protons being particles slow down as they enter the tissue, and they stop within the tumour and do not go any further. and that means that this form of radiotherapy can be used in really tricky parts of the body. for example, something like the brainstem, which we know is very sensitive to radiation. so, it is very much putting the beam precisely into the tumour and not going into the sensitive organ. all types of cancer treatments risk harming healthy tissue near to the tumour and research is ongoing around the world to try and minimise this collateral damage. there has been at least one recent, rather strange, finding. it is to do with how quickly and how hard you deliver the dose of radiation, and it is called the flash effect. so, you deliver the radiation in a very intense burst

to the tumour instead of on several seconds, for example. you condense it in milliseconds. for a physicist, this should not make any difference, but it seems like when you deliver radiation like this, the tumour gets damaged, the healthy tissue does not get damaged, and of course it could be game changing because you could forget everything about damaging surrounding tissues, etc, and it is as if the particles would know, "this is a healthy cell, this is a cancer cell." now, we have got recent results, not published yet, that seems to indicate that we do spare the normal tissue and we might do even more damage to the tumour, so it might be even better than people say it is. flash is tremendously exciting, and i think it is a bit "watch this space." back at cern, i am visiting a project that is looking for a different way

to specifically target cancer. this robot is handling a radioactive material created by cern's medicis experiment, which is looking at doing something really cool with it. they can attach it to specially engineered molecules that you can inject into the body and which will only stick to cancer cells. now, when that happens, the radioactive material shines like a beacon, and it can be picked up on scanners, so suddenly you can see exactly where the cancer is. then you can do something that i think sounds even better. you can attach a different type of radioactive material to those engineered molecules, and when they stick to the cancer cells, the radioactive material kills only the cancer cells. and they leave everything else around it unharmed. this combination of therapeutics and diagnostics is called theranostics, and its use

in the treatment of some prostate cancers was approved in the us in 2022. the peter maccallum cancer centre in australia told us that their ongoing clinical trials have shown it can improve the quality of life and extend life for some men with aggressive prostate cancer. this is a lab that attracts the heaviest metal. metallica, the pixies, arcade fire was here, my friend roger waters down here along the bottom, muse was here. all of the rock stars want to meetjeffrey hangst, whose decade—long project — nay, obsession — could be about to make him a legend.

in this building, they are making the rarest and most expensive material in the known universe. antimatter! antimatter is the stuff of science fiction that turns out to be science fact. our universe is made of tiny particles of matter, and in theory, every type of particle has an equivalent anti—particle. an evil twin that is the same in almost every way. but the thing is, there is almost none of it in the known universe. which is actually quite a good thing — because antimatter and matter do not get along. so what happens when matter meets antimatter? well, they are incompatible, they annihilate each other and release a bunch of energy or other particles. it is a microscopically nasty business. yeah, that is an understatement, shall we say.

the enormous release of energy when the two meet has inspired science fiction writers to imagine it being used to create the ultimate weapon, to power entire civilisations and to provide enough fuel to explore the galaxy. one of the popular themes in science fiction is we use matter and antimatter, combine them to produce almost limitless energy. is that going to be possible? well, when you state it like that, it's exactly true. if you had some antimatter and used it to annihilate matter, you make an incredible amount of energy per kilogram. that is what antimatter does. the problem is that we don't have any, we have to make it. and we kind of suck at making it, in terms of how much energy we need to put into it. so it takes much, much more energy than you would ever get out again — it is a complete loser from the science—fiction standpoint. so i can't help you out with the starship. that makes me a little bit sad. nonetheless, here at

the antimatter factory — yeah, that's its actual name — jeffrey has succeeded in creating the opposite of the simplest element in the universe... ..anti—hydrogen. once the antimatter is created, it flies really, really fast around a ring that is behind all of these thick concrete blocks. and you know what thick concrete blocks mean — it means you really don't want to be anywhere nearer to the stuff that is on the other side of them. and by looking at how anti—hydrogen behaves, jeffrey is hoping to answer one of the universe's biggest mysteries. why is there no antimatter left in the universe? shouldn't matter and antimatter have been created in equal amounts in the big bang, and shouldn't it all have just cancelled out, leaving nothing behind? jeffrey's project is looking

for an explanation, by testing to see if there is a slight imbalance — if anti—hydrogen does not in fact behave the same as normal hydrogen. maybe gravity affects it ever so slightly differently. this is the top of the alpha g machine, where g stands for gravity. this is the device that we are using to try and answer the question, "what happens to antimatter if you drop it in the gravitational field of the earth?" if your experiment found that anti—hydrogen falls up instead of down under gravity, what happens next? that would be super cool. that would be a complete revolution in science. that's a completely unanticipated result and would mean new physics, and probably a nobel prize for somebody who happens to be involved. i don't want to say me, because i helped bring the news to everyone, so can i get a bit of it?

i will invite you. he laughs and that's all we have time for in the short—cut of click at cern. please do check out the full length version. there is plenty more mind—blowing stuff waiting for you and it's on iplayer right now. thank you very much for watching and we will see you soon. in terms of flooding different parts of the uk it will of course the fats and strongest its as well 60 miles and strongest its as well 60 miles an hour gusts running to the north because bringing those large and battering waves for example sunderland and flooding in scotland

has been of course real concern where we have had a number of severe flood warnings. away from scotland, we have also got lots of flood warnings in parts of england but also if few for wales. you check the later situation on the bbc weather website. in terms of weather warnings, through friday night, the warnings, through friday night, the warnings from northern england will lapse and we will be left with these warnings in scotland for saturday. amber warning and another red warning into parts of angus and aberdeen sure. another 70—100 mm of rain rainfalling aberdeen sure. another 70—100 mm of rain rain falling off course on top of what has already fallen so we are likely to see some further severe flooding across these eastern areas of scotland in particular where we will also continue to be windy. the rain easing off of northern england to the robbers across this part of the world can take a day or two to respond to all of that rainwater —— the flooding could be worse for some communities even when the rain stops falling the brain starts to get a

bit brighter. intensive bit of rain skirting two parts of southern england to watch out for. heading through saturday night the majority of the rain finally pulls out of the way at least the bits left over in scotland will turn later in past year. we will get this ridge of high pressure building and from the south—west for sunday, what that means that the vast majority of the country, we are looking at a much brighter day, more dry weather. in some decent spells of sunshine. temperature is around 12—15 quite close to average for the time of year. whether dry, it could be some communities but flooding it keeps getting a bit worse before we start to see a bit more of an improvement. perhaps into monday it will be largely dried, perhaps apart from the far south where the weather system looks set to threaten later on. not a bad system looks set to threaten later on. nota bad kind system looks set to threaten later on. not a bad kind of day on monday, some mist and fog patch is clear exciting spouse are most in the cloud thickets of the south of hoopster to see some rain approaching the south coast of four southern england not particularly

been badly hit by babet in recent days and so we could cope with a bit more rain. beyond that as we head deeper into the new week low pressure is to cold and it looks like we will see since further pulses of rain across the country some of it could be quite heavy and the big problem with that is the ground is completely saturated after all of that recent heavy rainfall so probably won't take much more to see flooding concerns re—emerge. that rain again going into some of the wettest places that have been wettest places that have been wettest with a storm babet into northern england and parts of scotland as well for tuesday potentially something a bit brighter in the south temperatures 12—16 c. towards the middle part of next week, low pressure still firmly in charge with the rain or showers coming in off of the atlantic seeing unsettled and quite changeable. expect further outbreaks of rain deep into next week it stays unsettled temperatures generally

close to average the immediate concern is where we have those amber and red with the warnings which will tend to concentrate on saturday into parts of scotland where we could see some further severe flooding problems.

live from washington, this is bbc news. two us hostages held by hamas have been released. but hundreds more remain captive. 0ur position is clear — every hostage needs to be released and needs to be released now. the wait for aid drags on in gaza, as the humanitarian situation gets worse. officials say hospitals are near collapse.

hello, i'm caitriona perry. you are very welcome. we start with the news that hamas has released two hostages. both american, mother and daughterjudith and natalie raanan had been held hostage for nearly two weeks in gaza. this is the first image the government of israel shared of them after they were freed by hamas. they were handed over to the red cross in the gaza strip on friday. both hamas and president biden have said that qatar played a role in mediating their release. israeli officials say the pair are now in israel and are being being reunited with theirfamilies. the mother and daughter were kidnapped during the surprise attack by hamas on the 7th of october from the nahal 0z kibbutz. originally from illinois, they

were in israel visiting family. hamas said the pair were freed for "humanitarian reasons".