12 Mince Pies A'Popping in SLOW MO | 12 Explosions of Christmas with Greg Foot | Head Squeeze

Day 12 of BBC Worldwide's Interactive advent calendar - click here to see what other festive treats we have for you https://www.youtube.com/watch?v=YyjhcWDRnyM&list=PLO-wxIy9sHyYhRFlZR9n4EGQW1jBO05uR&index=1 Here is the first science explanation behind Greg Foot and Mike Sansom's '12 Explosions of Christmas'.

At the top of the list is 12 mince pies a'popping -- well we should say EXPLODING with flash powder!

All any explosion needs are the three elements of the fire triangle, a fuel, oxygen and heat. In this explosion there's plenty of all three.

Using a fuse made from string covered in black powder, leading to a trail of loose black powder, Greg and Mike set off a series of 12 mince pies each with 0.2g of flash powder in them.

Both black powder and flash powder contain fuel and oxygen which means they burn when lit with a flame, producing hot expanding gases. But what's the difference between black powder and flash powder? Flash powder burns quicker out of the two, producing even more hot expanding gases. Charles' law (a gas law) states that when the temperature of a gas increases, its volume also expands. So when the flash powder is confined (say for example, in a mince pie!) it creates gases that heat up quickly and need more room which makes the mince pies POP.

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Check out Greg and Mike's '12 Explosions of Christmas' bonanza here:

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Follow Greg Foot for more science daredevil mayhem: https://twitter.com/gregfoot

Follow Mike Sansom for all your firework needs: https://twitter.com/brightfirepyro

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