Susan Philipsz guns for glory at Edinburgh festival – the week in art

Exhibition of the week Susan Philipsz The One O'Clock Gun is fired nearly every day from Edinburgh Castle in a tradition dating from 1861. It once had a practical function as a message to shipping. At this year's Edinburgh festival, it becomes the focus for a meeting of the city's cheerful tourist side and coolest artistic ambitions as Turner prizewinner Susan Philipsz installs sound works around the city that respond to the gun at 1pm daily. Her voice replying to the gun can be heard by Nelson's Monument on Calton Hill, in Old Calton Cemetery, on North Bridge, Waverley Bridge, next to the National Gallery on The Mound, and in West Princes Street Gardens . • Edinburgh art festival , Edinburgh from 2 August until 2 September Other exhibitions this week Callum Innes This Edinburgh painter works with light to illuminate the underside of a beautiful bridge. • Regent Bridge, Calton Road, Edinburgh from 2 August until 2 September. Dieter Roth An intimate encounter with a fascinating European artist. • Fruitmarket Gallery , Edinburgh from 2 August until 14 October Catherine the Great This great patron of the 18th-century Enlightenment is celebrated with treasures from the Hermitage in St Petersburg. • National Museum of Scotland , Edinburgh until 21 October Ian Hamilton Finlay The poet and artist whose garden is a national treasure gets a welcome showing in the Edinburgh art festival. • Ingleby Gallery , Edinburgh from 2 August until 27 October Masterpiece of the week Goya, El Médico (The Doctor) This shadowy vision of the human predicament is one of the most haunting paintings in Edinburgh's greatest art collection . • Scottish National Gallery , Edinburgh Image of the week What we learned this week How a 10km-long computer "cemetery" in Ghana provides an income for many of the people living there – and how photographer Nyaba Leon Ouedraogo is bringing its health risks to light That Diana Athill remembers a London when Kew was exotic, Selfridges was vulgar and all men wore bowler hats Why Tino Sehgal's work at Tate Modern is the most difficult and dangerous project director Chris Dercon has ever put in the museum That more and more people are creating DIY photobooks, spawning a collection that celebrates "naughty pics" That Chief Joseph's shirt auctioned for $900,000 That two men have been charged with stealing a Henry Moore sundial And finally Post your personal images that sum up what London means to you on the Guardian Art and Design Flickr page Share your art on the theme of sport now Check out our Tumblr Follow us on Twitter Are you the person the Contemporary Art Society are looking for?