AST241 Introduction to Astrophysics

General Information


Prasenjit Saha


Davide Fiacconi
Irshad Mohammed

Vorlesungsverzeichnis: AST421

What is astrophysics? The branch of physics where gravity is important!

It was not always so. For thousands of years, astronomy had been about what happens in the sky. But in the 17th century, Newton started getting the Moon mixed up with apples, and soon astronomy became all about forces and accelerations. Through the 18th and 19th centuries, astrophysics was synonymous with orbits, ever more complicated examples, until Poincaré showed that real orbits are mostly chaotic anyway.

In the early 20th century, two previously unimaginable things appeared: quantum mechanics and general relativity. Quantum mechanics and its results, the theories of radiation, atoms and nucleii quickly saw themselves applied, together with old-fashioned Newtonian gravity to understand how stars worked. General relativity developed more slowly, but in time it led to black holes and the expanding Universe.

In the early 21st century, we are seeing atomic physics showing itself in a general-relativistic context, in the form of the cosmic microwave background. And meanwhile, older topics in astrophysics, once thought to have been completely solved, are producing new surprises through new discoveries, like extrasolar planets.

In this course we will try to understand something of this story. The ingredients will be basic physics, together with some mathematical methods and scientific computing.

This Course

This course will run in an inverted classroom (umgedrehter Unterricht) format. The basic material is put into video lectures, which students watch (whenever they want) in advance. The scheduled lectures can then spend more time on class discussion and on points that weren't clear in the lectures. Please see the

online platform for this course

and register there if you wish to follow the course. The platform is a local installation of the well-known openEdX platform. Please register there if you are taking the course. You will need to use a browser that supports mp4 video. If this video (MP4, 12 MB) plays in the browser, everything should be fine.

The local openEdX installation a sandbox, which means it does not really do all the things it claims. In particular, it does not really enroll you at the University, or give certificates. So you can enroll on the platform, join the discussions, and so on, even if you are not actually taking the course.