Apologies for the English, I don't know how to express this question in Japanese.
I'm a little confused with this. In English, "In fifty years" can mean "fifty years in the future" or "fifty years from now", but it can also mean "over the period of fifty years" or "during the period of fifty years". Does "50年で" also correspond to all of these meanings, or only some of them? I think this would be valuable for both Japanese speakers learning English, and English speakers learning Japanese, to know.