Anniversary Post: Planck’s Law

Max PlanckOn this day in 1900, Max Planck presented his derivation of black-body radiation. This followed off the ultraviolet catastrophe. According to classical physics, if you were to heat iron up to higher and higher temperatures, it should radiate light at higher and higher frequencies. But it doesn’t. Instead, it radiates according what we now call Planck’s law.

What Planck found was that energy was quantized. We tend to think of energy as a continuum. But it is actually made up of little packets that are equal to the frequency of the energy times the Planck constant. Based upon this, Planck was able to derive the black-body radiation function.

What still boggles my mind is that Planck could develop all this stuff and yet never accept quantum mechanics. He never even accepted Einstein’s work on the photoelectric effect, even though it is little more than an application of what Planck did. Some day I will have to read a biography about Planck and try to figure this out. He must have had his reasons.

14 thoughts on “Anniversary Post: Planck’s Law

  1. I don’t know much about physics but I do like to read on it. Especially about the personalities such as Bohr and Einstein. It seems like most of these great scientists disagreed with each other. Especially when it came to Quantum theory. As an aside one of my favorite movies is “Copenhagen” starring Stephen Rea and Daniel Craig. It’s more political than about Physics but it is one of the few movies I can recall that even discusses the subject.

    • So, lemme get this straight. There’s a movie about physics that touches on physics but is really more about politics. OK, I’m already interested. It starts Stephen Rea, who was so good in the largely silly “V For Vendetta,” he basically held it together with his sad-sack performance; he was great in that. Now I’m more interested. The movie is based on an acclaimed play (you didn’t write that, but I looked it up because you got me interested.)

      And — what! — it’s got Daniel f***ing Craig! As a physicist? I ran over to my library site. I am way, way down on the wait list for this movie. But now I’m on the list. This sounds really damn cool, I can’t wait to see it. (Well, I can wait, I’ll wait until I get it from the library for free instead of paying to watch on iTunes or some such. That’s what libraries are for.) But I’ll be looking forward to it. What an unusual and cool movie rec, thanks!

    • Yes, even Einstein didn’t accept formal quantum mechanics. But at least I understand why. He didn’t like the idea of a statistical approach. He seemed to think it was not a full rendering of reality.

      I haven’t seen the film. I’ll be on the lookout. But it isn’t at the library.

  2. Frank you know better than I but didn’t Einstein have quote about Quantum Theory like “God doesn’t play dice”. Also the movie Copenhagen is hard to find even on Amazon. I once saw a copy of it offered for over $400. I really like the movie but not that much.

    • Yes, Einstein said that. Although there are ways of looking at quantum theory that does not have God playing dice.

      I will be on the lookout for it. A film that I love that has never been put on DVD and is still $30+ for VHS is Medicine River. That’s a film that everyone should love. Why no DVD love?

      • Finally got it from the library. It’s a fine film. What it does it take a real meeting that happened between Heisenberg and Bohr about which nobody’s quite clear what happened and what each side meant to say. We do know the meeting ended abruptly and both men were angry about it and sad about it for the rest of their lives.

        The playwright presents the men (and Bohr’s wife Margrethe) as ghosts revisiting the encounter. It examines the possible meanings of the meeting, “Rashomon” style, as if the ghosts are challenging each others’ interpretations the way competitive collaborators might do. It never arrives at any specific conclusion.

        I did find a YouTube location for it:

        I can’t vouch for the quality of the whole video, but I watched a few moments and it seemed to be in good shape. There’s an intro; the film starts at 10:35.

        • Interesting. I’ll try to watch it. I’m feeling overwhelmed at the moment. But maybe Tuesday night.

          • Dude, it’s not homework! Just a somewhat pretentious play which gets more interesting as it goes (once the “Rashomon” gimmick kicks in.) Plus I liked seeing Craig talk. He’s a fine Bond, but as Bond he mostly grimaces. Handsomely. He’s an attractive scowler.

            • Yeah, I know. But I’ve got to schedule time to do things other than work. Day job is taking over my life now. It is seriously time for me to figure out what the hell I want to do with my life.

  3. I just ordered a used copy from Amazon for $33. I do like this movie for this price. For those interested, the story takes place during WW2 and reflects conversations between Bohr and Heisenberg, two great physicists.
    Bohr is Danish and Heisenberg is German and was a student/protégé of Bohrs. It is a morality play on making the atomic bomb. I will say no more except that it is a superb movie based on a live play.

    • There is a lot of drama to be found with a number of those scientists stuck under the thumb of the Nazis. Planck is a good example.

  4. Digging around the archives again … noted the “Copenhagen” thread and thought I’d add this bit. It’s my favorite baseball thing I wrote this year, don’t know if I’ve shared it already:

    There was this catcher who got hired by the spook agencies, and assigned to kill Heisenberg if the catcher thought Germany was close to a bomb! Amazing tale. Article’s too long, though, nobody read it.

    Basically a book report. But a pretty good one!

    • That’s amazing. I’ve got the article up. I’ll try to read it tonight. Yogi Berra gets all the credit for things like, “It ain’t over til it’s over.” But Moe Berg was earlier, with his saying, “It ain’t over til you shoot Heisenberg in the head.” I don’t know why that one never caught on.

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