CHAPTER 2 Particle Properties of Waves

The penetrating ability of x-rays enabled them to reveal the frog which this snake had swallowed. The snake’s jaws are very loosely joined and so can open widely.

In our every day experience there is nothing mysterious or ambiguous about the concepts of particle and wave. A stone dropped into a lake and the ripples that spread out from its point of impact apparently have in common only the ability to carry energy and momentum from one place to another. Classical physics, which mirrors the "physical reality" of our sense impressions, treats particles and waves as separate components of that reality. The  mechanics of particles and the optics of waves are traditionally independent disciplines, each' with its own chain of experiments and principles based on their results.

The physical reality we perceive has its roots in the microscopic world of atoms and molecules, electrons and nuclei, but in this world there are neither particles nor waves in our sense of these terms. We regard electrons as particles because they possess charge and mass and behave according to the laws of particle mechanics in such familiar devices as television picture tubes. We shall see, however, that it is just as correct to interpret a moving electron as a wave manifestation as it is to interpret it as a particle manifestation. We regard electromagnetic waves as waves because under suitable circumstances they' exhibit diffraction, interference, and polarization. Similarly, we shall see that under other circumstances electromagnetic waves behave as though they consist of streams of particles. Together with special relativity, the wave-particle duality is central to an understanding of modern physics, and in this book there are few arguments that do not draw up on either or both of these fundamental ideas.

2.1ELECTROMAGNETIC WAVES

Coupled electric and magnetic oscillations that move with the speed of light and exhibit typical wave behavior

2.2BLACKBODY RADIATION

Only the quantum theory of light can explain its origin

2.3 PHOTOELECTRIC EFFECT

The energies of electrons liberated by light depend on the frequency of the light

2.4 WHAT IS LIGHT?

Both wave and particle

2.5 X-RAYS

They consist of high-energy photons

2.6 X-RAY DIFFRACTION

How x-ray wavelengths can be determined

2.7 COMPTON EFFECT

Further conformation on the photon model

2.8 PAIR PRODUCTION

Energy into matter

2.9 PHOTONS AND GRAVITY

Although they lack rest mass, photons behave though they have gravitational mass