Sit people in a parallelogram or a hexagon for safest picnic

GROUPS should picnic in the shape of a parallelogram, hexagon or pentagon if they want to meet together while still maintaining social distancing and good hygiene, experts have said.

On Monday, lockdown restriction will ease so that six people can gather together for the first time since measures were imposed on March 23.

Experts said that it was safer to have a picnic rather than a barbecue, despite what Boris Johnson, the Prime Minister, said at Thursday’s press briefing.

Prof Sally Bloomfield, of the London School of Hygiene and Tropical Medicine, said: “If you really want to have a social gathering and a meal, and the more time we spend outdoors the better, then it should be a picnic, where we each bring our own food and knives, and forks and plates, and everything, and keep them to ourselves and take them away with us.

“Then we can have a really nice social gathering. But barbecues, please, no, at the moment.”

Bobby Seagull, a maths specialist who presents the BBC Two series, Monkman & Seagull’s Genius Adventures, suggested the most efficient way to keep people the correct distance apart is to form a series of triangles, with each person sitting at an apex.

When six people are positioned in this way, it forms a parallelogram.

Mr Seagull said: “My solution is not perfect but means anyone could leave without upsetting others’ social distancing. We think that this problem is trickier than at first sight.”

However, mathematicians at Oxford University believe that sitting in a hexagon or pentagon would be a more efficient solution, taking up less space and allowing minimum distance between people.

Jason Lotay, professor of pure mathematics at Oxford University, said that putting six people in a hexagon, each two metres apart, would require just 10.39 square metres. Forming a hexagon means the maximum distance between two people is four metres at the extremities, while the average distance that one person has to another person is around 2.29 metres. Alternatively, if one person is placed in the middle so that the other five form a pentagram then the maximum distance between any two people is just 3.80 metres.

However, although the pentagram requires a smaller area – 9.51 square metres – the average distance that one person has between another person rises to 2.72 metres.

For people who insist on hosting a barbecue next week, Prof Patricia Riddell of the University of Reading has said they should consider one-way systems and bring their own condiments.

“You could have routes of travel so people go round one way to the barbecue,” she said. “I think you could make it quite good fun.”