
The year is 2100 A.D.… And Man no longer stands alone in the universe. Now there are other worlds, other living beings. Alien beings who mate in threes and live on pure energy. New breeds of humans who have created their own environment and freed themselves from every social and sexual taboo. Yes, it is the future of new worlds, ever-changing worlds. And yet among them there is still Earth. Earth, where Man still strives to be the best. To advance himself beyond all other beings and their worlds. And this final, glorious step in mankind’s technical progress has been achieved: the discovery of an unlimited, non-polluting energy source. But what seems to be progress may, in reality, end in complete tragedy. Earth’s unlimited energy source is about to trigger unlimited destruction—and the end of a universe.
Tangentially related, but there's a great Asimov book about this called The Gods Themselves (fiction).
Fiction: The Gods Themselves Asimov.
These are the book I always recommend to friends and colleagues. There are runners up based on taste, such as Zero to One,The Making of the Atomic Bomb, and Anathema.
If you were actually looking for Asimov at his most "Lord of the Rings" I'd actually suggest probably "The Gods Themselves". There the worldbuilding was far more central and important to the narrative.
I second "The Three Body Problem" series (writing is meh but I think the ideas are excellent. Disclaimer: first half of book one is a slog to get through but the second half onwards is fantastic, in my opinion. I keep thinking about the book many years later on a near biweekly basis).
"The Gods Themselves" by Asimov isn't a book mentioned here yet—it has nice math-physics energy ideas.