what's your story. i mean when i was a women especially are victims of violence. take part and send us your story your train or with understand this new culture. another visitor another yes you want to become citizen. in for migrants your platform for a while information. hello and welcome to tomorrow today the science show on t w this week we need an engineer who plans to manufacture his own electric cars. why don't we see a moment of darkness when we blink. and we head to south africa where

elephants are being kept in line by beings. but first to a story that concerns many of us. today more than half of the world's population live in cities. in twenty eighteen tokyo was the world's most populous city followed by delhi and shanghai. these urban centers are referred to as megacities meaning they have a population of over ten million. for years the nigerian city of lagos has been the world's fastest growing conurbation satellite images show how lagos has ballooned in recent years. the city state of singapore is used to a high population density here high rise buildings make maximum use of the land could singapore be a role model for the future. how can densely populated

urban centers solve the living space problem in singapore a swiss team is developing solutions together with local universities and a project called the future cities lab. one of the first things you notice here is how heavily built up singapore is but that it's also astonishingly green. verdant see is largely down to visionary city planning rules here stipulate that any land used for construction has to be at least partially compensated for by green areas in and on the structures the future cities lab is looking at how people in green high rise buildings like these live neighbors know one another how does the vegetation affect the city's climate and how's the quality of life here. future cities lab research director tom a short five lives in a green high rise with his family the interlace is viewed as

a successful example of this type of architecture. its structure doesn't just rear up it's also interlaced horizontally. functional spaces are staggered over various levels communal areas on one the swimming pool on another and courtyards on yet others. but you thought he took you for an architect the mission is of course to create decent living space in a high density environment and i think the interlace is a very good example of how you can create that high quality of life while not accepting that high residential density will have negative effects. in coal for us . the scientist says that the people who live in the interlaced like it and it also provides opportunities to participate in a neighborhood and community. they. it's

a difficult and delicate challenge and a high rise. buildings in singapore have proven a lot less successful at mastering at. social scientist michele zhang as also part of the future cities lab project she's looking at how green spaces are used and how they contribute to community building . it to me that even if what you think of. this garden is used mostly by the people who live here like this retiree who comes here every day for a workout he's proud to show us the apartment he owns in the block not only does it have a great view he says it's area enough that he almost never has to turn on the air conditioning. like him most people in singapore live in public housing. places like sky.

three thousand people live here around the same number as an average village and the idea is reflected in the development which groups blocks of eighty units into villages. the green areas and sky velour meant for communal use but the project's roof terraces are nearly empty apparently building a community involves more than just providing spaces for it to happen. it's not just a provide a space and a boring. there we have to consider what kind of people what they use like to use is base what kind of nice they. are what kind of activities. even though the terraces are attractively laid out and could easily serve as areas for interaction they remain empty if certain key conditions aren't met. when we did a survey we understand that people conserve ery much as. part

temperature humidity direct sunlight and the noise if we cannot find a way to improve and then it's very difficult for people to go to an upstairs to. the pinnacle is a complex made up of over eight hundred apartments home to about nine thousand residents around the same number as a good sized town. the roof terrace is open to the public you can just stroll around and admire singapore skyline. fifty floors above rolling traffic a miniature biotope has formed here. still big questions remain even if life can be made pleasant and vertical spaces aren't we humans at heart more come. down on terra firma are plants on

a roof really an adequate substitute for green spaces on the ground. want to go out into nature ground to others specialists have said that time and again. but that means that humans are oriented towards green on the ground towards feeling real soil under their feet. that said humans have changed over the millennia. we've accepted certain influences. so i also think the ground well is like us except if the ground we're on happens to be up on the twentieth floor of the building. finding common ground between human nature and vertical living a challenge for architects today and in the future. on facebook we asked what are the biggest problems facing your city. mahmoud says cairo has

so many problems he doesn't even know where to begin. hilda ellison villain wave or a city of one and a half million that has no proper sewage system. that has lots of water but ninety five percent of it is polluted and there's little political will to change class. frederick says nairobi struggles with traffic emissions housing estates that are filled with smoke as a result of garbage burning and plastic that some bottles everywhere which also clog up drains. zeno says khartoum is a quiet city between two rivers which give the place a special charm but one problem is the lack of cleanliness in many areas very serious in concepcion in chile where rush hour traffic is a big problem he'd like to see an overhead railway system to relieve the pressure on the street. thank you for all you can.

most big cities struggle with traffic congestion and car emissions could images like these one day be a thing of the past what's needed is an environmentally friendly alternative to gasoline and diesel. which could come in the form of electric vehicles we meet an engineer who's not only designed his own electric car he's also forging ahead with manufacturing and. there it is again acceleration you could use your driver's license in a car like this you just want to speed up a little but then you look down and it's just topped the gas but now i'm doing over seventy. that's not good in traffic. certainly not in town anyway going to shooting signed go of the city car it began as a study at athens technical university the professor and engineer was determined to

see his model go into serious production but established car makers weren't interested. it's really annoying for scientists when good concepts they've developed over a long period just disappear into a bottom drawer so we said not with us i was getting all of this but i thought come on you can do this i wanted a mini porsche or a porsche killer so to speak as one anyone can afford. the ego might indeed annoy luxury sports car makers because it can be had for as little as sixteen thousand euros sixty eight thousand less the comparable models because she didn't just build it from scratch he also set up a tailor made production line one big advantage electric cars work with far fewer components than traditional field driven models. where a combustion engine production line and the entire building not be too small. fewer

parts equals fewer potential problems as well as low investment costs for components automation and assembly. working within the car industry's traditional structures are serious that churns out fewer than one hundred thousand units a year just isn't worth while that's because the initial setup requires such a big investment that you need huge production runs to turn a profit here we're showing that producing just ten or twenty thousand cars a year can still be economically viable on one saving using an aluminum frame instead of the standard integral body that saves the costs of expensive presses for bodywork components. drivers made by a german company. this company couldn't make an electric drive that won't last one hundred years that's what's special about electro mobility something not possible with internal combustion technology and we've built a body that will also last that long it looks so good we don't even painted it

can't rust it doesn't soften that's the basic plan for a car that can last for a century if that's what you want. the ego doesn't have necking panels that well made of plastic and i'm ready to mount so the eco punch doesn't need painting facility. if you can produce a painted surface like this and it's also extremely durable it takes four times the normal force to scratch it and then you can hardly see the scratch and because the material itself is colored there's no problem a coating that makes it a wonderful material. but the path from concept to serious production from scientists was anything but wonderful. and i think during the nearly four years since we set up the go mobile there have been six or seven disasters where we could easily have given up. just said ok that's that.

but you know what's really great about that what my team here have been through after you've overcome the problems they all appear wonderful in retrospect. is currently building two new production holes soon they'll be manufacturing an electrically powered berth and further ego models. oh there goes. and again. and again. most of the time blinking is an automatic reflex blinking helps to fend off germs and protect our eyes from sunlight. it also spread steere view it's which helps ensure that the surface of the i doesn't dry out. all good and well but it does still leave one question. every few seconds everything goes dark around eleven

thousand times a day we should be seeing this but we don't so what's going on in our brain. wanted to find out the neuroscientist at the german primate center in putting in studies perception. that we don't notice the darkness when we blink is old because the i actually reacts extremely quickly to change. it compare seaver back image lasting just ten milliseconds and the dark phrase of a blink is much longer about fifteen times longer. so we ought to notice it. for this few homes and for the brain one hundred fifty milliseconds are an incredibly long time when you close your eyes during a blink the brain isn't getting any input so it fills up that gap food and there's a look of. as a result you don't notice the one hundred fifty milliseconds of darkness but what fills the gap. to find out how to watch the brain in real time as it processed

visual. but he needed the help of electrodes to do it. the neuroscientist got the opportunity to carry out a test on epilepsy sufferers who had had electrodes temporarily implanted in their brains to treat that disease one group had electrodes in their prefrontal cortex is . the place for the prefrontal cortex is in front here traditionally it's associated with your higher cognitive functions for example how you concentrate how you retain things in memory and those are the functions typically associated with this part of the brain not perception but we suspected that the region does play a role with this feeling in effect such as when you blink. the electrodes read just a neural activity while the test subjects look at two images one after another showing lattices of dots. they have to decide whether the dots are oriented

vertically or horizontally or die acne harder than it sounds as the arrangement of the dots is ambiguous first picture vertical horizontal well to act no using the green point the subject selects diagonal to the upper right. second picture. again diagonal to the upper right. most of the patients showed a kind of memory effect. the image of the lattice they saw first had a strong influence on what they said they saw in the next image in the. those who chose vertical in the first picture and nearly always chose vertical in the second picture two at that moment the nerve cells in the prefrontal cortex were highly active even though the images stored in this part of the brain. only one patient make decisions at random in her case part of the prefrontal cortex had been

surgically removed. the composition she couldn't remember what she'd seen in the first image. so we concluded the information from the first image couldn't be merged with the information from the second which is what would normally happen. so it seems the prefrontal cortex is necessary for us to perceive images seen one after the other like the use that the separated by a blink. if outlet is right right behind it. do you have a science question that you've always wanted and say we're happy to help out and send it to us as a video text over a spell if we answer it on the show we'll send you a little surprise as a thank you cannot just ask. chuck well as your maku from nigeria wants to know what is de n.a.

. it's in every cell in the body along molecule that looks like a twisted rope ladder but it contains all the instructions for making a human being. it's rungs are made up of four different building blocks you can think of them as letters that can be used to create an infinite number of words what we call genes that endless variety and the d.n.a. is what makes each and every one of us unique. some sections of d.n.a. are like the different departments in a company that keep business ticking over they send for instance borders to the cells manufacturing facilities to make and deliver more of this or that product. the instructions in coded in d.n.a. are used to make a vast array of proteins and they control every aspect of metabolism and the body.

d.n.a. is found in every species on earth. that's made it a powerful tool for determining the course that evolution has taken since law. first began. the development of the tree of life is similar to that of a real tree whose branches continuously split and i urge. researchers used to determine how species were related by comparing their physical characteristics for example by looking at whether an animal had wings or not however that can be misleading. but comparing d.n.a. can help clear up mistakes because it provides a much more accurate map of degrees of kinship between species. some ancient human d.n.a. has survived and fossilized bones and teeth for over one hundred thousand years. that gave researchers the idea to use the molecule as a way to save other kinds of data. when d.n.a.

is dried it looks as in conspicuous as flour but a single gram of it could contain as much information as a trillion c.d.'s a medium that takes up little space and doesn't require any power. researchers have already packed artificial molecules of d.n.a. in tiny glass balls for saving and reading data a first step towards making the technology a reality. do you have a question or a comment this at our website or drop us a line on twitter or facebook. speaking of d.n.a. a colony of bees has a queen bee male drones and female workers whether a female becomes a queen or a worker is determined by the food she gets as another not her d.n.a. . nature does have many surprises in store.

there so surprising the unusual role bees play in the south african conservation project. in the middle of the south african bush right next to kruger national park seawall adjusts robin cook and. have set up fifty beehives. the two conservationists attesting whether honeybees can protect selected trees inside the park from the park's largest residents' elephants. just like people elephants don't like getting stung they have an acute sense of smell and hearing so one hint of a bee hive and they're all. and the reason we're doing that is that in our protected areas here in south africa we've got a build up of a lot. and densities and concern over the impact that they may be having on our large tree species and so we're trying to find ways that we can mitigate the effect

that elephants have on trees and they have by placing honeybees in these trees we hoping that we can find a new method to actually protect the trees from elephant in fact. while elephant populations are in serious decline in other parts of africa the numbers are growing in south africa he n.h.l. reserves a fenced in and equipped with also official richard holmes protected and well provided for the big animals have flourished so much so that they've become a problem the elephant stripped trees and shrubs naked often up brushing them in the process and destroying the habitat other animals and plants in the park rely on elephants are particularly partial to one of the park's largest trees the marina really trees are a highly sought after tree by elephants and that's because they got a lot of forage for the elephants and we're seeing a lot of impact on these trees and for example in the study site here we've seen a decline of around thirty five percent of the military since elephants have been

in the system so i'm really trees are very important in our ecosystems they provide a lot of food for species that provide habitat and so we know them as a keystone species. the elephants often flatten the religion just so they can get to the leaves but so fall them really is with bees living in them remain largely untouched out of fifty trees only one was damaged during the past year. cook speed project is a new approach in park management in the past a large number of elephants was simply culled nearly seven hundred thousand was shot dead in kruger national park to keep the population stable and protect the vegetation so when it comes to managing the effects that elephants have been launched there's been a mindset shift from controlling the elephant numbers themselves as previously thought to to mitigating the effects that they're actually have on the trees. so

you could have courses on a large scale where you could try and manage a different distribution. of actually managing the effects or managing the large trees and cells protecting the large trees themselves. with the bee hives. hoping to control the elephant's movements by keeping the moving when the animal stay in one place too long they can inflict extensive damage but above all the conservationists say bees are the perfect way of keeping elephants away from trees when one of the big animals has ripped off that bark they can fall prey to other assailants like termites in the villages around the park people have little experience with bees many are afraid of them and attitude running to calais is working to change he plans to start keeping bees in his village and to train some of the local residents as. we've heard.

from a. lot of these. producing honey about the can. go. back inside the park the conservationists have found another way of reducing elephant numbers in problem areas they've laid dry a number of watering holes that means the elephants have to keep moving to find fresh water relieving the pressure on the local ecosystem but smaller parks don't have that option so there is growing interest in the results of robin cook's experiments with bees he believes it's a groundbreaking method with huge potential but we would love to see it applied to new species particular. species which elephants are often such as the bat species and then to see if it can be applied to other projects such as the vault and this project to see if we can protect trees with faults in this in them using african honey and whether that relationship. they should soon find out the first

times already in place if it all works out the bees could in future protect not only trees but also the birds and animals that depend on the trees for their survival. that's all for now the next time we'll look at spiders as a creature many of us are afraid of but scientists say protein from a spider's web provides the perfect substrate for growing hard cell tissue that and more on the next edition of tamara today see that.

africa. coming president. of the modern major organ from. the rebel army and to the ninety four genocide wasn't doing well in the hopes it wasn't wearing clothes given you. need to reinforce the. a controversial leader

whose success is beyond question a good time to come on the wanted tragedy in seventy five minutes on t w. when the marginalizing people fight for survival the indicates that i get it but if i give up when there's a flood the water comes up to buy new clothes fast to everyone me but. the lack of water is equally dangerous. there's junk you can't see it will move south so they can plant crops and find food. floods and droughts will climate change become the main driver of mass migration you could not write any kind of peace not if you want and probably most of them to come to. the climate exodus starts if thirtieth on t.w. . during the civil chain reaction of the greatest. began around

six hundred years ago. in the renaissance the revolution in fawcett enabled us mentions that people became aware of their abilities and strengths in a new way there was an outpouring of self-confidence and. architects. scientists. and artists. are going to be invented completely new things and topple the ancient giants who had originally been its teachers even to. the culture of out of the darkest milliners into a new place. the red. stars of people twenty second m d w.

this is news live from berlin protesters in sudan demand an immediate transition to civilian rule pressure from demonstrators has already toppled two presidents in a week but the people want democratic leaders not military old. also coming up officials in southeast asacol plead for more aid after cycling

a month after the storm the u.n. says hundreds of thousands of people are still at risk. the squalid conditions facing palestinian dress.