all the planets including the earth revolved around revolve around and that's the picture that we have today copernicus was and is regarded as the father of modern science because of this great revolution and yet what's so fascinating is that this was built on two she's ideas yes so it shows the continuity of science copernicus owes this debt to these medieval astronomers from the goldeneye. islam itself was a significant reason behind many of the early explorations and discoveries in the stormy during the golden age there was a need to know the accurate time for prayer the direction to face towards mecca and the depths of religious festivals according to the moon a calendar astronomical instruments like yesterday played a very important role in this.

case. you were the earth moon. moon the luck of the. one of the requirements of islam was to know which direction mecca was in order to face towards it during prayer now during the early days of the empire it wasn't so large and this wasn't a problem the scholars of the golden age were very proficient at match making. but as the empire grew and stretched from india in the east all the way to spain and in the sea in the west it was much more of an issue because the scholars also knew that the earth wasn't flat now why does this matter well if you were a muslim in cordoba then facing towards mecca if you just looked at a flat map would involve pointing roughly se what on the globe is different if i

attach this string one end to cordoba and the other to mecca then you see the line actually takes you east to begin with and then curves down to the southeast so it's not at all obvious without understanding the earth is a sphere this meant that these stores had to develop an area of mathematics called spherical geometry which was exceptionally advanced four thousand years ago. but to use the spherical geometry first needed to know the size of the year the ancient greeks had provided several estimates of this their method was clever but crude it involved measuring the angle of the sun at a particular time of day and then walking in a straight line in a particular direction until the angle changed by one degree or they then needed to do was calculate how far they need to walk for the angle to change by three hundred sixty degrees that would give them the circumference of the earth the early night

century about it caleb moon wanted to improve on this estimate so he commanded a group of astronomers to repeat it however the method involved them trudging through the desert for over one hundred kilometers a method that was prone to error. two hundred years later in the eleventh century the persian astronomer rooney came up with a much easier and more accurate method of estimating the size of the earth but it did involve climbing a mountain that looked out over the horizon. i'll be really was a prolific scholar who even debated about whether the earth was moving he explained how to work out the size of the earth in his book on the determination of the coordinates of cities first he measured the mountains heights elbow room he then had to climb to the top of the mountain and armed with an astral ape and a plumb line he then measured the angle of dip from the horizontal down to the

distant horizon now this was just half a degree so he had to be incredibly precise but armed with this information he could then use a more clever geometry to calculate the circumference of the earth let me show you . imagine this circle is the earth. and this is the rooney's mountain now looking across horizontally he measured the angle of the. horizon. this angle here now if you draw two lines one through the center of the earth from the mountain and the other from where the line touches the horizon you end up with a right angled triangle now knew the angle he measured is the same as this

angle inside the armed with these two pieces of information the size of this angle and the height of the mountain he was able to use geometry to work out. the radius of the earth multiplying this number. gives him the complete succumb friends he got to within one percent of the value we know today about forty thousand kilometers which is pretty remarkable. it's easy to think that astronomy went to sleep after the ancient greeks didn't wake up again until copernicus in the fifteenth century but developments in the stormy continued in spain the middle east and central asia throughout medieval times there were nascent scientists of europe who created modern the strong army were building on the work of people like rooney and to see who in turn were building on the knowledge passed over to them from the earliest civilizations today

in the twenty first century international teams of scientists are still looking to the stars and mapping the cosmos using ever larger telescopes but we must remember that they owe a huge debt of gratitude to those astronomers of the morag observatory. the. next time we are cover how the scholars of the slammy quote mathematics science. we delve into the equations of flights and discover how the mathematicians of the golden age laid the foundations of algebra it's extraordinary that i made that step to the cubic equation. we see the role they played in the evolution of numbers themselves everywhere today we use this decimal system and we forget how difficult it was before it existed. and we reveal how their legacy has

led to the mathematics behind the fastest car in the world. is the longest standing record in history and up till this point nobody has broken it that's about to change we're going to go a lot faster. short films of the who and inspiration. stories of three young women challenging the world around them. al-jazeera selects. and then reported on the. u.s. and british companies have announced the biggest discovery of natural gas in west africa but what to do with these untapped natural resources is already

a source of heated debate nothing much has changed they still spend most of their days looking forward to for the dry riverbed case one five years on the syrians still feel battered or even those who managed to escape their country have been truly unable to escape the war. on counting the cost it was the worst performing stock market of twenty eighteen find out whether china is headed in twenty nineteen brazil's new president has an economic challenge plus taxing times for technology giants and from a profit warning from apple. counting the cost on al-jazeera. a

lion has. the top stories on or jazeera president donald trump says the partial u.s. government shutdown could last more than a year if he doesn't get funding for a wall along the u.s. border with mexico is threatening to use emergency powers if congress doesn't meet his demands that tickle him has the latest from washington. the two sides emerged from both sides of the white house with very different impressions of how their meeting went and we had a very very productive meeting length a and sometimes contentious conversation with the president. with democrats now in charge of one chamber of congress they came to the white house to try and find a compromise to reopen the government the president says he won't sign a bill that doesn't spend five billion dollars on a wall the democrats say they simply will not spend a penny to build it they only seem to agree on one thing in fact he said he'd keep

the government closed for a very long period of time months or even years absolutely i said that i don't think it will but i am prepared and i think i can speak for republicans in the house and republicans in the senate they feel very strongly about having a safe country but that is the key question can he keep senate republicans on his side if enough vote to fund the government it could override any potential veto reopening the government without a wall without that it could go on it for much longer both sides refusing to budge the president threaten to declare a national emergency to build his wall on his own but it seems unlikely he actually has the power to do that under the constitution political scientist eric campbell doesn't think the new house speaker nancy pelosi will cave i think the question becomes next week when they're when they're government employees who are not getting paychecks i think that's when we really get a sense of how dug in and people are on both sides of an open question about who

will win the political fight while hundreds of thousands of government workers and contractors are not being paid and for many not paying their bills for them it is a question of how much more they'll have to lose before this political fight is over particle hane al jazeera washington the murder of journalists is likely to be on the agenda when the u.s. secretary of state needs saudi leaders next week my pompei owings also looking to reassure allies of the president trumps decision to pull u.s. troops out of syria. the un human rights office says a trial in saudi arabia of suspects in the murder of ji is in their words not sufficient it wants an independent and international investigation sadie frost pewters are seeking the death penalty for five of the eleven defendants private data of german politicians including chancellor angela merkel has been published online it includes home addresses phone numbers and credit card details it's not

clear whether hacking or leak were to blame under the police have been deployed in melbourne australia where far right groups are rallying against crime they blame on people of african descent a counter demonstration is being held by a group supporting multiculturalism counting centers in the democratic republic of congo's capital kinshasa have started compiling the results of last sunday's elections the three main candidates have all declared they won the vote catholic bishops field of the largest group of election observers they say there is a clear winner and they're demanding that accurate results are published venezuela has accused the us of plotting with a regional bloc to overthrow president nicolas maduro government more than a dozen foreign ministers from latin america canada have said they won't recognize me as president if he's sworn in for a second term next week the lima group says elections in may were not credible

a fish has been sold for a whopping three point one million dollars in tokyo's famous new year to no sushi producer and wholesalers have been known to pay huge sums for the biggest and best fish but this is the highest price on record tokyo's fish market reopened in a new location in time for the annual sale those are the headlines right now it's witness.

yes she was a masterful artist. i'm there with real legendary guys man they've done a lot for the community and for the culture if. i had the honor roll it with some really good writers so i thought i was a man. as big annoyed some people doll as the level of belief i had of myself. they were known as being like a hotter but that sometimes i was again you know he played well in la but unlike a lot of guys got out i'm going to be in a lot but it was wrong. nobody could cause. i'd say both along the way.

godfathers and quiet graffiti. in a nice film was mostly about you naming it and just getting up. after doing so many pieces of your name you start to think well what else am i going to talk about . think maybe two years ago i had said i want the majority of my life's work going forward to come from my people and i met my whole line people and the people so from then till now has been this like intense immersion in the culture and learning as much as i can and promise had a big role in that his way of thinking of living is definitely whole way and it shifted how i think. we're still moving as far as who we are as hoeing and at this point in our lives i understand it more whereas if you told me one pound ago i will cheer because i was too busy being hip hop. but now i'm too busy trying to be home why it blew me away that somebody could do that with spray paint

it was a first time i had realized that hip hop culture and oil culture could make a nice mix. i mean that's the whole reason i connected them in the first place was to find. experts to come in to teach my students. this teacher named from the big island called prime and i and asked us if we could fly out to the big island and work with his students and teach them how to paint a mural i said hey you know making this million miles project and maybe you could be one of those toys yeah i'm millimeters of the project where we hope to go to other islands and teach the students how to pay murals mel it means songs so we used to lyrics as the foundation for the mural.

and. the. wind focus started school we teach culture language all within the school day. the vast majority of our population of native horn still are not fluent in our native language is a problem yes those it changed the trajectory of who a future yes it was and so there is a huge movement to shift that to be able to enable our identity to live in to

thrive through language. was. for me being whining this time with kind of hard is some people are just really darned mental why one time i went to ohio and someone thought i lived in a hut. but we're really privileged to have people who need us to stand around and bring back the ways that we feel grounded in our culture and like any project that i do i have to go out to the broader community to bring in experts and that was why i went to them in the first place oh everybody. so much but i hear us trying to hide until prime we've been here i've been painting get there by six seven years now and we've been going down this journey together

learning more about our culture and all of that has led up to this series of murals that we're doing called melamine else we can share with you how we paint how we grow each wall is going to tow a different story or a different song the students going to choose and we're going to translate that into a visual image and then teach them how to paint when i want. to with the kids when they first meet me really study legal. college girl feed me. gruffydd. show of hands how many of you like writing culture better known as graffiti. and.