# Astronomy 2: Special Relativity

Norman Gray's version, last presented Session 2013–2014

I delivered the A2 SR lectures for a number of years, up to session 2014–14. The notes below are still available, however, and you are welcome to consult them. Obviously, they may not perfectly match the current lecturer's aims, approach, or style for the course, so they should be regarded as strictly supplementary. The ‘podcast’ links below are to the 2013 set of lectures.

### Contents

Podcast
I make the lecture audio available as a podcast; see below for details.
Aims and Objectives
This is now the final version of the aims and objectives. It differs only marginally from the version distributed in October, by some slight rewordings.
Notes
The distributed lecture notes.
Tutorial questions
You are set four of these during the term; they count toward the final assessment. You can find these on Moodle.
Scribbles
The scans of the in-lecture scribbles are available.
What's new

The PDF files below are intended to be printed out on a double-sided printer; the nearby links marked ss are for printing out on a single-sided printer, the links scr are versions intended to be read on-screen.

## Podcast

I make available audio versions of the lectures, that is, a podcast. Please do let me know how you get on. I'm interested in whether you use these recordings, how, when, why, where, plus any other feedback that occurs to you.

If you have any problems with the feed, or with the enclosed MP3 files, do let me know fairly urgently.

## Notes and contents

From this page you can download the notes for each of the four blocks of the Special relativity course. These four blocks are

Part 1: Introduction
Central ideas and definitions. Inertial frames. How to measure lengths and times, and how to synchronise clocks. [ one lecture: pdf, ss, scr ]
Part 2: The postulates
Introducing and justifying the two postulates which SR rests on. [ one lecture: pdf, ss, scr ]
Part 3: Spacetime and the Lorentz Transformation
The central mathematical tool. The Minkowski diagram and the idea of spacetime. The invariant interval. [ four lectures: pdf, ss, scr ]
Part 4: Relativistic kinematics
Momentum, energy and force. [ four lectures: pdf, ss, scr ]

In the lectures, I will presume that you have already printed out the relevant part, and at least looked over them. You will not need to, and indeed should not expect to, understand things first time, but this preliminary scan should give you an indication of what bits of the lecture you need to pay special attention to. Having said that, don't be in a rush to print out everything – as I spot typos or other infelicities, I will occasionally adjust the notes as distributed here.

If anyone needs, for example, large-print versions of the notes, I can probably produce those easily.

The dangerous bend symbol introducing certain paragraphs is intended to indicate passages, or even whole sections, you might want to skip on a first reading. They typically contain technical detail for the curious reader, or subtle points which are interesting but might distract from the flow of the arguments, or even alternative ways of thinking about the material around them. Think of them as extended footnotes. The material in these paragraphs is not examinable, and I generally won't refer to it explicitly in the lectures.

## Other resources

Writing greek letters legibly
Aims and Objectives
This is the final version of the aims and objectives for this year [pdf, ss, scr].

## Recent changes

There's an Atom feed for the files in this directory, so you can be promptly informed of when files change. That's here. Follow that link (your browser may do the Right Thing) or paste that URL into a blog reader.