However, "critical mass" is a term commonly used in other contexts, such as:
* Nuclear physics: It refers to the minimum amount of fissile material needed to sustain a nuclear chain reaction.
* Social movements: It can describe the point where a movement gains enough momentum and support to become unstoppable.
It's possible that "critical mass" was used in a Marvel comic to convey a similar idea, perhaps:
* A gathering of powerful characters: A gathering of heroes or villains strong enough to dramatically alter the outcome of a battle or event.
* A turning point in a story: A point where events become irreversible or where the stakes are raised significantly.
* A specific event or power: A power or ability that can only be activated when a certain number of people or objects are present.
To give you a more accurate answer, please provide more context about where you encountered the term "critical mass" in Marvel Comics. For example:
* What comic book was it in?
* What characters were involved?
* What was the context of the phrase?
With more information, I can provide a more relevant and accurate response.