Tuesday, 22 December 2015

Christmas Science - The Crack in the Cracker

What puts the crack into crackers and how to always get the prize when pulling them?

Christmas dinner without the crackers would be just plain wrong. I can't quite explain why and I'm not even sure why I like having crackers, but they clearly fill a special place in my expectations of the festive season. Especially when you pause to consider the chemistry involved...

Inside the centre bit of the snap in a Christmas cracker is a tiny amount of a chemical called silver fulminate (AgCNO). This chemical is fantastically sensitive explosive. The weight of a feather is enough to detonate a small pile of the stuff the size of a penny. On one end of a thin card strip they paint the silver fulminate and on another bit of card then stick some sand. When you pull the snap apart, the sand rubs across the silver fulminate and it explodes. As an aside, silver fulminate is the same stuff they put in those little twists of paper that make a bang when you chuck on the ground (Snappiest maybe?).

When it comes to winning the cracker prize, my scientifically proven method is this. Just make sure you pull in a straight line with the main body of the cracker. If you pull at an angle, you put more pressure on one side of the gathered cardboard and it will being to tear. Once a tear starts the pressure on the other bits of gathered cardboard increases and it is a slippery slope to loosing the prize.

Talking of prizes, there is a Kindle and audio version of my new book available for instant download.

Just saying....

1 comment:

  1. Study of Christmas Science is really entertaining and a part of this study have this article. I think this one is good for the all christian people who like to celebrate Christmas with full excitement. Any how, I'm looking a source to buy your dissertation online but theme of this site is sound impressive and looking awesome. thanks for this articles.


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Science TV Presenter, live show performer, writer, strange prop builder and all round Science Bloke. All opinions expressed are mine alone. Not the BBC's, just mine.