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How to prove my dad is wrong?

  1. Aug 29, 2010 #1
    Hi, my dad is quite old and i had a big arguement about some completely stupid concept that he made up, ok what his theory is, is that he thinks that electrons moving around atoms are planets in the same way that the earth moves round the sun (and he doesnt mean this as an analogy, he actually thinks the electrons are like planets like the earth)

    Can someone give me some information that i can use to prove him indefinitely and unequivocally and indeedly WRONG, i already told him it just takes common sence to prove that he is wrong but i want some information who knows about this stuff.
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  3. Aug 29, 2010 #2


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  4. Aug 29, 2010 #3
    Would he grasp that contrary to planets, electron's position and speed can never be known at the same time due to the uncertainty principle?

    Also, it is a crude approximation that has been used for a long time, and not the worst thing in the world, maybe find something else to fight about and just let him be.

    It's not like he'll die because he incorrectly plotted the motion of his body's electron and thus disappear because his atoms all went crazy on him.

    If he incorrectly believed that he can plug in his toaster on the 240 volt outlet, and then he goes to the store to buy a 240volt outlet for his toaster, then yes, I'd strongly prove my point.
  5. Aug 29, 2010 #4


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    The idea of electrons orbiting the nucleus like little planets is a naive model i.e. it works up to a point as analogy, but it doesn't take much to prove that it can't be the case.

    The most obvious thing is that electrons orbiting the atom like little planets would be accelerating charge particles and would be constantly radiating electromagnetic radiation (which they don't, they only do this when changing in to a 'lower' orbit) which would also cause them to spiral in to the nucleus!

    The fact that classical physics can't explain electron orbitals was one of the motivators behind quantum theory.
    Last edited: Aug 29, 2010
  6. Aug 29, 2010 #5
    Tell your father to ease of the pot, if he really thinks that electrons are "like planets like the earth". Tell him that if he wants to prove his ridiculous theory, the burden of proof is on him, and that he needs to provide evidence. All you need is ANY textbook on Quantum Mechanics, Wikipedia, and more.
  7. Aug 29, 2010 #6


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    Remind him to the fact that accelerated charges will emit el.-mag. radiation which causes the electrons (due toenergy loss) to spiral into the nucleus.
  8. Aug 29, 2010 #7
    actually, according to the de Broglie Bohm interpretation of QM he's partially right, except the electrons don't move in elliptical orbits, but they do orbit the nucleus.

    But there's no way to prove this interpretation, in fact no one even knows if an electron has a finite size.

    Unless your dad knows different :smile:

    (dBB interpretation is promoted by a minority, but there are some smart people in that minority)
  9. Aug 29, 2010 #8


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    You are wrong too.
  10. Aug 29, 2010 #9


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    Therefore either he thinks electrons are mostly neutral or the Earth has a negative charge of roughly [tex]2\times 10 ^{-19} coulomb[/tex]. The first belief is wrong and the second is almost impossible to prove (maybe not to disprove though).

    Every planet has an absolute temperature over zero kelvin. Therefore they radiates EM waves all the time. It's not the case with electrons. Therefore electrons do not behave the way planets do.
  11. Aug 29, 2010 #10
    Actually, he is almost exactly correct in a sense. Well, in the sense that if you consider that really planets' motions are governed by Quantum Gravity, then a planet of very small mass around a very light sun would behave very similarly to a Hydrogen atom. (in the non-relativistic limit, they are both 1/r^2 forces - this analogy doesn't quite work in the general relativistic setting) But I don't think your dad realizes that things would look very different for small masses.

    Right. So Vic, you can tell you dad that according to the dBB interpretation of Quantum Mechanics, the electron does orbit the nucleus. However, the shape of the orbit is different than the shape of a planet's orbit, and it depends crucially on the state of the atom (energy, spin, whether or not there are other electrons - even ignoring the electrons' repulsion, this is still important)

    Also - and most importantly - in this interpretation, the electron doesn't just move under the force of attraction from the nucleus. There is also a "self-interaction" of the electron - the action from the wavefunction on the electron. This leads to all of the differences between classical & quantum mechanics.

    -- you need a lot more than just common sense though to see that there are fundamental differences between the classical motions of planets and the motions of electrons & protons.
  12. Aug 29, 2010 #11


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    I thought that dads are wrong by default and that it is only the opposite position that ever needed to be proven. At least that seems to be the opinion of most kids.
  13. Aug 30, 2010 #12
    I used to have stupid arguments like this all the time. The main problem here is that we give a crap about what our parents thinks. One solution to this problem is to get a therapist, so you can stop having stupid arguments with people whose opinions don't matter.
  14. Aug 30, 2010 #13


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    I remember quite a number of years ago, my Mum told me that the uncertainity principle was some sort of general statement about epistemology (not that she used that word!) i.e. that some things we are certain of, some things we are not certain of. Anyway I certainly knew enough at the time to treat her statement with total incredulity.
  15. Aug 30, 2010 #14


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    The deBB trajectories for electrons follow essentially the contours of the orbital isodensity surfaces.
    So it's pretty generous to say 'partially right' when you contrast an elliptical planetary orbit to something that looks like a figure-8.
  16. Aug 30, 2010 #15


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    It is not a ridiculous theory. It is just outdated. A theory which scientists like Bohr and Sommerfeld, I don't say believed in, but profitably worked with and that held up for some 10 years despite some worries until overtaken by what people still consider another stroke of genius, which has held despite some other worries, and survived because of its explanation of obscure facts hardly at everyone's fingertips, is not ridiculous. (However, I have noticed before it seems to attract almost as much obloquy on this forum as creationism!)
  17. Aug 30, 2010 #16
    You missed my point, and I think the OP's... I'm not saying that the Bohr model is ridiculous, I'm noting that the OP said that his father believes electrons are "LIKE PLANETS... LIKE THE EARTH". Not "Like planets in their orbit", but as in, "hey dude, what if we're all just a speck of dust in a giant's eye" kind of planets. Hence the reference to marijuana, and the usage of 'ridiculous'.

    The Bohr model is outdated however, and people feel some acrimony because maybe we're all bloody tired of seeing it taught in schools instead of current theories!
  18. Aug 30, 2010 #17


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    Tell him to reverse his telescope to look for electrons moving around. If he doesn’t see anything – you are right and he is wrong! :smile:

    If he still doesn’t believe you – show him the hydrogen atom orbitals:


    No planet could "survive" this... :biggrin:
  19. Aug 30, 2010 #18
    A planet is "a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity and is not massive enough to cause thermonuclear fusion and has cleared its neighbouring region of planetesimals." Your father's reasoning lacks critical qualities of a planet:
    1. Celestial length scales essentially opposes quantum length scales therefore one can argue if the atomic structure isn't celestial it is therefore incapable of being a planetary system. But one can also contend that the universe is a fractal where they actually are planets composed of atoms ad infinitum but our instruments aren't powerful enough to detect them. This approach although favoured by very few has certain aspects that our Universe doesn't inherit. A fractal Universe requires infinite mass/energy and this alone isn't observed or would allow a Universe to evolve.
    2. Atomic Nuclei by definition must be a Star or Stellar Remnant in order for this planetary idea to be real. The mass of stars is composed of the mass of it's constituents (Atomic structure) with added energy of fusion. It is clear that the Mass of a Nuclei isn't equivalent to a Star or our Universe would be in a singularity. One could use the fractal idea that they actually are stars but curve space-time at a smaller scale and appears large to the small scale observers. Clearly incorrect because immediately the fractal Universe requires an infinite energy/mass and particles aren't massive enough to have any effect on the curvature of space-time.
    3. Quite clearly, nuclei aren't thermonuclear fusion Structures (we don't observe photons being emitted or Neutrino oscillations), although through the weak interaction the nuclei does decay, [tex]\alpha[/tex]-decay and [tex]\beta[/tex]-decay, but this process is distinct and clearly doesn't occur at a great level as a star.

    Hope this helps

  20. Aug 30, 2010 #19
    You know what, just print these two pages and show them to your father. If he doesn't get it then, let it go... he's your dad and it might be a point of pride. Certainly in these two pages you have every kind of proof and explanation you could imagine!
  21. Aug 30, 2010 #20
    But historically, Sommerfeld, Lande,and Pauli tried to explain the spectrum lines of various atoms using Bohr model in 1920's.
    Of course there was already Maxwell's equation at that time.
    I think they were "wise" enough to understand Maxwell's theory at that point.
    (When there is only one model which explain the phenomina, people try to use this model "psychologically" even if various problems occur ?)

    See the books as follows;
    The Story of Spin (S. Tomonaga)
    Atomic Physics (Max. Born)
    The Historical Development of Quantum Theory (Jagdish Mehra)

    These books explain the detailed history in 1920's which are not written in other ordinary books.

    And the Bohr Sommerfeld model is not genuinely classical model, but the first "quantization" model.
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