Who was Max Planck?

For anyone interested in our modern view of how matter works and how light works and energy works, he's absolutely at the crux. I almost see him as a fulcrum about which physics pitched from the 19th to 20th century. I mean, literally he's in 1900, but he's a very classically trained physicist using classical tools as best he can to lurch and stumble and stub his toes into this confusing modern era. And not only in his own work, but I have to emphasize that he was the earliest and most highest, highly ranked proponent of Einstein's ideas. These crazy ideas of special relativity. Planck embraced them and promoted them and protected young Einstein when he was attacked. So moving into new ideas of how time and space work, also have Planck's fingerprints on them. He changed his mind every decade of his life about something very fundamental. It's not just like changing your opinion over congressional legislation or the role of one gene or something, but he changed his mind about very, very fundamental things. In physics, the existence of atoms, the existence of the quantum that he had stumbled across and Einstein's ideas of relativity. And then he changed his own ideas about the very fundamental reality of quantum mechanics much, much later and what humans could actually learn about nature. He changed his fundamental views on this as well. Just his ability to keep an open mind, I'd say would be the most informative and inspiring part about him. I think first and foremost, he was eclipsed by his younger friend, Albert Einstein, who became really one of the first international science celebrities with his discoveries. Einstein spent, of course, a lot of time in America and Planck never did. Planck had one visit to America and gave a series of lectures at Columbia University in German, but was not that well-known here. Also, a biography for Planck was difficult in a way because all his personal facts, his journals, his letters, his own notebooks, everything was destroyed in World War II. And so that might have stood in the way of him being better known in English as well.