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Why Do We Exist?: The Nine Realms of Universe that Make You Possible
A boundary-breaking astrophysicist reimagines the universe—and our place within it—in this audacious journey through the Nine Realms of the cosmos.
The universe gave rise to stars and cells, minds and memories, purpose and pain. But it doesn’t care about us. It follows its own rules. And now, according to Dr. Hakeem Oluseyi, we finally understand enough about those rules to ask the big questions like we mean Why do we exist? Are we alone? How did we get here? What comes next? And—perhaps most urgently—is there reason to hope?
Heck yeah, there is!
Dr. Oluseyi is no ordinary scientist. A former street kid turned world-renowned cosmologist, he realized something the story of existence can be told as a passage through nine interwoven realms—each revealing a new layer of cosmic truth.
There’s the Middle Realm, where we live; the Realm of Life, where organisms flourish across the vastness of space; the Cosmological Realm, where galaxies dance and collide; the Dark Realm, dominated by unseen energy and invisible forces; the Quantum Realm, where reality defies intuition; the Temporal Realm, where time begins, flows, and perhaps ends; the Multiverse Realm, where our universe may be one among many; the Realm Beyond Horizons, where observation breaks down; and the Realm of Imagination, where insight, curiosity, and creativity shape our understanding of it all.
In Why Do We Exist?, Dr. Oluseyi cracks open these realms with clarity, humor, and radical honesty, bridging cutting-edge physics, personal narrative, and philosophy. The result is a blueprint for understanding reality itself and a surprising case for human potential in an indifferent cosmos.
This isn’t just a science book. It’s a survival manual for the universally curious.
The universe gave rise to stars and cells, minds and memories, purpose and pain. But it doesn’t care about us. It follows its own rules. And now, according to Dr. Hakeem Oluseyi, we finally understand enough about those rules to ask the big questions like we mean Why do we exist? Are we alone? How did we get here? What comes next? And—perhaps most urgently—is there reason to hope?
Heck yeah, there is!
Dr. Oluseyi is no ordinary scientist. A former street kid turned world-renowned cosmologist, he realized something the story of existence can be told as a passage through nine interwoven realms—each revealing a new layer of cosmic truth.
There’s the Middle Realm, where we live; the Realm of Life, where organisms flourish across the vastness of space; the Cosmological Realm, where galaxies dance and collide; the Dark Realm, dominated by unseen energy and invisible forces; the Quantum Realm, where reality defies intuition; the Temporal Realm, where time begins, flows, and perhaps ends; the Multiverse Realm, where our universe may be one among many; the Realm Beyond Horizons, where observation breaks down; and the Realm of Imagination, where insight, curiosity, and creativity shape our understanding of it all.
In Why Do We Exist?, Dr. Oluseyi cracks open these realms with clarity, humor, and radical honesty, bridging cutting-edge physics, personal narrative, and philosophy. The result is a blueprint for understanding reality itself and a surprising case for human potential in an indifferent cosmos.
This isn’t just a science book. It’s a survival manual for the universally curious.
256 pages, Hardcover
Published April 21, 2026
31 people are currently reading
235 people want to read
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Displaying 1 - 2 of 2 reviews
May 3, 2026
In 2015, John Horgan wrote a book called The End of Science, arguing that physics had created a valid map of how the universe works and that little may remain besides filling in and correcting details. Horgan impressively buttressed this somewhat depressing thesis by interviewing the likes of Lynn Margulis, Roger Penrose, Francis Crick, Richard Dawkins, Freeman Dyson, Murray Gell-Mann, Stephen Jay Gould, Stephen Hawking, Thomas Kuhn, Chris Langton, Karl Popper, Stephen Weinberg, and E.O. Wilson.
This absorbing new book by astrophysicist Hakeem Oluseyi will convince you otherwise. Ranging through particle physics, quantum physics, astrophysics, and cosmology, Oluseyi rakes up huge questions everywhere he looks. The result is largely chaotic and sense-resistant. The reader risks gulping down too much too fast. But it is all fascinating.
Oluseyi does extremely well in three areas: 1) How a universe might unroll after a Big Bang, with special focus on the first few millionths of a second. His exposition seems more freshly informed than Steven Weinbberg's The First Three Minutes (1993); 2) The life cycle of stars. His description is a thermodynamic tour-de-force.; and 3) How life needs to take billions of years to emerge. In all respects this book provides the biggest and most comprehensive (though, mercifully, not the most detailed) delineation I've encountered. There are no equations or overly abstruse technical language. On the other hand, this book is not for youngsters or newbies; it assumes a fairly high level of familiarity with the material, if not actual former study.
One star is deducted from the rating for the misleading title. There are no answers to Why, or even How, questions. What the author offers is awe -- particularly in terms of scale -- and honest, subject-dictated confusion. Ours may not be a universe that wants to be understood by the likes of us.
I was a bit disappointed by his skimpy discussion of fine tuning and the multiverse. The author is better at sharing enthusiasm for what he knows well from lab experience, a bit less engaged when having to dive into pure speculation. But that seems fair enough.
Oluyesi seems very authoritatively up-to-date on recent and current developments.
This absorbing new book by astrophysicist Hakeem Oluseyi will convince you otherwise. Ranging through particle physics, quantum physics, astrophysics, and cosmology, Oluseyi rakes up huge questions everywhere he looks. The result is largely chaotic and sense-resistant. The reader risks gulping down too much too fast. But it is all fascinating.
Oluseyi does extremely well in three areas: 1) How a universe might unroll after a Big Bang, with special focus on the first few millionths of a second. His exposition seems more freshly informed than Steven Weinbberg's The First Three Minutes (1993); 2) The life cycle of stars. His description is a thermodynamic tour-de-force.; and 3) How life needs to take billions of years to emerge. In all respects this book provides the biggest and most comprehensive (though, mercifully, not the most detailed) delineation I've encountered. There are no equations or overly abstruse technical language. On the other hand, this book is not for youngsters or newbies; it assumes a fairly high level of familiarity with the material, if not actual former study.
One star is deducted from the rating for the misleading title. There are no answers to Why, or even How, questions. What the author offers is awe -- particularly in terms of scale -- and honest, subject-dictated confusion. Ours may not be a universe that wants to be understood by the likes of us.
I was a bit disappointed by his skimpy discussion of fine tuning and the multiverse. The author is better at sharing enthusiasm for what he knows well from lab experience, a bit less engaged when having to dive into pure speculation. But that seems fair enough.
Oluyesi seems very authoritatively up-to-date on recent and current developments.
April 25, 2026
This was a clear and fascinating explanation of some current theories in astrophysics. The author has a great narrator voice and is able to explain complex ideas with humor and clarity. I felt like the last chapter, for me, was just personal speculation. While the author obviously wants you to read the entire book from start to finish, I found it was easier to keep engaged and worked well to skip around a bit. So many good popular physics and astrophysics books coming out right now and this one was excellent but not the one I would begin with. Also, read the author’s previous book which is a memoir of growing up poor and Black in the US.
Displaying 1 - 2 of 2 reviews