[einhverfr]

But money is just an abstract idea that we exchange for those other physical things. It isn't really a representation of anything physical anymore.

It's not like a bank keeps a physical amount of cash equal to all account holders' deposits (if they did, they'd have nothing to lend). Instead all you do with your money is transfer it, or get paper vouchers for it in forms like checks, money orders, or federal reserve notes......

That people accept those for things that are physical doesn't change the fact that the money is in fact not a representation of anything physical.