Jorge Cham is the creator of PHD Comics and himself a Ph.D. holder from Stanford. Daniel Whiteson is professor of physics and astronomy at the University of California, Irvine. Put the two together and the result is the book We Have No Idea: A Guide to the Unknown Universe. Part comic book, part physics and astronomy text, and part compendium of hit-or-miss jokes, No Idea reviews unanswered questions in physics and astronomy and discusses possible solutions.
The first few chapters are about dark matter and dark energy. The next chapters cover the Standard Model of particle physics and "the mysteries of mass." The topic I found most interesting at this point was that of binding energy and its effect on mass. As the authors note, "...if you were to add the masses of three quarks... and compare that to the mass of those same three quarks bound together in a proton or neutron*... you would see a very big difference in mass. The masses of the individual quarks only account for about 1 percent of the mass of the proton or neutron. The rest is in the energy that's keeping those quarks together" (p. 63).
Greater mass of an object is associated with greater inertia (an object's"tendency to resist changes in its state of motion"). However, as Cham and Whiteson explain, "Even though we can measure it, we don't really know what inertia is or why it's tied to both the mass of the particles and the energy that binds the particles together" (p. 64). This is but one example of how the authors set up an interesting physical phenomenon and then disclose that physicists and astronomers "have no idea" how or why the phenomenon works.
Other poorly understood phenomena discussed in the book include: why gravity is so different from all the other forces; what is the nature of space; what is time; and whether extra dimensions exist. (How particle colliders could lead to the inference of extra dimensions is another fascinating example from the book.)
By fortuitous coincidence, a new discovery reported in yesterday's New York Times may help answer one of the questions raised in the book: "Who is shooting superfast particles at the earth?" (p. 185). More technically, Cham and Whiteson are referring to cosmic rays and they claim that, "We don't know where they are coming from exactly, or why there are so many of them. And we don't know what process in nature could possibly be making such energetic ammunition" (pp. 185-186).
The discovery reported in the Times involves the "Ice Cube" detector in the South Pole being hit by a neutrino that could be traced to its source: TXS 0506+056, "a type of quasar known as a blazar, in which our line of sight from Earth is along the jet — right down the gun barrel." As noted in the Times article, "Astronomers said the discovery could provide a long sought clue to one of the enduring mysteries of physics and the cosmos. Where does the rain of high-energy particles from space known as cosmic rays come from?"
As can be seen, there are many topics in No Idea that I enjoyed. However, at 340 pages, the book is pretty long and probably could have been condensed to a shorter length. The cartoons and jokes may grow on a reader or become increasingly irritating. Will you enjoy this book? I have no idea!
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*A proton consists of two up quarks and one down quark, whereas a neutron consists of two downs and an up.