Max Planck (1858-1947) was a German physicist known for his groundbreaking work in quantum theory. He revolutionized the field of physics by introducing the concept of energy quantization, leading to the development of quantum mechanics. Planck's constant, a fundamental constant in physics, is named after him. He was awarded the Nobel Prize in Physics in 1918 for his contributions to theoretical physics. Planck's work laid the foundation for modern physics and his legacy continues to inspire scientists worldwide.