Week 5 (Sep. 22, 24, 26)
Read: The sun, the moon and the calendar (Chap. 8)
Quiz: Monday. Covers Ptolemy's Almagest.
Homework exercises: The moon and the zodiac (Ex. 8.1), Optional: Crescent moon (Ex. 8.2)
Laboratory exercises: Building a cross-staff (Ex. 7.5). Your cross-staff will be used later, when you are doing your Planetary observations (Ex. 3.2) and your Lunar observations (Ex. 8.4). Your lab book should include a detailed description of how you built your cross-staff apparatus (including a careful sketch) and also an explanation of how it is used. Also: include an example measurement of the size of an object across the room, such as a window or a standing person. How accurate is your measurement? Scan your lab book pages (minimum 2) and upload them to canvass.
The sun, the moon and the calendar (1 video):
How are calendars constructed? In the following video, I'll explain some of the issues that arose when constructing a number of traditional calendars, such as the Julian, the Gregorian, and even ancient Egyptian and Hebrew calendars.
Interesting aside: the French Revolutionary calendar was introduced, along with the metric system, by the French Revolutionaries in the early 19th century. They tried to make a base-10 system of time measurement, like the base-10 system of distance measurement. This new calendar system rejected traditional saints days and other holy days. Here is an interesting article on the French Revolutionary Calendar.
Predicting solar eclipses (optional fun video)
The ancient Babylonians used the so-called Saros cycle to predict the dates on which solar eclipses would occur. They could not, however, predict the location(s) on earth from which such eclipses would be visible. How can scientists today predict, to a high level of accuracy, both the location and time of visibility of solar eclipses? Check out this video from Quanta:
The Sidereal day versus the solar day (optional fun video):
There is a difference between one solar day (our traditional 24 hours) and one sidereal day (a period that is just under 24 hours). Here is a video from Veritasium on these two different definitions of the "day". It begins with a poorly-worded SAT question from 1982 that everybody missed (because the correct answer was -not- an option.)
Homework exercises: The moon and the zodiac (Ex. 8.1), Optional: Crescent moon (Ex. 8.2)
Laboratory exercises: Building a cross-staff (Ex. 7.5). Your cross-staff will be used later, when you are doing your Planetary observations (Ex. 3.2) and your Lunar observations (Ex. 8.4). Your lab book should include a detailed description of how you built your cross-staff apparatus (including a careful sketch) and also an explanation of how it is used. Also: include an example measurement of the size of an object across the room, such as a window or a standing person. How accurate is your measurement? Scan your lab book pages (minimum 2) and upload them to canvass.
The sun, the moon and the calendar (1 video):
How are calendars constructed? In the following video, I'll explain some of the issues that arose when constructing a number of traditional calendars, such as the Julian, the Gregorian, and even ancient Egyptian and Hebrew calendars.
Interesting aside: the French Revolutionary calendar was introduced, along with the metric system, by the French Revolutionaries in the early 19th century. They tried to make a base-10 system of time measurement, like the base-10 system of distance measurement. This new calendar system rejected traditional saints days and other holy days. Here is an interesting article on the French Revolutionary Calendar.
Predicting solar eclipses (optional fun video)
The ancient Babylonians used the so-called Saros cycle to predict the dates on which solar eclipses would occur. They could not, however, predict the location(s) on earth from which such eclipses would be visible. How can scientists today predict, to a high level of accuracy, both the location and time of visibility of solar eclipses? Check out this video from Quanta:
The Sidereal day versus the solar day (optional fun video):
There is a difference between one solar day (our traditional 24 hours) and one sidereal day (a period that is just under 24 hours). Here is a video from Veritasium on these two different definitions of the "day". It begins with a poorly-worded SAT question from 1982 that everybody missed (because the correct answer was -not- an option.)