Travellinglight/Alamy
If Stonehenge is a giant calendar, how did the ancient Britons measure the length of days precisely enough to put the Heel Stone in just the right place to mark the solstices?
Eric Kvaalen
Les Essarts-le-Roi, France
They didn’t need to measure the length of the day. The solstices are the days when the sun rises the furthest north and the furthest south (in June and December respectively in the northern hemisphere). So they would simply observe where the furthest north or south sunrise happened.
Hillary Shaw
Newport, Shropshire, UK
This doesn’t require clocks, or any idea of what…
