I am sure by now many of you have viewed the "A Universe from Nothing" lecture given by Lawrence Krauss on YouTube or are familiar with its context. Much controversy has been stirred up as a result. I am interested in having a few things explained to me. 1. The term 'nothing' refers to what exactly? A quantum vacuum I believe, but is this true? Isn't a quantum vacuum a sea of energy governed by physical laws and therefore something rather than nothing. Please elaborate. 2. Quantum Uncertainty. Is this description correct: Pairs of qualities such as energy, position and velocity cannot be exactly determined simultaneously. The more precisely determine a particles velocity the less precisely we know its location, therefore, a particle could be located in more than one position. 3. We observe virtual particles popping in and out of existence all the time. Where exactly are they coming from? The quantum vacuum? Are there really uncaused? 4. I read a few articles written by physicists who said its a highly speculative notion that we can take what happens to virtual particles and apply it to our Universe. Is this true? If you have any other information that relates to this subject that you would like to add I would appreciate it. I realize I put much out there and many of you might prefer not to put in the time to answer my questions. If you could at least take on 1 or two of them I would appreciate this. Thanks!