Physics is...

Questions answered by Hermann von Helmholtz (1821 – 1894)(Sources: Leo Koenigsberger, “ Hermann von Helmholtz,” Braunschweig 1902/ Helmut Rechenberg, “Hermann von Helmholtz, Bilder seines Lebens und Wirkens,” Weinheim, New York, Basel, Cambridge, Tokyo 1994)

1. What were your reasons for studying physics? For financial reasons, Helmholtz was not in a position to study physics, but he felt he was “born to be a physicist.”
2. What university did you go to? Helmholtz studied medicine at the Friedrich Wilhelm Institute (the so-called Pépinière) in Berlin, committing himself to serving for eight years as a medical officer after his studies. On account of his scientific achievements, he was released from three of these years.
3. Did you know a physical experiment at school which particularly impressed you? What are the physical experiments which impress you? While his classmates were reading Cicero or Vergil, Helmholtz calculated under his school desk the radiation path through telescopes.
4. Your physical aha-experience? “To find the law of phenomena means to understand them.”
5. Do you have a favourite experiment? All his life, Helmholtz was engaged in tests on sensations.
6. Are you also interested in a completely different speciality? Philosophy
8. Have you ever had a chemical kit? No, Helmholtz liked to play with building blocks.
17. Do you master a musical instrument? Helmholtz played the piano.
21. A good measurement is always carried out very carefully, almost ceremoniously. Is this ceremony comparable with a sacred rite? One day on Helgoland was like an enlightenment when I saw that energy was constant in time. It was rather late in the night. I calculated it with difficulty – and it was correct. I climbed up a rock, saw the sunrise and felt lucky.
24. Would you tell us three important events of your biography? 1848 – release from military service as a medical officer (from that time on: physicist), 1850 – invention of the ophthalmoscope, 1888 President of the Physikalisch-Technische Reichsanstalt founded in 1887.
25. Do you think there are things which cannot be measured? In the affirmative, what? “What is wrong with the rigid formulation of the law of causality: “If we exactly know the presence, we can calculate the future” is not the clause in sentence final position, but the assumption. In principle, it is not possible for us to know the presence with all its determinants. This is why all what we perceive is a selection from an abundance of possibilities and a limitation of what will be possible in future.”
28. Which physicist do you admire? Johannes Müller, who was not, however, a physicist but a physiologist and an anatomist. His search for the “vitality” fascinated many young natural scientists. The search also covered physical and chemical investigations. When Müller’s students later turned away from the idea of universal “vitality”, this was a break in the history of natural sciences.
31. Do you remember the most important measurement of your life? Perhaps the serious and terminal illness of his wife. Helmholtz writes he “enjoyed the purest and greatest happiness earth can offer, it was too wonderful for this world.” “She died by his side,” her sister wrote (who had been living with Helmholtz since 1852). “During her last year, her emotional life had already died step by step – her interests and her sympathy had waned. Only when dying was she again intellectually and morally as fit as before. So Helmholtz was a lonesome man long before she died, and the prospects of a future with two small children and their grandmother – who was an old woman despite all devotion and willingness to make sacrifices - were very gloomy.”
32. There was a time when certain physical experiments were suddenly regarded as politically undesired. How political can physics be in your opinion? Helmholtz, who was among the founders of an institute for “scientific and precision-mechanical studies” which was later called the “Physikalisch-Technische Reichsanstalt,” was also called an “Imperial Chancellor” of natural sciences.”
35. Try to find a definition for coincidence. Coincidence in reality is only the term for the insufficiency of our knowledge and the clumsiness of our powers of deduction. A mind which would have exact knowledge of the facts and whose thought processes would be fast and precise enough to be ahead of future events, would see the harmonic reign of eternal laws – which we can only presuppose and suspect - in the wildest capriciousness of weather as well as in the movement of the stars.”