Answer
The answer is October 23, which marks the birth anniversary of Felix Bloch, a prominent Swiss-American physicist. Remembered for his significant contributions to the field of nuclear magnetic resonance (NMR), Bloch, alongside his colleague Edward Mills Purcell, was awarded the Nobel Prize in Physics in 1952 for his groundbreaking research. It paved the way for the development of MRI (Magnetic Resonance Imaging), a vital tool in modern medical diagnostics.