YORK is as much a city of science as art. They are not always the happiest of bedfellows – often falling out over which one should receive preferential funding – but they bond most beautifully every October half-term in a four-day festival of light.

India has Diwali, York has Illuminating York, not as pretty a name, granted, but the event has become a fixture on the city calendar and a magnet for tourists and the home crowd alike when the clocks go back an hour and darkness seems to come forward two hours.

To emphasise the link between art and science, the 2014 festival takes the theme of York's Leading Lights, "uncovering the rich history and the future of innovation in the city".

At its epicentre is Seeper's 3D projection-mapped animation, Hidden Worlds, mapped out on the walls and windows of York Crown Court at the Eye of York, with Clifford's Tower to the right bathed in soft, subtly changing lighting too. Designed by Alex Tennyson to the accompaniment of dub beat and bass and drum music, it could pass for a Midsummer dance festival locale, if you happened to stray across it. Not that you could, because Hidden World's is this year's paid event. Make the most of it, stay awhile; watch the loop more than once.

Seeper like to induce a sense of wonderment, and Hidden Worlds certainly does that in its celebration of John Snow, the 19th century physician from York who discovered how cholera spread and pioneered the use of anaesthetics. You won't fall asleep, especially when three huge skulls dominate the walls.

Head to Coppergate where the pages keep turning in Impossible Arts's illuminated book, Codex, as a somewhat strange child's voice introduces the stories of Margaret Clitherow, Guy Fawkes and plenty more. You may even Tweet a question to this interactive installation using #Codex York.

In King's Square you can take part physically in the festival, doing more than walking from light show to light show. Twist Design's car installation, The Wheels Of Industry, requires volunteers to pedal an electricity-generating bicycle to light up stained-glass depictions of coal mines, railways, steelworks and the Angel of the North in the windows. Most enlightening.

One small step for man, one giant leap for mankind takes you to Time and Space, Haydn Robinson's projection mapping piece that combines the spirit of Heath Robinson with a sense of awe for York's astronomers and our modern space explorers, beamed on the face of St Helen's Church. This culminates in the church wall taking on the shape of a space rocket with Yorkshire insignia; wishful thinking but witty all the same.

The wafting smells of York Cocoa House chocolate will draw you to Then Chocolate It Shall Be, a performance art piece by Viaperformance that rather smells of something else, in the garden murk at King's Manor where a ground-shaking bass guitarist and strange-shaped blobby figures are having a wild time.

Leaving them to it, hot chocolate provides the fuel to negotiate the Spark trail of seven commissions by emerging artists, ranging from a greenhouse to a meditative wall of concrete and Four Shadows Theatre's Remember Remember in the Treasurer's House garden, where a spinning carousel of speakers tellsGuy Fawkes's story to the sound of a crackling fire as actors carry powder kegs and a model of a ship.

Andrew Potterton's Wind Chimes invite you to bash them in an unholy din outside Holy Trinity Church, Goodramgate; inside, the candle-lit pews are the night's most peaceful and radiant sight.

Time for reflection before a brisk walk to the National Railway Museum for Locos In A Different Light. Six competing teams of performing arts students have lit locomotives in the darkened Great Hall, where steam rises from funnels and a soundtrack of locos rattling down the tracks is truly magical. The judges got it wrong by the way: runners-up York College's Evening Star should have won.

However, York at large is the winner again with Illuminating York, and now the festival steering committee is initiating plans to stretch the festival across the winter months. One way to keep York bright at night would be to encourage bookshops, cafes and the like to stay open later. Just a thought.