I'm not a physicist, nor a theologian. (or a philosopher for that matter) I'm just a dude with free time.
/disclaimer
I've been YouTubing physicist Lawrence Krauss and his lectures/debates about the how the universe came into being out of "nothing". There was a debate between him and theologian William Lane Craig. One of the things that Craig kept harping on was the definition of "nothing". While watching that debate, I found myself agreeing with Craig. This led me to realize that either Krauss was wrong, or I just didn't understand what he meant by "nothing". Fast forward through many of his lectures and debates and I think I finally understand what the problem is and why he runs into so much resistance when trying to convince others about the universe arising from "nothing".
Indeed, the problem is in the definition of the word "nothing", which is simply "not anything". A synonym that is much more revealing is the word "void" which is defined as "being without something specified". Now up until very recently in the history of the human race, we have understood the "void" of space to contain absolutely no matter or energy. If you wanted an empirical example of what "nothing" and "void" were, all you had to do was create a vacuum in space. And of course, the vacuum of space happened naturally and made up most of the universe.
The creation myth says that God created the universe from nothing, out of the void. Iron age myth makers would look at an empty sack, empty cup, or up in the sky and say there is nothing in there. They would have a concept of what nothing actually is. Therefore, they could imagine "a great void". As mankind became more technologically advanced we began to understand that while a sack or cup may appear to be empty, in fact there are billions of microscopic particles dancing about inside them; and the sky we now know to be an atmosphere full of all kinds of particles. The concept of "nothing" arose out of the human mind's inability to directly experience something that appeared to not be there. In other words, "if I can't physically see it, it's not there. PEEK-A-BOO!"
The way that scientific advancement played out, though, created an overlap between what we previously believed to be empty to a new concept of empty. No longer was the glass empty or the atmosphere empty, outer space was empty. Then later, the space between electrons and the nucleus of an atom was empty. As long as the concept of nothing had empirical evidence to show that nothing was a valid concept, then theologians would always be able to claim that before the universe there was nothing, with full confidence that "nothing" was something that could be fully understood by even the most mentally challenged individual.
Enter quantum mechanics.
We now understand that all of the visible matter/energy in the universe makes up about 1% of the total matter/energy in the universe. If you are to look at the vacuum of space, where we once thought we could look into nothing, we now understand theoretically and empirically that there are "ghost particles" popping in and out of existence. The void of space is not void. And since space is everywhere, there is no such thing as "nothing" or a "void". Everywhere in the universe, there is something. Nowhere in the universe can you find an true example of "nothing".
What does this do to the creation myth "God created the universe from nothing"? Well, it relegates this to the category of creating an alternate dimension to define God.
"nothing true can be said about our reality, because another reality may exist where truth equals falsehood." (Against the Gods? pg20 describing the agnostic argument)
The truth about our reality is that it is completely full. We are fish becoming aware of the water.
The human race has had a concept of what "nothing" is for so long that it seems obvious that it is a valid concept. Is the glass half empty of half full? It's always full! It is either full up on beer or it contains half beer and half atmosphere. There is always something there.
The concept of "nothing" is completely invalid. It is no different than talking about pink polka dotted unicorns orbiting Saturn on a unicycle while whistling Dixie.
So both concepts in the creation myth are now gone. God and Nothing. Both imagined fantasies that cannot be logically derived from observable reality.
The difficulty that even non-believers have with the idea of a "Universe from Nothing" seems to be a psychological attachment to the idea that "nothing" is a real state of being.
Lawrence Krauss would do better if he were to rework his approach to include the psychological implications of these findings.
Being a total layman in these matters, I'd love to hear what you all think.