Scientists have been revealing some of their secrets to the public in 200 events across the EU, organised for European Researchers’ Night.
Among the demonstrations: in Madrid pond bacteria generated electricity to make an MP3 player produce Handel’s Water Music.
The Natural History Museum in London allowed visitors to handle specimens behind the scenes.
And in Turin they demonstrated how they are helping people in third world countries to make their own medicines.
It is the sixth annual even, intended to promote careers in science and research.
And an estimated 500,000 people took the chance to have a look at what goes on behind laboratory doors.
Some researchers took the chance to make a different point about science. There was a lie-down protest Turin to demonstrate against recent cuts in Italian research funding.