you do not know the story of how he discovered the principle of Archimedes and the eureka exclamation? It is claimed that the tyrant of Syracuse had a goldsmith make a gold crown, however he was suspicious that maybe the crown was not really equal to the gold he had given. Since Archimedes was at hands, he asked him to solve this question. So Archimedes was taking a bath when he observed that when he had entered the water the level had rised. He now had an answer! He got out of the bath, and still naked ran crying 'Eureka!' 'I've found it' etc.

res humà m'és aliè

The ancient coinage was made from gold, silver, and bronze.  The coins themselves were alloys: silver and copper were added to gold, bronze was added to silver, lead and zinc to bronze.  Gold was mostly a currency-of-account and a savings vehicle since they were too valuable for the average shopkeeper.  The latter two were the usual currency-of-exchange.  

Ever since I learnt about confirmation bias I've started seeing it everywhere