The Counterfeit Money Spotting Machine - Idea for an invention
1)Every bank note has a different and unique barcode on it.
2)The anti-counterfeit machine, like a computer, has a record of every single barcode on every single banknote in circulation.
3) Every shop has an anti-counterfeit machine to check the barcode on every banknote used to buy something.
4) If two transactions are ever made at the same time using banknotes with the same barcode then one of them must, logically be a fake; because, remember, every banknote has a different and unique barcode (there can be no two with the same barcode) and, every time an anti-counterfeit machine spots two barcodes the same, alarm bells start ringing.
5)Similarly, alarm bells will ring if a banknote has a barcode on it that isn't stored in the machines memory.
What do you think?