An excellent, beautifully written and informative read. I'm not saying I understand loop quantum gravity or the notion of spinfoam but the idea of a granular universe universe without time or space is an interesting one. An excellent journey from Democritus to Hawking.

Roveli čovek dosta voli poeziju, te je gura i tamo gde ne treba, tojest kada piše o nečemu gde je, za potrebu lakoće razumevanja relativnih laika kao što sam ja, najbolje biti koncizan i precizan. Sa te strane mu se ima šta zameriti, kao i to što ne daje baš potpun prikaz svih fenomena (posebno) kvantne mehanike i opšteg relativiteta, već samo onih koji mu odgovaraju. Medjutim, sa druge strane, kao jedan od proponenata i osnivača loop quantum gravity teorije (te je malo i prodaje ovde), ovo je potpuno fascinantno štivo koje daje uvid u jedno od potencijalnih rešenja diskutabilno najveće nepoznanice teorijske fizike – kako spojiti nespojivo, odnosno šta se desi i šta može da se desi kada se sretnu kvantna mehanika i opšti relativitet. E sad, zašto je to toliko zanimljivo, mogao bih dugo i sa verovatno puno grešaka, pa neću. No, u par crta: beskonačnost ne postoji, prostorvreme ima strukturu, vreme je izmišljotina i, uz možda najradikalnije poredjenje knjige, nalik je na toplotu. Ne postoji stvarno, već je posledica naših aproksimacija, našeg nepotpunog razumevanja. A zna se šta je Ajnštajn rekao o ljudskom nerazumevanju (hint: beskonačno je).

Roveli priznaje da je sama završnica knjige, kao i kod većine sličnog štiva, izrazito spekulativna, ali ima li išta zanimljivije od tog nagadjanja? Drugačije se, na kraju, ni ne može pogoditi.

4+

Goddamn - an exposition from Democritus through to Loop theory. Beautifully explained even if I found myself scrubbing back a few times to try and wrap my chops around some of it (hell, most of it, if I’m honest).
Could I explain it back to you, nope.
Do I understand it from first principles, nope.
Do I have an eloquent and passionately recounted overview of theoretical physics, yes!

My brain is soup now but it makes me want to learn more and isn’t that the entire point of scientific inquiry?

Also, as a sidenote, it is narrated by Roy McMillan who also voiced The Old Ways by Robert McFarlane and I’m hooked.

If you're interested in cutting edge theoretical physics or just want to have your mind blown by how deeply the human mind has managed to penetrate into the bizarre nature of reality, make sure not to miss out on Carlo Rovelli's excellent introduction to loop quantum gravity. Although one of the most promising competitors to string theory, LQG still very much plays an underdog role in our ever-elusive quest to find a working quantum theory of gravity. Why? As fellow theoretical physicist and LQG pioneer Lee Smolin argues in The Trouble with Physics, over the last couple of decades the wider theoretical physics community has been somewhat spellbound by a not entirely deserving "string theory mania", hurting alternative approaches and running the risk of steering the field into an intellectual deadlock. Hence the value of books like this. Besides offering a lucid rundown of LQG's history, its open questions, and why it is a promising alternative to string theory, Rovelli's book also convinces through the author's deep love for philosophy, history, poetry and science, drawing inspiration from giants such as Democritus, Anaximander, Lucretius and Dante. Technically inclined readers may also be interested in Rovelli's Covariant Loop Quantum Gravity.

This is a really beautiful book.

This book came out January 2017. I thoroughly enjoyed it from beginning to end. It is written elegantly but simply for the non-scientist to understand. The book includes a plausible description of what everything and I mean everything is made of. Rovelli's writing converted me from a String Theory fan to a Loop Quantum Field fan!

I will now embarrass myself with meagerly trying to explain some of what I took away from the book. We know that our perception of the reality around us is limited, but Rovelli clearly explains how our five senses only see a small part of what is surrounding us. He moves away from the idea of an infinite universe to a finite one in which our reality is pocketed in a specific place inside what is actually there. Think of everything being a giant web with thicker and thinner spots of mass. We can't see the web connecting everything but it is there. Spooky but exciting.

One of my favorite excerpts:
"The quanta of gravity, that is, are not in space; they are *themselves* space (emphasis mine)."

It's a fun book mainly. He gives a good rendition of how he thinks theoretical physics should be done, which is interesting.

I'll definitely note there's some serious hand-waving done towards the latter sections :). But like I said, I enjoyed it.

Enjoyable brief summary of theoretical physics from ancient times to quantum gravity.

Greatly written explanation of the loop quantum gravity and the journey of unification of physical forces (which in the book starts in the ancient time of Democritus), of which the most focus is understandably given to the unification of general theory of relativity and quantum mechanics. Although a lot has been written about both of these forces, their history and the people who coined them, the book uncovers interesting new stories and facts (for example the story behind the discovery of Heisenberg's principle of uncertainty). Lastly, the book is written for any reader no matter how (in)experienced he is in the field of physics.

I finished it, for which I deserve five stars. The author used great illustrations, for which he deserves five stars.

However, I think the author should have described certain quantum ideas, like 'spin networks' and loops with more illustrations and longer chapters and more words rooted in common everyday language - but on the other hand, my brain grasps liberal arts with ease while I flounder and drown in math conceptualizations, not to mention in solving higher-math equations. Maybe the author DID describe accurately those things.

The author has extensive notes, an annotated bibliography and an index. As far as I can tell, this is a fantastic book. The author certainly tried very very hard to make quantum mechanics understandable.