Empty space means “Quantum fluctuations”. Right. It’s not nothing. It’s uncertainty around nothing. That uncertainty is even measurable. As far as I understand it.
From my point of view, I’m probably right. From yours I may be quite wrong.
I’m not quite sure what is most unlikely, though. These sentences above, or the fact that it’s all explained rather well on a school physics sort of level in the first paragraph of this Wikipedia article.