- "You recall what I told you of the Convergence?"
"Yes, the alignment of the worlds. It approaches, doesn't it?"
"The universe hasn't seen this marvel since before my watch began. Few can sense it, even fewer can see it. But while its effects can be dangerous, it is truly beautiful."
- ―Heimdall and Thor[src]
The Convergence is a cosmic event that occurs approximately every 5,000, when all Nine Realms are placed into alignment.
During the Convergence, all Nine Realms of Yggdrasil are in alignment. This alignment causes the dimensional boundaries between each realm to become thin, resulting in various physical and hyper dimensional anomalies occurring at random. These phenomena include shifts in gravity, spatial extrusions, and the fabric of reality potentially tearing apart. Perhaps most notably, invisible wormholes that allow matter to move between realms seemingly open and close at random. As the Convergence reaches its apex, several larger, visible wormholes open in the sky above central locations in each realm, with each portal acting as a window through which parts of other realms can be seen.
During a Convergence in the distant past, Malekith, the king of the Dark Elves sought to take advantage of the weakened boundaries between the realms to use a powerful weapon known as the Aether to revert the universe to the primordial state of darkness in which his race had once thrived. These attempts were thwarted by the Asgardians under the command of their king, Bor. Following their crushing defeat, Malekith and the surviving Dark Elves retreated, entering a prolonged hibernation until the time of the next Convergence, when Malekith made his second attempt. He failed once more, this time at the hand of Bor's grandson, Thor.
Jane Foster studied the effects of the Convergence both before and after it happened, making important discoveries in the field of astrophysics, and becoming a serious candidate for winning a Nobel Prize for her work.
Tobias Ford inadvertently caused a Particle Accelerator to explode and seemingly kill him and three others. The explosion caused a portal to another world to briefly open, through which Ford was transported. Ford became "stuck" between two worlds and he was able to traverse between them, seemingly a ghost to those around him on Earth, since he would teleport as well as materialize and become visible, and then vanish. Leo Fitz and Jemma Simmons deduced Ford's situation after discussing the recent events of the Convergence and the portals it opened between the Nine Realms, stating that the borders between worlds are not completely closed.
Behind the Scenes
- Thor: The Dark World director Alan Taylor stated the gravity changes caused by the Convergence in the past were meant to imply how ancient humans built structures like Stonehenge.