Light Created in Vacuum

Nothing really is something in both the cognitive and the physical senses!

Ryan S covered the cognitive bit quite thouroughly so I'll say this about physical vacuum: its "non-emptiness" has been pretty much demonstrated 60 years ago by the Casimir effect, which I think is really cool but I might be a nerd.
If we still have a concept of vacuum in science, it's only as a reference, an ideal case, like the absolute zero (which is basically the same thing, i.e. the lowest possible energy state).

Still, in everyday life saying that your glass is empty is less confusing than stating that it is full of air.

@KD

Well why didn't you say so sooner. You know how much time I've wasted wondering if nothing was really something, when all the while I just needed to hear you say how it is.

Nice speech Ryan S but flawed.
Nothing is something in your imagination.
In the real world, nothing is nothing.

I make sparks in my vacuum when I try to clean the tub.

Nothing is something. Our minds creating their relative phenomenal constructs create an image of nothing as opposed to something, but that 'nothing' is actually a something. We just don't experience it as something. There is no nothing, nothing cannot exist, if nothing existed it would be something. This is a very hard realization, even when you imagine nothing you are imagining something that is a nothing. This is one of those phenomenally transparent neuropsychological facts that account for how we experience the world as a something, mainly by imposing an imaginary sense of nothing. And this is such an inescapable fact that scientists who are generally bright thinkers will look at the space surrounding an atom and claim it is nothing. Later on they find that particles blip in and out of existence in that nothing, but ask them what is between the particles that blip in and out and they will say nothing. As conscious beings the sense of nothing is a requirement to contrast the sense of something, and so we will always experience and imagine it to be the real world.

When scientists put bonobos (one of the words from the spelling bee) or macaques into a room that is alight with a tint, be it green or red, they see habituation occur in the occipital lobes of the apes. Eventually their brains stop reacting to the colored-light, it merely becomes as if it was white light. The brain habituates to the most common features in it's environment. White-light is defined by the contrast with incidental light. So it is with us, that which is most common in our environment and our experience is made transparent, invisible, undetectable. The old saying goes; we are like fish trying to find water. Because we spend our entire lives in water, and because to see water clearly would seriously impede our lives, we never experience the water except as negation.