Rezension
Quantum physicist Florian Aigner explains why natural science isn't the only truth, and how that makes the world even more beautifulAll it takes is a few sulfur molecules. The substance is called dimethyl sulfide. Plankton produces it, and at the coast it drifts into our noses as the supposed smell of salt. Perhaps the rumble of waves mingles in our ears as well. And by the time we open our eyes, there's no doubt left: we're at the sea.We know this because our sense organs constantly collect physical mosaic pieces, whether light waves, sound waves, or chemical substances. But the "actual reality," the "interesting part of the world," arises in our heads, writes Florian Aigner. Aigner is a quantum physicist, and in that discipline one also deals with particles that can occupy two opposing states at the same time. Perhaps Aigner already understood reality differently as a student.In Reality Isn't True Either: The Fascinating Physics of the Senses, and How It Shapes Our Perception, he first explains how we and other living beings translate physical signals into sensory impressions. And it becomes clear that there is no single reality that reveals itself equally to every animal. Sharks, for example, have a sense that remains hidden from us: electroreception. They can perceive electric fields emitted by other living creatures, and a voltage of just a few billionths of a volt is enough for them. For sharks, this is a decisive advantage when hunting. Humans don't need this sense. In evolutionary terms, what we perceive is mainly what is relevant for survival.But Aigner doesn't stop at the natural-science perspective. Rather, he insists that it isn't enough to explain our experience.Sensory stimuli on their own make no sense. It is our brain that assembles the mosaic pieces into a meaningful picture. It filters, completes, and interprets. Through what we have learned and experienced, through language and upbringing, we can identify the smell of sulfur, name the light waves as blue, and, in the interplay of these impressions, recognize the sea.Physics, then, describes only part of what we experience. Psychology and sociology complement our picture of the world. "If I feel that I feel, then I feel," writes Aigner. "No other facts are closer to me."His book is above all an entertaining introduction to the physical foundations of perception. With humorous examples, Aigner makes even complex topics accessible. But the book's real strength lies in opening up the natural-science perspective and looking beyond the boundaries of individual disciplines. Aigner touches on the psychological and sociological dimensions only briefly. Shedding more light on them is left to other authors.
