It is that time of year again. The sun and Jack Frost are working together to paint the land.
In this photo of a dog-mauled football, we are looking southeast. But why does the football’s shadow appear longer than the patch of frost? Surely, since the sun is rising it should be the other way round?
Useless clue: it doesn’t have anything to do with the dog, who wisely avoids footballs until they are well defrosted.
UPDATE: The patterns of frost we see as the day wears on are shaped by more than one factor.
The areas that have received direct sunlight will of course thaw faster than those that remain in the shade.
The colour of a surface has a huge effect too. Dark earth will thaw faster in the sun than light-coloured stone.
The wind also has a big impact on any day with a light breeze or…
