Just because all of those things are in development, does not mean they'll actually come to fruition, they might even prove to be unfeasible or impossible. Remember that some scientists in the 60s' thought we'd be living on the moon by now ? It's not just a case of advancing knowledge, resources are required as well. If it turns out that a warp drive takes an insane amount of resources that we simply don't have (which it is...For now.), then it can't be developed. Also, if for example, a plasma weapon took a lot of rare resources and time to manufacture, of course you would go with the much more convenient option of using abundant resources like metal for ammunition, guns, etc. I'm all for optimism about the advancement of knowledge and technology, but 500 years of advances can't possibly be predicted. Some day, 480 years from now, a group of scientists will find the server this thread sits in and laugh, just as they will with every other prediction made by scientists of this era.