For two decades now, scientists have gathered at Harvard University to recognise unique and at times comical scientific discoveries for the Ig Nobel Prize.

This year, among other notably odd endeavours, a Russian researcher was recognised for crushing old army ammunition into new diamonds. Other winners included two Japanese researchers honoured for developing a device that forces people to stop speaking, and a group of US researchers for "demonstrating that brain researchers, by using complicated instruments and simple statistics, can see meaningful brain activity anywhere - even in a dead salmon".

The awards are adjudicated by the Annals of Improbable Research journal, which says that the aim of the awards is to honour research that makes people laugh, but also think.

Al Jazeera's Tom Ackerman reports.