I believe that disabled people should concentrate on things that their handicap doesn’t prevent them from doing and not regret those they can’t do … … - Stephen Hawking

Mankind's greatest achievements have come about by talking and its greatest failures by not talking. It doesn’t have to be like this.

There was a young lady of Wight Who travelled much faster than light. She departed one day, In a relative way, And arrived on the previous night. The point is that the theory of relativity says that there is no unique measure of time that all observers will agree on.

As I shall describe, the prospects for finding such a theory seem to be much better now because we know so much more about the universe. But we must beware of overconfidence - we have had false dawns before! At the beginning of this century, for example, it was thought that everything could be explained in terms of the properties of continuous matter, such as elasticity and heat conduction. The discovery of atomic structure and the uncertainty principle put an emphatic end to that. Then again, in 1928, physicist and Nobel Prize winner Max Born told a group of visitors to Gottingen University, "Physics, as we know it, will be over in six months." His confidence was based on the recent discovery by Dirac of the equation that governed the electron. It was thought that a similar equation would govern the proton, which was the only other particle known at the time, and that would be the end of theoretical physics. However, the discovery of the neutron and of nuclear forces knocked that one on the head too. Having said this, I still believe there are grounds for cautious optimism that we may now be near the end of the search for the ultimate laws of nature.