w. . why do you say it's all this way to bring you more conservation. how do we reach super screen or how can we protect have a chance we can make a difference. for a genius or a mental series akin to folsom d.w. and all morning. we leave traces everywhere and everything we touch. even when we breathe. most of the time these choices are invisible but they can still reveal a lot about us for example i think the prince and the proteins in our head. since the start of the coronavirus pandemic we've had to contend with the loss of these invisible traces we leave behind. viruses that are exhaled into the air for example . which have turned our world upside down.

join us as we play detective on tomorrow today the science show on d w. images like these have become the new normal people queuing to get tested for covert 90. the tests are meant to get the pandemic under control and better understand the spread of the disease. there are 3 space it approaches the antibody test detects a past infection and requires the blood samples. the blood is tested for antibodies that would have been produced by the immune system during the illness. the other 2 tests are meant to detect a current infection of cells kovi to. the antigen test requires

a swab from the back of your nose or throat and detects protein it's one of the surface of the virus. the results are quick but not as accurate as a p.c.r. test here you also need saliva or a nasal swab. these tests are engineered to identify genetic material called r n a. the p.c.l. a test is the most reliable. but it takes up more time and resources and so it cannot be easily used for mass testing. but pool testing for the virus could change that mathematicians in rwanda have now developed an algorithm to do just that. in the fight against the pandemic we wonder coronavirus task force relies on

comprehensive contact tracing. to get an up to date picture of how much the corona virus has spread the wonder regularly tests a cross-section of the population using an ingenious strategy called pool testing. the brains behind this strategy is professor wilfred defun who is director of research at the african institute for mathematical science or a i.m.s. global network. that's why if you go to the community and just people it doesn't tell you how many people are actually infected because you're going to everybody so you always sample and sort of go from the sample to the truth to reality you need my mind to go more those. are the calculations involve complex algorithms and define has translated them for us into an example from everyday life. the idea of

your important thing is really simple so imagine that you have 9 cups of beans and you know 2 or not all of those god has by bins and in order to church which core part of the bible is you was cool beans and best so you might find that the abuse that is bitter those who are being is there not only takes a long time for beings to go away and so use a lot of gas if you're doing 9 cooking main ports of beans. the mathematician resorts to a simple yet effective trick he combines been samples from different parts of it all the beans in this sample pool are good he no longer has to test each part individual he only has to perform additional tests if there are bitter beans in the sample. the principle can be applied anywhere you can create groups for testing that's why it can also be used to combat covert 19.

in rwanda sets of 10 and 20 samples are combined and tested simultaneously. if the pull test result is negative all the subjects in the pooled sample are declared as not having coded 19. if the pooled result is positive then each sample is retested individual. the advantages of their pulling out parties just to reduce the cost spend to the for the adults to do the turnaround time for the vote for results and also to test the massively in the community also the group does. which are that course and for the community so those are the men admitted is for this. but if the virus has spread dramatically pulled samples test positive too often and retesting becomes costly and time

consuming so far however africa has low numbers of cases compared to western countries and the method is proving useful there this is really hurtful for the african countries but not on the african countries even for the roping countries since we do love this and the problem is the. pulling up close tonight a paper route so we have been approached by similar countries. ghana and kenya are now applying the strategy to group testing enquiries have also come from the us and the university of edinburgh in scotland is using the method to test its students the method actually originated in 1903 american economist and researcher robert dorfman was the 1st to develop tool tests to screen u.s. army soldiers more efficiently for syphilis since then the strategy has been further developed and is also used to test for other sexually transmitted diseases

malaria and blood banking there's a lot of interest in this approach i think it's it's a no brainer that we need to be. optimizing the use of resources. to develop the method the cameroonian collaborated with his rwandan colleague tessa and a.m.'s founder neal to rock it's a pan african response to the continent's challenges. it's really extraordinary that you can write on the board so many questions and no tell you how. this is so spread in a population how what happens when you truly blown. out what happens to cars how computers work so all of these are my markets on the. resort of people just investigating doing analysis trying to understand better how things are around and work. the a ins network places great value on training young scientists across the continent

so they are confident that the next albert einstein will come from africa training young people to how to obvious knowledge and this ability to smarts to solve problems is wonderful and i'm very proud to be associated with this vision to be helping to drive it forward. book of it dawned on me for example as the room proof that this is vital thing to do. did you know that p.c.r. technology which detects. virus is the basis for many other tests. it's used to amplify specific d.n.a. regions such can be analyzed. d.c. also produce a breakthrough in forensic technology has made it possible to reach and this information from the smallest human traces this genetic fingerprint can be

invaluable information at the scene for crimes. on t.v. shows solving crimes always look so easy clues. however tiny are soon analyzed and lead directly to the perpetrator. in real life things often look quite different. this is the state police forensic science institute in kiel normally crime scene technicians go to a crime scene this time it's come to them then i would guess the photographer could come in with us to take a few pictures of the crime scene that will make it easier for us afterwards to. the 1st step is to look for fingerprints cupboards have been ripped open the interior is a mess it looks like someone has ransacked the mobile home. under the table there's a knife with a bloody blade. everything has to be documented and photographed where it's found

later it will be studied in the lab. a crime weapon but no victim whose blood is it. what investigators do what a crime scene is gather evidence as much as possible. even things that look irrelevant can prove to be extremely important. person in by what we found a small piece of paper on the floor between the front and say it's a candy wrapper have we secured it because it doesn't look like it belongs here it looks more like it might have fallen out of a pocket and under the table we found a knife that appears to have traces of blood so the knife is of interest not only for fingerprinting but also for d.n.a. analysis and possibly for any fibers sticking to it as well or definitely the pretty fast. there's a fingerprint on the candy wrapper but it's faint and incomplete this clue would

once have been impossible to analyze today however it can be enhanced by a process called sputtering. the wrapper is exposed to vaporized silver in a spotter in kota. the silver condenses on the wrapper highlighting the fingerprint the technique was developed here at this institute just a few years ago. a photograph of the fingerprint is then digitally enhanced it's now so detailed even sweat pours can be seen as tiny white dots on the lines of the print. there is indeed a fingerprint here right above the lettering that means the spattering has performed a small miracle by coating the wrapper in silver the fingerprint is raised against the background and we can see it more clearly. so. i think we should apply the tape to the back of the say that. meanwhile fiber specialists have taken over the crime scene. first and foremost we have

to secure the evidence wherever there might be any fire that's of course we try to imagine where the pepper trader was and have a crime was carried out that's our main focus but in principle we have to secure everything because we can never really imagine exactly what happened before and we just have to figure out if. even the slightest contact with upholstery is another to transfer fibers garments shared fibers all the time the nearby improve on have if the 2 of us were wearing pullovers and i hugged her or we rubbed against each other on the bus my fibers would get on her and hers would get on me and. everybody carries a distinct a mix of fibers around with them mostly fluff from their own clothes. fibers from a crime scene can't lead to the perpetrator by themselves crime scene technicians also need to compare them with the clothes of

a suspect. then they can tell whether or not it's fibers match ones from the crime scene. this involves picking out relevant fibers among found. of others. to ascertain the 1st thing i do is look at all the colors through the microscope magnified say 250 times i look at by 3 colors in the shapes of the individual fibers to say if it's them or not i'm i'm like a bloodhound on the lookout for a single fiber in this case i'm only looking closely at the red ones i mentally block out the others otherwise i go crazy doesn't really france and. once the visible clues have been identified and analyzed it's the turn of the invisible ones the expert in invisible clues needs breathing equipment and total darkness. the chemical he sprays lights up for

a few seconds wherever it's in contact with traces of blood hand prints appears next to the door and smears of blood along the side of the vehicle. is going to go through it all the evidence here is compatible with a person exiting the mobile home and moving perhaps injured unsteady on his or her feet and finding support along the side of the vehicle this is. it turns out things are not what they appear the police officer had left the wrapper in the mobile home and the fingerprint was hers. the fibers were indeed from that red pullover but it belongs to a colleague in the lab. and the blood on the knife came from the butchers around the corner so there was no crime it was a dummy run at a training exercise an internal police matter still the perpetrators are making a getaway taking the scene of the crime with them.

for almost 200 years now photographs have captured fleecy moments originally and black and white. soon it became possible to duplicate photos using a negative to make more prints each point of light became a dot in the image a lot of data to capture a moment. on 1st has faded with time but what about digital photos otoh i can from ghana had a question about. how long can data be stored. humans have recorded their languages and their knowledge in the form of drawings and symbols since prehistoric times. on the analogue data carriers from back then play tablets or stones much of the information survived for thousands of years. as a result of these ancient data carriers can be read and decoded today.

modern storage devices can carry a lot more data even though there are a lot smaller. but the lifespan of most c.d.'s and d.v.d.'s is estimated at less than 100 years. data that's stored on the kind of huge servers operated by large companies should theoretically last forever as long as the days is repeatedly copied and as long as defective hard drives are replaced. in order to keep the ever increasing amounts of data under control researchers are developing smaller and smaller storage devices in the future synthetic d.n.a. could replace conventional data carriers. these artificially generated genetic strands would have more than a 1000000 times the capacity of modern hard drives. on the reconstruction of neanderthal d.n.a. as shown the d.n.a.

molecules are still legible after thousands of years. another method of storing data in courts is 5 d. technology uses namo lasers to write information into 5 dimensional fused. mind boggling speed. these glass just the size of coins can store up to 360 terabytes. and they last a very long time to turn 18800000000 years. whether or not there's someone in 13800000000 years who can read the data is another question. $0.59 or binds the $59.00 with $21.00 zeros that is a lot of data and it's the amount estimated to have been created captured and consumed by the end of 2020.

in the next 4 years the amount is forecast to almost triple. in order to preserve the information it has to be constantly copied and uploaded onto new data carriers plus anyone can get in on the act producing more and more data. for example it's estimated that in 2020 over a trillion digital photos were taken from. data that is meant to capture memories. we asked our viewers what data would you save for ever and how. your rides your wedding day the moment of birth and anything to do with love so how romantic. it says here is a little more pragmatic we should preserve our knowledge of metal working as well as plants and seeds on a floppy disk in order to ensure food security in the future. mohamed recommends internal rather than external storage writing i want to store everything in my

brain we tend to lose the ability to remember things as we age hopefully in the near future we'll be able to upload data to our brain. finally randy writes his most interested in saving images thousands of family photos and videos from birth to wedding 2 grandchildren in his case 50 years or 28 terabytes intentional thanks for getting in touch. with. a snapshot can only capture so much of the person but these days it's possible to bring old photographs back to life all of a sudden subjects can move their hands. uncanny even if it doesn't look quite natural. legendary scientist marie curie is among those who have been given this kind of treatment in her case there's no doubt that this video isn't authentic with people who are still alive telling real from fake can be more

challenging. these days all it takes is one photograph to create a fake video in no time at all that's pretty impressive. 'd with the help of artificial intelligence research is can now bring any photo to life in under 3 minutes manipulating the image remotely. these examples took just a few minutes to put together and they show what this technology is already capable of. team of specialists chiefly working on ways to automatically identify deep fakes like these these detectors will be crucial in the future. also the fake detectors are not going to be perfect but they will be able to detect the majority of the deep content that is going to be distributed and in many cases this is good and what is important that the solutions have to be done in such

a way that they can reinvent themselves and evolve as the technology for the pricks . the fake so also an issue and. busy. it's becoming increasingly important to track down fake images in cases of insurance fraud for example. image analysts are researching ways to spot the markers of a phony image. intelligent image recognition software is fed countless fake images and videos and learns how to recognize anomalies. assoon as clear markers are detected a red box indicates that something has been manipulated. if you look at the plate technology 6 months ago a lot of the video was very very easy to detect they were distorted you could immediately see there's something wrong with if you look at them today they are at the verge of becoming very believable is becoming more and more difficult to detect

whether video is fake or not. it's a matter of 3 to 9 months before 99 percent of people when they watch fake video they wouldn't know that it is fake a bleak prospect or fact checkers fortunately fact checking company many common doesn't yet encounter deep fakes every day but without new detection tools expert is pessimistic. my hope for the future is that as more deep fake technology emerges the people tracking the fakes will have better tools to recognize the fixes . because so much misinformation is spread so fast on social media users will have to raise their game using the fact checkers golden rules. i'm functioning as i firstly does oneself i have to know myself in the media i consume that's very important. if you fall for something from

a media source that you trust deeply then it becomes difficult next just to see who's writing where something comes from so you need to master search engines clearly. i need to know how search engines work and be able to do comparative searches on top of that of course is the search for images so-called reverse image search finally speed up the rate of information consumption and if something sounds overdramatic then maybe it's better to ask people who know about us or to bypass when you started our skin but that alone is not enough more education is also needed. not to be a dozen of course we want something to happen in the schools now comes the big bucks are always shouting that schools need to do something yet we're saying that there's so much fake news on facebook this is a problem young people are not on facebook says it's the 35 to 55 generation and now we've identified the core of the problems and we're not doing enough educational outreach to adults facts. ok let's give it

a go what do you make of this video it was like ning striking a train track well it's a fake pay close attention to the trajectory of the flash it should really have some burn marks in its wake but there's not a trace also the camera operator is way too calm and steady. but there's also a clue in the title of the video here cd i computed generated images clearly faked . some also granted this video with a woman doing iraq in the middle of the military takeover in myanmar. so what do you reckon or is it real or fake. i'm just shadows seem to suggest it's a fake they seem very truncated but if you look more closely you'll see that there are steps behind her this supposed to be located at the royal lotus roundabout in

myanmar comparing the image to that in the video reveals the markings on the ground the street the flower pots are identical in the video the silver posts must have been installed since the google image was recorded in 2018 or so the location appears plausible and the shadows of the downs and that of the cars match. the lighting is the same so this video is no fake. because it is red white i am very glad only very few. do you have a science question you'd like us to answer. send it in as a video text ovoid snail if we feature it on the show you'll get in little surprise from us as a thank you come on you just ask. and

for more exciting stories check out our website or find us on twitter. that's all for now thanks for joining us on tomorrow today. will be back next week with more fascinating stories from the world of science and technology until then by.

its discovery was groundbreaking at the same time it was the beginning of unimaginable destruction. the thomas. whenever something goes wrong all laid down and hostile. to the industry and me because america hasn't. the energy our friends come. to. w.

. the fight against the coronavirus pandemic. the rate of infection been developing. what measures are being taken. what does the latest research. information and context. the coronavirus up to the go to special monday to friday long t.w. . they want to know what makes the jealous give just jump in love and banning the way. i live in other words my own daughter and everyone with little holes in everything they're getting are you ready to meet the germans then join me right just do it under a

w. one we take steps to restore a forest we play a vote in the something much bigger. when making a better world for our health and for the health of future generations. by replanting and managing the forests of stanley we create new spaces where plants and animals comprise become an economic activity that brings work and improves lives we make a real impact on climate change we improve the quality of the air we breathe the food we eat and litter we trade with create the environment for our children to grow it's never too late to take action let's restore the forests and create a better future.

to get. the be the big . this is to give you news live from berlin an outpouring of sadness and anger people defying a ban on gathering to mourn a woman murdered while walking home in london and a call for more safety for women in public places. and more locked down for large parts of italy after surging infection rates one of europe's hardest hit countries reintroduces tough restrictions. and then bundesliga football the defending champions byron munich showed they're still the team to beat and travel to bremen on saturday and easily took down the home team.