long-run equilibrium and interest rate

how long could this accumulation process of sacrificing current consumption go on ? it can go on until the interest is zero ,or until people want to do no net saving . At the zero rate of interest , if we could ever quite reach this point on the horizon , the plateau of consumption would be as high as is technically possible with the given labor ,land ,and primary resources . IT would be a kind of "golden age ."
in real life three or more things keep us from reaching the golden age :
1- people may be so important and so conscious of death that at some interest rate like 3 per cent , society won’t want to do net saving .
2- inventions may come along and offset diminishing returns by sifting upward
3- there is always riskiness in a dynamic society :long before the pure interest rate reaches zero , the profit-rate-inclusive-of-premium-for-risk may have hit a floor below which investment lags . we must examine this important matter .