The book is second only to the wheel as the best piece of technology human beings have ever invented. A book symbolises the whole intellectual history of mankind; it's the greatest weapon ever devised in the war against stupidity.

But quality of work can be expected only through personal satisfaction, dedication and enjoyment. In our profession, precision and perfection are not a dispensable luxury, but a simple necessity.

If you only think of me during Black History Month, I must be failing as an educator and as an astrophysicist.

I believe there should be breakfast, lunch and afternoon snack, all for free and for every child that goes to school. And all food that is good, clean and fair.

You may have an older audience in front of you holding the Bible and a younger audience holding an iPhone. You don't want to lose either audience.

We teach children to save their money. As an attempt to counteract thoughtless and selfish expenditure, that has value. But it is not positive; it does not lead the child into the safe and useful avenues of self-expression or self-expenditure. To teach a child to invest and use is better than to teach him to save.