
Member Reviews

This took a while to get through. Carroll's explanations are lucid, and helpful, but the material is occasionally a bit opaque and--frankly--mind-blowing. What this book lacks completely is sensationalism. Carroll lays out a case rationally, calmly, completely. This is a must-read for anyone who's interested in how the world(s) works.

I thought I would try something different.... but then realized why I never liked science in school.
Brilliantly written and so intriguing, but it missed the mark for what I prefer to read.
I DNF'd this one.
Thank you to the author, publisher and NetGalley for my complimentary ARC in exchange for an honest review. Please excuse my tardiness in posting my review as my TBR continuously grows and I keep finding so many book with so little time!
So much gratitude for this copy shared with me, always xo

I was granted an ebook ARC of Something Deeply Hidden by Sean Carroll by the Publisher Dutton on Netgalley to provide a fair and honest review.
Video review in progress
You can read my full review on my blog!
Introduction
I am beyond grateful to be offered the opportunity to review this book. I just recently finished one of Carroll's older books, and it is one of my favorites of the year. I know this book is already out. Nevertheless, the copy I was granted expires on the 31st of December, so intend to finish it before then to provide feedback for the copy I received. When I reviewed From Here to Eternity, I tried to review each part of the book. I think the result was a bit of mess; it was also a lot of work. Here, I will stop after each chapter to very briefly summarize his points and to discuss how effective it was as a chapter. Summarizing it will help me get a sense of how well I really understand it. Basically, I'm blogging my entire experience with the book. When I'm done, I'll summarize my thoughts above my blogging experience (right after this).
Final Thoughts
I absolutely adored this book. I am so grateful to NetGalley for providing me with an e-ARC of this. I didn't even realize it was already out, and I ended up using the audiobook (also amazing) to read the book. I still am happy I got the ARC because I may not have read it otherwise. I have only just started on NetGalley. I am a fan of Carroll, so I wanted the chance to review his newest book early. Even if it was already out, I may not have read it without the ARC because that was really the biggest motivator (the need to provide a review).
Otherwise, I might have read a different book by him because I was honestly very afraid of this book. The first time I saw the synopsis (prior to finding it on NetGalley), I read quantum mechanics and thought this was not for me. I have never understood it and was unlikely to start trying now. Then, with the added incentive, I decided to give it a try. Dear Sagan am I happy I did. I left this book feeling as though I actually understand quantum mechanics. Then add on the extra benefit of being beyond fascinated, intrigued, and excited by his discussion of Everett's Many World's hypothesis. I go in depth in my thoughts on that in my live blogging where I responded after each chapter. I would refer you there, jjoshh.com !, if you are interested in reading that.
All in all, this book did everything I want from a science book. It challenged my fundamental way of thinking all the while in a clear and structured manner. What's more, it is one that doesn't shy away from the tough parts of science while not creating a story that completely hinges on your reader to have an expert level understanding to follow along. I highly recommend this book and Sean Carroll (and his podcast Mindscape). This will probably be one of my top 10 books of the year. 5/5 stars
Rating Break Down
Writing Style: 10/10
Content: 10/10
Structure: 10/10
Summary: 9/10
Engagement: 10/10
Enjoyment: 10/10
Comprehension: 8/10
Pacing: 9/10
Desire to Reread: 10/10
Special: 10/10
Final Rating: 4.785/5
Note, each rating is weighted based on personal importance (see blog for more details).

I received a free digital copy of this book from NetGalley in exchange for an honest review.
I really like books like this because you learn while being entertained. I like Sean Carrol. I am a long time listener to his podcast. I really enjoy his entertaining way of explaining things that really should go over everyone's heads.
The book reads well. I really enjoyed it. I was a bit nervous to start this title. It seemed a bit daunting and complex. I do not have a background in science, so I was worried that this would all just go over my head but Carrol has a unique way of helping you understand super complex things.
Overall this is a great and intense read that we should all pick up.
Thank you to the author, the publisher, and NetGalley for allowing me to review this title.

This was definitely one of Carroll's more technical works. While his language as always as simple as it can be for the layman, there's only a certainly level of simplicity to which quantum theory can be broken down. That said, Carroll does good work interspersing all of the necessary technicalities with a more story-form description of the ideas behind quantum gravity, Many Worlds, and quantum physics, so if only half of the book sticks with you, you're still bound to learn something. Carroll's trademark humor, too, shines through in a lot of places, and serves as a good anchor point to bring even the most baffled reader back from the brink. Definitely not for beginners to the ideas behind quantum theory, but an excellent book to build on what a fan of popsci might already know.

TL;DR
Sean Carroll’s Something Deeply Hidden tackles the difficult many worlds theories of quantum mechanics. It’s weird; it’s funny; it’s deeply philosophical and worth reading. Highly recommended.
Review
According to quantum mechanics, it’s entirely possible that there are multiple copies of you reading multiple copies of this review. The many worlds approach to quantum mechanics says that the world decoheres into various branches. Branching reality is a difficult subject, but it is one that makes sense when interpreting exactly what quantum physics represent. Physicist, author, and podcaster, Sean Carroll attempts to explain these subtle and difficult philosophical questions in his latest book, Something Deeply Hidden, from Dutton. This is a book of big ideas explained to an audience of anyone. It doesn’t spoon feed the reader answers, but nor does it put concepts too far out of reach. For anyone interested in quantum mechanics, this is a must read.
Review: Something Deeply Hidden
I’m a fan of Sean Carroll. I like his podcasts and his appearances on Joe Rogan’s podcast. He’s entertaining while still conveying complex knowledge. So, this review is biased from the start. I don’t understand quantum mechanics, and for most of my studies, I’ve been told I don’t need to understand it because the math works. It’s an odd way to approach physics. To quote Richard Feynman, “…I think I can safely say that nobody understands quantum mechanics.” Certain physicists like Sean Carroll have decided to change that. Something Deeply Hidden largely succeeds for our current best understanding. It doesn’t rely on the fact that the math works out; it attempts to explain reality, which was physics original purpose.
The book reads well; it’s not full of equations, though there are some. Dr. Carroll’s style of explanation is clear enough without equations. He’s funny and fills the book with good examples and easy to follow illustrations. Dr. Carroll lays down a foundation of quantum mechanics history before moving onto cutting edge physics and then to the weird stuff. Something Deeply Hidden is an intensely philosophical book that I’m still thinking about.
The book focuses on Schrödinger’s equation and the Everettian interpretation, which is also known as the many worlds interpretation. In short, Schrödinger’s equation describes the wave function of the universe, and there is no collapsing of the equation. Instead of superpositions collapsing into a measured reality, the measurement causes a branching of the universe. Let me repeat that a branching of the universe. One where outcome A happens and another where outcome B happens. And guess what, we branch when the universe does as well.
The Many Worlds Interpretation
Decoherence, branching, and superposition are difficult concepts to understand. Honestly, I’m not sure I grasp it fully. Dr. Carroll does a good job explaining it in a way that I could start to understand. (This is a book that I will have to reread.) The idea that the universe branches has long been a popular idea in science fiction (see the TV show Sliders). But it’s much more complex than simply a person’s decision causes the universe to split. In fact, Dr. Carroll deliberately debunks this idea. The universe branches, but an individual’s decision doesn’t cause the branching.
Dr. Carroll explains the many worlds interpretation in plain terms that at the same time make you scratch your head. In Chapter Seven, Dr. Carroll writes a short story that’s a dialogue between father and daughter physicists. In a way, it reminded me of What We Talk About When We Talk About Love by Raymond Carver. This chapter was unexpected yet effective in conveying difficult topics around probability. It was an odd chapter in a physics nonfiction book, but it helped convey the information. Something Deeply Hidden is well written.
Part Three
Something Deeply Hidden is organized into three parts with a prologue, epilogue, and appendix. I kept up easily with part one; part two stretched the limits of my intellect; and part three simultaneously blew my mind and broke my brain. I don’t think I can adequately review this section without reading it again. And I will definitely read it again. In my review copy, one of the chapters in part three is titled, “Breathing in Empty Space.” A chapter title like that deserves re-reading.
Multiple Me's
One consequence of branching is that when the universe decoheres and branches, so does the person.
In other words, there are many copies of each of us on various branches out in the multiverse. Maybe. Dr. Carroll treats this as no big deal, and really after thinking about it for a while, it isn’t. Since we can’t interact with these other branches, contemplating the other me’s that exist is much the same as contemplating how many angels dance on the head of a pin. But I never did shake the weirdness of me branching with the universe.
This branching has direct consequences to conservation of energy and the concept of entropy. I’m not entirely convinced of the answer provided, but it’s an interesting answer. This is one of the rare moments in the book where I don’t think the answer conveys a physical meaning. Or, at the very least, one that I can understand. If the universe branches enough, does that mean it’s possible to lower the energy of the many worlds to almost zero? If so, what happens to all the me’s in those branches?
Competing Theories
Dr. Carroll states plainly that he subscribes to Hugh Everett III’s interpretation of quantum mechanics. But he does devote time to competing theories and gives them fair treatment. Then, he explains why he thinks the alternate interpretations are wrong but in respectful manner. Maybe I’ve been reading too much politics lately, but this was really refreshing. It’s important to see a thoughtful summary of and argument against a competing philosophy without a need to ‘win’ – whatever that means in physics circles.
This section also serves as a starter for investigating more about the interpretation of quantum mechanics. In this section, I learned the phrase quantum Bayesianism, which is just fun to say. Dr. Carroll’s description is quite interesting, and I might look into the topic in the future.
Conclusion
Sean Carroll’s Something Deeply Hidden broke my brain in the best way possible. This insightful, philosophical book explains difficult, complex concepts in understandable language. Based on the arguments, I’m now an Everettian convert. Somewhere out in the multiverse, there’s an Eric writing a better review of this book. In a different branch, there’s an Eric who didn’t get to read this book, and he’s all the poorer for it.
9 out of 10!

Something Deeply Hidden is that rare science nonfiction book that’s both easy to understand and incredibly complex. This is quantum mechanics laid out in an understandable fashion. With a combination of history, basic explanations, and visual aids that simplify its complexities, Carroll presents an essential guide to this mysterious field.
I’ll admit I was nervous as I started reading the book. At first glance, the subject matter seems too dense for a basic human without any scientific background. As you read, it slowly starts to make sense until you’re nodding along at things you never thought you’d learn. One of the most fascinating aspects of the book is the history of how the field came to be. It’s nearly impossible to imagine a group of people coming up with these kinds of theories but here we are.
Above all, you’ll learn so many things about the mysteries of the universe. I continue to have trouble wrapping my head around this fascinating field of science but I feel a big step closer after reading this thoughtfully written guide to everything quantum mechanics.

Sean Carroll of Caltech is an excellent writer and he has produced a wonderful book that everyone who has a solid science background must read. That said, "Something Deeply Hidden" is not for everyone. The general public should avoid this book. It is a bear to read with concepts like Hilbert space and countless other very technical issues and concepts. I give it five stars for those in the scientific community and those who possess a firm footing in classical relativity and the shift to quantum mechanics over the last 100 years. For everyone else -- Please avoid this fine book.