w. . they want to know what makes her jealous if you get. the love bigger than banning going away from her but i'm not even allowed to order my own daughter and everyone was laid a hold on everything. are you ready to meet the germans then join me rachel siewert on d w 2. global energy consumption rises every year many people's biological rhythms are no longer in sync with day and night but more with artificial light what does that mean for us our energy demands are also to keep eating natural resources renewable energies could help more if they were more efficient one idea is to use lenses to focus on light more precisely on the solar cells in the panel. welcome to tomorrow today the science show on g.w.

. stuff how do solar cells actually work so his cells are mainly composed of silicon . silicon atoms have full electrons in the outer shell and are stable but then the silicon is split into 2 layers. bosphorus is mixed into one like it has value electrons in its outer shell one too many which can orbit free. the 2nd layer is mixed with go wrong which has only 3 out electrons one to feel. that means the layer has gaps which attract the excess phosphorus electrons this creates a flow of negatively charged electrons from one layer to the other one layer loses electrons and becomes positive the other gains electrons and becomes negative creating 2 poles eventually all the gaps on the surface. of the layers occupied the

holes and the electrons are now too far apart to migrate them with the sun comes up when some light hits the surface layer energy splits off one electron making a hole under so close election. the electron is attracted to the positive and the hole goes another electron from another down to replace the one longs which in turn is split off inside. the electrons which of the arrived at the positive pole return via wire to the negative call that's an electric current. and it flows as long as the sun shines. if solar energy is to enable commercial aviation and satisfy our electricity needs in the future and there's still a lot of work to be done. research is forging ahead. florian gallies has come up with

a new method of extracting even more power from sunlight. but. what we've done instead of using normal silicon solar cells which have a maximum laboratory efficiency of 26 to 27 percent is to use somewhat more exotic cells their maximum level fission see is over 47 percent but they're expensive and above his expensive solar super cells yellowish months a panel of lenses each of which focuses sunlight on an individual cell throughout the day that boosts efficiency to 29 percent in real life conditions. the main challenge is making sure the light actually hits the cell if it doesn't and it won't produce any energy at all. up to manage you know. in gaelic celebratory we get my idea of how it works he uses a model to show how the lenses function each lens in the top panel focuses the sunlight on in exactly the. and radios covering

a super cell. because those cells are tiny barely one millimeter across. we use about $10000.00 cells per square metre and each has to have a high degree of tolerance. but now it's time for the engineers to put the lab behind them. right now we're still almost sticking everything together by hand with the theory but now the important step is going from the lab to mass production how can i produce a module every couple of minutes using machinery that's the really huge leap we're about to take that will fit in the of mafia. the european union is giving insulate almost 3000000 euros from its advent solar cell fund expensive science but worth it if you think looting insulation ourselves are about 20 percent more expensive but they produce 50 percent more energy and. improved utilization of solar energy is

one thing but it's also highly dependent on the weather it only makes sense when electricity storage facilities have been improved. lithium ion batteries are the standard today but scientists at switzerland's materials testing and research institute show us how dangerous they can be if the lithium ion cells insulation is compromised and the terminals come into contact with metallic objects such as coins the result can be disastrous. our approach to stabilizing the electrolytes involves a highly concentrated salt solution. the swiss researchers have developed a highly soluble salt that only needs a few drops of water here seen in fast motion to function as

a more conductive but much safer electrolyte in lithium ion batteries. that kind of storage battery would be enormously useful for storing solar energy in people cellars or in other very large batteries. to bridge the nighttime gap as well as bad weather. in the batteries or the ideal solution for delaying energy consumption for a few minutes or even days. solar energy for foggy days or the night time in future we could be storing it in less volatile batteries and we have today. it's energy that could become abundantly available thanks to a new generation of panels to collect it. ideally we wouldn't use any energy at all that's the idea behind the ancient dream of the petrol motion

a machine that moves without any energy source but the laws of physics teach us that it's not possible i can't eat everything up and simply hope the biscuit to pull itself. if i use energy i have to replace it on the other hand and with that it. might just one. phoenix looks like. but it's actually an airplane or to be precise and unmanned aerial vehicle. the prototype the wings and tail will be added shortly we joined the team amid preparations for the 1st test flight. the researchers have chosen a huge building for their 1st attempt to get phoenix into the air a tense moment for its inventors. scientists from various universities and companies in britain spent 3 years working on phoenix. aerodynamics professor andrew rank and set the team. says.

the goal was to build an aircraft that could propel itself without the need for an engine. has been around for a long time i've 150 years and it used underwater for remotely operated vehicles so there are various things are used underwater for surviving but nobody's made it work the night before because there is a 1000 times less dense and mortar that the physical process is more complicated phoenix is filled with helium the material for the outer hull had to be developed specially it needed to be lightweight but dense enough to prevent the tiny helium molecules from seeping through. the wings are made of lightweight carbon fiber both the wings and tail carry solar panels to provide the plane with power some is stored in batteries meaning phoenix can also fly at night. this is phoenix in its

fully assembled station the aircraft will likely be used as an atmospheric satellite or pseudo satellite either for telecommunications or for things like land surveillance after natural disasters to see where help is most needed one of the possibilities is as a suit our satellites are being able to do surveillance and monitoring and for that it would fly at 20000 meters and 20000 meters because that's where the weather is most benign. winds are a much lower than they are down on the surface phoenix is 15 meters long and weighs just $120.00 kilos without the helium. that means it requires very little power. its huge advantage is that because it has no engine it doesn't need to carry any fuel that means it can remain airborne for weeks or months at a time the mix is also relatively cheap to manufacture. it's propelled by what's

known as variable buoyancy propulsion this is how it works helium is lighter than air and therefore pulls the aircraft up towards the underside is equipped with 2 compressors which draw in air from outside and compress it filling a bag inside the aircraft. that makes the plane heavier causing it to sink again. the air is then pumped out making the aircraft lighter and causing it to rise again this ability to bleed as it were moving up and down combines with the lift generated on its wings to move it forward. half the time phoenix is heavier than air like an airplane. the other half it's the lighter than air like a balloon. the model has been through countless tests in wind tunnels.

andrew ray is responsible for the aerodynamics and element he's keen to improve further tests. using lasers and smoke his team is able to show how the air flows around the model. they needed to establish the most efficient design to allow the aircraft to maximize the use of its kinetic energy. here. after 3 years of development the prototype was ready for its 1st test flight. and it was a success phoenix flew in waves down the 120 metre long hangar exactly as it was designed to do.

we were all pleasantly surprised that it worked as well as it did. we initially had hoped to. do one series of tests where was like the narrow one heavy the night but it flew so well to begin with that we were able to do multiple transitions between the 2 when it flew forward repeatedly during flights or sting's our work is now underway to build the next prototype it's said to be 4 times as new miss phoenix and capable of flying at the target altitude of 20000 meters. the earth by night covered by an iraqi of tiny luminous dots it could be beautiful in another context electric light does make modern life possible independent from the 24 hour a day night rhythm would have freedom but also what a catastrophe it confuses the environment and least spend too much time an artificial life and not enough an essential sunlight time for an experiment.

these 3 people are exposed to different levels of light during their day. boss john works in an office which means spending long hours in artificial light. thomas is a goat herd and is mostly outdoors. then there is not to be. a doctor who works as a surgeon in a hospital and she works at night when her body is telling her it's dark and time to go to bed. we equip our test subjects with a special device that measures the brightness and composition of the lights they're exposed to. and then we track them around the clock for a week. we want to know how much and what type of light our test subjects are

exposed to and when. sleep researcher alfred riata and light expert because it gets analyze the results so. what will they show how much like do our subjects receive at what time of day. tomas the go to tends to be out in the open with natural like the lord even in gloomy weather he's subject to several 1000 locks per day. after sundown he manages without a television or mobile phone which both emit a lot of blue light and are disruptive. this shows the amount of natural light tomas is exposed to over the course of several days in the. mall going on site there's a very high a luminance in the morning and around noon up to 7000 lux and looks on and in

the afternoon it drops significantly. around $100.00 lux or lowered looks on immediately went in and at night the light exposure is reduced to an absolute minimum of absolute minimum that would see it is in accordance with the natural j.j. night rhythm effect the stock knocked over at most and pushed. past young's case 30 takes place almost exclusively indoors despite having large windows he always turns on the light but artificial light is usually very weak whereas goatherder trauma's can reach 7000 lux bastions level is just 220 buss channel so spends most of his evenings in front of a t.v. or computer screen in addition to being low light the emit primarily blue light this lowers the wake sleep regulating hormone melatonin and reverses his inner rhythm essentially turning back his biological clock and the result for

a boss john is this modest hour by hour exposure to light on a typical working day then cut in but while working in the office we have 2 $100.00 to $220.00 blocks which is far short of daylight light and found that our stack what we notice is that he still has a relatively high illuminance after work until he goes to bed. who are. at this so and that he definitely has a negative effect on his sleep wake behavior and. and they got the 5. diem is a doctor who likewise works with little light most of it artificial. and sometimes with practically none. and come out i'm just arrived for a night shift saturday night which no one likes to see but i'm not properly rested even after. commission. but she needs to be wide awake

not least when stitching up a wound at 1 am. the surgery room light is particularly strong which helps right now but for her biological clock it's unnatural side of course it's dark. if she's lucky and it's a quiet night nadine will be able to take a break and catch up on her sleep. but it's only a matter of time until she's called to the next patient which means getting up again pronto. the rude enough to. even so my night shift is over and my colleague is now taking over for the daytime shift at which display i'm to feel that you can't really look forward to going home when you know you'll be back again this evening when it was the end this is what her light exposure chart looks like. in the. tongan come on for

the 1st 3 days you can see a relatively good day night rythm after that her night shifts begin. and then there's no daylight rhythm at all as far as light exposure is concerned the least exposed it's on when she's more or less exposed to continuous lighting. and that constant light is anything but natural. her biological clock has no means of orientation. in order to reset her clock back to normal she needs daylight in the morning between 8 and noon the time of day where our 3 subjects differ substantially in exposure. look blue line shows the light on a typical morning for office worker. read who's that abductor 19 and green go to her tomas whose exposure is 10 times higher in those crucial morning hours. so how

come no office worker and doctor get more like. we'll have the solution for you in a moment but 1st of all we are asked how much you have to rely on artificial light and if you have strategies for avoiding too much of it. brown says they don't have too much artificial light in nigeria so they don't really depend on it. rising from columbia most have tells us it really makes us sad that light pollution means she can't see the greatest show on earth the milky way it's like a cascade of diamonds spotting in the sky. and doctor tells us that pakistan's rule areas have barely any artificial light at night the people there are healthier than city people they're also very strong emotionally they stay calm laurie legs and mostly smile thanks for writing in.

even if in some regions night time still looks like night time the world as a whole has been getting brighter recently. many professionals are rescheduling work to have another nice song only work at night but how can you stay healthy despite that. fact tell a daylight experiment. tomas spends most of his days outdoors so he gets plenty of natural light in the evenings he tends to avoid screens with their eye blue spectrum output he's just fine but bass john's office job means he has a serious light deficit problem and not just because his office is too dark. an office worker circadian rhythms are completely disrupted and we should try to adjust his biological clock. so he'll be more capable and alert in the morning and

the highest for boss john that means 1st thing in the morning it's out into the fresh air and natural g. light not exactly a grueling task skipping one stop on the subway into work is all it takes. we also install a standard daylight lamp on his desk for him to use during the morning that way he's getting 2000 lux even in the office. and in the evening a book is always better than a screen. measurement show just how even a smartphone can influence our sleep patterns normal display light is dominated by the blue spectrum that suppresses melatonin the hormone that steers our weak sleep rhythm however many smartphones now feature a filter called night shift it cuts down the blue spectrum components sharply. it lets you use your smartphone and you think without feeling guilty about

disrupting your sleep the stuff they start out. but others do the time to see something with the daylight lamp and walking in broad daylight i've got a feeling that i get tired very much earlier at night and want to go to sleep. i'm trying to give it it gets on my nerves a bit because i like to stay up late. so what i don't feel like i'm struggling to get through the day like i used to before this whole experiment published michoud just. instead and quite often much more alert the. hospital dr dean really gets much daylight and counter to her biological clock adrenaline is what keeps her remarkably awake at work they. feel she's doing a lot right she's limited by her night shifts of course what is important is that she at least grabs whatever sleep she can when on shift. the sleep experts offer

her another suggestion after a night shift should try specially colored glasses which filter out that studies are melatonin level and she'll sleep easier when she gets home the experiments outcome is that the most important thing is to get a lot of natural daylight preferably in the morning that way the biological clock settles into its natural rhythm and also to try to go without screens in the evening and if night ships are a must then only a few of them at a time grouped together a well maintained biological clock never needs reminding. so some lines its best that much we know it also helps us to produce this mental essential for development and also said to boost the immune system but getting the right amount of sunlight is important too much. isis unhealthy the will of long ago

that tapped into the sun's 24 hour over them its regulated human life for thousands of years but did it in the balance amos from zambia wanted to know more. how was the son created. it's been burning away for over 4 and a half 1000000000 years and it's not even halfway through its projected lifespan. one in which human history is just the blink of an eye. but while we may be just a transitory moment in cosmic terms we are at least able to study the life cycle of the sun. all galaxy is home to billions of other stars like it. space telescopes have given astronomers a closer look at how stars evolve. our own son was born from

a cloud of gas and dust over the course of millions of years. it's a magical process reproduced here on a computer. this cloud of dust contains regions of dense a gas like pearls on a necklace. the astral embryos that emerge there continue growing until they have sufficient mass to ignite the sun spire. if outlet is red white button it. says you have a science question that you've always wanted on state we happy to help out send it to us as a video text ovoid smell if we answer it on the show we'll send you a little surprise as a thank you can i just ask. you to find us on the way. d.w. dot com slash sides or check us out on twitter and. that's

all from tomorrow today for this week the next time we'll be looking at the power of thought we'll be able to operate machines just by thinking the 1st models are already being tested more on that next week to see them.

after. christmas time you can hear it in dozens of languages. now countries all over the world. come to disarm come from and how did it become such a part of christmas. our song for the world cyber night. 15 minutes on d

w. every day counts for us and for our planet. the ideas is on its way to bring you more conservation. how do we make c. the supreme or how can we protect habitants what to do with all our waste. we can make a difference by choosing smaller solutions overstrained said in our ways. the ideas limited series of goofballs a double down on my. post story of producer and propaganda. they were called the rhineland

bastards born after the 1st world war the monkey was an illegitimate child there were many of them even from. their mothers or germans living in the occupied drying land their fathers soldiers from the french colonies. the couple dozen piece after german children had a hard time and because they were reminder of the german defeat. they grew up in a climate of wounded national pride and racism to further the european population felt that it was important to be white and to stay right by sublight. exclusion and contempt culminated in forced sterilization under the nazis. this documentary examines the few traces that we made of their existence we called them the children. storage january 11th on d w. this

is due to the news life from birth in germany a 101 year old resident of a care facility has become the 1st person in the country to receive a covert 1000 vaccine this as an unprecedented mass immunization campaign gets underway across the e.u. . also coming up americans police say in a closure international tennessee was an intentional bombing 3 people are injured and so just suspected human remains are found in a huge motor home explodes damaging buildings and shattering windows.