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New to atoms - Looking for some advice/clarity

  1. May 15, 2005 #1

    I've just been studying the Bohr model at school and have had a nagging thought in my head.

    If we have electrons wizzing around an atom. They will slowly collapse into the nucleus (due to gravity & magnetic forces of attraction) and well I guess something will happen that won't be good for that model to continue to exist.

    So, I started thinking or something that wouldn't be affected by gravity, and I couldn't think of anything initially - time is, but then the idea of a wave popped into my head. But that cannot be right!!

    And then there is the whole idea of energy levels or 'shells' where 2, then 8 then 8 electrons may occupy a shell. This clearly breaks down so simply with the transition elements and valencies as one quickly sees in chemistry. Furthermore, i just didn't like the idea - it doesn't sit easily in the mind.

    Anyway - i have mused doubtless on a number of different areas and I would very much like some ideas + solutions on what I have said.


  2. jcsd
  3. May 15, 2005 #2
    Many bright minds solved the problems of the atom in the early 20th century by inventing quantum mechanics. No need to reinvent the wheel.
  4. May 15, 2005 #3


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    Incidentally,gravitationally speaking in Newton's theory,there's no reason not to assume that the proton & electron are like Sun & Earth...

  5. May 15, 2005 #4
    No offence intended but quatam mechanics (the way the very small works) is not an answer! :tongue2:

    If i was more well versed in physics perhaps it would be - maybe if you could point me to some other ideas/posts/books/websites I might be able to understand!

    Oh and people constantly reinvent the wheel, and mathematics, and physics, gravity is no longer taken to be 10N/kg on Earth is it? :tongue2: But i do take you point all the same!!

    dextercioby - didn't newton or somebody else at least say that every body exerts a force of gravity on every other body, no matter how small. Wit hthe nucleus being around 2000 times more massive than the electron there will be a slight force, as there is between the Earth and the sun. But I also see that this reasoning is not helpful i nthe long run.


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  6. May 15, 2005 #5
    You reinvent the wheel when you need to. For example, if experiment gives results that are inconsistent with theory. Quantum mechanics works perfectly for the atom in the sense that it is fully consistent with experiment, therefore there is no need to reinvent it.

    Try learning quantum mechanics first, before casting it off as incorrect.
    Last edited: May 15, 2005
  7. May 15, 2005 #6
    You are correct, but the way you are wording it is that theory should be manipulated to fit experimental results.

    I am not so all embracing, I believe that theory should be thought up, and based on, sound axioms, and sound logic. In mathematics, we know this makes the new theory a certainty.

    In physics I acknowledge the difference, where some unforseen variable can knock a theory out, and this can only be seen by experimental work. But if a new theory is built to fit experimental data, the theory is weak. And if another counter example is found, the theory is once more forced to be changed. This makes the theory messy and unnice!! We shouldn't reinvent the wheel because it isn't working, but because we have looked at it and seen how to make it roll better.

    I also acknowledge that sometimes - as was the case with rutherford's scattering experiment,experiments MUST be used to verify theories, theories should not be built upon experiments.


  8. May 15, 2005 #7
    Is classical mechanics messy and unnice because it doesn't work at atomic scales? No.

    You are asking for the impossible. There's no such thing as a self-evident theory of everything.
  9. May 15, 2005 #8
    People thought it impossible that man would land on the moon, that the world could be round.

    But it was possible. And so is perhaps, The Theory of Everything, a Grand Unified Theory, may exist. And it may be amazingly complex, but it may also be very obvious and simplistic.

    Let us look at the Greeks who could not conceive of irrational numbers, they do exist and are simplistic yet they did not see them. As a human race we are not so intelligent that we can see and grasp everything, it may well be the same leap of though is not that hard, just it runs against our underlying principles.

    Or maybe not :tongue2:


  10. May 15, 2005 #9
    Your man on the moon and flat earth arguments are bogus. People thought the earth was flat because they were unscientific. As for landing a man on the moon, no rational scientist would have claimed it was "impossible", meaning that had a zero probability of being done. It was just freaking hard, that's all.

    If you come up with some theory of everything, you have to show that it works under ALL experimental conditions. That is physically impossible. For example, I can keep increasing the energy scale. Your particle accelerator cannot test infinite energy scales. Plus, you don't know a priori whether the measurements you get out of the particle accelerator are slowly varying over time in a way that is inconsistent with your theory, but you don't have enough precision to measure. Therefore, whatever theory you come up may not be the theory of everything.

    Classical mechanics was supposedly the theory of everything until higher energy, short-distance experiments proved otherwise.
  11. May 15, 2005 #10
    I accept your points as being valid and i have idead wrestled with them myself, and have, as hinted at, in my last post moved more to believing that the break through may indeed move against current axioms. And in some way not be affected by the experiments you describe.

    Let us of course that particle accelerators are not good experimental devices (Hisenburg's uncertainty).

    And let us also remember that Newtonian physics was thought to engulf all of the things we saw until einsteinian physics took over. The same can be shown with Euclidian geometry.

    And finally, your attack on the flat earth believers as unscientific, they are only unscientific according to our reference points, to them they may well have seemed very scientific and rigorous. In the same way, millennia from now we are seen as slow, backward and primitive.


  12. May 15, 2005 #11


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    This website has a purpose: to teach science to those who wish to learn it. If you wish to learn something other than science, I encourage you to go elsewhere. You've barely begun your science education, yet appear to adamantly believe that you know the truth or falsehood of concepts that you've yet to learn in their entirety.

    If you continue that path of self-congratulation, you will just become a crackpot, like so many others. Try to learn science before attempting to discredit it; anything else would be foolish.

    - Warren
  13. May 15, 2005 #12
    What have I discredited?

    And how have I self-congratulated. I pointed to Newtonian and Einsteinian physics as I have seen and heard debates of how they differ and the later has superseeded the former.

    With regards Euclidian geometry I do know a fair bit about it to call it one way or the other. And yes i am 16 but I have understood Tensor products and the rest of the basic number theory, I may not know much but I comprehend pretty quickly - not that fast but none too bad. I of course bow to your degree level knowledge, but many physists, such as hawking say. it is the children who do not know any bette that ask the right questions, the big questions. The rest of you are too afraid to ask.


  14. May 15, 2005 #13
    That is BS. You don't understand the HUP then. Anyhow, I thought you didn't believe in QM.

    I made the same exact point - please see the last sentence of my last post. Whatever theory you come up with, there's also a chance that a better one may be out there that covers higher energy scales. HOWEVER, that doesn't mean that the older ones are not useful since, for example, the methods of classical mechanics are still essential for many real-world applications.

    BS. You are overstating the relativism here. The essential principles of the scientific method have not changed. The problem has always been people attempting to mix non-scientific (e.g. religious) beliefs into science. Some people still think the earth is flat - they don't count.

    That's my last post on this.
    Last edited: May 15, 2005
  15. May 15, 2005 #14
    Well lets see how I do at bashing out my ideas, Heisenberg’s Uncertainty Principle essentially means this. As you attempt to measure an elementary particle's position to an absolute, you create more uncertainty as to the particles velocity. And visa versa. Also, as you attempt to examine the particle, you effect it creating more uncertainty.

    I hope i'm somewhere near right.

    i did not mean that - i meant that i wanted more detail in your answer!

    Of course

    I was making a point not a thesis


    But there may always be something more accurate!
  16. Jun 1, 2005 #15


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    Yes, but how does that fact ensure a theory will apply at higher energies? Right, it doesn't.
  17. Jun 17, 2005 #16
    electrons are in fixed energy orbitals and to remove the electrons from there either its needed to absorb energy(for moving to higher energy levels) or to emit energy in some form for the e- to jump to lower energy level...it cant fall in to the nucleus without transfer of energy.

    whats gravity??? is it there in nucleus??????? call it gravitational force NOT gravity!!!!!!!dont try to correlate classical mechanics and quantum mechanics!!!!!!!!!!!!!!

    shells are outdated concepts...there aren't any shells as such but energy levels as i told above...
  18. Jun 24, 2005 #17
    Hey Ben, I don't mean to be rude, but you've made some silly errors in your 'scientific analysis'. You seem like a good guy so I don't think you're distorting what you're saying, but let's just correct one thing....

    "If we have electrons wizzing around an atom. They will slowly collapse into the nucleus (due to gravity & magnetic forces of attraction)" ---- One important thing to remember is that electrons do not continuously circle a nucleus; this isn't like the planets orbiting around the Sun (where you can always tell where they're going to be). Their paths are discrete....this is partly why quantum mechanics is so weird...an electron simply jumps off from this point to that point. So this invalidates your next sentence, where you say they will "slowly" fall off into the nucleus. The reason why people are telling you that you should learn quantum mechanics is, partly anyway, not to confuse yourself, as you did with that statement. You would not have even made the "slow" comment had you known that an electron does not travel around the nucleus in the same manner that a planet travels around the sun (another reason why Newtonian mechanics break down at the microscopic level).

    The main problem (I think) is that your perceptions of the macroscopic world are filtering through into your analysis of the microscopic world. If you let that happen, however, you're not going to get anywhere in terms of clear understanding.
  19. Jun 24, 2005 #18


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    Ok you really just asked people for an idea to help out your understanding and then completely dismissed the idea of quantum mechanics as the answer. If your looking for an idea to help you, quantum mechanics is THE answer.

    No one ever said gravity is 10 N, its simply a rounded number. To that definition, 9.8 is wrong as well because it also is a rounded number.

    You later in this thread stated that experiments must change to match theory. Im sure a majority of the people around here would agree that that is WRONG. If a theory is made and an experiment says its wrong, the THEORY is wrong (of course, experiments are normally done multiple times to verify it). To make a theory stronger, the theory must match experimental data and be able to predict any related experiments.

    Well i could say that i dont like the idea that theres anything more out there then our own solar system but hey, guess what, there suuuuuuuuuure is more out there. Simply not liking an idea does not mean it is wrong. I'm sure a lot of people didnt like the idea of 300,000 km/s being a speed barrier for all matter because that really makes things crappy for our hopes on traveling to other solar systems or galaxies but hey, we've researched it, studied it, and come to realize that 300,000km/s is the limit no matter how much we hate it.

    Also, when people tell you something on this forum in particular, take their information as correct information compared to yours. There are people on this forum who are incredibly smart and there are people here who have dedicated more years to learning and understand physics then you have lived (and probably a few people have more then 1 of your life-times in research down). When peopel tell me physics related stuff on this forum... to me, thats it, i can ask follow up questions or ask for a clearer explanation, but i never tell someone they are wrong simply because i think they are wrong.
    Last edited: Jun 24, 2005
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