Whats money worth anyway?

Bottom line. Why can't we simply change the value of money? We let people keep what they currently have, and change what its worth. Seems it would solve all economic problems world wide. Make all old and new debt payable and the new value. Then when inflation gets stupid in another 200 years, we do it again. Apparently the notes represent a portion of gold in ft. Knox. That's total bull. Inflation is caused by businesses raising prices and the consumers will to by the items at that price. Value is an abstract consept so there is no reason why we can't just change the value.