ASTR152i Spring 2011
Astro/Phys 152i: Freshman Seminar in Astrophysics

Work

Lectures

Instructor: Beth Willman
INSC L108
610.896.1201
bwillman at haverford dot edu

Class: every other M 7:30 - 10 pm in the observatory
First class is Wed Jan 19.
Office Hours: M 9 - 10 am, 3 - 4 pm; Tu 10 - 11 am; W 3 pm - 4 pm; by appointment


Prerequisite:Physics 101a, 105a, or Bryn Mawr equivalent.
Supplementary text: Just Six Numbers by Martin Rees. We will also use some outside readings.

Nutshell:

This course will introduce you to exciting topics in astrophysics by asking you to apply fundamental physical principles to a variety of astrophysical phenomena. Steve Boughn developed the majority of the concept and material that will be used in this course.

Details:

The theoretical framework needed to investigate many astrophysical phenomena can be expressed in terms of fundamental physics at the level of an introductory college course. Although the details of these phenomena are quite complicated, we can construct simple models and make judicious approximations. This is not a limitation of the course. This is exactly what working scientists often do.

Working scientists also must often draw from many different areas of physics to pursue the answers to questions, at great difference from typical coursework which requires you to apply restricted techniques to solve a set of restricted problems. For example, to understand why stars shine requires a combination of thermal and statistical physics, gravitational physics, hydrodynamics, electrodynamics, nuclear physics, radiative transfer, quantum mechanics, etc. The relationships between different areas of physics will be underscored as we deal with astrophysical problems without restriction on our techniques. This course will therefore provide you insight on how to go about solving general physical problems the way scientists do.

The skills that this seminar will emphasize include: the ability to identify the most important feature of a complicated problem, the ability to build simple models to capture the important feature(s), the ability to make approximations, the ability to perform back-of-the-envelope calculations, and the ability to judge whether you have obtained a reasonable result.

Just Six Numbers by Martin Rees, is not a resource for achieving the above goals. It is intended primarily for a non-technical reader. However, it provides a backdrop for the topics we will study. It will also provide examples of the inter-relatedness of physics. Finally, it tells a fascinating story of how a few seemingly unrelated quantities have conspired to allow the existence of just the kind of Universe that can have us in it. Some of the discussion seems more philosophical than physical and illustrates Rees's particular take on the subject.

Class Format:

In addition to the first introductory lecture, there will be six classes that meet every other Monday evening. A reading assignment will be given in advance (from Rees, your current physics text, and from a few other sources). You will be assigned questions and problems based on these readings that will be due at the beginning of each class. The workshop nature of the course necessitates that assignments be completed before class. Solutions for each assignment will be handed out at the beginning of each class and no late assignments will be accepted. If you must miss class, you need to get advance permission from me; I'll assign a short 3-page paper on the night's topic to make up the missed assignment and workshop. These assignments constitute an integral component of the course and its very important that you put considerable effort into completing them.

Each class will begin with an introductory lecture that will help set up the topics for the night's topic. The remainder of the class will be a workshop in which we will discuss the topic and break up into teams to work on several defining problems. During the workshop there will be a coffee/cookie break. The workshop problems will not be typical textbook problems, but rather questions like, "Why is there a maximum mass of a neutron star, what is this mass, and what happens when this mass is exceeded?" These will entail marshaling information from the written assignments, the readings, your overall knowledge of physics, and your ability to make simple models of the systems - in short, doing physics. One student from each team will be called on to report to the class on their deliberations and another team member will be appointed to write up the solution to the team's workshop problem. These solutions will be distributed to the entire class.

Assignments and Grading:

Doing real science is not about plugging and chugging, therefore the qualitative portions of the homework and the requests for commenting on your results are at least as important as any calculations.

Due to the nature of this class, attendance is mandatory. Any missed class will result in a severe grade penalty unless it is excused and a short make-up paper is completed.

Your grade in this course will be based on participation (45%), homework (40%), and a short final exam (15%). "Participation" is broadly defined and includes attendance, completing reading assignments, engagement during lectures and workshop, quality of homework effort, and the writeup of workshop problems.