when i was asked. is the world really getting better. a global $3000.00 special reports. starts august 19th sunday to. welcome tomorrow today the science show on d w coming up are micro plastics harmful to our health scientists are studying fish to find out more. clicks shares and likes what makes social media so addictive. and. doctors with headsets how augmented reality is changing medicine.

we play with a. lot of it. we even sit on it it's hard to imagine modern life without plastic almost 350000000 tonnes were produced worldwide in 2018 but plastic pollution is a serious environmental problem as the life cycle of an ordinary water bottle shows . plastic bottles are made from petroleum that light particle and can be found pretty much everywhere. globally every single minute of the day a 1000000 are sold. placed end to end the plastic bottle sold in 2016 would form a chain stretching all the way to the planet mercury. so you've bought a drink in a plastic bottle and finished it what happens. next. in an ideal scenario it will

be reuse some can be refilled up to 15 times if they're washed properly most are not sturdy though. many end up in a shredder where they're ground up into flakes of plastic. these can be used to make products like fleece clothing very nice except for the fact that every time the fleece is washed it releases plastic particles into the water. as for the rest of the plastic bottles they get thrown away dropped right in the street or somewhere out in nature a large number of them land in dumps or are eventually carried out to sea. between 5 and 13000000 tons of plastic garbage end up in the ocean every year a huge problem because plastics can take up to 450 years to decompose. if plastic trash doesn't get caught in propellers on ships or isn't washed up on a beach then the floating pieces grow smaller and smaller as they drift with the

currents. algae grows on their services and that smile draws fish and sea birds they think the particles off food and swallow them when too much of it collects in their stomachs real food no longer passes through and they starve. and if those fish end up in our nets they enter our food supply directly be the rest canned or fresh seafood. is that really something we want to eat. it doesn't sound tasty from sea salt to beer tiny bits of plastic have been detected in many foods so far though surprisingly little is known about the impact of micro plastics on our health researchers are taking a closer look. how dangerous and micro plastics to human health. professor thomas brownback is researching the

effect of micro plastics on different fish can the particles permeate the intestinal wall of the zebra fish and reach our organs their digestive system is very similar to ours. obviously we're just as interested in how fish are affected by micro plastic particles in the outside world in rivers lakes and other bodies of water in the back of our minds there's always the hope of learning something about the potential affair. it's on humans. but on back adds a fluorescent substance to the micro plastic then he feeds it to small cross stations that fish feed on micro plastics research is still in its infancy and the vast array of variables is a headache variables such as the multitude of different types of plastic. plastic. like this has different properties to a micro plate like this. which is very firm but also totally clear totally transparent. so we can expect their plastic particles to cause different effects.

if they. would have been that means generalisations about micro plastics are commonplace when the issue 1st arose are not really legitimate i. start off. there's a range of factors to take into account when analyzing particles their size alone varies enormously any plastic particle up to 5 millimeters in diameter is defined as a micro plastic in this case there are around 10 micro meters the surfaces of particles also very elaborate particles have smooth surfaces whereas those exposed to the elements outside are rougher but collecting particles in nature would be too time consuming and expensive. it's possible but only in really small amounts which would barely be enough for experimental purposes it might be enough for an in vitro experiment with a cell culture where you only need small amounts for an extended exposure of fish

larvae and you need a lot more material. over a to begin university professor peter trips corn is similarly wary of sweeping generalisations about micro plastics she is trying to find out how polystyrene particles affect trout row and the larvae of non biting midges she works with 1000000 particles of water as a standard what's new is reducing the concentration to levels found in nature to own. 10 particles police that's why previous research results shouldn't be extrapolated into general conclusions says professor. the problem is that when we get an effect with a 1000000 particles a liter we shouldn't start screaming that it's bad for the environment or for trout it's not environmentally relevant. because water air and soil are already full of natural particles does comparative experiments using clay problems may be caused

more by the number of particles than the substance itself a possibility that was previously neglected this is vents if you get caught in a sandstorm you're also affected by tiny particles. and then they get into your lungs it doesn't have to be my plastic it could be send. us i think that will be a key issue and one where results can be relative especially with regard to high concentrations. back in the fluorescent agent makes the micro plastics visible in the cross stations which are now fed to the fish despite many trials with a number of variables no micro plastic particles passed through the intestinal walls of the fish the experiment fails to provide evidence that micro plastics are absorbed by fish or humans. are really bright spots on the micro particles straight out the back and left the fish inside 5 hours. so was it all

a false alarm well partly so far tests of only covered relatively large particles. still can't say it's safe in particular because it's also possible that nano particles form and they would probably be absorbed by tissues and we don't know what would happen after that. so one widespread suspicion is that micro plastics helped to spread pollutants this experiment shows fish larvae in water that also contains a nerve toxin and micro plastics will the micro plastics transport the toxin into the larvae the larvae begin to twitch a typical reaction to a nerve talks in. the entire body contracts because of the toxin absorbed by the micro particles. the toxins also get into the fish without the micro particles except it takes a bit longer. so outside in nature it's rather unlikely that

micro plastics are significant additional factor and pollution it lies that. i see no grounds for general alarm. professor cohen also says people shouldn't panic she found no evidence of micro plastic damage in either trout eggs or the non biting me. there are however initial indications of a health related impact with her german brown trout the freshly hatched fish whose eggs were exposed to micro plastic are quicker to stretch out into a swimming position although only in particle concentrations 100000 times higher than they occur in nature. there's still no evidence that micro plastics in the environment have any harmful effect on humans. we didn't this is. based on current knowledge i think we can relax a little but not get too comfortable we need to focus on issues that are

environmentally relevant with. the sheer diversity of micro plastics means we're currently in no position to make generalisations but researchers do say they know one thing that whatever the case the vast amounts of plastic waste circulating in the environment have to be reduced. classes are more environmentally friendly alternative to plastic packaging but it also has drawbacks it's heavier and it's more fragile. from morocco has a question about the. why does glass shatter. let's 1st take a look at how this transparent material is made. the usual ingredients for

commercial glass are sand soda ash lime and often recycled glass it's all crushed together and melted but well over a 1000 degrees celcius. when the molten mass cools it undergoes a transformation into a tough but amorphous solid meaning it can be shaped into everything from bottles and drinking glasses to window panes. while other solids like metals may be pliable and flexible glass is hardened brittle. when it's put under too much pressure it doesn't deform it breaks. and for that reason it rarely survives a fall. or a big temperature difference between say ice cold water and a hot glass bottle while filling a cold glass with boiling water is likewise not a great idea.

unlike metals glass is a poor conductor of heat. so if you pour cold water into a hot glass the inside surface of the glass contracts. with the outside remains warmer creating a strain inside the material small fractures form and spread causing the glass to break. glass can also be shattered by sound when of the right frequency the sound has to be very loud and sustained over this to work. when it is the glass begins to also late rather like this bridge and that can result in what's called a resonance disaster amplifying the oscillation and causing the glass to break.

the glass will also break more easily if it has a flaw such as a tiny fracture or material weakness. and if that doesn't work. there's always this option. if outlet is right why i mean by only thing i. do you have a science question send it to us there's a beauty o. text or voice mail if we answer it on the show we'll send you a little surprise as a thank you. just as. you'll find us online and on twitter and facebook and we had a question for you too on facebook we asked. how much time do you spend on your smartphone and what do you do. i don't even know what it feels like without a smartphone mr google always answers all my questions. so it's either one

card or tehran also spends plenty of time online about 6 hours a day she reads messages and posts on what's out and facebook looks things up on google or watches videos on you tube. or you sophia is also a fan he's on facebook a lot usually until midnight. but what's behind our craving for social media. catalina and phillip a typical of the social media generation she has an instagram account devoted to lifestyle topics. posts now and then and shows how much time they spend a day unless mark phones 3 hours. i mean with me it's between 4 and 6 hours. i'm trying to cut down a bit even if i just want to check something quickly i end up spending half an hour

on instagram or wherever. is one of the handful of researches in germany systematically researching the impact of online media. believes we need to improve our grasp of social media and use it constructively rather than being inflated by it social media companies use sophisticated methods till you are in users and keep them. here are 3 examples 1st the like button facebook invented the thumbs up idea 10 years ago now all social media platforms have that inversion. such as the instagram haunt. as far as an extra day appreciate every single like my posts get because i put a lot of work into them like so basically instagram is currency on instagram. it's essentially a social reward it's relatively clear that this simple forms up leads to increased

activity in the brain's reward system. something researches can see in scans a high number of light activates the same parts of the brain as eating cake terms taking drugs as it happens facebook and co have plenty of insight of their own into our brains as evidence by a leaked internal document facebook's algorithms can analyze. online activity to determine when we feel worthless insecure and anxious and that allows advertisers to pinpoint when we need a confidence boost and therefore target us more precisely. we want some point bought something we later regretted or something we might do if we're feeling good and think hey i'll treat myself my looks woman convince. me of what that means is that emotional stimulation can often lead to irrational behavior

and i might be more inclined to do some impulse buying. and social media companies they keen to spark an emotional response in new zealand and they can test how to do so for free for example number 2 by experimenting with users. and 2012 facebook conducted an experiment with 600000 users without their knowledge group 8 found primarily positive emotional content in the news feed and group being primarily negative emotional content using group a went on to themselves post more positive content while group b. wrote negative posts if there was no emotional content in their feed at all uses simply don't last. feel. companies have a vested interest in finessing their platforms so they conduct similar tests with thousands of users who have no idea that part of an experiment. but the ultimate

goal is to keep users logged on for as long as possible not saw. the strategy that's evidently working in the case of catalina and philip on i've been staring at my screen for ages i'm always really hurt i know i've been on the phone too long but i see the time and say it's one of the morning time to call it a day with a view for. that's example number 3 pull to refresh a function that keeps us well and. stuck to our screens. in our day to day lives the activities we engage in normally have a beginning and an end for when we finish them we can cross them off our list and move on to the next thing some form of it man. just a start that doesn't happen with these tech platforms and if they're on you tube prigs sample once one video ends another one starts like this next so when we're using these platforms we can theoretically just keep scrolling endlessly. and the

more we do so the more data the companies collect on us which they can then parlay into advertising revenue if it does mistress here to prevent that from happening and it can happen very easily i set myself a deadline that after 10 o'clock at night i put my cell phone away and either read a book or got a bad name when i 5 and oh yeah. if we go out for dinner then we both try not to get our phones out but also. so there's at least one hour of the day when we can have an actual conversation going to come and also take the opportunity to just switch health. but don't switch off just yet another kind of digital technology is taking off augmented reality is making inroads in all sorts of places intertainment in museums architecture

and many different industries. they are technology overlays digital information onto the real world it's already expanding that arises of medical education and surgery. where deep in the basement of the munich university hospital a team here is working on the future of surgery but they aren't doctors this simulated surgery is being carried out by computer science students the technology they're developing could revolutionize surgery. they're using augmented reality glasses at software recognizes the surgical instruments and provides instructions. play video. voice command. scalloped information displayed in the headset such as step by step instructions on how to set up an use the various surgical instruments . back

room and. play video. users can ask for more explanatory videos graphics and photos. the system means everyone knows precisely what they have to do where and when. surgical assistance to not only to. assist during alter operations can now also help special operations with the system. and high tech operating theaters it's not uncommon for the surgical instruments they aren't all that familiar with using augmented reality glasses means they don't have to spend hours reading instruction manuals. in the parks either so we request that the instruction manuals for surgical instruments be available in the operating theater instrument then we check there then how the instruments are put together. that is not an unrealistic

scenario it happens very often so i can imagine that this new system would make the job significantly easier business with. the team of computer scientists at munich's technical university are world leaders in the field of augmented reality applications in medicine and surgery constructions are just the beginning one day doctors might be shown a are images overlaying their patients would allow them to see inside the body the organs vessels nerves and tumors. the doctor can directly feel in the patient. block for over there the know there is a narrowing of artillery there is more it can be that it's location inside the body so i think intelligently correctly in visualizing it correctly in your demented reality we're hoping that we would

improve the health care. to make that possible the software we need to integrate. data from regular x. rays cat scans or m.r.i. scans to generate a precise 3 d. image super imposed inside the patient's body the doctor would see a 3 d. image of the bones inside the leg and use that information to for example attach an artificial knee with much greater precision. and with really was a few that they are making in this direction i think very soon. the being used on them every day basis. such complex technical developments in the field of medicine have to be thoroughly tested before they can be used on patients so it will likely be a few more years before augmented reality is deployed and knee replacement surgery but it's already being used to train medical students. at munich university hospital they're already using software developed by the team

led by nasa. it's called the magic mirror and is used in the teaching of anatomy it can generate 3 d. images they can also generate 2 d. cross sections of the body instead of learning anatomy by dissecting you could have or they can study using augmented reality. we can't do this with a human body we can't cut one into slices with this technology we can examine the topography of each organ and where exactly it is. and the advantage of integrating magic mirror into this course is that the students can investigate their own bodies and find out exactly what each blood vessel it's. this kind of work with augmented reality also helps prepare medical students in munich for the clinical practice of the future to. be good to

realise preclusion. to work with patients. rehat solutions using 3rd mounted display were going to do your duty for the operating room they would be ready to to use it because they are complicated from the neighborhood that . the medical students also get to work with the augmented reality surgical class since its display replaces the magic mirror each student can study the inner structures of the body even when they're working in large groups of the new look it up but there are often 10 or 12 of us gathered around a real corpse in a not to me class. but with small glasses we can all see each muscle full scale courses of. augmented reality a set to transform medicine. anatomical models that get up and walk away are just the beginning. that's all for today

trying our next show we meet other xander for norm book in 1799 he set off to explore central and south america a natural scientist and humanist he traveled not for conquest but to learn and he always had his plan ready to record what he found joining us next week as we retrace his journey until then good bye.

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cut. on. this is d w news coming to you live from china gives a rare news conference addressing the un rest in hong kong the move comes after another weekend of violent clashes between protesters and police in the territory also coming up a doctor for russian opposition leader alexina bonnie says he may have been poisoned upon he was rushed.