Art of the engineer

As ART HAS become more ideas-based and less about reproduction of the world around us, engineering's role in it has grown in importance. Creating gravity defying mobiles, rearranging the pieces of an exploded shed, building an inside-out sculpture of a house, and designing a fountain from tipping water hoppers, are all 20th-century works of art whose success is underpinned by engineering. How much of what we call art or engineering is about context? Do the materials and technology we use matter? And can the passage of time change our views on what is or isn't art?