This day in 1969 saw UK introduce fifty pence piece, replacing ten-shilling note, in anticipation of decimalisation two years later.
To celebrate this 50p fact, soundtracked here by Sinatra's Three Coins In A Fountain, we've invested some time in sourcing fun (we'll let you be judge of that!) facts about currency, whose design still today owes huge debt to arguably our greatest ever scientist.
So, in for a penny ...
The pound is oldest currency still in use.
Two 1ps weigh the same as one 2p while two 5ps weigh same as one 10p.
Copper coins are no longer made of copper, which means you can tell how old 1p piece is by trying to pick it up with a magnet - coins made after 1992 are magnetic steel plated with copper while older versions are bronze and not.
Originally 240 silver pennies weighed one pound with “pound sterling” literally being worth the same as pound of such silver, legal basis of our pound for hundreds of years.
Old 5ps and 10ps are worth more than 5p or 10p as, like copper coins before them, value of metal in such currency increased until they were being made at a loss. 2012 saw Royal Mint start making 5ps and 10ps of nickel-plated steel rather than copper-nickel mix.
Regardless of if it looks silver or gold, all our coinage worth more than 10p is made mostly of copper.
Ridges on edges of currency is thanks to Isaac Newton, who spent 30 years as Royal Mint warden, recalling all plain-edged coins in circulation and re-issuing them with milled edges to stop unscrupulous types shaving bits off to make new coins.