david and this is a climate change sex. happiness increase books. this is the conference. you're smarter for free we'll be looking for you to. 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 also to keep the 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 d w. how

do solar cells actually work so hisself are mainly composed of silicon. silicon atoms have full electrons in their counters shell and are stable but then the silicon is split into 2 layers. bosphorus is mixed into one like it has 5 electrons in its outer shell one too many which can orbit for. the 2nd layer is mixed with boron 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. occupied the holes and

the electrons are now too far apart to migrate with the sun comes in when some light hits the surface layer splits off one electron making a hold on the soap and select. 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 and so on. the electrons which have arrived at the positive return via one head 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 lab efficiency is over 47 percent but they're expensive and above his expensive solar super cells 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. in gallic celebratory we get an 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 an exactly defined. radius covering

a super cell. those cells are tiny barely one millimeter across. and 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 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 and. 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 and 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 5 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

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 in hopes that this will itself. if i use energy i have to replace it on the other hand. without an engine that might just one. phoenix looks like. but it's actually an airplane or to be precise and unmanned aerial vehicle. it's to . the prototype the wings and tail will be added shortly we joined the team amid preparations for the 1st test lines. 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 teen. 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 over 150 years and it's used underwater for remotely operated vehicles so there are various things are used underwater for surviving but nobody's made it work in a before because there is a sound sometimes less dense in water 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 the next 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 it would fly at 20000 meters and 20000 meters because that's where the weather is is most benign. winds are 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. and is lighter than air and therefore pulls the aircraft upwards 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 police 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 lighter than air like a balloon. the model has been through countless tests in wind tunnels.

andrew ray is responsible for the aerodynamics and elements he's keen to improve further. 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. 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 lighter than air and one had to navigate through so well to begin with that we were able to do multiple transitions between the 2 when it flew forward repeatedly during the flight systems. work is now underway to build the next prototype it's said to be 4 times as enormous phoenix and capable of flying at the target altitude of 20000 meters. the earth by night covered by a right 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 your 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 light 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 analyze the results. what will they show how much like to our subjects receive at what time of day. tomas the go to that 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 amid a lot of blue light and are disruptive. this shows the amount of natural light thomas 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 on and

in the afternoon it drops significantly. around $100.00 lux or lower looks on. and at night the light exposure is reduced to an absolute minimum of absolute and many more that it's yet in accordance with the natural rhythm that the stock knocked over most and pushed. past john's case that to take place almost exclusively indoors just by having large windows he always turns on the light but artificial light is usually very weak whereas goat heard thomas can reach 7000 lux bus john's level is just 220 bus general so spends most of his evenings in front of a t.v. or computer screen in addition to being low light they emit primarily blue light this lowers the wake sleep regulating hormone melatonin and reverses his in a rhythm essentially turning back his biological clock and the result for us john

is this modest hour by hour exposure to light on a typical working day then cut him while working in the office we have $200.00 to $220.00 lux which is far short of daylight bite and found that august least 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. it's got the 5. now 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 arriving for a night shift saturday night which no one likes to go see but i'm not properly rested even after. we finish. but she needs to be

wide awake not least when stitching up the wound at 1 am. the surgery room light is particularly strong which helps right now but for her biological clock it's unnatural outside 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 as a bitch to spy i could feel that you can't really look forward to going home when you know you'll be back again this evening mind with. and 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 rhythm after that her night shifts begin. and then there's no dana rhythm at all as far as light exposure is concerned at least expose it's own 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 when noon a time of day where our 3 subjects differ substantially an exposure. line shows the light on a typical morning for office worker boss john read is that of dr 19 and green go to her tomas whose exposure is 10 times higher in those crucial morning hours. so how

can the 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 head tells us it really makes the sat that light pollution means she can't see the greatest show on earth the milky way it's like a cascade of diamond spots in the sky. and fucker 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 larrie less 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 with simply. many professions of rescheduling work to have and i have a nice song working nights but how can you stay healthy despite that it's. that daylight experiment. thomas spends most of his days outdoors so he gets plenty of natural light. in the evenings he tends to avoid screens with their high blue spectrum output he's just fine but bastions office job means he has a serious like 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 with

the highest for bastiaan that means 1st thing in the morning it's out into the fresh air and natural daylight 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. measurements 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 component sharply. damn it come on all lets you use your smartphone at night without feeling guilty

about disrupting your sleep the stuff they start out. but at least to the time you see something with a day like last time and walking in broad daylight i've got the feeling that i get tired very much earlier at night and want to go to sleep. it gets on my nerves a bit because i like to stay up late. but i don't feel like i'm struggling to get through the day like i used to before this whole experiment published michoud t. just. instead and quite often much more alert the. hospital doctor 19 really gets much daylight and her chips go counter to her biological clock adrenaline is what keeps her remarkably awake at work. to 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 shifts 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 is best that much we know it also helps us to produce this mundane essential for both development and also said to boost the immune system getting the right amount of sunlight as opposed to too much. isis unhealthy the will of long ago tapped into the sun's 24 hour over them it's regulated human life for thousands

of years but how did it come the balance amos from zambia wanted to know more. how was the sun created. it's been burning away for over 4 and a half 1000000000 years and is 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. our 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 necklace. the astral embryos that emerge there continue growing until they have sufficient mass to ignite the sun spire. if outlet is right why up it. do you have a science question that you've always wanted on state we're happy to help out with a little less as a video text ovoid smell if we answer it on the show would find you a little surprise as a thank you can i just ask. you to find us on the way. d.w. dot com slash science or check us out on twitter. that's

all from tomorrow today for this week 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 there. the be. the be. the be.

the be. the be most certainly me but how did he keep to 2020 below the bummer was come lately did read. our presenters bret observed discovery i admire him one important insight the big fish in a much much better the be coming up on w. . any time he can achieve some ai strong

telepathic conducted the best musicians she. could bring in to make. me a musician. consummate the exit you see hard part. one tack. to ask. can you hear me now yes yes we can hear you and how last year's german chancellor will bring your uncle our mascot as you've never had her before to surprise yourself with what is possible who is magical really what moves back and what off the bat who talked to people who followed her along the way admirers and critics

alike how is the world's most powerful woman say to her legacy diagnose the metals last up. the story of producer and propaganda. they were called the rhineland bastards born after the 1st world war the monkey was an illegitimate child and there were many other new from. their mothers or germans living in the occupied rhineland their fathers soldiers from the french colonies. are forgotten please after german children had a hard time and because they were a reminder of the german defeat. they grew up in a climate of wounded national pride and racism the thought of 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 remain of their existence as they call them the children. storage january 11th on d w. on the. business day w. news and news are our top stories the european union has officially launched its covert 19 a mass vaccination campaign the elderly and health workers are at the front of the line those who received their shots 1st have reacted emotionally most e.u. states are receiving an initial batch of 10000 doses of the by.