SPOILER WARNING: This article contains major spoilers for Justice League of America #17 (and DC Comics greater Rebirth storyline), on sale now.
Steve Orlando and Ivan Reis' conclusion to the "Panic in the Microverse" storyline not only confirmed <"/tag/justice-league-of-america">Justice League of America's unexpected connection to the central mysteries of DC Comics' Rebirth, it also hinted at how precisely Dr. Manhattan was able to so fundamentally rewrite the laws of the universe. Issue #17 also saw a legacy passed down from one hero to another, and suggested the imminent return of another team of heroes, in an issue packed full of action, resolution and setting the stage for the next big battle.
Dr. Manhattan and The Krona Connection
Longtime DC fans will have encountered at least one, and possibly several, variations of the Krona myth. Krona was a scientist, one of Oa's Guardians, who was obsessed with probing the origins of the universe. The other Guardians warned him against his hubris, but nevertheless Krona built a cosmic viewer to witness the beginning of time. Where he saw…
… a hand emerging from the void.
Cataclysm immediately followed, and Krona was banished. From there, the legend changes depending on who's telling the story (in some versions, it turns out the hand is Krona's), but when Krona appears in anything but a flashback, he's usually presented as a mad god.
Relevant to the current issue of JLA, though, is that this origin myth features prominently in Crisis on Infinite Earths, DC's original universe-shattering epic. In the classic series by Marv Wolfman and George Perez, part of the Anti-Monitor's plan involves being there at the dawn of the universe so that his is the hand Krona views, and thus all of creation can be remolded in the Anti-Monitor's image. This scheme is thwarted by the Spectre, who arm-wrestles the Anti-Monitor to a draw at the dawn of time.
The suggestion here, then, is that Dr. Manhattan has succeeded where the Anti-Monitor failed, and reaching his hand through the void on a quantum level -- as well as, perhaps, at the beginning of the universe, since he can time travel -- is what allowed him to create the New 52 universe.