Preview: Bath Festival of Children's Literature, various venues, Bath

The novelist Lucy Hawking has written a children's book about theoretical physics with her father, Professor Stephen Hawking. He is more famous for his black hole research than writing books for children, but when his daughter came up with the idea for an adventure story for children that explained the wonders of the universe, they joined forces.

"In both my adult books, Jaded and Run For Your Life, there is a sinister hidden dark force, and in George's Secret Key to the Universe we probably have the darkest, the most powerful force that exists, which is the black hole," says Hawking.

She will talk about working with her father at the first Bath Festival of Children's Literature. "What struck me was the clarity of his thought. This makes working with him very easy," Hawking says.

It was also a chance for her to gain a better understanding of his work. "I also thought it would be nice for my nine-year-old son, William, if Dad wrote a book for him that would explain the work of his grandfather."

All the adventures the young hero has are based on physics. It covers phenomena such as stellar formation, the solar system, gravity, and how dying stars can form black holes. "It is an educational book because we have made sure all the science is accurate, but it is presented in an entertaining and creative way."

Hawking will also discuss the trend of adult authors writing for children, with Joanne Harris and Tim Lott. Among many other events, Jacqueline Wilson talks about her character Tracy Beaker and her new autobiography Jacky Daydream; Nick Hornby discusses his debut novel for teenagers, Slam; Anthony Horowitz introduces his new Alex Rider novel; Roald Dahl's widow, Felicity, answers questions about the author; Darren Shaw reveals the sixth book in his Demonata series; and Julia Donaldson, creator of The Gruffalo, introduces her new character, Tiddler.

21-30 September (01225 463 362; http://bathkidslitfest.co.uk)