Monday, November 23, 2020

That Star: How Far? The Cosmic Distance Ladder

Welcome

Welcome to That Star, How Far? (TSHF), Gale Rhodes's summer 2021 course at OLLI, the Osher Lifelong Learning Institute at the University of Southern Maine. 

Schedule

This course was taught in summer 2021.

Description

It's a simple question: How far away is that astronomical object? But you will be surprised how many different, fascinating areas of science you need to get to know in order to answer that question for all known objects: the moon, planets, stars, galaxies, and the most distant objects at the far edge of the universe. 

In this course, we will study not one method, but a set of methods for measuring cosmic distances, each method good for a specific range of distances, but none suitable for everything. Fortunately, their ranges overlap, so that all together they can get us from nearby objects, like the moon, to the most distant objects, which we see as they were near the time the universe began.

The full set of methods is called The Cosmic Distance Ladder. The primary "text" for the course is PhysicistMichael's series of videos on this subject at YouTube. 

I hope you will be delighted as I am at the number of fields and topics in modern science that bear upon the simple question, and at how broadly and deeply you can learn by following this seemingly thin thread. No science background is required for full appreciation of the matters we will discuss. No question is too basic to be worthy material for this course. 

Course Organization

Each week, usually during the weekend, I will send you email with a link to assignments of videos and readings for the coming week's class. We will watch specified videos together in class, but if you also watch them beforehand, you will get much more from them. Class will be mostly discussion of the assignments, largely driven, I hope, by your questions. My main goal is to fill in basic science background to help you understand the distance methods, as well as to help you understand science itself better, and also to give you tools to help you build a better understanding of the world around you.

On the right-hand column on this page (and every TSHF page) a list of class links will grow, each link taking you to the assignments and resources for the specified class meeting.

At the bottom of this page (and every TSHF page) is a form for submitting your questions, comments, and suggestions. The questions and comments that occur to you as you read or watch assignments help me greatly in planning the upcoming class. If you submit a contribution at least 24 hours before the next class, I can usually incorporate class material to help answer your questions. There will also be plenty of time in class for questions, but questions ahead are particularly useful in my planning.

Join me as we start with a tape measure and end with science's most powerful instruments in learning how scientists measure cosmological distances, and how they use the results to understand the history and future of the universe.

About Gale Rhodes

If you want to learn more about me, go to my website, One Culture, and look for About Me near the bottom of the right hand column. One Culture also contains other resources that might interest you, some of which we will use in this course. Look it over.