This was a really engaging and well prepared novel. I found the science to be a little over my head at times and a little lengthy, but I never mind that - I like struggling to work through and understand, and appreciate the attention to detail and the trust that the reader will be able to get enough out of even complex material to follow along. . I found the characterizations really excellent and the plot moved along at an excellent pace that I thought was perfectly suited to the story. I really enjoyed this one and will definitely be looking up both authors for follow up reads.

Excellent, well written, and thought provoking novel. The characters are well realized, with real world problems and some new types of problems as well.

I appreciate that the book challenged me about the universe and alternative views of the universe. I appreciate a book that make me think and challenge myself while providing a great story.

In the Kindle edition there were two places where there was no space after a semicolon, otherwise the formatting worked well.

Thank you for letting me read this book!

The book seems well-written and well-thought-out. Unfortunately, I can't connect it and started to feel like forcing myself to finish it. I decided to DNF it for now, but I want to emphasize it's the case of "It's me, not you" DNF :)

Thanks to the publisher for giving me the possibility to try it. I may give it another try soon.

I picked this up largely because it was co-authored (or, I suspect, "entirely written, based on ideas by Robert Lanza") by Nancy Kress, who I knew to be a highly competent SFF writer. I have a couple of her books on the craft of writing, and they're excellent, so I expected a well-told story. Nor was I disappointed. (I'll note that there's at least one other award-winning writer whose writing advice I respect, but whose actual fiction I've never enjoyed or been impressed with, so the two skills don't inevitably go together.)

It needed someone with the skill of a Kress to make this a readable story, honestly. There is a <i>lot</i> of exposition, and a less competent author wouldn't have been able to make it interesting. Also, the premise doesn't make a great deal of sense if you think about it in any depth, so it needed an author who was able to keep up a constant patter of misdirection by telling an engaging story with well-drawn characters.

That premise starts with some features of the observer effect in quantum physics and boldly makes the observer central - so central that the theory is that observers create the universe, rather than vice versa. Building on this, a Nobel laureate in medicine (who is dying of cancer), his old friend the theoretical physicist whose theory I have just outlined, and a tech billionaire have come together to attempt to enable people who are implanted with brain stimulation equipment and linked up to powerful software to create new universes by "observing" them in a kind of virtual reality within their own minds. In these universes, they are able to create counterfactual situations: for example, the door of a room in the Caymans, where they are based for legal reasons, opens into the theoretical physicist's house in Britain in a universe where his wife did not die 15 years before, but is still alive. Not a simulation of her - actually her. Never addressed is where the version of him from that other universe is, why his wife isn't surprised to see him, how he gets from the Caymans to the house in Britain by walking through a door... There are a lot of holes in the basic idea, in other words.

Although Kress is known as a "hard" SF writer, meaning she makes a lot of use of actual science, she's not one of those whose characters are simply cameras exploring the clever setting. She tells a story, and her characters read like people. The main point of view belongs to Caro, the Nobel laureate's great-niece, a neurosurgeon who, after a failed attempt to hold a more senior male surgeon to account for drunkenly groping her at a party (which led to her being heavily trolled on social media by toxic men), is prepared to take a chance on what sounds like a weird and maybe even borderline unethical project implanting the brain stimulation devices. <spoiler>I wondered for a long time whether Julian, the dubious tech bro, had manipulated the MRA situation in order to get her as their surgeon, but this was not the case - or if it was, it was never revealed.</spoiler>

Through most of the book, Caro remains skeptical about the reality of the experiences people have through the devices she implants, and this provides a good point of tension and makes her character feel strong and distinct, given that she's surrounded by true believers.

There's a solid B plot involving Caro's sister, who's dealing with a disabled child and also a non-disabled child who is finding her younger sister's needs and the demands they place on her mother increasingly difficult to bear. There's also a romance subplot for Caro, which gives her a conflict between relationship and career, and several friendships of different kinds with other members of the project. It's all very solid storytelling, and it's where the book shines. It doesn't have the all-too-prevalent issue of contemporary or near-contemporary SF, where the characters are alienated people with no values who don't particularly want anything but just have to react to events. Caro comes through as a character with multiple dimensions, needs, desires, and the ability and determination to work towards what's important to her.

From an unpromising and dubious premise, then, Kress builds a highly readable novel with engaging characters, a feat for which she should be commended.

OBSERVER is already one of my Best Books of 2022, and with January release will be one of the Best of 2023.
Hopeful, inspirational; heartwrenching and heartwarming; infuriating and invigorating, OBSERVER is the seamless collaboration of two excellent authors with a firm grasp of Science and a flair for Speculative Science Fiction. The Quantum Science is graspable, illuminating, inspiring. I read it in one session and had no situational awareness of my surroundings, as I was so deeply into the novel. I came away Hopeful, excited, inspired, determined! This is a novel I expect to return to again and again and again.