being invited in by syrian kurds fearing an attack by turkey but the u.s. military disputes the claim israel's prime minister binyamin netanyahu is in brazil and is promising stronger bilateral ties he's been meeting the far right president elect j. it was so narrow in the rio de janeiro it's the first visit by an israeli premier to the country or so narrow has promised to move brazil's embassy in israel to jerusalem that hasn't come up in meetings so far. the army and the paramilitary have been called in to provide security during sunday's general election in bangladesh campaigning for the vote has ended with more violence and arrests the opposition bangladesh nationalist party says nineteen activists have been held there head of sunday's vote police say a supporter of the ruling army lee was killed those are your headlines the news continues here on al-jazeera after science in and golden age stay with us.

more women more diversity the new look of the u.s. congress what it needs for the first time on january third will what it means for the democrats and for president all join us for coverage of this historic shift in american politics the new tone on old zero. the nature of life it has intrigued scientists throughout the ages today it's used in all sorts of the cations from lasers and communication to particle accelerators we're living in a science and technology boom period but the roots of our understanding of optics and light can be traced back to a period between the ninth and fourteenth centuries that's when a revolution in science took place in the islam it quote a golden age of science. a british professor of theoretical physics but born in baghdad i'll be looking at the states of the off topic cases of optics and tracing

back their roots to those pioneers in the islamic world who revolutionized a new understanding of light during the golden age. this is sesame in jordan it's a synchrotron a giant particle accelerator that's going to produce high energy light for groundbreaking experiments now sesame stands for synchrotron light experimental

science and applications in the middle east the light it will produce will allow us to study the structure of matter with incredible detail so learn more about for example how cancer grows in living cells or to analyze cracks in concrete to see why bridges failed for pollution in the soil this facility is a pioneering collaboration that's bringing together scientists from around the middle east the neighboring countries to carry out fundamental research that transcends political and cultural differences in a way that hasn't been seen in this part of the world since the golden age a thousand years ago. the ruling of the medieval islamic world together around the globe to further scientific knowledge. among their achievements they revolutionized the way we think about vision and paving the way from modern understanding of life.

isn't yet fully operational but today i've been given exclusive access to this enormous experimental apparatus to see how. by using very fast moving electrons. this is the mystery this is the which increases in energy. right and where the electrons produced in the schools ok. so this is where. soul begins this is the latest foam which produces electrons and cylinders them up till specific intelligence so that they can be injected into the blister effect they look for are produced from this source which is electron gun and they are isolated by the other source which we call the megatron is the same device in the microwaves at home but with larger power and when the electrons are it's integrated we can

extract and then through the cluster like it do that with the singleton and it's in the booster ring that they are accelerating to round in a circle faster and faster yet to get more in of just so their speed will be almost the speed of light and then they are injected into the storage of it where we accumulate their elixir been there all the produce the same performance and that's when you can use the light exactly for the exits to do the experiment yes so there are several stages to sesame first the electrons are produced in the microphone which accelerates them around. when they're fast enough they get injected into the . with their accent or a city even faster and finally as they approach the speed of light itself there fades into the storage room as the electrons a stage around using powerful magnets they lose energy in the form of light this is the synchrotron light we should be used for all sorts of experiments.

even without the synchrotron lights some experiments are already underway at sesame . is a scientist who's using infrared light which is invisible to the human eye to see the effects of drugs on skin she's using a special infrared microscope which allows her to determine the chemical composition of samples of skin. i can see here on your computer screen here what the microscope yet of course can see this is the surface of our sample that we are studying it is a skin cell if you click and you want you want you can get the infrared the stick around for this boy when you add a drug or treat your sambit in a new way these peaks will be different so you can study what is the effect of your drug on this by studying the changes on your infrared spectrum will

route research currently uses its own infrared light source but once the synchrotron is up and running she'll be able to do her research one of the experimental stations that will be built around the storage ring and she'll use the synchrotron light when we have the beam line which is from the synchrotron we will have a lot which is very bright so our sample can be said it was a very high resolution and so our result will be bitter. the experiments that would be carried out here at sesame will all rely on a precise mathematical understanding of light and it was the scholars of the medieval islamic world as they sought to mathematicians science who first laid the foundations of our understanding of light.

isaac newton studied here in cambridge in the seventeenth century and is regarded by many as the father of optics but there's another father of optics who goes back much earlier and who is often overlooked his name was no haitham born in the tenth century he's probably my favorite scholar of the golden age because like me he's a physicist. born in basra it know haitham excelled at optics math astronomy and much more as a young man the prodigious of no haitham travel to cairo. the story goes that he was invited to egypt after he promised the ruling kailash there he could stop the nile from flooding by building a dam. however he soon realized that this task was technically impossible and so he feigned madness to escape the caleb's anger and was instead thrown into an assignment there he still to have written much of his important work key tarbell my novel the book of optics which was hugely influential the centuries.

method had died is an iraqi engineer at cambridge university together we're going to recreate one of the mill haitham as most famous experiments the camera obscura pharmaceutical you think very very nice what's the view like. we have this power of ok i think that clock tower be perfect. all we need to do is block out the windows and get the screen in place. the camera obscura is essentially a giant pinhole camera the size of a rube so that we can stand inside it although the idea of the camera obscura was known about previously it no hey thumbs accounts is the earliest to mathematically explain how it works he used it as proof that light travels in a straight line ok i just know i need to make a hole so if you get the screen. i'll

turn the lights out we'll see if we think that our. well that's going credible it looks like a painting doesn't it doesn't always doesn't look real and you know all we've done is block out the light from the room and then allow it to come through the small hole that is the clocktower you can see such detail just from across the across to even see the highest yeah they're not in focus because you could make them in focus if you made the whole smaller right but of course they're less like can get it so we wouldn't be so bright whereas now you see in all these do you know the vivid colors and it's so simple that we're going to hate them would have set up an experiment like this in a darkened room such a simple thing to create without any lenses or all modern equipment you know

a thousand years ago for him to have explained how this image is created through through the hole i must make you proud as an as an iraqi who comes from just down the road from where i'm hoping was born that is exactly what i was you know i'm from an area very close to one of them was born so it makes me proud. i don't hate them as explanation of the camera obscura helped us understand how vision works the i is itself a camera obscura the same principles apply to modern photography after all that's where the word camera comes from. i'm going to stumble to the museum of the history of science and technology is now . saying that kool-aid has been studying no papers work including

his explanation for why the camera obscura makes an image that's upside down. he's well regarded as as the first scientist to correctly explain the camera obscura talk me through how this works if you press the button there. this is the primary light source and this is the object lighted by it to slight the light has to go into the box is through discipline hole you seed of here and if you look at from here you will see that the. f. is converted it is upside down. yes because the way the lights from the top passes in the hole in. and they cross over cross over because the light takes the shortest way and it travels in straight lines and this was something that he was able to show improve the fact that light travels in straight lines was known before him but he heard the first time proved it mathematically.

it will hate them skitz album a novel is often cited alongside isaac newton's principia mathematica as one of the greatest textbooks of physics ever written let in translations of it influence such men as division chief galileo descartes among others such as his fame today he is commemorated on the back of an iraqi ten thousand d.n.r. banknote he's probably most famous for being the man who explained how vision works . until then the accepted view had been that of the ancient greeks men like plato in euclid who argued that the way we see objects is by shining light out of our eyes on today. it will hate him knew of this view from arabic translations of greek texts but he

challenged it arguing instead correctly that the way we see is by light entering our eyes from outside either reflecting off objects or directly from numinous bodies like candles or the sun. what was most impressive about them is that he combined theory and experiments so not only would he devise careful experiments to demonstrate particular ideas like light traveling a straight line he also put mathematical flesh to these ideas he map. i'm a thai's whole fields of science. professor stephen sweeney is a colleague of mine at the university of sorry he works at the cutting edge of laser physics today. in the medieval world there's one stall in particular that i'm passionate about it no hate them and he wrote a book of optics

a thousand years ago in which he was doing all those sorts of things that you sociate with with experiments with light today so reflection and refraction of light even down to designing experiments with camera obscura is to prove that like travels in straight lines but those aspects of understanding the properties of light are upset a key to modern science technology actually but perhaps the idea that light travels in a straight line is one of the most important ones and it's one that we really now make use of in technology and science and actually we've got a nice example of that here that i can show you today just based on research we're doing right now we're going to be using a laser and we need to wear these just to protect our eyes for the experiment. ok so what we've got now is there's a beam of light and a visible beam of light shining a nice straight line from this laser down to this detector the other end now if i put this card in the way you can see that there's a nice spot nice red spot when i take that away the lights traveling through and

it's hitting this piece of material here that's got a photovoltaic cell so you've heard about solar cells for collecting sunlight this is a particular type of photovoltaic cell for collecting laser light and it's actually then driving this little motors that's just little fancy five like that again these stops if i pull that away you can see the fan starts again ok so it's another way of transmitting energy essentially so not using electricity but using light itself is the medium and what sort of applications might this device this set up one of the key projects that we're interested in at the moment is transmitting energy from space. yes because in the infrared we can actually get straight through the atmosphere without losing energy we use a system like this in space we could transmit solar power twenty four hours a day anywhere on the planet that we needed this has huge implications the world over in terms of producing power we wouldn't need pylons and power lines yet power could be delivered to remote areas or disaster zones and this technology also has

implications for the internet we obviously use the internet for dates transmission but use infrared light actually but if we also put in some so high powered components that we can also deliver the energies we can actually deliver the power signal for the internet as well and this this light you see infrared so if i put my hand there i don't see it i can sort of i imagining i can feel what you're probably imagining. although it's infrared light it's not quite far enough into the infrared to be measured as heat the reason we use infrared light is purely because it's a better way of transmitting that light through the atmosphere and actually more than ninety nine percent of the energy can transfer through the air now in the real application that we would use this for we don't use an even further in for it laser and that would allow us there not have to wear these safety goggles so it's what we call the nice safe wavelength. sort of wondering what your haitham would think of doing experiments with candles and pinhole cameras. well he wouldn't even be able

to imagine a world a thousand years later i think it's come a long way but we using exactly the same principles but he was thinking about batman. today we understand the physics of how light behaves but back in the hay can stay this wasn't a tall obvious his book changed everything and he's regarded by many as being the father of modern optics in fact i'd go further than that and say he was the greatest physicist in the two thousand year span between archimedes and isaac newton. so many modern cities around the world today are lit up spectacularly by light it seems the applications of optics or reverie where have a look at this beautiful fountain behind me it looks as though the colored beams of

light are bending round following the path of the water however that's an optical illusion lights in fact a shining up from the base of the fountain and then reflecting off the water droplets into our eyes like always travels in straight lines however there is a way that light can be made to bend. if i shine this laser pen through this glass of water if you look carefully you can see that the beam of light bends as it enters the glass in the water this is something that every physicist knows snell's law of refraction but it was known many centuries earlier let me show you this rather remarkable diagram from a text that was discovered only twenty years ago partly in tehran and partly in

damascus it's by a little known scholar by the name of. and it describes refraction beautifully let me explain this line represents the boundary between. water if a beam of light enters the water at an angle it will refract bends towards the vertical. this angle is larger than this one or draw a circle around it the ancient greeks understood that this angle of incidence the angle the beam enters through the air is no larger than the angle of refraction in the water but they knew that the ratio of the two angles remains constant if you doubled this angle that angle doubles the way they described it was in terms of the ratio of these two parts of the circles perimeter that was wrong what i've been so help understood was that it was in fact the ratio of two straight lines he said

that this chord divided by this chord is always a constant number this is the correct way we understand it today now europeans argue about whether it was snell or descartes who should be given credit for the mobile fraction in fact it was discovered by six hundred fifteen years area so really it should be known as it been so hands nor a fraction. and another little known scholar from the golden age who fascinates me is a man called it in who in the eleventh century came up with one of the earliest estimates of the heights of the atmosphere there he worked out that after the sun sets the last remaining daylight comes from light reflected off the top of edges of

the atmosphere he figured out that this would take place when the sun was nineteen degrees below the horizon. imagine that i'm standing on the surface of the earth at this point a. the sun has gone nineteen degrees below the horizon above me is the atmosphere and i can see the last light of the day reflected from the top of the atmosphere at b. . we can draw this triangle to the center of the earth that. knowing the size of the earth calculated by the astronomers of baghdad in the ninth century they've been marked was able to use geometry to work out that the atmosphere was about eighty kilometers high that's not bad for almost a thousand years ago. throughout the golden age. and many other scholars wrote detail texts on optics

but none were so comprehensive and influential as if no haitham ski tarbell menarche. at the same money a library in istanbul professor. shows me an ancient copy of it will hate them scrape work. other than the book of optics. of course this isn't in the original copy this was written in the mid fifty's century. mohammad who founded the autumn an empire is written for his library. filmy what's amazing is that we all around the world we talk about newton as being the father of optics and yet here we are

a thousand years ago seven hundred years before newton and his away diagram this is there's a there's a convex lens and there's a focal point and there's all the but the rain lines and power lines and the angles of refraction here it is a thousand years ago. optics are all around us from the glasses or contact lenses you wear to the screen you're watching me on right now to the particles of light produced in the synchrotron everything we know about top six today is built upon the work of scholars like even so had they been was and the father of modern optics if no hate who first opened our eyes to the science of life. next time i'll be taking a look at modern day astronomy in the case and i'm exploring the contribution made

to these fields by the scientists of the golden age that's where his genius comes in because this diagram which was a couple simplified a lot of that complicated math we see the role they played in the evolution of astronomy we still have had to develop an area of mathematics called spherical geometry which was exceptionally advanced four thousand years ago and we reveal how scholars from us from the world consolidates who didn't respond to the astronomy of the early civilizations and came up with ideas that have influenced the story of the right through to the present day the pernice owns this debt to these medieval astronomers from the golden age. in the next episode of science in the golden age i'll be exploring the

contributions made by scholars during the medieval islamic period in the field of astronomy. copernicus is this day to these medieval astronomers from the golden age. streams in many ways with all the computers of the day you can use it to find the time you could navigate science in a golden age with germany on a. day one of a new era in television news we badly need at this moment leadership and values this encampment that we're in today it didn't exist three weeks ago now there's at least twenty thousand for him to refugees who live here. i got to commend you all i'm hearing is good journalism president turns to the public has resigned. after all the lies the attempts of cover ups the high water diplomacy. his loved ones some form of closure we saw the syrian army flag hoisted high in the city as

well as posters of syrian president bashar assad to record. it's a good cinema song sublime to the hundred meters away from us we're on the frontline but. at the doesn't happen now but politically. they wanted forty three billion dollars worth of weaponry that was six billion pounds in commission. there's no hope of any more because there's always a small people for really really good misfits. in essence we in the united states have privatized the ultimate public function more shadow on al-jazeera.

east and the differences. and the similarities of cultures across the world. al-jazeera. i'm sam is a van in doha with a look at the headlines here in al-jazeera now three foreign tourists are among four dead in a roadside bomb attack near the giza pyramids in egypt at least ten others were injured when a towboats was hit south of the capital cairo paul chatted jan reports. egypt security services quickly cordoned off the area where the roadside bomb exploded the improvised homemade bomb was placed near a wall on my.