Astronomy of Other Cultures - Muslim Astronomy - Habash al-Hasib
Introduction to Astronomy
[{'start': '0.000', 'end': '6.440', 'text': 'Greetings and welcome to the introduction to astronomy.'}, {'start': '6.440', 'end': '11.320', 'text': "In this week's astronomy of other cultures, we continue our look at the Muslim astronomy"}, {'start': '11.320', 'end': '19.560', 'text': "and we're going to talk about Habash al-Hasib and his contributions to astronomy and mathematics."}, {'start': '19.560', 'end': '21.400', 'text': "So let's go ahead and get started."}, {'start': '21.400', 'end': '23.320', 'text': 'So what do we know about him?'}, {'start': '23.320', 'end': '29.880', 'text': 'Well we know that he died in the year 869 at the age of about 100.'}, {'start': '29.880', 'end': '34.760', 'text': 'So it looks like he had lived to about 100 years old.'}, {'start': '34.760', 'end': '39.160', 'text': 'And he did work in both mathematics and astronomy.'}, {'start': '39.160', 'end': '40.840', 'text': 'So what did he do?'}, {'start': '40.840', 'end': '46.080', 'text': "Let's look at the mathematics first and one of the things that he did in math was to work"}, {'start': '46.080', 'end': '48.320', 'text': 'on trigonometry.'}, {'start': '48.320', 'end': '54.440', 'text': 'So trigonometry is looking here in this case at some of the other functions, so sine and'}, {'start': '54.440', 'end': '61.800', 'text': 'cosine were known at the time, but he developed and discovered the functions of tangent and'}, {'start': '61.800', 'end': '69.320', 'text': 'cotangent, which would become very useful in various types of calculations of astronomy.'}, {'start': '69.320', 'end': '76.920', 'text': 'And in fact, related to this on the astronomical side, he did compile several different astronomical'}, {'start': '76.920', 'end': '78.640', 'text': 'tables.'}, {'start': '78.640', 'end': '84.160', 'text': 'So developing various different tables and having to do the calculations there to figure'}, {'start': '84.160', 'end': '89.760', 'text': 'out positionings of things like the planets over the course of time.'}, {'start': '89.760', 'end': '95.840', 'text': "He also discovered a relationship which we now know as Kepler's equation, but was actually"}, {'start': '95.840', 'end': '103.480', 'text': 'known here well before Kepler, almost a millennium before Kepler, about 700 years or so, before'}, {'start': '103.480', 'end': '105.680', 'text': 'Kepler did his work.'}, {'start': '105.680', 'end': '112.040', 'text': "And that was what is now known as Kepler's equation, but actually developed here by Habash"}, {'start': '112.040', 'end': '113.800', 'text': 'al-Hasib.'}, {'start': '113.800', 'end': '119.160', 'text': 'Now he also did some other work on the book of bodies and distances.'}, {'start': '119.160', 'end': '125.680', 'text': 'Now this was a way of looking at the sizes and distances of things like the earth, the'}, {'start': '125.680', 'end': '127.560', 'text': 'moon, and the sun.'}, {'start': '127.560', 'end': '129.840', 'text': 'So how far away are they?'}, {'start': '129.840', 'end': '134.040', 'text': 'What are their specific distances and sizes?'}, {'start': '134.040', 'end': '136.600', 'text': 'And those are things that are very difficult to measure.'}, {'start': '136.600', 'end': '141.040', 'text': 'If we think about them even from a modern standpoint, we have a little bit more of an advantage'}, {'start': '141.040', 'end': '146.600', 'text': 'because we can use things like radar to figure out how far away the moon is.'}, {'start': '146.600', 'end': '149.920', 'text': 'And we can use other methods to figure out things like sizes.'}, {'start': '149.920', 'end': '152.640', 'text': 'So right now we know them very accurately.'}, {'start': '152.640', 'end': '157.760', 'text': 'And while his measurements may not have been accurate by modern standards, they were actually'}, {'start': '157.760', 'end': '160.400', 'text': 'pretty good considering the time.'}, {'start': '160.400', 'end': '166.080', 'text': 'And the fact that many of the distances that we have in astronomy are vastly larger than'}, {'start': '166.080', 'end': '168.640', 'text': 'we would normally expect.'}, {'start': '168.640', 'end': '174.580', 'text': 'So trying to even imagine some of those distances is difficult, but really trying to make some'}, {'start': '174.580', 'end': '180.760', 'text': 'of these measurements was things that had been done earlier by the Greeks and now here'}, {'start': '180.760', 'end': '186.640', 'text': "by the Muslim astronomers that we're looking at, trying to measure those sizes and distances"}, {'start': '186.640', 'end': '194.960', 'text': 'to figure out how far away these various objects are from earth and their relative sizes.'}, {'start': '194.960', 'end': '201.320', 'text': 'So those are a few of the things that he did that contributed to both mathematics and to'}, {'start': '201.320', 'end': '203.120', 'text': 'astronomy.'}, {'start': '203.120', 'end': '206.760', 'text': "So let's go ahead and finish up with our summary here."}, {'start': '206.760', 'end': '213.000', 'text': "And what we've looked at so far this time is we talked about Habash al-Hasib and he"}, {'start': '213.000', 'end': '219.800', 'text': 'is believed to have died around 869 at over 100 years old.'}, {'start': '219.800', 'end': '226.400', 'text': 'For in mathematics he did discover the trigonometric functions we now know as the tangent and the'}, {'start': '226.400', 'end': '234.000', 'text': 'cotangent, and he made estimations of the sizes and distances of objects like the earth,'}, {'start': '234.000', 'end': '236.560', 'text': 'moon, and sun.'}, {'start': '236.560', 'end': '243.200', 'text': 'So that concludes this discussion on Habash al-Hasib and his contributions to astronomy.'}, {'start': '243.200', 'end': '249.120', 'text': "We'll be back again next week to talk about another astronomer of the Muslim world."}, {'start': '249.120', 'end': '255.160', 'text': 'So until then, have a great day everyone, and I will see you in class.'}, {'start': '255.160', 'end': '265.160', 'text': '[ Silence ]'}]