Julian Bell, Joseph Wright and Britain's Titian triumph – the week in art

Exhibition of the week: Dreams of Here Julian Bell's paintings are fireworks wrapped in brown paper. They are unassuming, but contain luminous wonders. Bell paints what look like meticulous images of real life, from a magazine stand to an English village. In fact, his compositions are imaginary, but the sense of reality is not an illusion. He is a very traditional artist in that he observes nature and the world closely, and his fantastic scenes arise from what he discovers: his skies are real skies, behaving as skies behave. While David Hockney seduces multitudes with his return to rustic reality at the Royal Academy , so in this exhibition three painters – Tom Hammick and Andrzej Jackowski alongside Bell – affirm the delights of landscape and figuration. Hammick's nocturnes and Matisse -like tapestries of colour are vivid and romantic, and Jackowski's scenes of cruel relationships in small rooms are rats that bite at the skull. Dream (or nightmare) and reality merge for these three artists. But it is Bell who really startles and fascinates me, because he is doing something so deeply original and distinct from fashion. Bell is also a critic and writer on art , and that may help explain why he can start from a different premise to most of today's artists. He has the intellectual equipment to make decisions about what he does based on on his own beliefs, instead of absorbing the received ideas of art colleges. To do the obvious is now a very sophisticated act. Not that Bell's paintings are obvious. Beginning in the quotidian, they leap to amazing heights. His scenes are carefully, painstakingly drawn, but what flames them into life is a brilliant painterly feel for colour. He has learned to create almost blinding light effects – a white glow against a pale blue sky, a golden, heavenly newsagent's display, and – most dazzlingly – the flaming gas crater, like an impossible volcano, in his Wright of Derby-like painting Darvaza (2011) , which is full of alchemical colour combinations. Bell is a modern painter. In his 2004 picture Exercises at Imber , tanks aim their guns across a dreamy English landscape. The village nuzzling in a valley is actually an abandoned settlement at the heart of the military zone on Salisbury Plain . But in the painting it looks inhabited, warm and lovely – and archetypally English – as the guns brood over it with monstrous intent. • At Brighton Museum and Art Gallery until 10 June Also opening Johan Zoffany A very welcome exhibition for a very curious and fascinating 18th century painter of British life. • At Royal Academy, London from 10 March Diana and Callisto Titian's great painting of mythology and the nude, secured for the nation , and on display as part of our public collections. What a joy. • At National Gallery , London until 1 July Thomas Ruff: Nudes Massive images of nudes enlarged from internet pornography. • At Gagosian Gallery, Davies Street , London from 8 March Imagined Lives Fascinating portraits of unknown people invite you to make up their lives. • At National Portrait Gallery , London until 1 July Masterpiece of the week Joseph Wright of Derby, The Orrery, 1766, Derby Museum and Art Gallery Children and adults gaze in wonder at a model of the solar system in brilliant lamplight . The lamp or candle appears to be actually inside the brass astronomical contraption of the orrery , shining out on rapt faces, so it is as if these people are literally being illuminated by knowledge. This is a painting that captures the atmosphere of the Enlightenment, the 18th-century cult of science and reason partly inspired by Isaac Newton . The British scientist and mathematician Newton found calculable laws in the mechanics of the universe, laying the foundations for the Enlightenment belief that science can save the world. Wright's picture is a manifesto for knowledge, a poster for curiosity. Yet it is paired with a more troubling work, Wright's Experiment with a Bird in the Air Pump , which shows a darker side to scientific progress – the domination of nature. Here, by contrast, wonder is truly innocent, and the universe unfolds in the imaginations of people gathered in a Georgian house one evening to travel in space in their minds. Image of the week What we learned this week How and why Alighiero Boetti opened his own hotel in Afghanistan in the name of art The life lessons Guardian readers would give David Hockney What Caravaggio taught today's rock stars That the National Gallery has stumped up £25m to keep a Titian in Britain That the Pritzker architecture prize has not – shock, horror – been won by a starchitect this year What Angelina Jolie's now-infamous Oscar leg took from Renaissance art Lastly Follow us on Twitter Like us on Facebook Sign up for our Art Weekly newsletter