Need Smart Person (math question)

Discussion in 'Science and Technology' started by Zoomie, Apr 12, 2007.

  1. dirtydog

    dirtydog Banned

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    Fat Tony's response is valid in most ways. However, if the exam cannot be given on day 57, and if it hasn't been given until day 56, and if the premise remains true that the exam must be given on some day of that term, than it must be given on day 56, as I said before. The most important thing Tony said, and this is critical, is,
    "this is more about the definition of surprise than logic."

    So, we each have to think carefully about the meaning of the term "surprise" before applying it to a logical argument. Does it mean an event which is recognized as going to happen, 10 seconds in advance? 1 minute in advance? 1 day in advance? 1/10 second in advance? My position is that the term "surprise" is so slippery, so subject to misinterpretation, that no logical argument such as the one posed can be reasonably discussed. There isn't an objective true/false value acceptable to most listeners, and the subjective meaning of the term is wholly dependent on context.

    The professor could have well said, without using the word surprise, "One day this term there will be an exam, and I am not specifying which day it will occur."
     
  2. dirtydog

    dirtydog Banned

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    Your location is 'East Pole'? I like it. It would make a name for an indifferent chess opening.
    That is almost as bad as Timothy Ferris's references to magnetic monopoles in his book "The Whole Shebang" (1):
    Inflation does away with the magnetic monopole problem. When discussing unified theory we saw that the vacuum of space, in undergoing phase transitions that broke a hypothetical primordial force into the four forces manifest today, would have been fraught with Higgs fields, which are said to have endowed particles with mass. Knots in the Higgs fields should have generated lots of magnetic monopoles. These are massive topological defects that have only one magnetic pole. Never yet observed but reasonably well established in theory, they are alluring objects, little onions whose anachronistic layers retain the primordial physics that ruled the earlier universe.



    That's kind of like a magnet with a North pole but no South pole, or did I get it wrong? Am I dumb, or just stupid?

    (1) Ferris, Timothy, "The Whole Shebang", Weidenfeld & Nicolson, London, 1997, page 234.
     
  3. MikeE

    MikeE Hip Forums Supporter HipForums Supporter

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    My location is determined by the physical properties of my home, not the magnetic ones.
     
  4. fat_tony

    fat_tony Member

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    Magnetic Monopoles are very contentious. After doing classical electromagnetism and relativity most people take the very defensible position that there are no magnetic monopoles. However you can use quantum field theory to re-muddy the waters, and I don't really get the subtleties. However the search continues, I guess I say it seems like there could be a mechanism but I remain a skeptic.
     
  5. dirtydog

    dirtydog Banned

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    Sounds like maybe you're a sailor.
    The physical properties of my home are determined by my location. Currently my location is on the Canadian prairie, which means I'm not in danger of falling over a humungous cliff when I step out the door.

    So, I have time and a sense of humour. Tell me more about this East Pole. Unless it's another Pole joke as in, "people from Poland".
     
  6. ronald Macdonald

    ronald Macdonald Banned

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    All these people are talking crap and dont know what they are on about. You can get a better answer if you look somewherelse

    I suggest you try somewhere that people take an interest in geometry rather than speculating about stuff they dont even understand
     
  7. ronald Macdonald

    ronald Macdonald Banned

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    Actually you are wrong dirty dog, as the idea that offer as logic is merely one of setting the barrier ever lower and deducing it cant be a surprise. However. The real logic of these events is

    lets just say someone tells you they can piss a surprising amount of liguid surprisingly high into the air. Ok well the only surprise would be the length of their dick - lets just say that a guy with a 3 inch dick pissed 20 metres into the air now that would be a surprise but it wouldnt be a surprise if the guys dick was 10 metres long thet he could piss 20m high
     
  8. Leopold Plumtree

    Leopold Plumtree Member

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    A very speculative post, in itself.
     
  9. dirtydog

    dirtydog Banned

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    Ronald is back!

    I thought he'd been banned. There's only one Ronald on this site, and we all appreciate his insights. See Writer's Forum for more!
     
  10. Zoomie

    Zoomie My mom is dead, ok?

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    Gentlemen, gentlemen, I asked a simple question of geometry and now you're into a debate on geography?

    Next time I'll go to ask.com. Sheesh!

    At least I know Ronald is proud of me for admitting my substandard American education and asking for help...:jester:
     
  11. ronald Macdonald

    ronald Macdonald Banned

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    zoomie when people get to your age we are all just proud that you can still comprehend enough to know who you are !
     
  12. Zoomie

    Zoomie My mom is dead, ok?

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  13. dirtydog

    dirtydog Banned

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    I have a simple question of geometry as well. Let's assume just for a moment a spherical earth rotating as a rigid body (radius = average of polar and equatorial radii), and we'll assume there's a pilot flying from point A to point B on this sphere. Given the theorems of spherical trigonometry, and given that the pilot has the precise latitude and longitude of both his origin and his destination, but neglecting rotation of the sphere, it is simple enough to compute the bearing (azimuth) and mileage to his destination. (In fact I have written a computer program that does just this for any two points.)

    Now, since the Earth is rotating, if the pilot wants to set an initial bearing that will take him straight to his destination, does he have to allow for Coreolus effect? If so, how? (Let's not drag in the oblate spheroid question for the moment.)

    I'm sure ronald Macdonald can help us with this one.
     
  14. ronald Macdonald

    ronald Macdonald Banned

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    well yes of course he does but only under certain conditions, the major one being that his navigation systems dont work. , Pilots going from London to New York actually fly quite a distance north for two reasons, one) its quicker to fly over the arctic circle, and two) If a pilot tried to fly direct to his destination he would soon find the earths rotation had moved his target some degrees north or south. Of course these days its not the pilot that takes care of that but the navigation systems
     
  15. MikeE

    MikeE Hip Forums Supporter HipForums Supporter

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    The wind is a bigger factor than the Coriolis effect.

    Lets try some more geometry/geography: Assuming that the earth is a sphere.
    If you are at the north pole and you walk one mile south, then one mile east, then one mile north, you will end up at your starting point.

    Is there any other place on the earth's surface can you walk one mile south, one mile east and one mile north and end up at your starting point? If so, where?
     
  16. dirtydog

    dirtydog Banned

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    South Pole won't work, you can't walk south from there.

    Northern hemisphere (0 < latitude < 90 N): Your final point will be east of your origin, but less than one mile east.

    Southern hemisphere (0 <= latitude < 89.9855 degrees S): Your final point will be east of your origin but more than one mile east.

    Southern hemisphere with starting latitude less than one statute mile (.0145 degree ) from South pole: It is impossible to walk one or more miles south.

    Southern hemisphere with starting latitude exactly one statute mile from South Pole: Maneuver cannot be done since, once at the South Pole, you cannot walk east.

    Short answer is, no.
     
  17. MikeE

    MikeE Hip Forums Supporter HipForums Supporter

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    any other opinions?

    O.K. I'll give a hint: dirtydog's analysis is incomplete.
     
  18. fat_tony

    fat_tony Member

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    Are we talking about the geometry of spheres or the flight paths of planes. Projecting a 2D plane onto a 3D surface is something that always plays with my mind, a shame really its quite important in relativity. But I would have thought that walking east at the South pole would involve rotating on the spot, though the concept of traveling a given distance wouldn't seem to be a useful quantity. That said in Mike's argument the distance you travel East is never an important quantity. It that fact that if you are n miles south of the north pole traveling north by that many miles will always take you to the north pole. Or was it a point about a 90 degree turn on a surface? It kinda came from nowhere so im not sure what its highlighting.

    The relationship between the Earths rotation and objects is complex. On the ground we are fixed to the Earth so we rotate with it. The atmosphere is largely coupled to the Earths rotation so even at high altitudes I would effect any effect to be small. But effect of wind is massively dominant over any rotation effect. This is why a more 'arctic' route is taken from London to New York than from New York to London.
     
  19. dirtydog

    dirtydog Banned

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    We're all waiting with held breath to find out why my analysis is incomplete. (In the first post I wrote 'one or miles' when I meant 'one or more miles', but this has been corrected.) I never was very good in school.
     
  20. Ghost-in-the-Snow

    Ghost-in-the-Snow Banned

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    Starting one mile above the equator...
     

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