Gorgeous, sumptuous, thrilling: here comes Abstract Expressionism riding into town, the first major overview in London since its own contemporary heyday in the 1950s. A clunky, unappealing label for such fabulously appealing stuff, it's best just to relax and enjoy this total immersion, for colour and gesture can never have been combined to such memorable effect. Nurtured by the melting pot of New York, this was the first homegrown group of American artists, its activities destined to put New York on the international culture map, wresting the crown of art capital from Paris.

Of all the mesmerising images in William Kentridge’s major Whitechapel show, the one that lingers most, perhaps, is that of the artist himself, now turned 60, hunched and thoughtful, wandering through the studio in Johannesburg where he lives and works. He paces, meditates over a "magical" cup of coffee, imagines, draws, tears paper, works, adjusts, observes, directs – all in the gentle manner of a Buster Keaton-style silent film star. Time in this metaphoric space is thick with possibilities, under-stated humour and conundrums.

If you’ve had half an eye on BBC Four’s conceptual art week, you’ll have noticed that the old stuff is where it’s at, with Duchamp’s urinal making not one but two appearances, equalled only by Martin Creed, that other well-known, conceptual stalwart (who actually isn’t as old as he looks). The BBC would say that this is because 2016 marks the centenary of Dada, the anarchic, absurdist art movement (if a movement is what it was) that saw artists begin routinely to challenge and ridicule accepted ideas about art – what it is, why it is and what it’s for.

The wilder shores of contemporary visual art are now ephemeral or time-based: performance, installation, general carry-on and hubbub. But once upon a time – say, the 1960s – it was the nature of objects, pared down to essentials, and often made from real materials sourced from the streets, builders’ yards and shops, that startled: the idea made manifest without old-fashioned notions of the hand-made, craft or manual skill.

Guiseppe Penone’s lyrical and tactile works, made from the simple elemental materials that typify the 1960s Italian Arte Povera movement (of which he is a key exponent), belong largely to the outside world of woods and gardens. But they also find an ideal setting in the serene light-filled spaces of Marian Goodman Gallery, where Penone’s perennial fascination with the relationship between man, nature and art is fruitfully explored in an exhibition entitled Fui, Sarò, Non Sono (I was, I will be, I am not).

Neon was once the triumphant glowing symbol of commerce and capitalism. In the 1930s the distinctive tube lighting gleamed above broadway theatres and on prominent billboards in the world’s great metropolises from New York to Paris. These glory days were not to last. Within just few years neon signs were removed from their downtown pride of place, demoted instead to apologetically jutting out from roadside motels and peripheral dive bars.

This exhibition includes one of my images, so I hesitated when I was asked to write about it – but I only hesitated for a moment. I have learned that if you are reluctant to promote your own work other people are even more inclined in that direction, so you should seize any chance you get.

“Outside the day may be blue and gold, but the light that creeps down through the thickly-muffled glass of the small iron-barred window beneath which one sits is grey and niggard. It is always twilight in one’s cell, as it is always midnight in one’s heart.” Oscar Wilde’s description of his incarceration in cell C.3.3 at Reading Gaol hits home when you stand inside the mean little room (now number C.2.2) imagining what it was like to spend 23 hours a day locked in this claustrophobic box. 

It has been 350 years since the Great Fire of London. A festival of art and ideas by Artichoke, the company behind Lumiere London, has brought a series of free, inventive installations and performances to the capital. These curated events and live art happenings don't so much teach us about the events of the past, but enable us to take stock of what's happening right now in the world, and challenge us to change for the future.

Australia and Japan were first to host Björk Digital, but it lands at London’s Somerset House with fresh, never-before-seen work. The immersive virtual reality exhibition collates several digital- and film-based works born from Björk's critically acclaimed album Vulnicura. Arguably her most revealing release to date, Vulnicura – in all its forms – documents the destruction of her marriage, with devastatingly unguarded lyrics.