Next month a tiny sundial will arrive on Mars.
Last month work began on the biggest sundial in the world, near Chesterfield.
Architects incorporate sundials in the most modern designs.
On the internet you can tell the time - by sundial.
Why, as we become more technologically sophisticated, are we turning again to the most ancient and simple method of measuring the passage of time, by the movement of a shadow? Paul Allen investigates the renaissance of the sundial as sculpture and technology, science and art.