Sir

Alfred Nobel left a fortune to finance annual prizes to be awarded “to those who, during the preceding year, shall have conferred the greatest benefit on mankind”. One part, he stated, should be given “to the person who shall have made the most important discovery or invention within the field of physics”.

Nobel did not emphasize discoveries. But these are much more respected by the scientific community than are inventions: 77% of Nobel prizes in physics have been given to discoveries, compared with only 23% to inventions.

This emphasis on discoveries has moved the Nobel prize away from its original intention of rewarding the greatest contribution to society in the preceding year.

Discoveries and inventions depend on each other. Many discoveries were only made possible through the invention of certain measurement instruments, and without earlier theories, many inventions would have been inconceivable.

The fundamental difference between the two, ho wever, is that the result of an invention is typically an artefact or process, whereas a discovery is an abstract theory. Although both require prior theories and a process of experimentation, and both have a utilitarian function, discoveries aim to be as general as possible, whereas inventions strive to be concrete.

A closer look at the 17 inventions that won Nobel prizes before 2005 reveals that 11 of them (64%) are measurement instruments, for example the scanning tunnelling microscope.

Only three winning inventions have had direct practical applications to society: the gas regulator-controlled buoys made by Nils Gustaf Dalén were subsequently used in lighthouses; the transistor invented by John Bardeen, Walter Brattain and William Shockley is widely used in electronic devices; and Jack Kilby's work on the integrated circuit led to the development of personal computers.

Awarding more Nobel prizes for inventions would encourage inventors to tackle important problems such as global warming or the gap between the developed and developing worlds. The award given to Kilby for the development of the integrated circuit is a good example.

The invention of the electric telephone, first patented by Graham Bell, was a missed opportunity for a Nobel prize to acknowledge an invention that has brought the world closer together. But there is still hope for Tim Berners-Lee's invention of the World Wide Web.