Via Twitter, Michael Barton is looking for some good books about physics. I was Twitter-less for a few days around the period of his request, and this is a more-than-140-characters topic if ever there was one, so I'm turning it into a blog post.
The reason for the request is that he's going to be working as an intern at the Einstein exhibit when it visits Portland, which makes this a little tricky, as relativity is not an area I've read a lot of popular books in (yet-- that's changing). That will make this a little more sparse than it might be in some other fields.
There's also an essential disclaimer here regarding the "teaching physics"/ "teaching about physics" distinction. If you want to learn physics at the level needed to do physics-- solving problems, reading journal articles, etc.-- there is no substitute for a good textbook. Read it, and do as many of the problems as you can, and try the ones you can't. If you want an intro-level survey of the field, pretty much all introductory texts are equivalent-- go to your local college bookstore, pick up whatever they're assigning for Physics 101, and start working through it.
(If you want something specifically about relativity, try Six Ideas That shaped Physics Unit R. It's got some idiosyncracies, but it's a good explanation, and very readable as these things go.)
Assuming you want to learn about physics, rather than plowing through all the math needed to do physics, though, there are a number of good books out there.
In the field of relativity, the recent book Why does E=mc2 by Cox and Forshaw has one of the best explanations of the theory I've ever seen. It's not a very historical treatment, and thus has little to say about Einstein, but if you want a feel for the modern view of the theory in terms of spacetime, it's hard to beat. It's got some overly precious bits, though, and I say this as someone who has written a physics book featuring a talking dog.
Sean Carroll's From Eternity to Here is really about the arrow of time, but in order to explain why this is a problem, he provides a nice explanation of special and general relativity, with an emphasis on the time aspects.
If you want a broader overview, Robert Oerter's The Theory of Almost Everything is an outstanding survey of the Standard Model of particle physics, which includes some relativity. If you want to know what the deal is with "unified theories," he's got a good explanation of the problem and the various approaches to it.
Going in a more historical direction, I really like David Lindley's Uncertainty, which describes the early years of quantum theory, and the philosophical debates between Einstein and Niels Bohr and Werner Heisenberg and others. Louisa Gilder's The Age of Entanglement is another excellent historical look at the development of quantum physics, and Einstein's role in it.
If you want something that's just fun and whimsical, I recommend George Gamow's Mr. Tompkins books (there are several different editions out there). These dramatize the odd effects of relativity through the daydreams of a bank clerk with a tendency to doze off in physics lectures. They're a little dated, but still great fun.
Other books that will certainly come up in any search for material on Einstein include Abraham Pais's famous scientific biography Subtle Is the Lord... which includes both a thorough description of the science that made Einstein famous and also a biography of the man himself, and the processes by which he arrived at the physics results. I'm a couple hundred pages into this, and it's very good, but highly mathematical. The descriptions of the science are both technical and sketchy, so they'd be pretty difficult to follow without some prior knowledge of the science.
Another book that gets cited a lot is Einstein's Clocks, Poincare's Maps by Peter Galison, which deals with the origins of relativity (Poincare almost came up with the theory before Einstein, but didn't quite get it). I haven't read this (yet), but it's mentioned so frequently that I figured I should include it.
That ought to be more than enough to keep you busy reading. And I'm sure some readers will chime in with titles I forgot to list...
Are these books recommended for someone who has a basic understanding of physics? someone who is studying high school physics? or someone who has completed high school?
Some of my favorites from a historical perspective
The Making of the Atomic Bomb - Richard Rhodes
The first third of the book is almost all scientific discovery (electron, nucleus, neutron, early quantum, radiochemistry, fission) and details more of the personalities of the scientists, and what some of the key experiments actually were.
Black Holes and Time Warps - Kip Thorne
Maybe a bit fanciful in places, but also an interesting story of how the theory of relativity, and the implications of relativity on stars. It describes how symmetry influenced the development of relativity (symmetry is one of my favorite physics 'tricks'), and tells stories about a major theory that was constructed by a student on a boat trip from India to England.
I would also include the Six Easy and Not-so-easy Pieces as an intro to Feynman. Part physics, part theater. The symmetry one (my earlier bias noted) and a good intro pair on both quantum and relativity are in this. (I'm not sure if these are still available, I got mine before the lectures were being released separately.)
These are some of my favorites, anyway.
And then there's Isaac Asimov's Understanding Physics, which is beautiful for comprehending the scope of pre-relativistic physics.
I'll very happily add my recommendation for the Galison. (Cie: I'm sure the Galison is accessible, but I think it's definitely more History than Physics).
Also from the Philosophy of Physics, you might add Harvey Brown's "Physical Relativity: Space-time Structure from a Dynamical Perspective" (Oxford University Press 2005), which won the Lakatos Award in 2006,
The main thesis, as I understand it, is that the Lorentz group is a symmetry of the dynamics, from which follow the kinematic strangenesses (insofar as they are strange). This somewhat reorients special relativity towards Poincar'e. (disclosure: I have an Oxford connection to Harvey. Also, Harvey may be as tall as you).
If you want to learn physics and, more importantly, how to think like a physicist, consider Epstein's Thinking Physics. It presents a series of little physics puzzles and their solutions, but they build on each other, so at the end of the book you understand force, momentum, mass, density, energy, time and so on. The problems sometimes seem to be gotcha's, but they are actually making points about the things a physicist has to think about to think about physics. (His Relativity Visualized is pretty good, but doesn't nowhere near as good.)
I completely second the recommendation of Gamow's "Mr. Tompkins" books. Dated yes, but still wonderful and mind expanding. I absolutely love this series, although "Mr. Tompkins in Wonderland" is, of course, my favourite.
Don't forget 'Genius: The Life and Science of Richard Feynman', by James Gleick. Another marvellous, unavoidable biography.
By the way: I read Einstein's biography by Pais during my preparation for an examination of Physical Mathematics (i.e.: Relativity, Special and General), and, well: the techincal part of Pais' book and my teacher's notes were very, very similar. A bit demanding, neverthless fascinating book.
Thank you, Chad, and others for your recommendations - I have added all to my wishlists on a book-trading website...
Do you have any book to recommend to explain the meaning of momentum? In his retirement, my father has taken to studying all of my old physics text books and I am able to adequately help him along and explain most concepts to him but the one thing he has never been satisfied with is his understanding of momentum. What is it, what does it describe, etc. Kinetic energy he can easily wrap his head around but momentum to him is an abstraction. Any good layman level, even algebra or light dif/int calculus? He's reading through the Feynman lectures now but is still not satisfied. If anyone could clarify the concept, I figure it would be Mr. Tompkins but all the Gamow I read back in the day dealt with modern physical concepts.
I have Asimov's Understanding Physics cited above...in storage somewhere. I'll have to dig it out to see if it fits the bill.
I haven't read most of the books in this list but the most influential book of my life was "the Universe and Dr. Einstein" by Lincoln Barnett. I haven't read it in almost 30 years so I don't want to sound foolish by praising it too highly. But it was completely accessible to me as an 11 year old and one of the most thrilling things I ever read. I am grateful my father had a copy of this book on his bookshelf.