For me bitcoin cannot replace gold. Because gold is widely accepted in every country and use in curriencies for almost 2000 years from now or in the jewelries because of mining under the ground and we can say that in gold we can found the assurance because we can already see, use and keep it. While the bitcoin is a digital money, it is completely virtual although both gold and bitcoin is get through mining but the matter is that gold is already real or already a physical object while the bitcoin is just digital. But in contrast, we cant say what will happen next specially in this generation where technologies are continuously changing and evolving.