The sculpture, called Quantum Leap, is one of seven which will feature in the grounds surrounding the dome in south London.

Others include a vending machine which dispenses prayers for 20p-a-time and a cross section of a ship which will be sited in the River Thames.

Seven sculptures will be on display outside the dome

Quantum Leap, which has been created by 1994 Turner Prize winner Antony Gormley, is made up of 3,500 square steel tubes, inside which a human figure can be seen.

"It is very exciting to have such bold and talented artists working with us at the Dome," said Jennie Page, chief executive of the Dome organising body, the New Millennium Experience Company.

For his sculpture, Mr Gormley has sought to create what NMEC describe as "a radical vision of the human being as a zone of light and energy".

The cloud will sparkle both in sunlight and at night, when it will be illuminated, while the human form inside the cloud will be visible from some angles but invisible from others.

On his appointment to the Arts Council of England last year, Mr Gormley said: "I passionately believe that art is the thing that gives us our identity today.

"I don't want to make an argument for it on monetarist grounds, I want to make an argument for it on creative grounds."

Antony Gormley has created a "vision of the human being as a zone of light and energy"

Mr Gormley's 65-ft Angel of the North, which was erected next to the A1 (M) in Gateshead in 1997 at a cost of £800,000, received a mixed reaction from local people and art critics.

Of the other six sculptures to appear at the dome, Parabolic Waters by 1991 Turner Prize winner Anish Kapoor, is a large eight-metre diameter drum in which a volume of coloured water is spun.

The 1988 Turner Prize winner Tony Cragg has come up with Life Time, which features three forms made from a fabric called carbon-kevlar which is used in the manufacture of yachts, motorbikes and rockets.

Another work is Slice of Reality by Richard Wilson, a cross-section of a ship that will sit on the Thames to reflect the Meridian Line slicing through Greenwich.

A ventilation shaft which will emit sounds from different ports around the world is the contribution of Tacita Dean, who has named the work Friday/Saturday.

Bill Culbert has come up with Skyline, four blue 30-metre long lines which will move across the sky.