A teaspoon and an open mind
The book starts with that special ability of the Doctor, time travel. It goes on to consider whether there is life elsewhere in the universe and what it would look like. White also examines the possibilities for interstellar travel, both in starships and using teleportation. Moving away from the physical sciences, there are chapters on telepathy and a look at whether there have been advanced civilisations on Earth before us, such as Atlantis. The chapter on robots doesn't relate much to the Dr Who programs, but the final chapter does get back to on of the Doctor's characteristic abilities - regeneration.
Confusingly there is an unrelated Dr Who fan fiction archive with the same title as this book.