Here are some works of artists that I revere ; James Turrell has made a number of observatories all over the world. His intention is to make people look at the sky in a new way through his interventions. The work I visited in Unna is a circular tower with a round hole in the roof. People are invited to watch the sky from inside the tower as the sun sets. The darkening sky, which is all that is visible throught the hole, is offset against subtle led colours on the inside of the ‘watchtower’. It becomes clear after a while that the sky never gets black; in fact it doesn’t get darker than a beautiful deep dark blue.

I visited a work of Olafur Eliasson in Aarhus, Denmark. He had a huge colour wheel made of coloured glass put on the roof of the town museum.

Sigmar Polke (Summer 2014,Tate Modern) works with light in a very different way. The glass panels shown here have drawings of soot on them. The wall behind reflects light through the partly transparent images. I have turned the images 90 degrees. His most famous works are partly transparent. He plays with the idea that people want to look inside the artist, to have transparency in a hidden world of ideas.