Greg Foot: Hey guys, so hopefully by now you've seen our '12 Explosions of Christmas' video.
It was a lot of fun to make.
Sorry, I should probably introduce myself.
I'm Greg -- Mike Sansom: And I'm Mike.
Greg: Mike is a professional pyrotechnician.
So we joined forces and took this thing to Head Squeeze and said 'hey would you guys
like to put this on your channel?' and they were like 'YEAH!'.
So we wanna make some making of films and also look at the science behind each explosion
so let's start with number twelve, which is twelve mince pies a'popping!
So this was just a dead simple explosion.
So first up, what is an explanation?
Well every explosion for something to burn it requires three things.
It requires the three corners for what we call the fire triangle, which is a fuel, oxygen
and heat.
And we used a few different explosives for this first explosion of Christmas.
So what do we use first?
Mike: Right, so, first of all we lit a fuse.
This is a fuse here, this is basically a length of string covered in black powder, and when
we burn this it burns nice and slow.
OK, then it lead to some black powder, here I've got some black powder.
I'm going to place it on here.
Now black powder is very rich in oxygen and fuel so when we light it, it produces a large
amount of hot, expanding gases.
It burns very quickly.
Greg: And that is the brilliant thing about black powder, you'll be seeing black powder
a little bit later, in one the later explosions of Christmas.
So it's got all three elements there, as Mike said, it's got the fuel and the oxygen inside
it and you're giving it the heat.
All three elements of the fire triangle, explosion!
But we didn't use black powder in our mince pies.
Mike: We couldn't use black powder in our mice pies, it wouldn't go bang.
So we used something else called flash powder.
Now this is a lot more explosive!
It produces a lot more hot expanding gases, very very quickly.
On the drum here I've got about 0.2g of flash powder, exactly the same amount as what was
used in there.
If I light this -- (poofff) -- it's a LOT quicker.
Greg: I shouldn't have looked at that should I?
Mike: You shouldn't directly look at it, no.
Greg: You can see why it's called flash powder, that is what was used in flash photography.
It burns very very quickly, you get loads of hot expanding gases.
And if you confine, which is what we did in our mince pies, then that's what causes the
explosion.
Mike: Can't wait!
Greg: Yeah, let's do it!
Oh and don't try this at home!