Rambert Dance Company, Sadler's Wells, London

Shower caps on, photons ready - it's Einstein a-go-go

'Human beings, vegetables or cosmic dust, we all dance to a mysterious tune," wrote Albert Einstein. But even his stupendous imagination cannot have reckoned on key concepts of physics turning into a format for dance. One hundred years after Einstein published his three ground-breaking theories, the Institute of Physics has asked Rambert's Mark Baldwin to celebrate them on stage. And while the idea of choreography inspired by Brownian motion, the photoelectric effect and E=mc ² sounds ponderous in the extreme, in the event Baldwin's piece is an absolute hoot.

'Human beings, vegetables or cosmic dust, we all dance to a mysterious tune," wrote Albert Einstein. But even his stupendous imagination cannot have reckoned on key concepts of physics turning into a format for dance. One hundred years after Einstein published his three ground-breaking theories, the Institute of Physics has asked Rambert's Mark Baldwin to celebrate them on stage. And while the idea of choreography inspired by Brownian motion, the photoelectric effect and E=mc ² sounds ponderous in the extreme, in the event Baldwin's piece is an absolute hoot.

It's the blithe incongruity of Franz Lehar's 1905 operetta tunes that sets Constant Speed on its course, giving a bubble-bath froth and twinkle to every fiendish step. Molecule girls in bubblewrap shower caps dash dementedly about, and boys impersonate photons with dazzling athletics. The Sadler's Wells audience laughed out loud at the zaniness of the equation, but incredulity turned to admiration for the way the dance stays true to its source. After all, the basic concepts of physics - the relationships between energy, time and space - are also the fundamentals of dance. And Baldwin's bid to represent the sheer excitement of Einstein's discoveries in their time is wholly apt.

Bold designs by Michael Howells and lighting artist Samantha McNern create a brilliant prismatic effect. On a second viewing I will be more clued up to the progression of light breaking into its component parts - first white, then red and blue, and finally the Smartie hues between. First time round I was absorbed in the human razzle-dazzle: Mexican waves and aerial flips and Angela Towler's upturned splits. And the fizzing finale when all 19 dancers bob and torque and twizzle to the suave lilt of Lehar's White and Gold Waltz is the ultimate filip. As a joyous reminder of the physical matter of our lives, it couldn't be more effective.

As Mark Baldwin's first creation for Rambert since becoming artistic director, his piece also settled any doubt as to whether he would keep the company true to its roots. Surprise has always been an element in Rambert's programming, and it was cheering to find Baldwin not only springing a new one, but also reviving startling stuff from the archives. Antony Tudor's 1938 Judgment of Paris may be short and even slight, but it's gorgeously suggestive of how racy Rambert once could be.

Where the Greek myth tells of three goddesses who compete for a golden apple, Tudor's version centres on three dejected old tarts in a sleazy bar. Their dances - and the comedy - hinge on the idea that although they are ostensibly competing for the custom of the bar's one sozzled patron, none of their hearts is really in it. The only prize they lust for is his pocket watch.

It's always tricky for dancers to play old, being mostly in their twenties, but the present trio try hard to play down their natural lustre. Weasel eyes, lethargy, and a hobble that makes you think about parts of the anatomy you'd rather not, all give grist to the illusion. Ana Lujan Sanchez is gloriously squalid as she scratches an itch while holding a pose. Mikaela Polley's way with a feather boa makes it seem even more flea-ridden than it is. And Angela Towler's petty avarice - violently breaking off her solo to stop one of the others polishing off her drink - was worked up with fine comic timing. Onstage pianist Stephen Lade dealt with the unpianistic crunches of Kurt Weill's music with panache.

The same choreographer's Dark Elegies, of 1937, was revived by Rambert last season and has gained in depth and subtlety. A setting of Mahler's Songs on the Death of Children, supported by an exceptionally fine performance by the London Musici and baritone Ashley Holland, it now comes freighted with thoughts of tsunami and Beslan. There's no need even to read the lyrics. The full gamut of grief is there, in the circle dances of a community grimly seeking consolation, in the split between two parents unable to comprehend their loss, in simple domestic actions that no longer have a point. Extraordinary insights, lyrically conveyed.

And finally, as a more than satisfying makeweight, there was apprentice work from a company member - another Rambert tradition that Baldwin is all for. Set to sleek and airy music by Patrick Nunn, Mikaela Polley's Momenta is tightly crafted and classily danced. Catch this whole fabulous programme on tour in the autumn.

jenny.gilbert@independent.co.uk