by santa100 » Tue Jul 17, 2012 10:08 pm
It's true that we are mostly "empty". As an analogy, imagine each atom that makes up our body has the size of a football stadium, the nucleus would have the size of a....single blade of grass at the center of the stadium while all the stuff in between is just empty space. The reason we perceive matter to be hard and solid is because of the electromagnetic force. This force is also the one that stops our body from going thru walls. The best way to see it is to imagine someone holding a piece of string tied to a rock at one end and spins it extremely fast. If a second person tries to insert some object into the spin zone, it will automatically get repelled. This creates the perception of a solid sphere with solid outer crust that prevents outer object from penetrating it, while in fact there's really nothing other than the guy's fist (stands for the nucleus) and the fast spinning rock (stands for the electrons).
About the concept of "something coming out of nothing", it's become less and less mainstream as new discoveries and researches at the bleeding edge of modern physics keep showing up: parallel/multi-verse, string theory, super-symmetry, dark matter and dark energy, etc.. An electron that all of a sudden starts showing up seemingly from no-where could might just be because it's already existed in a parallel universe or a higher dimensional "brane" out there. Once they've really tracked down the God particle(Higgs boson), scientists would be able to go even further back before the moment of the Big Bang to see if the "Bang" really came out of nothing or not. So, with all the exciting new researches, we might find out that there's really nothing that could come out from...nothing...after all..