Sir, – My thanks are due to John McGrath (Letters, September 3rd) who asks me to explain how we can distinguish truth from untruth, to which there is a straightforward answer – by evidence which is persistently corroborated, or not as the case may be, worldwide by almost all competent observers.
Philosophers will continue to tease out this question but in the meantime this answer seems to work. Scientific ideas have indeed been discarded but this happens because of new evidence – since Galileo and friends that is the way science has made progress.
It was widely accepted from the 1920s that genes were made of protein, but there was little evidence until 1944 when Oswald Avery reported exquisite experiments showing they were made of DNA. This was treated with much scepticism until 1953 when Watson and Crick proposed a structure for DNA that explained how DNA could do the work of genes.
Our ability to explain and combat the coronavirus epidemic would have been impossible without the general theories of molecular genetics which stemmed from those discoveries in genetics made in the 1950s and 1960s.
There are many puzzles which remain unsolved or may be unsolvable and it is often hard for non-specialists to know just what is going on.
A geneticist should stay out of physics which, as McGrath mentions, is now in a very interesting and challenging phase but we can be fairly sure our electric lights will continue to work no matter what new theories become established in cosmology and sub-nuclear physics.
I like McGrath’s mention that Stephen Hawking once said it is possible we may be living in a giant goldfish bowl but, following Epicurus, this does not interest me because the maker or owner of the bowl has never contacted me – or Hawking so far as I know – and I don’t know how to contact them.
– Yours, etc,
DAVID McCONNELL,
Smurfit Institute
of Genetics.
Trinity College.