3.25X4 Vintage photograph signed in the lower margin in blue fountain pen ink by Arnold Sommerfeld. Affixed to a piece of cardboard. In excellent condition.(1868-1951) Arnold Johannes Wilhelm Sommerfeld was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and mentored many students for the new era of theoretical physics. He served as doctoral supervisor for many Nobel Prize winners in physics and chemistry (only J. J. Thomson's record of mentorship is comparable to his).He introduced the second quantum number (azimuthal quantum number) and the third quantum number (magnetic quantum number). He also introduced the fine-structure constant and pioneered X-ray wave theory.This lot came from the Jim Wiggins collection we purchased in July 2022. Jim Wiggins accumulated the most unique and valuable autograph collection over a period of 70-plus years. He obtained his collection either in person or by writing to persons of fame and notoriety. Comes with a full Letter of Authenticity from Todd Mueller Authentics.