There is much to be commended in this likeable history of an idiosyncratic recent period in science, but despite David Kaiser's engaging approach, the material feels thinly stretched and some of his assertions don't hold up to scrutiny.
For a start, the physics of the title doesn't refer to all of physics, but rather a small subset, quantum theory. The hippies were a loosely connected gang of misfit PhDs, based in California in the mid-1970s, who were fuelled by their disillusion with the formulaic and prescribed nature of their studies. They went by the name of the Fundamental Fysiks Group.
Kaiser argues well that, in universities in the postwar period, the approach to physics shifted from a philosophical to a more practical one. In the wake of the frenetic race to invent the A-bomb at the end of the Second World War, and the subsequent cranking up of military development during the Cold War, academia got into bed with industry and was churning out graduates fit only for weapons research production lines.
Gone were the heady days of Einstein and company sitting around perusing the philosophical implications of relativity. But this approach was something that the Fundamental Fysiks Group wanted to return to, and up to a point at least, it was successful.
The group wasn't only fuelled by a quest for knowledge, of course. This being California in the 1970s, its members were also fuelled by psychedelic drugs, and with them some rather loopy ideas. Para-psychology, telekinesis, ESP and a search for extra-terrestrial communication all came under these guys' remit (and they were mostly guys), as they approached their work with a more open-minded attitude than their predecessors.
But they were still trained scientists who largely employed rigorous scientific thinking and methods. The basis for most of their research was a well-recognised feature of quantum theory, non-locality or entanglement, which basically implies that, even when separated, two elementary particles can still have an instantaneous effect on each other. When this phenomenon was originally discovered in the 1930s, Einstein didn't like it at all, calling it "spooky actions at a distance".
Along with other quirks of the quantum world, such as the fact that the act of observing a particle inherently changes that particle's behaviour, quantum entanglement fanned the flames of inquiry in the Fundamental Fysiks Group, which dreamed of mathematically verifying telepathy or discovering faster-than-light travel.
Neither of which, of course, it did. Although interesting in its own right, the Fundamental Fysiks Group didn't usher in a new scientific paradigm or age of Aquarius. It did, however, give a kick up the backside to the scientific method of the time, and its work has been successfully built upon in recent fields such as quantum encryption and quantum computing. The hippies didn't so much save physics, as give it a good bong hit that opened its eyes a little.