Stephen Hawking, the scientist who has turned ideas of time and space on their heads, fulfilled a lifelong dream of riding in a hot-air balloon.

　　On Monday, the 60-year-old theoretical physicist, who has been confined to a wheelchair for most of his life, floated across the Cambridgeshire countryside with his wife, Elaine.

　　Changes were made to the hot-air balloon's basket to accommodate a wheelchair, according to Virgin Balloon Flights, which arranged the trip.

　　"It's something he had always wanted to do and had been a lifelong dream for him," said a Virgin spokeswoman, who declined to be named. "But to take a balloon flight in a wheelchair is extremely difficult."