it will try every possible combination one at a time. but give a quantum computer a code to break, and it can try all the codes at once! this is a huge area of application of quantum computers, and it's financially the driving force of putting money into the industry, and persuading people to build the things. the first government which has a functioning quantum computer which can break into secret messages is going to be at a big advantage, and maybe will want to try and hide away the fact that they've got those capabilities. and, if superposition wasn't weird enough, a quantum computer's qubits can be paired up or entangled, and then can instantaneously affect each other from anywhere else in the universe. well, that's all very well in theory, but it is really hard in practice.

at sussex university, researchers are preparing for the challenge of scaling up their prototype quantum computers to take them from handfuls of qubits on the lab bench to an industrial scale. so what you see is an actual working quantum computer. as we are filming this, you can literally see an atom, for example, being in one state and another state simultaneously. and what you see on this screen is the evidence that that really occurs. that really is the atoms is this very strange and counterintuitive state. so quantum computers have been on the way for a long time, the holy grail of science, and with that, it actually seemed nearly impossible to build them. so people felt maybe it's just never possible to build such a machine. the reason why it's so hard is because to control quantum effects in such a way, allowing us to build a large—scale quantum computer,

it is tremendously hard. quantum effects like if an atom can be an two different places at the same time, or entanglement which einstein referred to as spooky, he said it is so hard to control. at the moment these prototypes offer a glimpse of how these computers might work in the future, but how will we use them when we have them? what does a quantum computer programme look like? the basic building blocks of a quantum computer programme are really very alien to us. they're things like superposition and entanglement. those are the right high—level concepts to put into our quantum computer programmes, but it's very hard for the human brain to understand what entanglement is and what its consequences are. thinking of qubits connected by pieces of string actually works extremely well, to help us design and predict quantum programmes, and predict what they'll do. so perhaps a high—level quantum programme manager of the future could look like a knot or could look

like children's game of untangling fishing lines and seeing who has which fish. you imagine going up and down, and coiled around, and the pattern of how those strings interact has a bearing on your quantum programme. i do feel the programmers have a little bit of time to sort their software out, though, because the hardware is also still a work in progress. i've gone underground to see oxford university's quantum computer. the lab is a wizard's paradise of lasers, vacuum chambers, and traps for atom—sized particles. it's an ion trap. in the lab, they've achieved a world—record level of control over their quantum bits. they can even show off by making a single qubit glow in morse code. c-l-i-c-k. what will your quantum

computer look like? it won't be this size then? so ideally, it looks incredibly boring and incredibly small. so take an optic cable, two metres by one metre high. we think we can get this down to something the size of a shoebox in the next five years. once you have everything in the right place. once we have everything the right place, machined down, optimised — and rather than made by physicists, made by engineers. to make something that works rather having knobs, when you have enough people twisting them. you're not looking to put more and more qubits into the same box, are you? what we want to do is build some devices which contain five or ten qubits, but build many of these devices. so it's the same as if you have a supercomputer. nowadays, you don't have one big computer.

you have lots of small computers, and data centres humming with lots of different machines. that's what we envisage these things are. it does sound like it is not the most efficient design, if you're plugging lots of these things together with optic fibre, rather than making a quantum computer that has 50 qubits in one place. yes, the most efficient device we could ever build would have all the qubits being able to talk to every other qubit. that's ideally the place where you want to be. but you always get to the point where you can't put any more qubits in the device. at that point, we want to have a network we can build up. so, once you've got as big as you can with these techniques, you can then network them together to build bigger networks. the huge potential of quantum computing has attracted big tech players. google told us it will have something big to announce in march 2018. ibm has a 20—qubit quantum computer that researchers can programme over the internet. both these companies are trying to build reliable quantum computers of around 50 qubits. now, at this point they will achieve something called quantum supremacy, which sounds world—changing, but it might not be.

why i don't like the phrase is that, when you cross that boundary, nothing instantaneously magical happens. it's just the point at which you can't predict what the machine would do. it's the point that the machine might be useful for something. but to be honest, we haven't worked out anything that at say, a 60—qubit quantum computer could usefully do. so it's into the uncharted territory, very exciting, but it's not at the point where the quantum hardware is supreme. you should not throw away your iphone or your laptop or your desktop and have a quantum computer instead. so, with more tech companies getting serious about quantum computing, there is now a place for them to show off their ideas. it is the quantum technologies fair in london and kat hawkins

has been along to see what is on the quantum horizon. when it comes to quantum computing, a lot of the research seems to be happening in academia. but i wanted to find out how much of it is being taken away from the lab bench, for applications in the real world. every stall at this fair is using the same tech used in quantum computing — the principles of trapping, manipulating and measuring tiny, atom—sized particles. but the practical applications here are creative and potentially life—changing, from diamonds used in heart disease sensing, to capturing individual virus particles. they're really designed to be able to measure very, very sensitively, at very small lengths. so it's idealfor things like nanoparticles, like viruses, and indeed, for measuring chemical signatures, as well. use the mouse to move that scale bar back and forth. it should be fairly obvious, when it flashes really bright. there you go, that's it. when it wiggles around, that's when you've got a particle trapped in your resonator. the ultimate aim is that viruses could be picked up using this diagnostic tool.

but the main focus now, for most people here, is on overcoming the engineering challenge of making large, bulky systems a lot, lot smaller. heavy industry, all the way through to defence and security, transport, and healthcare technologies. it is incredible to see how many stalls here are researching so many different areas when it comes to quantum technology. and they're all working together with an open—source mentality, along with a lot of investment. the british government spent £270 million over the last five years on quantum technology research. the collaborative element, especially the number of things that npl is involved in because we have a lot of the core technology and science and we're just looking at what are the actual applications in the uk business world? from afar, a lot of the applications here still look like complex machinery, but anne curtis has been looking into its potential in an important area, far, far away.

so one of the main applications we can use the quantum technologies is quantum sensors. what we're doing in this experiment is we want to sense greenhouse gases, and measure how much there is, how that is changing over time. and one good way to monitor large—scale systems is from space. to put something properly on a satellite, it has to go through all the space qualifying tests, so every item in there would have to be space—qualifying. most of the fibre technology isn't so good in space, due to radiation effects. but there's no reason why this couldn't be miniaturised and put up into space. it's just the next stage of funding. it is so hard to be here today and not feel excited about quantum technologies, but one thing everybody has said to me is that their particular real—world applications are a few years in the future still. so, when it comes to quantum computing, it is still very much

a case of watch this space. hello, and welcome to the week in tech. it was the week that the federal communications commission in america voted to repeal rules on net neutrality, which had stopped internet service providers from offering different speeds and priorities for traffic online. the extraordinarily elongated asteroid called oumuamua was being checked for signs of alien technology. and, here on earth, the faces of two billion people can be compared in a matter of seconds with a minority report—style system, dragonfly eye, unveiled in china. it was also the week that netflix was caught up in a creepy viewing controversy, after revealing on twitter that 53 subscribers watched the holiday film a christmas prince every day for 18 days in a row. netflix defended the tweet, saying it represented overall trends, and not specific individuals. the city of san francisco has banned the use of delivery robots on most of its sidewalks, stating not all innovation is all that great for society.

meanwhile, dutch police say it may not have been such a good idea to use eagles to catch drones after all. who could have guessed? seen here on click, the birds were trained to snatch the machines from the sky. but the cost of keeping them was too high, and they didn't always do what they were told. and finally, if you're missing harry potter, don't despair. artificial intelligence may have a solution for you. a new chapter has been created for a book called harry potter and what looked like a portrait of a large pile of ash. its plot twists include harry dipping hermione in hot sauce, and ron turning into spiders and trying to eat hermione‘s family. wizard. earlier in the year we looked at some of the 360 cameras which have taken off in 2017. dan filmed with the new kid on the block, the insta one in berlin. and he came back very pleased with it. easy to use, lots of features, including this bullet—time mode, a bit like the film the matrix, where you can get a picture of yourself from all angles.

but what have the more established names in photography got to offer us? well, with christmas just around the corner, this time we sent dan to a suitably festive place to put two pro—sumer 360 cameras through their paces. the ancient city of bath hosts a very traditional christmas market, one that i want to catch in the round. i've got two cameras for the job. one is from kodak, the other is nikon's. they look pretty similar, with two ultra—wide—angle lenses capturing everything, before the two images are stitched together in—camera. but look closer, and you will see the kodak sporting two different lenses, one smaller than the other, superwide 235—degree lens. it also has the tiniest remote control in the world, and a slightly higher price tag than the nikon. our producer has the kodak, while i'm putting the nikon through its paces. now, we don'tjust want to test

these cameras out in the daylight, when all the conditions are absolutely perfect. for these cameras, we want to test them out to see what they're like as it starts to get dark. will the bright lights be a problem, and will we see all of the detail? time to go for a wander and see whose 360 is best. please dive in, ladies. don't let me get in your way. and, in no time at all, i found the festive liquor stand. not just wine, but flavoured vodka here, and the nikon is not put off by those flashing lights. but the image is a little dark, so we will brighten it for you in postproduction. there you go, and now you can see the other problem. the image stitching means i've almost lost my head, before touching a drop. the kodak's picture is brighter than the nikon, but we found that the quality from that super—wide—angle lens was softer than the smaller lens on the other side of the device. of course, you're best off

with a stick attached to both of these cameras, otherwise your hands get sort of in the way. now, to make the test fairer, we decided to see how these cameras fared back to back. or front to front. or back to front. well, it's difficult to tell, to be honest. we shot them side by side. look at this. we found a 360 globe for a 360 camera. and it's the nikon showing off more natural colours, benefiting from a more accurate light balance, although some might prefer the warmer kodak results, because it is very christmassy. at the chilled cider shop, the kodak warmed things up, while nikon kept things more natural and crisp. both cameras struggled to stitch their shots together perfectly. this is the raw footage, with no touching up, and the nikon has done a reasonablejob. the stitching point is more

visible on the kodak, partly because of the different qualities of those two lenses. on the upside, it's kodak that offers the ability to play with how the images are stitched together in its free software, something the nikon's more basic offering lacks. for sheerfun, the kodak also offers greater flexibility when playing back what you shot. this is little planet mode. and, if you want to do it on the nikon, then you'll need some third—party 360 software, which may mean additional cost. finally, the thing everybody forgets when they use a camera — sound. it is very odd being filmed by two cameras. we're being filmed as well, it is 360. oh, goodness me. you can tell she's had too much cider, because hers moves around a bit.

i'm just cold! we reckon both do a greatjob, but the nikon is slightly clearer, although the kodak offers the possibility of attaching an external mic. so which camera will enthusiasts be hoping santa brings them this year? we think the kodak edges it for easier post—production, while the nikon has a better shot. but, if you're hoping for a trouble—free, cinematic, seamless result for under £1100, you may have to wait until something else takes off. at least for now. this is acute art, a virtual reality arts platform, and a gallery without walls. and it's about to launch, with vr works by some of the world's leading contemporary artists. amongst these works is one by marina abramovic, the self—confessed grandmother of performance art, who pushes her own body to the limits to challenge