you know our duramax theory is that that kind of violent society like trying something. i love even if she was a specimen looks like a stuffed swiss like me despite says the 15 nations 50 stories and 50 very personal tips on berlin's very best features. books now in atlanta currently on g.w. . welcome due 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 it. we need out of it. 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 it's the life cycle of an ordinary water bottle show. plastic bottles are made from petroleum light particle and can be found pretty much everywhere. clean globally every single minute of the day a 1000000 are sold. placed end to end the plastic bottle.

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 re used 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 30000000 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 smell 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 all fresh seafood. is that really something we want to eat. it doesn't sound tasty from honey to sea salt to beer tiny bits of plastic have been detected in many fruit so far though surprisingly little is known about the impact of micro plastics on our health researchers are taking a closer look. at how dangerous are

micro plastics to human health. professor thomas brownback is researching the effects of micro plastics on different fish can the particles permeate the intestinal wall of these fish and reach other organs that 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 the variables such as the multitude of different types of plastic. 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. what has been that means generalisations about micro plastics are commonplace when the issue 1st the roads are not really legitimate. there's a range of factors to take into account when analyzing particles the 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 was barely big enough for experimental purposes it might be enough for an in vitro experiment with a cell culture where you only need small amounts but for an extended exposure of fish larvae you need a lot more material. over a tubing and university professor peter trips cohen is similarly wary of sweeping generalisations about micro plastics she is trying to find out how polystyrene particles affect trial grow and the larvae of non biting midges she works with 1000000 particles police or 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 very dense 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 sand. i think that will be a key issue and one where results can be relative especially with regard to high concentrations. 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 a fish the experiment fails to provide evidence that micro plastics are absorbed by

fish or humans. popular really bright spots on the micro particles that go 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 forgotten 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 in pollution it's lies that. i thought oh i see no grounds for general alarm. professor tweets going 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.

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. class is a more environmentally friendly alternative to plastic packaging but it also has drawbacks it's heavier and it's more fragile. i'm a programmer 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 so the ash lime and often recycled glass it's all crushed together and melted but well over a 1000 degrees celcius. when the molten must 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 really survives a fall. says. 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. but the outside remains warmer creating a strain inside the material small fractures for months 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 oscillate 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 deception. if outlet is red white i mean. do you have a science question send it to us there's a beauty oh text or voice mail if we answer it on the show we'll send you a little surprise as a thank you just ask. 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 smart from mr google always answers all my questions. so it's either one terrible tear on also plenty of time online about 6 hours a day she reads messages and posts on what's up and facebook looks things up on google or watches videos on you to. meet you sophie who's 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 here and he posts now and then and shows how much time they spend a day unless mark phones i mean 3 hours. i mean you know if you're with me it's

between 4 and 6 hours. and 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. my. question montauk is one of a handful of researches in germany systematically researching the impact of online media he believes we need to improve our grasp of social media and use it constructively rather than being in slaves buying it social media companies you 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 their own version. such as the instagram haunt. as far as an isolated. every single like my posts get because i put a lot of work into them like so basically instagram's currency be able when in fact

. costs the next it's essential to social rewards and it's relatively clear that this simple thumbs up leads to increased activity in the brain's reward system to deter the students do. something researches can see and scans a high number of likes activates the same parts of the brain is eating cake or 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 our 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. at some point or something we later regretted it or something we might do if we're

feeling good and think hey i'll treat myself looks woman components a ha 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 a 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 fuses. and 2012 facebook conducted an experiment with 600000 users without their knowledge group they found primarily positive emotional content in the news feeds and group being primarily negative emotional content users in 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 users simply logged on less. companies have a vested interest in finessing their platforms so they conduct similar tests with

thousands of users who have no idea they're part of an experiment. as the ultimate goal is to keep users logged on for as long as possible in the movie. strategy that evidently working in the case of catalina and philip. been staring at my screen for ages i'm always really hurt and i know i've been on the phone too long but i see the time and say it's 1 in the morning time to call it a day with a view for. example number 3. to refresh a function that keeps us well and truly 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. thus a start that doesn't happen with these tech platforms if they're on youtube 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 and it does miss posts 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 cellphone 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 then you also. so there's at least one hour of the day when we can have an actual conversation with him to come and also take the opportunity to just switch off. 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 in entertainment in museums architecture and many different industries. technology overlays digital information onto the real world it's already expanding the rhizomes of medical education and surgery. 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. that they're using augmented reality glasses at software recognizes the surgical instruments and provides instructions. play video. voice command. scalloped information displayed in their headset such as step by step instructions on how to set up and

use the various surgical instruments next. back to the brain 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 order of operations can now also help special operations systems. and high tech operating theatres it's not uncommon for the surgical instruments they are all that familiar with using augmented reality glasses and means they don't have to spend hours reading instruction manuals. you know. we request that the instruction manuals for surgical instruments be available

in the operating theatre 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 and. the team of computer scientists at munich's technical university are world leaders in the field of augmented reality applications in medicine and surgical instructions 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 a patient. do know there is a narrowing of artery there is more it can be that it's location inside the body so why localizing intelligently correctly and

visualizing it correctly in our 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. really was a few minutes spent if you're measuring in the structure i think of. being used on an everyday 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 in the 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 nasir nava. it's called the magic mirror and is used in the teaching of anatomy it can generate 3 d. images it can also generate 2 d. cross sections of the body instead of learning anatomy by dissecting it could have or they can study it 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 is. this kind of work with augmented reality also helps prepare medical students in munich

for the clinical practice of the future. to realise preclusion. to work with patients. real solutions using code mounted display we're going to do your duty photo printing room they would be ready to to use it because they are complicated from. the medical students also get to work with the augmented reality surgical class since it's display replace is the magic mirror each student can study the inner structures of the body even when they're working in large groups but in a new book a couple there are often 10 or 12 of us got that around a real corpse in anatomy class. but with small glasses we can all see each muscle full scale courses. granted reality is set to transform medicine.

anatomical models that get up and walk away are just the beginning. that's all for today trying our next hero we meet alexander often on book in 1799 he set off to explore central and south america the natural scientist and humanist he traveled not recount quest but to learn and he always had his plan ready to record what he found join us next week as we retrace his journey until then good bye.

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restraint. also coming up the us president donard.