Some inventions are practical attempts to solve real problems. Others are essentially frivolous, but end up making a genuine difference to our lives.
Some are neither, but are really funny anyway.
Enter British Inventor Colin Furze, and his latest contraption: a giant bum designed to launch a gigantic fart at France.
The tinkerer, who has also been responsible for the world's fastest toilet, created the enormous metal arse and fitted it with a pulsejet, after he realised that the jet sounded just like a bottom burp.
Furze thinks the resulting fart was loud enough to be heard across the Channel.
Here's the fart itself:
Here's how he made it:
And here's a timealapse of him doing just that: