Why is the number 13 evil?

In Sunday school last week, our teacher explained to us how numbers can be evil. I don't like going to Sunday school anymore since my friend Steve got kicked out. (If you want to know how it all happened, you'll have to read my post on 'So, when was God invented, then?'). But my parents think it's a good idea to have at least some religious education. Most of the stuff we get told doesn't make any sense to me, but I still go because my dad promised to get me a new bike for Christmas...

I think what our teacher was trying to tell us was that the devil has a number and that we should avoid using it (it's 666 - in case you're interested). He wanted us to know that 13 can be evil too. I didn't believe any of it and so I tried to think of more interesting things (such as building a fort this winter and playing Quidditch with my friends - we use broomsticks as well, but none of us can fly). I also tried to think of my new bike.

But I know that some people like to believe in strange things. My mom for example thinks that our uncle Herbert is special because he was born on Christmas Day. He believes in angels and sees people who aren't there. (He also uses aluminum foil to wrap his furniture in case aliens want to steal his lunch.) I think Uncle Herbert is schizophrenic. But my mom is convinced that he has visions. And when I asked her about the numbers, she couldn't explain any of it. So I decided to do some more research ...

Here's what I found: a normal year in our calender has a little over 12 lunar cycles, so there's an odd month every four years or so. In the old days, some of the monks who were responsible for coming up with new calenders didn't like this because it was too difficult. That's probably why they thought the 13th month was unlucky. (Find out more about lunar cycles and the blue moon on space.com)

13 is also important for Christians because, when Jesus had his last supper, there were 12 apostles at his table (13 people altogether). One of them betrayed him, so I guess he must have thought 13 was evil. 

In the Jewish religion, a boy achieves maturity when he turns 13. He then becomes a full member of the community (although I don't know if this is a good or a bad thing.) I think witches are cool, so I think it's important that there are normally 13 witches in a coven.

I guess people are a little afraid of the number 13 because there are some very complicated things you can do with it in Maths (and Maths is always scary). There are 13 Archimedean solids, for example, and people say that there are 13 ways for the three fastest horses to finish a race (if you're into this kind of stuff, you will be interested to know that this is because 13 is the third ordered Bell number - you can find out more about Bell numbers here). 

I also think people believe 13 is unlucky because it's an odd number that doesn't seem to fit in anywhere. Some people think it's bad to start a new project on a Friday or on the 13th. But I think that's mostly because you would run way into the weekend before you could finish it...

I like funny words, so I think it's pretty cool that fear of the number 13 is called 'Triskaidekaphobia'. But - as it turns out - the number 13 is not an evil number after all, it's just been a bit unlucky. Not because it's evil but because superstitious people don't seem to like it very much. 

I'll have to talk to my Sunday school teacher on Sunday. Steve and I wanted to start building a boat next Friday. If I talk to him about his superstitions this week, I think there's a good chance that we'll have enough time to finish it next Sunday morning. If I do it right, he'll kick me out too and I could tell my dad it wasn't my fault ...

If you want to know a little more about why people don't like the number 13, check out this post on mentalfloss.com. I took the Quidditch picture from Harrypotter.wikia.com. The first 13 came from the Telegraph website and the calendar with Friday 13 came from a blog called blog.pch.com.