Ah, at last, the crux of the problem! I assume that what you meant to say was “Possibly the great mistake of modern physics is to assume that everything in modern physics is true.”
If so, you are assuming that modern physics is a bunch of made up ideas that physicists assume are true. This is completely backwards!! Nothing in modern physics was assumed to be true when first proposed. All the ideas, all the little bits and pieces that make up modern mainstream physics, have been subjected to rigorous testing, peer review, matching to observations, again and again and again. And will continue to be. That is the nature of the scientific method. Please, read the Wiki article here:
http://en.wikipedia.org/wiki/Scientific_method Science is NOT a faith system, it is NOT a “Let’s assume this is true” system of untested ideas. See the quote from korjik below.
CosmoQuest is a summation and a celebration of 1000+ years of meticulous work by thousands and thousands of scientists over millions of person hours using the scientific method, and continuing that work by observing, theorizing, predicting, and analyzing. If you want to post here, be sure you have your facts straight, or evidence to back up ATM ideas.
Go slow. Read. Listen. Learn. Repeat as needed. Don’t get stuck on your own ideas being correct. They might not be. Open mindedness is a 2 way street. If you only look in one direction you will get run over from behind.
Regards, John M.