About The Universe 3: Scale of the Universe and our Closest Neighbours

DISCLAIMER: I am not an expert in astronomy or physics. If you spot factual or numerical errors below, please report them in the comments section. If you have corrections to empirical distances or object data, please cite upto date authoritative references (ie. not Wikipedia), as I believe I have used the most recent accurate data available. Some figures have been deliberately rounded for simplicity and may contain rounding errors.

This document is in its 3rd draft and is not yet complete.

Welcome to chapter 3! In this chapter I’m going to talk about the scale of the Universe – that is, how big and old it is.

I’ve put off writing this chapter for almost a year. Part of the problem is that there is so much diversity around us that it’s impossible to summarise in a few pages. Another problem is how to describe and visualise the huge distances and times we’re going to look at – and that’s where we shall begin.

About The Universe 2: Our Neighbourhood: The Earth and The Nature of Planets

When I was a kid, I had a Time Life book called The Universe. It was published in 1967, two years before man first set foot on the moon. The Universe went into great detail about the neighbouring planets in our Solar System, but hardly talked at all about what lay outside. Without the internet or the money to buy books to find out more, I wondered about what is out there beyond the Solar System for many years. If you’ve been wondering too, then I’m going to tell you soon enough!

But first, let’s start at home with our own planet: Earth. In this chapter, I’m not going to try and explain the ‘how’ or ‘why’ of Earth, just the ‘what’; I’ll explain the overall behaviour of the Earth without explaining why it came to be this way. We’ll go into that later.

About The Universe 1: Introduction

Disclaimer: I am an expert neither on science nor religion. I have tried my best to ensure everything written herein is accurate, but if you spot a factual mistake, please post any suggested corrections in the comments section below and I will make the appropriate changes as soon as possible.

Inspiration

Some years ago, I had a young American girlfriend. One day, she told me she “didn’t believe in evolution” (evolution is the process by which plants and animals evolve over thousands or millions of years into more complicated or refined species). She said it as if evolution was something you could choose to believe in or not – like Santa Claus.

I was quite startled by this – it made me wonder what kids are being tought in schools in the U.S. these days – but, I should not have been so surprised. Nobody had ever bothered to explain evolution to her and she had no reason to ask: as a Christian with strong faith, for her, God created the Earth and put plants, animals and humans on it.

I am still friends with my ex-girlfriend and recently I approached her with renewed enthusiasm to try and give her meaningful answers about evolution and the general nature of physics and the universe, partly inspired by reading some books and other scientific material including an overdue re-read of Stephen Hawking’s A Brief History of Time. Brief History is meant to be a no-nonsense guide to modern physics for the layman, but in my personal opinion is still far too complicated for the person with no science background to understand. So I decided it would be interesting to publish a mini-guide of my own.