If we brought all the virus particles of the Sars-CoV-2 virus from every human currently infected, how much would there be? This was a question posed by one of our listeners. We lined up two experts to try to work this out. YouTube maths nerd Matt Parker and Kit Yates, senior lecturer in mathematical biology at the University of Bath, UK give us their best estimates. One believes the particles would fit into a small can of coke, the other a spoonful.