Principles of Lasers Book

The book is a good, long history on the nature of light. In the early years, light was about the emanations of God, bathing the earth with its divine beauty. In the last few centuries, light emerged as a natural entity that reflected this divine origin. Or, as it was in many quarters, light was stripped of its sacred origins altogether.

Though I found the writing of the divine nature of light tedious, if not overdone, Zajonc does an excellent job of describing the natural basis of light. Light covers the electro-magnetic spectrum, only a portion of which is visible to humans. Light is emitted via oscillation in discrete, quantized units. These are the massless and chargeless photons that move in a straight line unless acted upon. Light in a vacuum moves at a speed that is independent of all external phenomena. This means that the speed of light is independent of the speed of its sources (Einstein's second postulate). But as a material entity, it was never clear until Einstein whether light (energy) is a particle (albeit, massless) or a wave. Einstein helped to resolve this debate by saying that matter and energy were different forms of each other. I think what this might mean is that energy is the cosmic essence that is expressed in massless (pure energy along the electro-magnetic spectrum) or particle form (some mass, as seen as atoms and molecules and gravitational collections of such). This raises an interesting question. Energy and mass are said to be equivalent, but could it be that ("pure") energy is primary and matter is secondary?

Even with these advances in the understanding of light, Zajonc argues that we do not know what a photon (electro-magnetic energy) is. Here, he moves back into light's divine potential. He sees light as something more than a natural entity and the cosmos as more than matter in motion. Zajonc draws upon both Plato and Einstein to make his case that light is the expression of a cosmic intelligence. It is a divine cause. It is Plato's "mind" that is "good, fair," and separate from physical "necessity." It's Einstein's doubt about the quantum world (and his statement that "God doesn't play dice"). At the heart of Zajonc's argument is that photons are entangled. They operate holistically; the whole is greater than the parts (it's only the human mind that disentangles, via "measurements"). Wholes are, simultaneously, one and many, particle and wave, and "a single thing with the universe inside."

In the end, while Zajonc separates the cosmos into the sacred and profane, he sees the "nitty-gritty" physical world of nature is an expression of the rationality of the universe. With this, he claims Reality's crown. Today's science is instrumental nihilism, he says. It's applied knowledge without going deeper to the realm of True Knowledge. The photon is nature's expression of the divine. It doesn't operate by attraction (pull) or repulsion (push) like gravity. Rather, photons are "self-moving." They are the vehicles for divine energy. They are a fusion of physical reality with spiritual reality. They are the candle, solid matter '"that takes flight to wing.'" "Coarse matter," Zajonc writes, "is purified in the flame becoming light." Lux ensouls space. Lumen is our perception of divine light. Human consciousness, he summarizes, has evolved and is evolving yet today. Its task has been, and is, to more fully understand this history of light. We are moving toward "an ecological consciousness," an integration of human, animal, plant and mineral communities."

Zajonc ties together all pieces of evidence and constructs a good narrative that is neither exclusively sacred nor secular. It is both. It is a "felt unity." Yet, it's also clear that like Plato and Hegel, the sacred for him trumps the secular. Does he give up too easily in sticking to a secular agenda? And, I wonder, what deep inner needs might be driving him to see the physical world as but the expression of the divine.