quantum-world
Kenneth Ford’s 2004 book The Quantum World: Quantum Physics for Everyone is a conversational introduction to quantum physics. The book is a short, but dense read that took me about two weeks. This is a book where the author tells you to “buckle your seatbelt” periodically. He’s definitely not joking. A quick synopsis is in order.

We first learn about the basic units of measure used in quantum mechanics. My favorite bit from this section: Can the Enterprise really prance about the galaxy at speeds greater than that of light? Sadly for me, probably not is the book’s answer. Lighter objects can be more easily accelerated than heavier ones. You can easily push a kid on a swing, but have a rough time pushing a Hummer. So, we realize that a massless particle is the easiest to accelerate. A particle of light, the photon, is massless and instantaneously jumps to the speed of light. Cool? Further, “if anything at all were able to go faster than light, then light itself, being composed of massless photons, should go faster.” Which means that you’re still not going faster than light. Of course, we do have hypothetical tachyons, which do go faster than light. Physicists haven’t found tachyons, but they still keep looking.

We then go on to meet the lepton family: electrons, muons, and taus with their respective neutrinos. We then meet up with the quarks, social and antisocial particles, quantum lumps and quantum jumps. This is a large portion of the book were you acquire quite a bit of the jargon of quantum mechanics. This is also the section where the most equations are presented. I personally was giddy with all of the particle collisions.

Finally, the thing everyone knows about quantum mechanics: the wave-particle duality. This is where quantum mechanics has gone into the non-technical culture with the double slit experiment.  A wave from a light source contacts a sheet that is opaque expect for two slits. The waves hit and pass through the slits and continue on to a detecting screen. On the detecting screen, we have a very wave-like pattern as a result. The question: does the photon pass through one slit or the other? Each photon passes through both of the slits. Freaky, yes, I know. “The photon is created at a point. It is detected at a point. Between its creation and its detection (really its annihilation), it behaves as a wave.”

What governs where the wave will disappear, turn into a particle again and hit the detection screen? No mention is made of whether I, as the observer, have any bearing on the matter at hand. The actions of the photons are subject to the mathematics of probability. The probabilities of quantum mechanics are what disturbed Einstein so much that he is quoted as saying, “God is subtle, but not malicious.” Unpredictability is built into the basic laws of quantum mechanics and this is troublesome for physicists even today.

After your mind tries to handle the wave-particle duality, the book finishes off with discussions of anti-matter. Yes, anti-matter. (a nerdy explanation of antimatter: the electron has a companion particle with the same mass and spin as the electron but with opposite charge—enter the positron!) In 2002, scientists at CERN (European Center for Nuclear Research) were able to create and store millions of antiprotons and positrons (antielectrons). With these, they made antihydrogen atoms. Yes, freaky but cool.

That is where I’ll leave the brief synopsis. This book is a bit mind bending, but is an excellent introduction to quantum mechanics. I recommend it to any one who wants to know what the science says about this stuff. I have a feeling I’m going to be following this book up with a more rigorous one.