Why do we use the terms West and East to describe parts of the world?

A simple answer to this question is to point to a map. There you have it: West is on the left, East is on the right. But this leads to another question: Why are most maps set out that way?

We humans a bit obsessed with trying to order the world. We give labels to everything in it, including the tiniest molecules, so of course it follows that we have divided the actual globe into segments. These can be called the Northern, Southern, Western and Eastern hemispheres. 

Most people are aware of the Northern and Southern Hemispheres, and since the Earth spins on its North-South axis, these don't change, so they are an easy concept to understand. 

A Pacific-centred map

However, what makes the Eastern and Western hemispheres more difficult is perspective. From New Zealand, Africa, Asia and Europe would be West, the Americas, East. 

To make things clear, people got together back in 1884 in the USA and had a conference. At this International Meridian Conference, they decided to agree that one spot on the globe would be referred to as the international zero longitude reference line, or the Prime Meridian. 

Probably because of where a lot of these people originated from, they decided on a place in the United Kingdom, called Greenwich.

A line running North-South through Greenwich thus divides the Earth into Eastern and Western hemispheres. Using this point as zero longitude and the Equator as the North-South divide, we can reference any point on the globe using numbers. Clever old humans. 

What about the Western/Eastern world in terms of politics?

Err, yeah. I'm not getting into that. But, in short, these terms are often used without reference to the lines on the map. When people talk about the Western world in terms of politics or wealth, they often mean the First World. So Australia and New Zealand are the 'West' in terms of way of life, despite being in the Eastern hemisphere.

My kid is lost

I don't blame it. You will need to explain latitude and longitude. An easy way to do this is to look at a map, or even better, a globe, and point out the lines that run through it. Everything is new to kids, so to tell them that people all agree that this one line is where we divide the world into West and East should be pretty simple. 

You could get out the compass and have a bit of an orienteering session on the lawn to get directions sorted. This concept is probably a 4 years+ Why, or maybe older? Those of you with 4-year-olds will be able to tell me this...I'm still dealing with the terrific twos. Good luck!

Next time

I don't have another Why just yet, so I'm going to call for questions again. Comment below if you have one. You have two weeks to think about it. Get whying.