Black hole (phenomenon)
From MediaWiki
A Black Hole is an astronomical feature that occurs when a massive star collapses into a extremely small singularity so dense than not even light can escape its gravatational field.
Transformers have encountered Black Holes on a number of occasions and they have frequently been show to function as portals between alternate universe:
A Quintesson ship with captured Autobots and Decepticons aboard passed through one to a universe where the color spectrum was reversed.
A specially outfitted Powermaster Optimus Prime journeyed into one to discover nucleon.
The bounty hunter Axer traveled through one from the Generation 1 continuity to the Robots in Disguise continuity.
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