Museum of Tomorrow: a captivating invitation to imagine a sustainable world

Rio de Janeiro's new museum, focusing on ideas rather than objects, ecology more than technology, is a little trippy, a little hippy, very worthy but rarely dull

Jutting diagonally into the sky from the old port of Rio de Janeiro is an other-wordly edifice that looks like a cross between a solar-powered dinosaur and a giant air conditioning unit.

The Museu do Amanhi (Museum of Tomorrow), which opens on Thursday, must already rank as one of the world's most extraordinary buildings. But once the public starts to visit this weekend, it may soon also become known for one of the planet's most powerful arguments for sustainability.