no they arent worthless. I still have mine- see the image earlier in this thread- from '76. and I still go over and grab one whenever I think i want to look up something or my son asks a question. its so easy to grab it from the shelf and flip it open. the information, barring better understandings from scientific advancements, is still as accurate today as when they were printed. i read them from cover to cover as they arrived and have read the entire set many times over. i havent managed to remember it all but there's still time
