The Amazing Story of Quantum Mechanics Read Online Free Page A

a straight line along a highway at a constant speed of 55 miles per hour, I must continue to provide a force in order to maintain this velocity. If I take my foot off the accelerator, I do not remain in uniform straight-line motion (even if my tires are properly aligned) but rather slow down and eventually come to rest. This is, of course, due to the influence of other external forces acting on my automobile, such as air drag and friction between the road and my tires. We do not find the effects of friction strange or mysterious, as we have had a few centuries to accept the concept of dissipative forces. These forces appear “invisible” to us, and it required tremendous insight and abstraction on Newton’s part to imagine what an object’s motion would be like in their absence. This strange idea of drag and frictional forces, no less counterintuitive than anything quantum theorists have suggested, applies to large objects such as people and apples.
    The quantum realm is more mysterious, as most of us, aside from superheroes such as the Atom or the Incredible Shrinking Man, do not regularly visit the interior of an atom. Nevertheless, it took roughly sixteen hundred years for Newton’s first law of motion to overturn Aristotle’s proposal that objects slowed down and came to rest not due to friction, but owing to the fact that they longed to return to their “natural state” on the ground.
    In the century preceding the development of quantum theory, physicists such as Michael Faraday and James Clerk Maxwell suggested that the forces felt by electric charges and magnets were due to invisible electric and magnetic fields. Faraday was the first to suggest that electric charges and magnetic materials create “zones of force” (referred to as “fields”) that could be observed only indirectly, through their influence on other electrical charges or magnets. Scientists at the time scoffed at such a bizarre idea. To them, even worse than Faraday’s theory was his pedigree: He was a self-taught experimentalist who had not attended a proper university such as Oxford or Cambridge. But Maxwell took Faraday’s suggestion seriously and was able to theoretically demonstrate that visible light consists of an electromagnetic wave of oscillating electric and magnetic fields.
    Changing the frequency of oscillation of the varying electric and magnetic fields yields electromagnetic waves that can range from radio waves, with wavelengths of up to several feet, to X-rays, with a wavelength of less than the diameter of an atom. Each of these forms of light are outside our normal limits of detection but can be detected with appropriate devices. The weird ideas of Faraday and Maxwell are the basis of our understanding of all electromagnetic waves, without which we would lack radio, television, cell phone communication, and Wi-Fi.
    If the nature of progress in physics involves the introduction and gradual acceptance of weird ideas, then why does quantum mechanics have a particular reputation for bizarreness? It can be argued that, in part, the weirdness of the ideas underlying quantum mechanics is a consequence of their unfamiliarity. It is no less counterintuitive, in my opinion, to state that electric charges generate fields in space, and that we are always moving through a sea of invisible electromagnetic waves, even in a darkened room, than to say that light is composed of discrete packets of energy termed “photons.” Phrases such as “magnetic fields” and “radio waves” are part of the common vernacular, while “wave functions” and “de Broglie waves” are not—at least not yet. By the time we are done here, such terms will also become part of your everyday conversation. 5

CHAPTER TWO
    Photons at the Beach
    Light is an electromagnetic wave that is actually
comprised of discrete packets of energy.
     
     
    The cover of the August 1928 issue of Amazing Stories, shown in Figure 1, which contained Buck Rogers’s debut,