Pretty technical book, but not as technical as a text book. You must have an advanced hobbyist knowledge of modern physics to appreciate and learn from the book. The most telling line was loosely: "You can never prove something true in science, but only prove claims false." I've been ruminating over this for days, it is so powerful considering our currently politicized science. ( )

“And why does the Higgs exist, if it does? Is there a more fundamental theory that explains its existence, along with that of electrons, quarks, photos, and W and Z particles?”

In “Fear of Physics” by Lawrence M. Krauss

“Electricity and magnetism are the different ‘shadows’ of a single force, electromagnetism, as viewed from different vantage points, which depend upon your relative state of motion.”

In “Fear of Physics” by Lawrence M. Krauss

“We appear, with reasonably high precision, to live in a flat universe.” (*)

In “Fear of Physics” by Lawrence M. Krauss

NB: (*) This book was published in 2006. In 2019, my take on this is quite different. The statement that the Universe is 13.8 billion years old is a statement of universal simultaneity, either that or it is a meaningless statement. A universal simultaneity is a direct contradiction of Relativity Theory under which there can be no universal simultaneity! At root, the "expanding universe" model rests on two early 20th century assumptions that are almost certainly wrong. The first assumption, implicit in Friedmann's GR solutions to a universal metric (now commonly called the Friedmann-Lemaitre-Robertson-Walker metric) is that the cosmos constitutes a singular entity possessed of a universal frame - the metric. In itself this is contradictory of Relativity Theory which does not admit a universal frame. The second assumption is, of course, that the redshift-distance relationship discovered by Hubble is a consequence of a recessional velocity of some sort. That assumption reinforces and doubles-down on the cosmos as unitary entity assumption. The resulting ΛCDM model is the modern day equivalent of Ptolemaic cosmology. Despite the fact that it can be massaged to agree with actual observations (by the injudicious use of free parameters), the model bears no resemblance to the cosmos we actually observe. The big bang and inflation are an unobservable creation myth. Substantival space, time and/or spacetime are not empirically observable; they are relational concepts like temperature that have no physical correlate. There is no empirical evidence for the existence of dark matter or dark energy, that combined supposedly comprise 95% of the ΛCDM "universe". Modern cosmology is an empirically-baseless, unscientific mess. What is needed is not "new physics", just a new, realistic model of the cosmos we actually observe. Unfortunately, such a model is unlikely to spring forth anytime soon from the scientific academy. As long as the academic community remains mesmerized by the erroneous mathematicist’s belief, that mathematical models are more important than empirical evidence - most especially negative empirical evidence, the absurdities will continue to pile up - as unobservable, but oh-so exciting, "new physics". Modern cosmology is deeply embedded in a new dark age, where a sacrosanct model holds sway over the evidence of our lying eyes. It ain't pretty if you care about science. Don't forget particle physics and string theory. Future sociologists are going to have a field day with the degree to which theoretical physics has gone totally off into fantasyland. Curved spacetime and expanding space are a modeling of energy radiating out and mass coalescing in. The fact these two balance out is already fully accepted by the cosmology community "Omega=1." That this relationship is best described as a cosmic convection cycle is simply not considered. This problem doesn't occur occasionally, this is the operating paradigm in modern theoretical physics. It is the way science is now taught and conducted. Anyone who learned theoretical physics since the late 1970s - early 1980s is steeped in this approach; it is the watery realm in which they swim and it is invisible to most theoretical physicists. It is simply the way things are done.

The study, care, and feeding of preferred mathematical models has become the work of theoretical physicists. Physical reality itself is now studied as an adjunct, explored only in search of empirical verification for a particular model.

Better observational data will be needed to confirm or refute these models of so many unknowns. Older estimates will yield to newer, better estimates (and better methods of making those estimates). That said I have a few questions. To wit:

1) Can we be confident that the Hubble Flow is symmetric in all directions? Should we accept that Hø is a constant at all?

2) It seems that ΛCDM is a more rickety model than first thought?

If I am still alive 20 years from now, I won’t be surprised to know that these questions haven’t been answered yet... ( )

Not quite what I'd hoped for and much less engaging than I'd expected, though bit throughout resonated with me. ( )

As much as I would love to understand modern physics, I have yet to find a book that I, as a lay person, can really understand. Unfortunately, I have to include Fear of Physics among these. This is probably more of a comment on me than the book. I think Krause's later book, Something from Nothing does a better job of explaining, while sacrificing none of the author's enthusiasm so evident in both books. ( )

Krauss's attempt at popularising Physics is a lot more thoughtful than most, but it suffers from the usual problem - it gets serious too quickly, and moves into the world of quantum mechanics when it shouldn't really.

As interesting as QM is, I'd rather leave it out of most popular accounts of Physics; I don't think even a basic knowledge is essential when one wants to learn something about the world we inhabit. Even relativity can be a bit of a push. There's a reason why most of these topics is left until university, you know. ( )