Crisis on Finitie Earths - One and Two - and their Cosmic Energies

Prior to the Crisis on Infinite Earths, there were other incidents were Earths One and Two were very nearly eliminated. Two such occasions were in 1978 on Earth-One and 1972 on Earth-Two, involving temporal displacement.

An unknown alien entity sought to use Earth-One as a projectile aimed at the world of its race's enemies. With the combined efforts of the Justice League, Teen Titans, Metal Men and various other heroes including the visiting Inferior Five of Earth-Twelve, the heroes loosened the grip of the alien's massive ship, with assorted historical allies restored to their native eras.

A massive cosmic hand, consisting of nebulous energy, gripped Earth-Two while threatening its survival. Its creator, the Iron Hand, demanded absolute rulership of her world as payment for its salvation. With the combined efforts of the Justice Society, Seven Soldiers of Victory... also known as Law's Legionnaires, and the visiting Justice League of Earth-One... the heroes were able to destroy this hand after retrieving those Legionnaires scattered throughout history. 

The means of doing this was the construction of a Nebula Rod, a type of "lightning rod" device that could be used against entities or objects composed of Nebuloid energies. Decades earlier, the Seven Soldiers originally designed the Nebula Rod for use against the extraterrestrial threat named Nebula Man. Through some undisclosed means, the heroes were able to ascertain the creature's origins and nature of its being. However, due to the volitile nature of this energy, both Nebula Man and the Legionnaire equipped with the rod would be destroyed. While that person, Wing, gave his life to save Earth-Two, the spacial displacement of Nebuloid energy sent his teammates through time and space... until the Society and League retrieved them years later.

A comparable type of energy on the Justice League's Earth were Zeta-Beams, which could bend time and space. While the true nature of the stasis field used by the mystery alien in 1978 wasn't identified, interestingly this conflict pulled Adam Strange into the battle. Strange had been exposed multiple times throughout the years to Zeta-Beams, which teleported him to the planet Rann-One and back to Earth-One on several occasions. This Zeta energy was also known to allow those riding its waves to travel through time as well.

With no record of Zeta-Beams existing in Earth-Two's universe, and no Nebulous energy existing in Earth-One's universe, it seems likely due to varying physics of these parallel realities, these were divergent manifestations of the same teleportational effect.

And in fact Zeta-Beams and Nebuloid energy wasn’t the only fantastical forces unique to these two universes. The Emerald Energy discovered and harnessed by the Guardians of Earth-One’s Universe and the Q-Force harnessed by the residents of planet Myrg in Earth-Two’s universe were each distinct to their native dimensions. While the emerald energy originating from planet Oa could solidify light constructs while Q-Force manipulated mass and gravitational fields, they each were complimentary forces.

Early in the history of both universes, the Guardians extracted and expelled the chaotic elements of their Emerald Energy, unleashing it in Earth-Two’s dimension. This caused the Q-Force to lose its dominance in its own reality. Eons later, it would then be Q-Force’s turn to be unleashed upon Earth-One’s reality. What effect either of these forces had on the Zeta and Nebuloid forces in each universe is unknown, although both seemed immune to adverse affects when mingled together.