The Bohring Part of Physics is Wrong

Atomic Rant

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Overall I agree — there are a lot of people who seem to remember the Bohr atom but not that it’s wrong. Unfortunately, some of them seem to want to build their own personal physics theories on it. I understand the motivation to teach it — there is an historical context, and it’s an opportunity to dip one’s toe into some quantum theory rather than jumping into the deep end.

One nit, though. Even thinking of electrons as “buzzing around the nucleus” still implies a trajectory and motion, and you get into trouble trying to reconcile those classical notions with angular momentum, which is one of the failures of the Bohr model: the S orbital has no orbital angular momentum.

I do like the orbital ballon animals, but I don’t recommend a science clown doing them for kids’ parties.

6 thoughts on “The Bohring Part of Physics is Wrong

  1. This frustrated me to no end in high-school. The prescribed text did not even mention anything other than the Bohr model.

    Your point about the S orbital is a good one as well, and I think it boils down to there being nothing in our every day experience like a wavefunction.

    A wavefunction isn’t like anything but a wavefunction, and I think far too many explanations of quantum phenomena spend too long trying to equate or compare it to various classical objects.
    Sure the analogies can be a useful tool for describing some of its properties, but the student/reader should at least be informed that it is an entirely new concept that they are going to have to build a mental model of.

  2. Lisa Randall PowerPointed at Caltech 10 October 2011, Baxter Lecture Hall, hawking her new book. An early slide featured “lithium-5” and a trefoil of orbits of its three electrons (illustrating scale hierarchy, atoms down to quarks). Q&A afterward, Uncle Al politely informed Dr. Randall that Li-5 does not exist, and electrons don’t do that. Has anyboy seen a later presentation? 40 years of physical theory since Suskind got stuck in an elevator with Gell-Mann have zero empirical validation.

    LCAO treatment of atomic electrons and atomic bonding is silly. LCAO is your only hope to pass first term organic chemistry. Nobody in the art looks at molecules and synthesis any other way until subtleties like boranes, the Woodard-Hoffmann rules, or isolobar this and that intrude. MO theory is useful if you have a rack of CPUs at your disposal.

    Elegant earns accolades, useful earns income. Only one buys lunch.

  3. For me the use of orbitals was not important in demonstrating an electrons potential for motion. I think that the Bohr Model made it clear to me that electrons are standing waves around the nucleus and whose development must be treated as such. I always thought of orbiting as simply a visualization that was inaccurate, but demonstrated the concepts. I mean how do you visualize a cloud of constituent matter popping in and out of existence(or place best description here) as a standing wave?

    I was taught that the Bohr model concept of orbiting was false in high school. But no one told me that electrons manifested within their probability density clouds as standing waves and this was the important part. Reading about the Bohr model more recently I felt privy to seeing the cross over from Physical Chemistry’s to Particle Physics and most of the insight I had gained was from my review of the Bohr model.

  4. someday a physicist is going to say something like “lets try to dumb this down without a inaccurate model but still correctly explain the concept”
    and physics will make sense once again. 🙂

  5. So what were the pictures he showed from the textbook “that physicists use”? I thought that physicists used the s,p,d,f balloon shapes just like chemists do.

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