Published Wednesday, July 28, 2021 5:21PM EDT Concerns about a revenue growth slowdown pushed Facebook's shares lower in after-hours trading Wednesday, not long after the company reported that its second-quarter profits doubled thanks to a massive increase in advertising revenue. But CEO Mark Zuckerberg set his sights far beyond the second half of 2021, exalting what he sees as the next phase of how people experience the internet. What the rest of the world might know as augmented and virtual reality with a dash of science fiction, Zuckerberg and others are calling “the metaverse,” a futuristic and somewhat vague notion that encompasses AR, VR and new, yet-to-be-imagined ways of connecting to one another via technology.