An incredible pile of unscientific gibberish
There's one aspect in which Lee Smolin's newest book is less irritating than his previous book, The Trouble With Physics: the main purpose of the new book isn't to mindless attack and lie about the best results of the contemporary theoretical physics research. Instead, if we ignore the mega-arrogant and super-dishonest subtitle "From the Crisis of Physics to the Future of the Universe", "Time Reborn" tries to attack physics from the times of Newton and "constructively" present Smolin's own ideas about physics – or something he apparently calls "physics" – and it's a stinky junk of the most despicable kind, indeed.
You may read some reviews before you decide whether you want to buy this tome or not. But let me summarize some basic points and some characteristic elementary mistakes that may serve as examples of what this pile of paper is all about.
If one suppresses the actual atrocious content of the book, its main thesis may be summarized by the slogan "time is real". What does it mean? Smolin opposes the idea that time may be emergent or the spacetime is doomed – without offering a tiniest glimpse of evidence for his prejudices. Everything must be a slave of time. You may recall his delusions about time-dependent laws of physics – this preposterous and ill-defined concept is given some attention, too.
You might think that the book is therefore a sequence of inconsequential quasi-philosophical babbling that is entirely disconnected not only from the advances in physics of the last 40 years – which was the case of "The Trouble With Physics" – but it is also unrelated to the physics research of the 20th century and probably physics as we have known it for 300+ years. And you would be mostly right. Most of the book is composed of scientifically meaningless words of the author who knows nothing about science but who can't resist to preach about his medieval philosophical prejudices.
But it would be just a part of the truth.
In fact, he does mention some things related to modern physics but almost always negatively so. He makes it very clear that he wants physics, science, and Nature to obey the prejudices of this super-arrogant would-be thinker and he wants to pay no attention whatsoever to what Nature and science research are actually telling us. He is clearly the polar opposite of a good physicist – or an honest human being, for that matter.
How does it influence his proclamations about physics? For example, he predecides that time has to be fundamental but he also predecides that space is not. He seems to think that he is being told such insights directly from Heaven. However, we've known since the 1905 discovery of the special theory of relativity by Einstein that space and time are related by a symmetry – the Lorentz symmetry – so when it comes to certain properties such as their being "real" or "fundamental", they must have the same properties. How does Smolin deal with this fact?
He simply ignores (and spits on) all the evidence in favor of relativity. The scientific evidence – empirical facts and/or credible observations – never play a role in decisions about his portrait of the world. Well, more precisely, they do play a role – a negative one because Smolin seems to be obsessed with writing gibberish that contradicts the maximal possible number of scientific results.
It's not just relativity that gets spitted upon in this way. All these negative statements are being extrapolated to downright pathological dimensions. So you will find an almost literally endless tirade attacking the concept of symmetries in physics. Symmetries has to be destroyed, Smolin preaches. Every theory that has too many symmetries in it has to be banned. Given the importance that symmetries have played in physics for a century, we can only say one thing: What an amazing imbecile!
Needless to say, Smolin – who has no clue why relativity is not only right but an important finding about Nature – has no chance to understand quantum mechanics which is arguably much more inaccessible to the eternally hopeless laymen such as himself. So there's another endless tirade in which we "learn" that quantum mechanics has to be wrong as well and it will surely be replaced by a hidden variable theory. There isn't a glimpse of evidence supporting this bold claim, either. And all the evidence proving that this statement by Smolin is demonstrable bullshit are completely suppressed.
Even this theme isn't enough for Smolin so it gets generalized. Everything about physics has to be wrong. Moreover, he seems to assume that as soon as he convinces you to agree that something about the current picture of physics will be modified in the future (which is conceivable), you will have to accept his delusions instead (which is not conceivable). No suggestion that his delusions could be wrong as well can ever be found in the book. He behaves like a fungal cell that conspires to eliminate the good bacteria from your guts and instantly wants to occupy their place. Fungi may be hard to fight with but at least some imperfect fungicides and fungistats exist. I am not sure whether there exist efficient enough Smolinocides. At least in the institutions that are supposed to do science, they're badly needed.
The diversity of "obviously right and important" insights of science that Smolin can't resist to attack because they contradict his medieval dogmas is unbelievable. For example, he tells you – without any apologies – that electrons in the Universe are not indistinguishable. To "prove" this point, he says that one electron may be on Earth and another electron may be on the Moon so they're distinguishable.
He both misunderstands what the identical nature of particles means; and why it's true. Or he at least pretends to misunderstand both of these things. Location may effectively distinguish two or several electrons but the point is that if two or several electrons share the same region or come to occupy "states" that are not separated from each other by a "gap", e.g. during a collision or in the atom, we can't say "which one is which one" and connect the electrons in the initial state with those in the final state. For example, in terms of Feynman diagrams, we must sum over all the histories including the possible permutations of all the electrons to get the right result (the right probability amplitude). He can't possibly understand any of this basic undergraduate physics about (anti)symmetric wave functions. Or he understands it but finds it OK to hide all the evidence known to him that unequivocally implies that this whole book is a pile of shit.
If someone writes hundreds of pages of an incoherent text that dismisses not only the Lorentz symmetry, quantum mechanics, and (of course) quantum field theory and string theory (the only other known framework that is capable to reproduce and surpass the successes of QFTs: all these essential facts are totally censored in the book) but also any symmetry and probabilities and almost every other important result of the 20th century physics – such as the indistinguishability of particles – don't you agree that a "hardcore crackpot" is a very accurate description of the person? I don't believe that there exists a competent physicist who doesn't agree that Lee Smolin is a hardcore crackpot – although there may be folks who, probably for egotist reasons, try to hide this understanding of theirs.
The last three chapters resemble a speech of an Islamic fundamentalist preaching before the execution of a heretic who is being stoned to death. There isn't a trace of science in those chapters. It's pure religion and screaming that everyone must act to agree with Smolin's unscientific delusions.
The book is so terrible that it got a very negative review from Smolin's other most notorious fellow sourball, too.