The Einstein field equations lay at the heart of general relativity.
On the Earth of his previous life, they were equations that used a heap of obscure mathematical symbols to explain what gravity actually was.
And these equations had two maximally symmetric vacuum solutions.
One was de Sitter space, abbreviated as dS;
The other was anti-de Sitter space, dS.
In dS space, the cosmological constant was greater than zero, describing a universe with positive curvature that kept expanding, just like the real universe.
In dS space, however, the cosmological constant was less than zero: negative curvature, a static, empty universe.
This spacetime model did not exist in reality. It was merely a "laboratory" theoretical physicists used for thought experiments.
And Greeza's true nature was a local anomalous solution forcibly squeezed out of an otherwise stable dS universe, catalyzed by Juda's power to distort the laws of the universe.
It was like someone pressing hard against the surface of a balloon as it inflated, creating an inward dent.
There was nothing inside that dent.
No matter, no energy, not even time.
And because it dipped inward, things on the normal balloon surface around it would inevitably slide down the slope and fall inside.
That was why Greeza could devour everything...
Boom!
Another bolt of purplish-red lightning struck.
Ultraseven rolled halfway over in the vacuum, narrowly dodging the thunderbolt that could vaporize an asteroid.
The Head Slugger in his hand gleamed coldly as he hurled it again.
A silver arc sliced through the vacuum, cutting straight toward Greeza's chest.
But the Head Slugger passed through Greeza as though through a holographic projection, emerging from his back before spinning through the vacuum and returning to Ultraseven's hand.
"Damn it! What the hell is he made of?"
Ultraseven caught the Head Slugger and cursed.