Astronomy:  How Our Calendar Came to Be

Why don’t days, weeks, months, or years divide evenly? Why do our months have different numbers of days? Were you aware that most days (sunrise to sunrise) are NOT 24 hours long? Or that the equinox does NOT have equal 12-hour day and night times? Have you heard that, even within the modern western world, different calendars were used for centuries which did not agree on what date it was, or even what year? Why do we have regular leap years—and then skip some of those anyway? Why do we have leap seconds? Why is December (the name means 10^th) the 12^th month? Why does the new year start on January 1^st? (For most of history—it didn’t!) Did you know that Halloween, and even Ground Hog’s Day (Wednesday, February 2), are astronomically determined dates? Plus—what are the planets and constellations doing this month? Join us by Zoom to learn more!

Please register to receive the Zoom login. You may register up to the presentation start time or even during the meeting to join us.

https://msu.zoom.us/webinar/register/WN_YIs9rvkbRs6gzufqGrDTHg

Time allowed for live Q & A throughout the event. ASL Interpretation featured during the event.

Join us for a presentation focused on the modern western calendar. We will show you how ancient civilizations measured things like the length of a month or a year and determined the cardinal directions N, S, E, and W (did you know that directions are based on astronomy, not the compass?), with great precision, all without the use of telescopes or even clocks. You can make these measurements yourself! We will follow the development of the calendar as it changed through time: sometimes improved, sometimes not so much. Along the way, we will provide answers to all the questions raised above. Finally, our monthly technology update will focus on the recent activity of our sun.

And, as always, we will show you how to find many fun things in the sky this month. Have you noticed that one part of the winter sky features more of the brightest stars than any other season? Do you know how to use Orion as a pointer system to locate many other stars and constellations? Were you aware that four bright planets will be lined up in the morning sky this month? We will help you see all of these things for yourself.

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Michigan State University is committed to providing equal opportunity for participation in all programs, services, and activities. Accommodation for persons with disabilities may be requested by contacting 989 374-9904. 

Programming is made possible through the support of several local organizations: the Herbert H. and Grace A. Dow Foundation, the Rollin M. Gerstacker Foundation, the Charles J. Strosacker Foundation, and the Dow Chemical Company Foundation.