수학과 천문학

• Constellations of the zodiac, 2009, http://www.youtube.com/watch?v=eeQwYrfmvoQ&feature=youtube_gdata_player.
• How to make and use a planisphere, 2009, http://www.youtube.com/watch?v=EP0AhYGXp2g&feature=youtube_gdata_player.

해시계

http://mysite.du.edu/~jcalvert/astro/gnomon.htm

태양의 declination http://www.wsanford.com/~wsanford/exo/sundials/DEC_Sun.html

지역의 latitude http://www.travelmath.com/city/Berkeley,+CA

지역의 태양 고도 altitude http://www.timeanddate.com/worldclock/astronomy.html?n=791

A+L-90= D

astrolabe

• http://wymarc.com/artifacts/classes/The%20Astrolabe%20in%20Theory%20and%20Practice.pdf
• astrolabe 제작 http://www.eso.org/~ohainaut/bin/astrolabe.cgi
• http://www.ted.com/talks/tom_wujec_demos_the_13th_century_astrolabe.html
• How It's Made (Season 14 / Episode 7 / Part 2), 2010, http://www.youtube.com/watch?v=V8ja_4_IgHY&feature=youtube_gdata_player.