our reporters from fortune and mit technology reviews martin jooils, this week on "press here." >>> good morning, everyone, i'm scott mcgrew. this is a ledger. i bought it at office depot for five bucks. you can make an argument this is one of the most important inventions in public history. public ledgers help people keep track of who owned what property. important in the growth of colonial america and as far back as egyptians, they allowed banks and businesses to offer credit and make payments. today ledgers are on the computers and there's a new computerized ledger that captured everybody's attention, called the blockchain. i cannot show you the blockchain because it's inside computers but all it is is a ledger, who has paid what to whom. what keeps it honest, there are copies of that laedger on computers all over. the change is reflected in ledgers all over the world. brad garlinghouse runs ripple. martin jiles with m.i.t. technology review. how did i do? is that what the blockchain is? >> you did a really nice job. >> so lots of people have heard of this. they know it's important, w

our reporters from fortune and mit technology reviews martin jooils, this week on "press here."