I want you to think about, for a minute, the notion that you can have a number bigger than all of the atoms in the universe :-). From that, you can see that its possible to have more 'dollars' than there are atoms in the universe. Specifically, without defining 'growth' you can't reason about the limits on that growth.

The other point that simplified analysis fails to consider is that you are inside the system so as it "grows", it also "changes". If you lived in the 70's with the tales of how we're going to run out of fossil fuels by 2000, looking back you can see how things changed (cars got more efficient, other sources were discovered, etc).

My macroeconomics professor had a funny saying that you could take any segment of a sinusoid and use that to extrapolate forward and get the wrong answer about what the waveform was going to do. In my differential equations class we got to see how you could predict some things if you new both the initial conditions and you continued to refine your model. But to predict all things your model needed to take into account all variables and their impact, and it was the unknown variable problem that messed up predictions using that method.

> its possible to have more 'dollars' than there are atoms in the universe

We are absolutely not printing money fast enough to realize this dream, unfortunately. I propose we mint a new bill, the 100 trillion non-Zimbabwe dollar, and 10x our printing speed.