Wilhelm Wagner (1848-1900). Part 1: A forgotten pioneer

Sometimes waves do not seem to move; rather, they just vibrate in place. Unmoving waves can be seen on the surface of a glass of milk kept in a refrigerator, which is one example of standing waves. Vibrations from the refrigerator motor create waves on the milk that oscillate up and down but do not seem to move across the surface. These waves are formed or created by the superposition of two or more identical moving waves in opposite directions. The waves move through each other, with their...

The German physicist Heinrich Hertz (1857–1894) was the first to generate and detect certain types of electromagnetic waves in the laboratory. Starting in 1887, he performed a series of experiments that confirmed the existence of electromagnetic waves and verified that they travel at the speed of light. Hertz used an alternating-current RLC (resistor-inductor-capacitor) circuit that resonated at a known frequency and connected it to a loop of wire. High voltages induced across the gap in the...

Sigmund Freud, an Austrian neurologist born in 1856, significantly influenced psychology through his exploration of the unconscious mind. His interest in patients suffering from hysteria and neurosis — conditions without apparent physical causes — led him to theorize the existence of an unconscious mind, a repository for feelings and urges beyond our awareness. Freud's innovative approach included techniques such as dream analysis, free association, and attention to slips of the tongue to...

Gestalt psychology, founded by Max Wertheimer, Kurt Koffka, and Wolfgang Kohler, emphasizes the importance of understanding perception as an organized whole. Developed as a counter to Wilhelm Wundt's structuralism, this approach posits that our perceptions are more than just the sum of sensory parts; they are comprehensive wholes where the relationships between parts define the perception. The principle "The whole is greater than the sum of its parts" encapsulates this view, illustrating how...

Alfred Adler, a prominent figure in psychology, founded the school of individual psychology. In contrast to Freud's emphasis on sexual or aggressive motives, Adler suggested that individuals are primarily motivated by their purposes and goals. He believed that people strive for perfection rather than pleasure. Adler argued that individuals could creatively act upon their genetic inheritance and environmental experiences to shape their own lives, emphasizing conscious motivation over unconscious...

Carl Rogers, a key figure in humanistic psychology, believed that individuals possess an innate potential for growth and fulfillment. According to his model of personality, three significant components define an individual: the organism, the self, and conditions of worth.
The organism refers to an individual's inherent blueprint, which Rogers saw as innately positive and directed toward helping others, unlike Freud's view of the id as driven by base impulses. The self is a person's...