If, my friend, we hadn't have the quantum mechanical phenomena, do you think that we could calculate our behaviour to the end of universe? No! That's why the Chaos Theory is made. We live in nonlinear world and for nonlinear systems one has to have infinitely precise computer. Because otherwice the calculation will very soon deviate prominently from reality (think about weather forecasts, if we would have tenfold the computation power we have now for forecasting the weather, we could maybe achieve only an additional hour more or less accurate forecast). We all would know that our lives are predetermined, but it would not be possible to know ahead what we would do!