Hello and welcome to more or less on the BBC World Service. We are the program that

loves to chat about the numbers in the news and in life, and I'm Tim Halford. This week,

governments around the world are trying to prop up their economies, their loans and grants

for businesses, schemes to subsidise workers while their jobs are impossible, and lots more

besides. But where does the money come from? But first…

Social distancing is important, so please keep at least 2 metres away from other travellers

on the station, onboard the train and when queuing at ticket barriers.

As lockdown starts to lift, many countries are relying on social distancing to continue to

slow the spread of coronavirus. In the UK, the rule is that people should stay 2 metres apart,

but it's different around the world. So where does this figure come from?

These recommendations are based really on the physics of these particles.

This is Werner Bischoff, professor or infectious diseases at Wake Forest School of Medicine

in North Carolina. He's conducted studies to see how far away from influenza patients,

he can find the tiny virus filled droplets which are emitted when people just lie around breathing.

What we found was that larger droplets were found close to the patient head.

The smaller ones then took over when you got to the end of the patient bed and then away from

the patient bed. It wasn't that some droplets were clean and some droplets were infested with

virus particles. It was the size of the droplets was different.

Exactly. We had a distinguishing between roughly 2 sizes. One is greater than 5 microns.

These are large droplets. They behave like a ball that you throw so that falls down once it is

kind of emitted from a patient's mouth. Gravity simply pulls these larger particles to the ground

within 1 meter. And so we have the very fine particles that can float through the air for an extended

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