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Ideas on Infinity.

  1. Sep 6, 2005 #1
    I gave roughly an hour's thought to infinity, and came up with these statements and questions;

    If infinity exists, where would it go? The only infinity that would make sense is the size of the universe, because you couldn't have an infinite amount of any matter without it taking up literally every available itty bitty bit of space within the universe. Time: It has a start, and an ending, but what's outside of that? If there is no motion without time, how can we have come into existance, from nothing to something? (Impossible question at this time alert)


    Anyway, I forgot what else I was going to post, so i'll post that later. Cya!
     
  2. jcsd
  3. Sep 6, 2005 #2
    It seems impossible to imagine these things. It's like trying to visualize... a hypercube.
     
  4. Sep 6, 2005 #3

    selfAdjoint

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    Exactly; it is as hard to imagine a simple geometric figure in four-dimensional Euclidean space as it is to imagine infinity. Therfore our imaginations are not to be depended on when we study these things, and we resort to mathematics with its axioms and theorems and proofs.
     
  5. Sep 6, 2005 #4
    I would argue that space and time are infinite.

    It can't be known if time will ever end, although I would agree what we call "motion" must have had a starting point.

    Things can only exist if their opposites also exist. Light can't exist without darkness, matter cannot exist without emptiness, life cannot exist without death, and so on. As such, "nothing" can only exist if "something" also exists, so the universe exists out of logical necessity, and it must have come from nothing also out of logical necessity.

    As to how the universe can be created from a motionless nothing, the answer goes along the same lines. Movement is what allows motionlessness to exist. The "nothing" couldn't be motionless in the absence of a universe to serve as a point of reference, and thus logic forces a moving universe to exist due to the fact that a motionless nothing also exists. In fact, notice that if the universe is finite and space infinite, the universe is just an infinitesimal point in a sea of nothing. The nothing which preceded creation is still out there.

    It's all a play with words, I know, but the basic logical structure is there. Which particular words we choose is irrelevant. If you've ever written a computer program, you know how you call your functions and variables is just a matter of personal preference, what really matters is the logical structure.
     
  6. Sep 6, 2005 #5
    there is a theory that we cannot imagine any object or idea that had more than dimensions than the 3 dimensional world we live in, and indeed an entity in any dimension cannot see into dimension which is more 'complex' than its own.

    For example a particle that is constrained to move along a line has only 1 dimension, this is all it can experience, it cannot imagine a 2-d world.

    And the particle constrained to a page cannot see beyond its 2-D world and so on and so forth.

    Thus imagining 4D Euclidean Spaces is perhaps impossible?

    I am not sure about this theorty however i heard it somewhere.....once.....:tongue:
     
  7. Sep 6, 2005 #6

    Gokul43201

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    How about your definition of this "infinity" ?

    How can we discuss something effectively unless we know what you are talking about ?
     
  8. Sep 6, 2005 #7
    Infinity is unlimitedness, or a never-ending amount of something.


    By the way, I heard this definition of a line: A line is an infinite amount of points connected, no matter how long or short.
    How can this be? Wouldn't planck length be the minimum amount of distance between each dot, creating limitedness?

    That, and it makes no sense for a 1 inch line to be made of the same amount of 0 dimensions as a 2 inch line.

    That, and it doesn't make sense for a 2 foot cube to be made of the same number of planes as a 1 foot high cube.
     
  9. Sep 6, 2005 #8
    I think you are misunderstanding what space is, or matter for that matter.
     
  10. Sep 6, 2005 #9
    What is time? No really, I'm serious. I've always (ok not always but recently) considered time as the idea representing....wow, how can you put something like this into words? I've been typing and then holding down <backspace> and then typing again for the past 5 minutes trying to think of how to word this.

    Somebody want to help out?
     
  11. Sep 6, 2005 #10

    Hurkyl

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    It does make perfect sense: it's very easy to show how to "count" the points of one line segment using the points of the other line segment.

    The thing you're forgetting is that there's another concept at play here: that of a measure. The measure is the gadget that tells you how long your line is.
     
  12. Sep 6, 2005 #11
    In our universe there are only ones, one at a time, where time is the nothing ones are composed of.
     
  13. Sep 7, 2005 #12
    hmm, maybe i'm just confused about the "dots into line" part.

    Anyway, time is the expression of motion, I believe.

    If there is no time, there can be no motion... can there?
     
  14. Sep 7, 2005 #13

    Gokul43201

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    This quandary is easily resolved. The "infinity" that appears in the definition of a line is different from your concept of infinity (this was why I asked you for its definition). The first has a methematical definition, the second does not.
     
    Last edited: Sep 7, 2005
  15. Sep 13, 2005 #14
    The illusion of infinity

    Infinities are created from linear thinking which in itself is an illusion.
     
  16. Sep 13, 2005 #15

    Hurkyl

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    Would you care to:

    (1) Define what you mean by linear thinking
    (2) Explain why you think linear thinking is an illusion
    (3) Explain what it means for an infinity to be created
    (4) Explain why you think infinities are created from linear thinking
    (5) Explain why you think there is no other way to create an infinity

    ?

    And for good measure

    (6) Your definition of infinity

    would be good to have as well.
     
    Last edited: Sep 13, 2005
  17. Sep 15, 2005 #16
    Ok there are a few things I believe are incorrect here. For instance, "Things can only exist if their opposites also exist." While this seems to a person as a logical conclusion, "darkness" and "emptiness" themselves do not exist but infact are defined to be the absense of something that we define exists. Light could not be DEFINED if darkness was not also defined. Darkness is just absense of the perception that we get when we "experience" light.

    Also, "How can this be? Wouldn't planck length be the minimum amount of distance between each dot, creating limitedness?" is false logic because you apply an infinite mathematical concept to our limited universe. From what I have gathered from any science that studies our universe at the smallest of scales, state that the universe does not go infinitely small. Therefore, you can not say that you can "zoom" in, in our universe infinitely.

    Further, "If there is no time, there can be no motion... can there?" This is correct. Motion is completely dependant on spacetime. Without one or the other, motion itself can not be reasoned to be apart in this universe. If there is no time, there is no space. If there is no time or space, there is no matter to exist in the stage of spacetime, our universe. Therefore, there is not an existing universe at all. These concepts are fundamentally defined to be dependant on one another.

    Finally, "Infinities are created from linear thinking which in itself is an illusion" is a vague statement which nobody here can definitively specify what he meant, exactly. From what I can guess, he is defining the concept of infinity to be false reasoning because of the way it is perceived, through linear thinking. What he is trying to get of this I really dont know (except to disprove infinity). If anybody can shed light on the subject or to even correct myself, it would be appreciated.
     
    Last edited: Sep 16, 2005
  18. Sep 16, 2005 #17
    Infinity is not a one size fits all kind of thing. There are several versions of infinity and we can't really know if we have properly conceptualized any one of them. I have a simplistic view, and say you are a line in one dimension that somehow can consciously inspect every point from here to there, there is a lot to see, and for infinity to be inspected, our species runs up against a problem with time. I think that going farther and farther into subatomic space, and then outward from there to macro phenomenon, in a straight line, in either direction from the small to the large, or large to small, there is an infinity there, in any direction you choose to travel.

    If we are to do with infinity what we have done with everything else, then infinity will look like a huge human being (with a gun *snicker*).
     
  19. Sep 16, 2005 #18
    I think by linear thinking he was refering to duality or something.
     
  20. Sep 17, 2005 #19
    As for the physical nature of infinity.. Obviously there is a limited amount of atoms in the universe, or energy, if not a constant value of energy, therefore spacetime is not infinite.
    However people start to ask themselves, "what is outside the universe?"
    And that's when it gets complicated because we have no idea what lies outside spacetime, unless you want to get into string theory and the higher dimension.

    Regardless, the question is infinitely recursive, and to me pretty pointless, since we can never imagine what infinity is.
    About time, here's my little theory on it;

    Like every rule in the universe, time is also a rule, or property, of the way particles interact.
    The particles themselves make up certain rules, like gravity's force, the speed of light, electromagnetisms force, et cetera.
    So when these particles bind, you cannot for example travel faster than light.
    Now what if time is an emergent property of the elementary particles?
    Time itself doesn't control the motion of the particles, rather time emerges from the particles as they themselves create more and more rules the more they bind and gain complexity.
    That's maybe why time and space was warped during the big bang, because the universe was at its simplest.
    As the particles started to bind and cool down, it gained complexity and certain possibilities were erased from the plane of reality.
    Time may be one possibility that emerged.
     
  21. Sep 17, 2005 #20

    Hurkyl

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    No, it is not obvious.

    String theory doesn't go outside of space-time -- it says that space-time has more dimensions than we think it does.

    A rather bold statement, in face of the many people who think they can imagine what "infinity" is, not to mention give precise definitions and make fully rigorous arguments involving it.


    As for the rest of your post, it appears you're trying to hijack the thread -- what does your pet theory on time have to do with infinity?
     
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