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Weird probabilities

  1. Mar 29, 2010 #1
    I assume a lot of strange stuff could happen. Is it possible for anyone to approximate the following probabilities?

    Walking through a wall.

    Walking on water for a minute. (Jesus for example)

    Dropping a ball but it goes up.

    A ball teleports 5 metres away.

    (I know all of it is pretty much impossible, still it would be great to know if it's closer to 10-100 or 10-1000).
     
  2. jcsd
  3. Mar 29, 2010 #2

    DaveC426913

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    If a highly unlikely event is going to happen in a finite time, then many less unlikely events would occur in a shorter time.


    Think of a million monkeys on a million typewriters typing Hamlet. Before it gets typed perfectly just once, there are going to be a million instances where it gets typed perfectly except for one word. And for each one of the those, there will be a million instances where it gets typed correctly except for one page, etc.

    So, for every person who is able to pass through a 6" thick wall, you'd find a thousand who might only pass 3" into the wall and then the phenomenon fails. For every one of those, you might find a thousand who pass only 1" into the wall.
     
  4. Mar 30, 2010 #3

    Demystifier

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    If the universe is infinite, then there will be a planet with an intelligent life on which an intelligent being called Jesus will walk on the liquid water. In fact, there will be an infinite number of such planets.
     
  5. Mar 30, 2010 #4
    In fact, in an infinite universe, we can all have our own personal Jesus. :)
     
  6. Mar 30, 2010 #5

    DaveC426913

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    Not true. Granted, an infinite universe is a universe in which all things that can happen will happen. But it does not mean laws of physics can be violated.
     
  7. Mar 30, 2010 #6

    Fredrik

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    Definitely closer to 10-1000. Actually I think the numbers are going to be more like 10-101000.
     
  8. Mar 31, 2010 #7

    Demystifier

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    The idea was that laws of quantum mechanics allow (with a ridiculously small probability) violation of classical laws at the macroscopic level. In particular, according to quantum mechanics, the classical Newton law of gravity is valid only on average. This opens the possibility of walking on the water by violating the Newton law of gravity.

    By the way, you have received the award for the best humor. How come that you haven't recognized that the post on quantum Jesus walking on the water was actually a joke?
     
  9. Mar 31, 2010 #8

    DaveC426913

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    You mean the opening post? I guess I thought that was actually the gist of the OP's post.
     
  10. Mar 31, 2010 #9
    A better question for the OP, and the answer is inherent in the question, is to look at the wikipedia article for a hydrogen atom. Look at the probability that an electron will be found in a given "spot". You could think of that as a microscopic and simple model of probablities that CAN be mapped.

    @Demystifier: The OP... I don't know, I thought that what Dave said was his gist too. I didn't get a lot of "haha" from him. Ask yourself where this question leads, and why it was posted in QM? The classic example most kids learn is, "There is a low, but definite possiblity that all of the oxygen molecules in the room could be found in only half of it for a moment." To bring such extreme violations of physics into it seems to be that he was looking for an excuse for some New-Agey horse****.
     
  11. Mar 31, 2010 #10
    Thanks for the answers. I'm a philosophy freak but not a religious freak. The reason I asked this question is to see if anyone possibly can approximate stuff like that, but I guess not.
     
  12. Mar 31, 2010 #11

    DaveC426913

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    We can.

    The straightforward answer is this: the probability of such an event would require waiting many times longer than the lifetime of the universe for it to happen.
     
  13. Mar 31, 2010 #12
    As was my joke about a personal Jesus for those of you who grew up after Depeche Mode's song was popular.

    - Curtis
     
  14. Mar 31, 2010 #13
    I heard that song when I was 12 years old at camp, and spent 5 years humming it off-key to anyone who would listen trying to find out what it was (I forgot the lyrics). Finally I heard it in a shop and cornered some poor cashier and demanded to know what song this was. I think he believed I was going to get angry... poor guy. It must have been odd for him when a 6'+ guy in a trencoat (I WAS YOUNG!) skipped out the door humming the name of the group... :blush:
     
  15. Mar 31, 2010 #14

    DaveC426913

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    How do you hum a Depeche Mode song??? It's one note... :biggrin:
     
  16. Apr 1, 2010 #15
    I already said what I believe about the probabilities of such events so I don't need to know I need to wait for them...

    Just forget these questions. But it is very interesting that some of you somehow percieve these questions as some kind of threat.

    Extremely small probabilities might explain why we are here. Some people believe that the universe started when all the atoms "went to the same corner of the room" by chance. I don't believe that but it's still theories I need to relate to and therefore I want a better feeling for sick small probabilities.

    There are also a lot more strange probability discussions going on. http://en.wikipedia.org/wiki/Boltzmann_brain is one interesting example. Great references to read on that page.
     
  17. Apr 1, 2010 #16

    DaveC426913

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    It is very interesting that you perceive our answers as some kind of indication that we feel threatened.

    I think we're more humouring your questions because it's apparent you kind of already know there's no meaningful answer; you are just making discussion fodder.

    Your opening post has the smell of an agenda that you have not yet shared. Let's just have it then.
     
    Last edited: Apr 1, 2010
  18. Apr 1, 2010 #17
    I'll post another question and u will be able to speculate a lot more about my agenda.
     
  19. Apr 1, 2010 #18

    Demystifier

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    I meant my (first) post.
     
  20. Apr 1, 2010 #19
    I didn't say it was a pleasant thing, to listen to me hum... :rofl:
     
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