Why must the entire chain be included in calculations if it's already been validated. Why can't the validated portions be archived to save energy? I'm new to this so don't laugh.  If all of the previous transactions in a blockchain have been validated as authentic, why does the entire chain have to be carried forward in the calculations?  Why can't the validated portions be hashed and archived to save energy costs from handling so much historical data.  When accountants calculate the current years income, they don't go back to when the company started and add up every income and expense item, they just add the current years results to the archived past totals.  What am I missing.
There is no difference between those two things. If you have a data set that includes only things that you have fully validated all of and you confirm that something is in that data set, you have fully validated all of it. So checking that it's in a data set of things you have validated cannot be done instead of validating the entire chain because it does validate the entire chain.
I'm not sure what you mean by &quot;archived to save energy&quot;. If they aren't archived, they're stored. If they are archived, they're stored. So I'm not sure how energy would be saved.