Kids need to encounter kids like themselves - kids who can sometimes be crabby and fresh and rebellious, kids who talk back and disobey, tell fibs and get into trouble, and are nonetheless still likable and redeemable.

Strength is the capacity to break a chocolate bar into four pieces with your bare hands - and then eat just one of the pieces.

Most of the characters I have in my children's books are grouchy or annoyed about something or are calling each other unfriendly names. Like my own kids, they're not honeys and sweetie pies and little angels. They're kids. Sloppy, dirty, stinky.

Kids are always writing me: 'I had a bad day too.' 'I got gum in my hair.' And the kids also write to me to pass on advice to Alexander. My favorite one of those being, 'The next time you have a bad day, blame your brothers.' I didn't expect this. It's certainly the most successful of my books.

Moreover, the concern of some that moving DNA among species would breach customary breeding barriers and have profound effects on natural evolutionary processes has substantially disappeared as the science revealed that such exchanges occur in nature.

In Old Europe and Ancient Crete, women were respected for their roles in the discovery of agriculture and for inventing the arts of weaving and pottery making.

We are all enormously indebted to the National Science Foundation of the United States and the American public for steady support over close to 50 years.

There are some countries where there is not an issue with women in physics. Malaysia, for example, has physics departments where 60 per cent of undergraduates are female, and France and Italy are strong, too. It is not about ability but more about what the culture says is appropriate.