ah, ah no da vinci's, mysterious masterpiece is perhaps the greatest leonardo masterpiece of the collection of the louvre, and no, it is not the mono laser. it is the virgin of the rocks. was there another symbolic meeting to this beautiful baby that perhaps we just don't understand today? the search for answers starts february 10th on the double you open your eyes is everything clear? if so, then perhaps you are still young. we'll be taking a look at how the eyes change as we age. but thus we're digging into the construction industry a major driver of climate change. there are some solutions like poorest concrete,

recycled materials and cement from plants. ah, hello and welcome to to morrow to day this science program on d. w. the construction industry is booming, more is being built around the world than ever before, with serious consequences for the environment. because almost everything is made from concrete containing the binding agent cement. the main is made in special kills this combustion process makes it a real climate killer. it's responsible for almost 10 percent of c o. 2 emissions caused by humans, but thus could hopefully change the carbon footprint of concrete could be reduced by using this material. expanded clay small airfield clay ball austin,

are mixed in the concrete to reduce its weight. it also works with glass being their clue. and the driver thing about both materials is helping corporate air into a solid structure. and the more air, the more finely distributed, the better the quality than the i'm so. so home in from light concrete contains so much air than it even floats. i at the food is very university and munich. christiane tennis team is testing the formula for their in for light concrete 1st expanding clay than water. and finally cement. this mixture weighs less than a quarter of standard concrete because it's so light, the material is harder to work with on construction sites on the team. it's

satisfied. it is on the i to the special feature of concrete is that it has to flow like a fine chocolate mousse, where the concrete can be used to build walls that provide excellent insulation because of the trapped air digging that one's really cold, right? again, for light malls don't need extra insulation like polystyrene. and this concrete also helps the climate in other ways. but he does it because it's porous an air containing c o 2 can get inside and then react with the calcium hydroxide in the concrete. so the calcium hydroxide binds the c o 2 from the air, and so offset some of the c o 2 that was released during production utilized by the product. so in 5 years it's put through it's open pours the in for like concrete breeds in the greenhouse gas. the county em hydroxide contained in the concrete

form during the concrete mixing process absorb c o. 2 from the air. and over the years, turns back into calcium carbonate or limestone. and yet the concrete remains stable . using a scanning electron microscope, the research team observes how needles form inside the concrete, interlocking with each other, and providing stability. yes, shawn, we had, we look at how the micro structure has developed and we can, we see that the strength, building needles, who formed well to produce a highly robust concrete at small and magnifications. we can also see the porosity of the micro structure or that there are many mole pulls. and so much more air is contained in the ultra like concrete than in normal concrete. hi, it is as good as from the my, the talking them. but how strong is ultra light concrete compared to normal concrete? a blank of regular concrete is exposed to pressure at

the freight. but only under 60 tons of pressure. when it's the turn of ultra light concrete and it breaks under just 9 tons of pressure. this is the ultralight, concrete, has a stronger overall structure than standard bricks are, is highly robust. as you can see from the way it to performs under stress for form, you can use this concrete in an earthquake zone. it still has half of its load bearing capacity, even though it's totally broke. i will try to put this. this is enough for a standard house as close cantino, but not for bridges or skyscrapers. ah, old buildings are often demolished to make way for me once. but what happens to the

old building materials most of the time they're disposed of, but almost all the components of a demolish building can be recycled. this may significantly reduce the carbon footprint of the construction industry. in berlin's sure, in a back district this student residence has long stood empty. now the old building is set to become something new, a multi generational house, thanks to annabel fund whiten. lot of as a typically it would just be torn down this week. exactly. that's why we're happy you're here. so we can go through the building together and see what parts can be kept and we used. the aim is to save resources, reusing something avoids having to produce it all over again. it reduces c o 2 emissions but requires more planning as good as this and felt like the good thing

is that compared to the much than a granite flaps that were used. the loss in the 1919 is the smaller tourette's. so tiles are about 4 centimeters fake and they can believe it out quite easily. all saving come on a bit of annoy ton is an urban mining expert for her sites set for demolition. our sources of raw materials for new building projects. i fenced on as lid windows in the problem is often that use energy saving regulation and sat, sat in one's can no longer believed. they simply can't me to day standards used to building materials can't always be re used in their original form. adhesives, like glue or mortar, make for added complications. the material must be removed, re cleaned and hauled away, which requires more work and often a rethink. during planning. at the calls were institute of technology, professor dia cable teaches butting architects about circular construction. he's

been monitoring sustainability in the building trade for over 2 decades to hardly listen yet seeds in recent decades, if not centuries, yada. we followed a linear business model name. that means we extract materials from the earth's crust to produce things like buildings. then we demolish them and deposit the materials as waste and landfills. these a thing this way of thinking must change in the future of nines at 1st because resources will be in short supply doyenne and 2nd. it to take responsibility and protect the climate better martyrs. bisset, so to think circular wouldn't and no longer follow this linear model that's led us to a dead end. denise, what it does once in he's a cousin, shouldn't switzerland is a pioneer when it mister resource sufficient construction in basel, they're even considering a voluntary commitment to using recycled building materials, architect, caston miller and her colleagues have already realised numerous innovative

buildings this way, often unsightly can for we need some advance loaning about buildings that are about to be torn down simply so that we can go there early enough. then we have the time to evaluate the construction component and save them so that we'll get to evolution for a current project. they're salvaging tons of electricity, pylons they are real climate killers, to produce recycling. the steel supports allows the architects to reduce c o 2 emissions during the entire production process. the macand us mail met want a name. we're noticing that more and more companies are adopting this concept and making the homes us at 1st, they're quite skeptical and only see the problems and huddles i. but as soon as they've done it once have been through the process, they view it as an opportunity to position themselves from the market and carry it further toxins. it wasn't as tough as it looks at 1st because i'm on phone shined. one of the architecture firm's biggest projects is the cups bow holler in the city

of into to a 70 percent of the building was made from repurposed materials, the anal starsky length we learned from it that you need a launch platform for lease construction materials, hydrophilic as they come in at different time and you need an interim storage facility to prepare them for a specific buildings and such an internet platform as being developed in berlin called consular. it creates so called material passports which include a materials age, condition, shape, and color. they're then posted online. when a property developer finds a component, they can use a matches made soon. it could become even easier if the stands are fastened. the inventory that we're doing now is only necessary because there aren't any material possible as yet. if in future such passports, why required for every new project on the continental platform that just have to be activated at the right time, i guess i'd have been assessing which materials can be recycled and whether it's

worth the effort requires experience and know how the architects know that some materials are more popular on the 2nd hand market than others. steel is sought after other materials, much less so. and it's too costly to recover and transport materials just to have them sit in storage. there are other hurdles to regulations about warranties and liability when employing used. building materials still need to be established in germany. sustainable construction requires more than just the will of architects and builders. it also requires a legal framework that's not me got it mostly doing isn't just nice to have. it's the future. we must plan and build this way, although be no construction revolution. and without that, no climate revolution, we won't meet the $1.00 degrees target. if we don't radically changed the construction industry, so in the, near a few sure, the architect's 1st job could be,

see what construction materials are available on the circular market place and plan accordingly. concrete can also be recycled. and if it can, it should be because the manufacturing process is extremely climate damaging concrete as might have water, sand, gravel, and cement. the cement itself is composed of limestone and clay. it's kiln fired at up to $1450.00 degrees celsius. one of the most climate damaging stages of production. the combustion process requires enormous amounts of energy and releases carbon dioxide. c o 2 is also released in the chemical reaction. when limestone, c, a, c o 3 becomes quick, lime c, a o, and c o 2 ave alternative ways to make some main production more environmentally friendly. could

there be huge potential locked away in the humble cassava materials? researcher voice from schmidt wants to use it as raw material for cement, and use it to produce high quality concrete. cassava, also known as manioc, or yoga, is a starchy tuber grown as food in many countries. but the peel is poisonous, which can cause problems when it rots. will not move on a little. we're, we're making a form of cement from the ash of cassava pio and water is on. we would later add sand to make it into something like concrete at all. this is like a precursor to concrete. we want to see if we can get the same properties from cassava peel ash that we can from the normal cement to mixtures. linesman one in the middle, schmidt's concrete does contain some meant, but also the ash of cassava, peel,

and sand and gravel like normal concrete schmidt burned the casino of appeal to ash, and then placed it in a kiln and almost $800.00 degrees celsius. this releases a substance that's contained in the peel silicon dioxide. and that's the key to schmidt's concrete when the fun of so now it's time for the sand and we've got course medium and fine sailings. and this will pour that all in together now. and then the cement and water. and finally, the cassava ash, with a silicon dioxide. we've got new charges installed on the cassava. peel is also used for cleaning more so in places word grows allotted, which makes sense, like sierra leone and gonna sit with her often with

a high line was the biggest exporter of cassava, and huge amounts of it. grown brazil out among there, they call it yoko or mun joker thought what visionaire put a futile for the country grows way more than it eats all. so there's a lot left over that could be used to make semantical dollars. and then kathy, both lum, schmidt's research colleagues and nigeria are already experimenting with cassava. ash. the technology is improvised by effective simple ovens are used to produce the ash. the cement alternative is already being successfully produced and large quantities listed here. so this is lucky, i was issued, it's important that the material flows nicely, but that the air bubbles can it by themselves. they're not trapped,

didn't because that would reduce the strength of the concrete, the amino this winter constant. the life of this is a nice consistency of some kid flows, but it's stable or particular the milton wouldn't even the course particles don't sink to the bottom. we've made some good concrete here that only has 50 percent of the normal cement content by replacing it with limestone, powder, and cause sob appeal ash, and wish as hello, time, ocean half as much cement as normal means lower, c o. 2 emissions vase lam. schmidt wants to use test blocks like this to demonstrate its strength. the concrete is put under pressure until it breaks and it manages to withstand the same load as normal concrete. this pavilion at lake os university and nigeria is made of cassava concrete, a solid,

new eco friendly alternative in construction. if i'm a blood is red, why i gave you a now over to you? what have you always wanted to know? if he had the question about science nature technology, all medicine, then just dos. if we answer it on the show, we'll send you a little surprise as a thank you. rise or send a video message to tamara today at d, w dot com. this makes question comes from wilberforce, mixon in nigeria. oh, how long can a person survive without eating? fasting or freely choosing to go without food is a common custom around the world. people ought to fax for a certain time for religious health or political reasons. but how

long a person can survive without eating depends on many factors. the amount of fact reserves they have, their age and general health, all play an important role. someone who stops eating and drinking will die within a matter of days. those who go without food, but stay hydrated will live longer. for the 1st days, the body goes without food. it draws on its blood sugar reserves, mainly to keep the brain functioning. because that requires a lot of glucose under normal circumstances. around half of our daily glucose requirement is consumed by the brain. but if there's no more sugar intake, the brain secures all of the glucose reserves, leaving the rest of the body to go hungry. once the glucose is gone, protein is next. the body starts to break down muscle. it turns amino acids

components of muscle proteins into glucose germain chain supplies to the brain. but the body also burns fat until it's all gone to oh, starvation mode begins. bodily functions gradually shut down the heart rate, blood pressure, and body temperature all sink the body does everything to reduce the amount of calories it burns in order to conserve energy that can prove dangerous for children in particular. like here in the horn of africa, children's bodies react to much quicker to mound nutrition. they can starve to death as a result of long periods of drought and failed harvests. if there is no more energy left in the muscles, the body starts to draw on its own organs, which can shrink to half their former size as a result. because the heart muscle is also broken down,

starving people often die of heart failure. ah, scientists figure that people can survive for 2 to 3 months without eating, but going without food for so long results in lasting damage, including a weakened immune system, as well as major muscle and memory loss and know why al vision declines as we become older. usually this happens to adults in the mid forty's, the eyes accommodation 2 objects near or far away becomes limited. seen, clear without correcting lenses depends increasingly on light and visibility conditions. but why? what happens? we're about to find out starting with a popular children's game that requires the keen eye is

their eyes by with my eyes, isn't i something that is read? this is child's play for 10 year old emily whose eyes see colors brightly and details sharply, but not for her grandma, the game leaps. huh. looking old. like you said, i tell you is over there. but why is that? what happens to our eyes as we age? oh, emily's grandma, ingrid noticed the 1st changes in her early forties. ever since she's increasingly had trouble seeing things clearly up close. a classic case of pres, bio, pia, or age related farsightedness. many think the, i muffles it's a blame, but ophthalmologist antonia shackle off has more insight. 9 has to be in the lens. that's the problem. it gets harder and less flexible as we age. and so the accommodation, the close up focusing no longer works as before. and still only mccord from $20.00,

during childhood the lens is still elastic, allowing it to bend to vary the refraction over the years. this ability, termed accommodation, is lost as the lens harden's, the muscle has a tough a time reshaping it, especially up close. the refraction isn't sufficient to focus light precisely on the retina. the image becomes blood, so emily's grand mom keeps her reading glasses at hand. it's an easy way to rectify the problem. yeah, yes, i've got one up is to me to a great but that's not ingrid's only problem. objects in the distance are also blurry and sometimes everything's foggy. and a few rays of sunshine can make her eyes water. that's due to the lens is to children's still transparent and clear. but over the course of our lifetimes,

certain proteins inside the lenses start to clump together. as a result, they get claudia, causing some of the light to diffuse and become glaring. the image on the retina then appears to be blurry or foggy. or i'm thinking this clouding of the lens of the i is known as a cataract is in business for the examination of ingrid's. eyes shows that she has the mild cataracts, but it's not problematic yet. dylan's intense rice or enormous sign of aging, they only become problematic, require surgery if they lead to subjective impairments of vision for pick blad the inability to distinguish colors or contrasts. there's farms ins as compressed infants foot the changes occur gradually. simenon, can you give me a light blue m o, than even a mild cataracts, means colors don't look as bright to her grandmother,

than to know that the dark name to her white looks yellowish and shades of blue, a launch li filled it out as a t class o, the classic problem is the patients dress strangely as they no longer recognize the colors in their closet. clarifying, although wash the drapes constantly because they look so yellow look at a time. but what worries ingrid far more is not being able to see well in the dark . she can no longer distinguish between slight differences in brightness, which poses a danger while driving. several faxes come together to produce what's known as night blindness. first, the cloudy lens absorbs a lot of light, but the retina also shows signs of aging and isn't as well supplied with blood and nutrients. over time,

around 30 percent of its photo receptions die above all the rods that are responsible for night vision. it doesn't make for a rosy outlook when comes older from a 3rd of the light sensitivity of young people, human mention. but isn't there a way of turning back the clock or at least slowing it down? there's no secret recipe to stop eyes from aging. though eating lots of fruit and vegetable certainly can't hurt bittman a and other corrosive noise like looting, which is found in leafy greens, are essential. the good i health. otherwise the best advice is to avoid risk factors. kotik house down to rags can be triggered or worse, and by over exposure to the sun's rays and heavy smoke angles or otherwise, there's not really much you can do on the shore. naturally, a healthy diet is always good, which and a healthy lifestyle overall. because on the limbs, pfizer and scott, and that includes uv protection from

a young age. but even the best precautions can't stop the ais normal aging process . so old eyes don't stand a chance against young ones. izzy of i spy with my little eye wife, emily in her grandma might soon have to find a different game to play that so for this edition of tomorrow to day, thanks for joining us and see you next time. until then state curious. ah ah ah, with

ah, with russia to support or resignation the war machine has a firm grip on the country. but not everyone supports the president's war.

this report takes a look at what ordinary russians actually think close up in 30 minutes on d, w. o. these places in europe are smashing the wreckers stepped into a bold adventure. it's the treasure map for modern globetrotters. discover some of you up to record breaking sites on your back, youtube and now also in book form. sometimes a seed is all you need to allow the big ideas to grow. we're bringing environmental conservation to life with learning packs like global ideas. we will show you how climate change and environmental conservation is taking shape around the world

and how we can all make a difference. knowledge grows through sharing. download. now i many of the woods i am lana. see i was kaya, i am running for president of the republic of beller road, c o b b o with you. she is a wife of an upcoming petitioning i think bates who should been then in a moment. she tries to stand up for her husband's pedestrian changes and she herself becomes a politician. john dunn dark searches for the truth. again. this time, the exile to turkish journalist meets svetlana, seattle, sky, exiled leader of the opposition and beller roofs. huge. of course i'm tired. i'm tired. physically untied. morally, it's too much on my shoulders, but i have to hold. they swayed because i'm responsible for the future. follow

contra for the people far behind the boss. sh. guardians of truth starts february 18th on d. w. ah ah. this is the w news live from berlin. grief in pakistan as a suicide bombing claims more than 90 lives in a mosque inside of a police compound. most of the hospitalized are police officers and the search for survivors continues. now there are questions about the pakistani tell.