CASH,CHEMISTRY,AND COUNTERFEIT

摘要

If you earn cash from babysitting,mowing lawns,or other jobs,you might have noticed that not all bills’designs and colors are the same.That's because money has changed a lot over the years;today U.S.currency is more complex and colorful than ever before.These changes have primarily come about for one reason-to beat counterfeiting.From currency's inception,people have tried to trick others into accepting fake money.The Aztecs,a 14th-to 16th-century culture that thrived in what is now central Mexico,used cacao beans for currency,and even these were counterfeited.People would fill empty cacao pods with clay and try to pass them off for the real thing.The oldest surviving paper banknote,dating back to 14th-century China,displays a warning that(translated into English) reads”the counterfeiter shall summarily be decapitated”-leaving little doubt about how counterfeiting was viewed in that era.Today,producing fake money remains a serious crime.But thanks to ingenuity on the part of scientists,designers,and printers who work on banknotes,genuine cash now features several attributes to ensure that producing counterfeits doesn't pay off.