Topologists are not concerned with angles and lengths, which are clearly altered by stretching the rubber sheet, but they do care about more fundamental properties.

I'm happy watching 'The Simpsons' at home.

I don't want to write books that are intellectually staggering if nobody's going to read them.

The age of the universe is not just 'a guess', but rather it is a carefully measured number that is now known to a high degree of accuracy.

In fact, scientific results are a careful attempt to objectively measure reality, and although they may be refined over time, they are always our best hope of getting at the truth.

As soon as the idea of the Big Bang was proposed in the 1920s, astronomers set about trying to work out when the bang happened. Initial estimates were, not surprisingly, wildly inaccurate, but by the 1980s it was known that the universe was 15 billion years old, give or take 5 billion years.

In 2001, a systematic review of five studies revealed that roughly half of all chiropractic patients experience temporary adverse effects, such as pain, numbness, stiffness, dizziness and headaches. These are relatively minor effects, but the frequency is very high, and this has to be weighed against the limited benefit offered by chiropractors.

The only consolation is that homeopathy can only be practised on animals by a fully trained vet or under the supervision of one, because it is forbidden for the average high street homeopath to treat animals on their own.

Bearing in mind that homeopathic remedies are generally so diluted that they contain no active remedy, it seems obvious they can be nothing more than placebos.

Cern's colliders usually shut down for a winter break, because the cost of electricity increases as the temperature drops and the Swiss turn on their heaters and tuck into their fondue.