Can you tell real laughs from fake?
3 July 2012 Last updated at 03:51 BST
The Royal Society - the UK's academy of science - has opened its doors to the public for its annual summer science exhibition.
Researchers there are putting the latest in science and engineering on display - from a laughter lab to robotic footballers.
The BBC's science reporter Rebecca Morelle has been taking a look around.
Video by Rachael Buchanan