spirits and explore resonated with cultural heritage sites. d.w. world heritage three sixty. i'm not laughing at the germans a number of them but those they're laughing with the german i think they've in the german culture. muted seem to take their grandmother their own belief because it's all about who they know i'm rachel join me for me because everybody of course. means. hello and welcome to tomorrow today the d.w. sign show coming up. the time inside as an internal clock ticks in every one of our cells how do the bodies timekeepers we're. getting out of sync with our by rhythms can brought us of rest

a sleep study shows what that does to us. our internal clock also determines when we're peak performance which times of day a best. we have some power over clocks at the end of march europe will be setting the clocks an hour ahead to daylight saving time the first time the clocks will switch like that was in one thousand nine hundred eight in a small town in canada the two world wars put the change to summer time over to europe the idea was to utilize daylight hours better for the weapons industry. in the one nine hundred seventy s. came the oil crisis europe figured it could save energy with the time change but that didn't actually work as we now know. today some eighty countries change their clocks twice a year but our internal clocks can't be reset that easily. our

lives are often dominated by rigid schedules but ignoring your inner biological clock can be harmful it's known that early or late shift work is bad for you and daylight saving time can likewise cause problems. logical terms it's bad that we destruct our number that is twice a year yeah now i just can't concentrate i mean i get tired really tired just. to really feel it you just eat all the time at least. you can see in people's faces that. it all plays out against the backdrop of light and dark humans are a dire in all species which means we're mainly active during the day nighttime when we're protected from ultraviolet radiation is when cell division and regeneration occur this is something we share with single cell organisms most cells in muscles and other organs have their own clock genes these cause them to produce activity at

night and be active during the day so even if you choose to stay up late your cells in some sense know it's time to rest in fact wombs incurred at night he'll more slowly than those acquired during the day a recent study in britain provided clear evidence of that says chrono biologist. barbara blast cells alter their cellular skeletons in order to move the knots regulated by the cells in a clock they move faster at certain times of day than on. fibro blasts are central to wound healing on the left is a wound incurred during daytime where the cut closes fast on the right and one time around which closes much more slowly. head like a star and his team want to know how nutrition and metabolism affects one another if clocks in your intestinal tract and liver tick in harmony there's less chance you'll become overweight. if your gastrointestinal clock is thrown out of step

because you eat at the wrong time then your intestines and liver no longer work together as well as they should that leads to more energy storage units. being deposited in. the first results from the lab reveal that eating sugary meals late in the evening can disrupt the nighttime insulin response in your liver and if you need an alarm to wake up in the morning you're fighting your own circadian rhythm the people who do that most often are those who like going to bed late night out. typically human beings slowly grow more active after waking up a plunge in the early afternoon is followed by a second peak for those people known as early birds this pattern can begin much earlier where as night only really get going in the afternoon there curve is also shifted in the other direction. our society as

a whole gets up to. the majority. risers and they're always a bit at odds with the demands that are made by society. we each have a chrono that reflects when we ought to be getting up and going to bat early bird standard riser. and those differences appear to be underpinned by genetic variants by identifying the genes responsible researchers hope to develop blood tests with the capacity to detect individual chrono types and show where people are in their cycles at given times. that could help optimize medication schedules for patients for example we already know that some medicines can be more effective if administered at certain times. works best early in the morning some kinds of pain medication are more effect. it in the afternoon around ten at night is the best

time to take medicines aimed at allergies and dramatic diseases. but that doesn't mean everyone should take it at the stroke of ten night owl should take it later early bird so little earlier. if we can determine in advance when a medication works best then we can use that information to reduce the number of possible side effects and to fight disease more effectively. effective. research shows that chronobiology is more important than we once thought the idea of inner biorhythms isn't new age fantasy it has a major influence on health. if you're a late type it's of course better for your health to work late shifts rather than early ones because then you don't have to get up and concentrate on what for you biologically is the middle of the night. that doesn't work. regular

meals and passes between them also determine daily rhythms intermittent fasting restricting intake to say an eight hour block each day can have a big influence. on a biological terms intermittent fasting makes a lot of sense because the rhythm of intake and non intake synchronizes the peripheral clocks that stabilize daily rhythms improving interaction. for. daylight in particular plays a key role in setting natural inner rhythms so if daylight saving time is soon dropped in europe as planned most experts agree it will have a positive impact on health. our internal clock also tells us when to go to bed so-called clock in the brain regulate. electric light long work hours and shift work disturb them.

the best rested people in the world according to a study at the dutch they sleep an average eight hours and five minutes a night people in singapore sleep the least on average more than thirty minutes less than the recommended eight hours. what happens if we get too little slate. the finally a good night's sleep for nine days that was out of the question for ben all in the name of science and from that first it was a challenge not to fall asleep but the difference between before and after was very noticeable. a week and a half earlier than arrived at the german aerospace center in cologne to take part in a sleep study. eva maria conducted the investigation in come up. aeration with scientists

from the unit research center she studies the effects of chronic sleep deprivation most people think they get enough sleep. very many people get to that all sleep day in day out the current recommendations are to get at least seven hours of sleep per night to avoid damage to your health. what happens in the body when we get too little sleep to provide some answers ben and the other test subjects undergo a nine day long insurance test they're under constant observation they're often awakened after just five hours to do some tests. conic lack of sleep is the norm for many people in germany for example one out of four adults gets just six hours of sleep every tenth person only spends five hours a night sleeping. that can be many different reasons a heavy workload stress and a need to be constantly reachable mean that many people take time problems to bed

with them and miss out on. study shows how dangerous. for three nights in a row ben and the other participants have slept only five hours a night now a test will show how that affects their performance. to recall several lessons that he has already seen supposed to react when the letter. the researchers will compare his working memory capacity with that of well rested test subjects. and the ones who had a good night's sleep usually perform well on the test and the ones who aren't rested make a lot of mistakes. they either think the letter wasn't there or they lose the rhythm and have to start over during the test. people who regularly get too little sleep perform less well at their jobs that usually leads to more so. stress

resulting in more sleep deprivation some try to make up for the deficit by sleeping longer at the weekend but the test shows that doesn't work. there seems to be a kind of memory for chronic sleep deprivation if we regularly sleep too little and then try to recover by getting a normal night's sleep and we were able to show that those test subjects had a much more rapid decrease in their performance than other subjects who hadn't prattle on that sleep deficit. isn't. that effect may make working life more difficult for sleep deprived but it's not life threatening but another effect of sleep deficiency can be banned it's also taking a standard reaction time test as soon as he sees a running stop watch he's supposed to press the button the well rested group react within two hundred milliseconds as do the sleep deprived subjects and at least at first. but suddenly we also see very many slow reaction times mixed in

and if the person is really tired they may stare at the monitor staring with their eyes open at the running stopwatch but not reacting. the brain seems to switch and communication between the eyes and the brain doesn't function anymore and that's one of the very dangerous things about sleep deprivation as we know from the problem of microsleep while driving. the german society for sleep research and sleep medicine says that microsleep may be responsible for twice as many deaths on germany's roads as alcohol related accidents. lack of sleep is very risky because in a state of permanent sleep deprivation we can't judge our own capabilities and. a look at the brain also gives a clue as to how important sleep is during sleep the brain please. out information

also goes hand in hand with metabolic processes that can strengthen the immune system. the brain prepares for sleep over the course of the day with the help of a substance called adenosine which is produced by the body as its levels in certain areas of the brain rise so does the number of adenosine receptions to which the molecules bind. that seems to lower. and in juice. because the receptor is are increased along with the adenosine the urge to sleep growth and that's something that everyone experiences after one or two nights without sleep and it's practically impossible to stay awake. you can fall asleep in any situation even while talking or sitting up. in the toughest phase of the test ben had to keep awake for thirty eight hours

using positron emission tomography the researchers were able to confirm that sleep deprivation lead to a high density of available adenosine receptors. they conclude that staying awake when your body is telling you to go to sleep is not only bad for brain performance but for the entire body. to look at that in more detail they took regular blood samples from the subjects and found that their sugar metabolism was out of whack a possible sign of early diabetes. and then another thing that interested us was how quickly will they recover when we let them sleep for eight hours in one night. this one night wasn't enough to normalize sugar metabolism so young they continue to be impaired. and there are other health issues sleep deprivation promotes obesity because it disturbs the reward system in the brain. and it makes us more vulnerable to infections. so then the findings are food for thought about your

sleeping habits you know. definitely try to get enough sleep from now on because i now know how much it impacts my performance it has an enormous influence on your ability to concentrate and those are all lessons that i've learned a lot that's coming up and. when i asked you how many hours a day you sleep is it enough or do you feel sleep deprived. verdi is familiar with sleep problems and says my sleep is constantly disrupted by mosquitoes i slap my poor cheeks a thousand times a night vanessa would also like to get more sleep she says she normally sleeps only five hours a night. jose doesn't seem to have that problem. says he sometimes only gets four hours sleep and feels more alert than with eight but when he's able to sleep light he can stay in bed for fourteen hours.

will freighters says when you're young you can cope with lots of bad habits when you're older you'll pay for it you'll see he says. thanks for that warning and for all your comments. when we start to get sleepy we often yawn. it is a reflex and it's contagious if you or your name right now you might be very empathetic. according to some studies most mammals are known to yawn by the way except for giraffes that is whether in the wild or ensues it's said no one's ever seen a giraffe you on more have you then less has no other version of right such as birds and reptiles definitely do your own that's been proven some researchers believe

that yawning is connected with intelligence the longer the animals you own the more nerve cells there are in a cerebral cortex and the more intelligent it is and what about animals sleep well we're all familiar with cat naps but what about animals that live in the water no are similar to our valentine had a question about that. how do sharks sleep when just a nodding off could be fatal. that's a real danger for some sharks pelagic or open ocean sharks breathe bypassing water through their gills to get oxygen to keep that flow going they keep swimming if they stop to rest they would suffocate and drown. blue sharks may catch a nap during their so-called yo-yo swan and this one up to the surface and rest as they descend into the depths. in general the underwater world this pretty ingenious

when it comes to grabbing some z's the sleeping habits of the sperm whale were a mystery until a group of researchers saw a pod dozing off the coast of chile they drift upright in the water for a daily total of one and a half hours. that's not much compared to the six to nine hours a day that we sleep. other whales have other methods of getting shut eye the humpback whale does it head down but why sperm whales and humpback whales sleep in a vertical position isn't known. like whales dolphins have an unusual form of sleep they shut down one half of the brain and close the opposite eye while the other hemisphere keeps track of what's going on they can even keep using their echolocation system and orient themselves using clicking sounds so every species sleeps in its own unique way even underwater. if outlet is red white

and black only a few. do you have a science question that you've always wanted and said we're happy to help out you send it to us as a video text over smell if we answer it on the show we'll send you a little surprise as a thank you can i just ask. you find as i did have a dot com slash science or drop us a line at e w underscore site tech on facebook d w dot science. what about you are you more of an early bird or a night owl. some of us a most productive in the morning others in the evening it's a question of biorhythms that's true for athletes too. many people think they know the best time to exercise it turns out that's not always true.

i can't imagine a life without exercise because it gives a good balance to my everyday life it's fun and that's why i love it. fabio exercises more than once a week like thirty two percent of germans most jog or go to the gym fatty and prefers outdoor sports or martial arts like kickboxing his choice of sport varies according to the time of day. in the morning i wouldn't do pick boxer. not awake enough. but a relaxed royd in a kayak is far and early in the day. so what is the best time of day to train xabi on is studying sport and wants to find out he's taking part in a test at the university of basel in switzerland where professor i know schmidt took sas examines him the focus is on biorhythms. gets

up at about seven am and goes to bed at about eleven pm which is about average. around sixty percent of germans fall into this category their mental performance is highest between ten am and noon and four pm and six pm but what about muscle function before and also in this test we're studying and durrance we want to find out whether performance varies over the course of the day we have various tests beginning at seven am and ending at nine pm spread throughout the entire day. fabiani is put through his paces on six different days at a different time each day sometimes in the morning or at noon in the evening or late evening day to keep pedalling go go go come on push yourself. the researchers record heart rate oxygen saturation and lactate levels in the blood along with

a range of other parameters. meanwhile ford is investigating whether certain muscle groups have more strength at certain times of day sergey is one of his test subjects. i would use to use my preferred to try to run two to three pm if that's perfect for me my performance is probably the best of the times. we'll see about that. until now researchers assume that athletes with a normal bio rhythm like surrogate perform best between four and seven pm that's when they have a slightly higher body temperature and peak metabolism but in this study the scientists found the athletes reach their best performance at varying times of day sergei's best time is seven am. the best. so right now we're assuming that everyone has their own ideal time of day to train. the time when they're also about their best and you can see how. further studies will be conducted to check the

results but what about the endurance test does that also reveal big variations in the athletes in our body clocks. but there was one time of day where all the test candidates dept in their performance and that was one pm that might be linked to the midday meal time but we don't know yet what was. the performance of many test candidates also dropped after ten pm that's when the cardiovascular system slows down and the body gets ready to go to sleep this can be a problem for professional athletes as many sporting competitions take place late in the evening to coincide with prime time television so i know schmidt took says has come up with a way of kickstarting athletes sporting performance late in the evening using light . blue lights what we call now a no pick light affects the ganglion cells on the right now that's held that in

turn sends a message to the part of the brain which controls how awake we are and as we've discovered also affects athletic performance. during the test he had athletes sit in front of a predominantly white light some in front of a blue light and others in normal room lighting each for sixty minutes then they had to ride an exercise bike for twelve minutes. andrea has also been experimenting with blue light in cooperation with light bulb maker us from he's developed glasses for athletes fit with l.e.d. lights. we're working with the german skiing association and stefan knew it and other high profile skiers like put stops. have all given very positive feedback. the athletes wear the l.e.d. glasses for fifteen minutes before a late night race to give them an extra kick so is this

a form of doping yeah. we're putting these athletes into a situation where normally they couldn't produce their top performance all we're doing is. giving them back what the daylight would have done for them during the day. so i wouldn't call it doping as a sports nish coping with. the glasses are expected to go on sale to the public later this year. many of the athletes taking part in the tests in basel also perform better after the blue light therapy. they were eight point five seconds faster which on a time trial of ten kilometers makes a world of difference and the results are impressive but be careful too much blue light can mess up your inner clock leading to sleep disorders. but bobby and says he doesn't need l.e.d. glasses to improve his performance he's happy to just keep training as it suits him best. the air. that small for

today next time we'll be looking at spatial junk hundreds of thousands of pieces of old satellites or rocket parts are orbiting the earth and they present a serious risk to the international space station now scientists are testing a cleanup satellite designed to help remove debris in space there are a couple of ideas for how that might work join us for more next wait until then by .

who holds the power in germany. to both. the corporations government the ones with the money. what do lawmakers think about voter opinion. among such a. big business the business leader those of us which money have to get involved we

are the state who holds the power in this land of inequality in fifteen minutes if you don't. boy boy. stuff. you can see. an extravagant venue. to hosts who really know their stuff. groups. with the building and the funny stone for. the party and chat with musicians from around the world from the other live. make roofs every week to double. our.

favorite. angle so that the bathroom was there for. the us at. alcoa first but that i lack. a red herring. i man i don't know what. i will follow. what i mumble for. warm i want. well we're arming. the gal

over and the more i am or. what i am. i like there's. nothing. more. the government of mozambique says hoff a million people have been affected by the devastation of cyclon each day more than seven hundred people have now been confirmed dead after the storm raged across mozambique zimbabwe and the week major relief operation is underway to help survivors. united states tony general william ball has given lawmakers his

summary of special counsel probe into russian interference in the two thousand and sixteen election he said mulla found no evidence.