Hello; This is my first post, and I am not sure I am posting in the right forum, if not, please move my post and I apologize. Ok here goes: Bear with me as I am not a professional; I never learned physics, my work doesn't involve physics (well, it does a little as I code video games and sometimes I code physics engines, but that's really superficial). But I am interested since I was little, I read a lot about it, I've read Hawking, Einstein, Reeves numerous blogs and forums posts, and I regularly buy scientific magazines. After reading Hawking's most popular books something like five times each, I'd even I have a fair grasp of physics concepts. My question is: how do you explain relativity and quantum physics to people that are not used to the concepts? When I am with friends and family and we are watching a movie that talks about time travel, or speed of light, or sometimes just in casual conversation, there is always a point where I have to explain why time is just another dimension, and should not be considered like a current flowing in one direction, how it is relative, how there are more than 3 dimensions, etc. I use all the "easy" visualizations, as "consider how a video-game character in a 2D world would relate to 3D, this is how we relate to 4D", and the large ball on a stretched sheet of paper that deforms it, and the cat in the box, etc. Usually people, after struggling with the ideas a little (and I can't really blame them as to be honest I still struggle with most of those ideas), finally understand the point. Where I really get stuck is the next part, when they tell me "ok, it's very nice, it's sci-fi, it's mad scientists sitting in their labs and blabbering whatever". Then I tell them that most of these ideas have verified empirically, and some of them have very real applications in our world. But I am unable to convince them as I do not know myself what are the experiences and the outcomes of those theories. So, to sum it up, I have three questions: 1) Is there any resource on the net that explains in layman's terms what relativity and/or quantum physics are? 2) How do scientists know what they are talking about? I mean, if a quark is smaller than an atom and can't be observed, how are they observing it? I am always asked that question and I have no idea of how to answer it. 3) Can you give me some example of down-to-earth, real, applications of those theories, or at least some way to convince people that what I am talking about is not just stupid aimless thoughts? Or, more easily: How do you about not only explaining, but convincing people that, say, time is relative? I realize it's a lot of questions for one post so maybe just some links or pointers will be enough. I have also questions of my own about concepts I have troubles to grasp, but that will be for later posts. Sorry for my English!