Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Examples of infinity in the physical world

  1. Nov 21, 2003 #1
    examples of "infinity" in the physical world

    Can anyone give me examples of "infinity" in the physical world around us? Ie. evidence of its existence as more than merely a mathematical concept.
  2. jcsd
  3. Nov 22, 2003 #2


    User Avatar
    Staff Emeritus
    Science Advisor

    Why "merely"?
  4. Nov 22, 2003 #3
    measure the distance to the farthest reach of nothing in the universe you will go forever, thus finding infinity.
  5. Nov 22, 2003 #4
    Let a1 = 10
    Let a2 = a1a1
    Let a3 = a2a2
    Let a4 = a3a3
    ...and so on
    is reached.

    How about this number a1000000000000000000000?

    Can anyone give me examples of this scale of number in the physical world around us? Ie. evidence of its existence as more than merely a mathematical concept.

    Unlike infinity, this is just a plain ordinary finite number.
  6. Nov 23, 2003 #5
    To Adam

    I find your question interesting.
    I too have thought about that and have looked in
    many sciences for the answer and other ways.
    So far no luck,but I'm still trying.

    Anyhow could you give some further idea on your
    thinking in this regard?

    "If the infinte you want to stride,just walk in the
    finite to every side."
    Johann Wolfgang Von Goethe
    Last edited: Nov 23, 2003
  7. Nov 23, 2003 #6
    I read in a book a while ago that the largest number that has any mathematical significance is Skewes Number: 10^10^10^34

    It's the upper bound on the number where Gauss's prime number approximation Li(n) switches from overestimating the number of primes to underestimating the number of primes.

    That's a one followed by 10^10^34 zeros; more zeros than there are atoms in the universe. There's something like 10^80 protons in the universe, and 10^10^50 possible games of chess. If you imagine the universe as a chess board, and switching any two protons constitutes a move, the number of possible games would then be comparable to Skewes number.
  8. Nov 23, 2003 #7
    well there is now way to show infinity in the real world because the world is based on finite number see what i mean? space is the only thing that comes to mind, however we may just not be able to reach the end because our travel speed is too slow.
  9. Nov 26, 2003 #8
    What about infinitely small and infinitely large within which we exist in between!?
  10. Nov 27, 2003 #9
    When you flip a coin a finite number of times, you will get approximately 50% heads and 50% tails if the coin is "fair". The only way you will get exactly 50% heads and 50% tails out of a "fair" coin is if you flip it an infinite number of times. Everything in life is like flipping coins. As a physicist you probably know that the fact that you do not disintegrate from one second to the next is pure coincidence. Sure, chances for your staying in one piece throughout any given second are better than 50-50, but in principle you or I don't exist any more or less than infinity.
  11. Nov 27, 2003 #10
    No arguments from me on that!
  12. Nov 27, 2003 #11
    first of all even with real world examples the human mind cant even comprehend 1000 let alone skewes number. try it try to imagine 1000 nails in a box in front of you ..........................you cant and even if you tink you have COUNT them and dont add any more you will come up with a number much lower than 1000
    and also the only thing infinite is the number of universes because the number of possibilities of things is endless and each one makes a new universe and if quantum teleportation were possible now the future and past would exist as one allowing time travel by teleportation to alternate universes where things go a little differently no matter how small the change and if you traveled this way you would never get back to your original universe.

    SORRY got caught up in this rant
  13. Nov 28, 2003 #12
    That's kind of what I was getting at, Sniper... I just didn't feel up to trying to lavish my rather simplified statement:

    "Infinitely small or Infinitely large"
  14. Nov 28, 2003 #13


    User Avatar
    Science Advisor
    Gold Member

    Quite often physicists describe a real number divided by zero as 'infinity' when it occurs in their equations, of course if this happens the situation is usually then described as unphysical or it is taken that there must be a flaw in the theory.

    The only physical quantity that I can think of that may have a value equal to infinity in a physical situation is the thermodynamic temperature in Kelvins.
  15. Dec 8, 2003 #14
    If I draw a circle on the ground, is it not considered an infinite path?
  16. Dec 8, 2003 #15
    Well, if you take that as an infinite path than anything that starts and ends in the same place would be infinite, this would include say a square, just pointing out the obvious though, so please ignore me
  17. Dec 8, 2003 #16
    Yeah, but with spherical objects, such as a circle you would not be able to put segments on it. While with a square you could. Thus infinity still holds true to spherical objects, whereas infinity can't be done with geometric angles, such as the square which has two or more lines with distinct points.
    Last edited: Dec 8, 2003
  18. Dec 8, 2003 #17


    User Avatar
    Science Advisor
    Gold Member

    Well, what's a path? most definitons in the broad areas maths and physics roughly define a path as something inbetween a start and a finish, even if the start is the same as the finish (i'm thinking discrete maths here). In this (very) broad defintion a circle is not a path unless you define a start and a finish in which case it is not an infinite path.
  19. Dec 9, 2003 #18


    User Avatar
    Staff Emeritus
    Science Advisor

    What do you mean by "infinite path"?

    A circle, like any curve, no matter how short, contains an infinite number of points, but that is not what we normally mean when we talk about an "infinite path". A circle has a finite length and that is what we are normally talking about.
  20. Dec 9, 2003 #19
    What I mean is, if you draw a circle on the ground and start walking along the line, you will never reach the end of it.
  21. Dec 9, 2003 #20
    That means that it does not have a boundary, which, to me at least, is not equivalent to "infinite."
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Examples of infinity in the physical world
  1. Infinity ? (Replies: 3)

  2. Is infinity = infinity? (Replies: 20)