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What is the hardest thing for you to wrap your brain around

  1. Dec 26, 2012 #1
    Maybe the sheer size of the universe? The speed at which light travels? The size of a quark?

    Out of all the things in the universe, what is hardest for you to possibly imagine, as long as it's generally accepted it doesn't have to be proven.

    For me it's both the size of the universe and the size of a quark. I mean, sitting here trying to wrap my head around how something can be so unbelievably large, yet also thinking how something can be so unbelievably tiny.

    Kind of ironic a little bit, how something like a solar system is similar to an atom even though their sizes vary beyond belief.
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  3. Dec 26, 2012 #2
    I used to have a problem with infinity. I kept using it like it was a number.
    For example, I couldn't understand that the amount of numbers between both 0 and 1 and 0 and 2 were both the same.
  4. Dec 26, 2012 #3
    My brain.
  5. Dec 26, 2012 #4


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    I haven't quite wrapped my brain around it yet.
  6. Dec 26, 2012 #5


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    The structure of the human eye and how the process of vision functions, and then dreams.
  7. Dec 26, 2012 #6
  8. Dec 26, 2012 #7
    What is the hardest thing for me to wrap my brain around? Has to have to been a tarmac road surface ... well, I suppose wrapping my skull around the road and my brain around the inside of my skull is technically more accurate.

    Other than that it is probably why anything exists at all (and, please, do not try and expound some hypothesis involving quantum theory and zero point energy fluctuations ... such hypotheses presuppose the existence of a quantum field and so on)
  9. Dec 27, 2012 #8
    The Riemann Hypothesis. I don't understand it.

    But I'm not even very good at differential equations.
  10. Dec 27, 2012 #9


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    The platypus. Need I say more?
  11. Dec 27, 2012 #10
  12. Dec 27, 2012 #11
    Why diamonds?
  13. Dec 27, 2012 #12
    Aren't some infinities larger than other infinities?
  14. Dec 27, 2012 #13
    In a way, yes, that's what Cantor demonstrated in the late 1800s.

    If you took the number of numbers in between 0-1 and divided it by the number of numbers between 0-2, you should get 1/2.

    Let x be the number of numbers between 0-1. There are an equal number of numbers between 0-1 and between 1-2, so the number of numbers between 0-2 is x + x, or 2x. So you have x/2x, and even if x is infinity, they cancel (they're the same infinity).

    I'm sure mathematicians will murder me for doing it that way, since I probably did all kinds of things wrong, but I think that's the general idea.
    Last edited: Dec 27, 2012
  15. Dec 27, 2012 #14


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  16. Dec 27, 2012 #15
    Hard to say.
  17. Dec 27, 2012 #16
    Jimmy Snyder likes to joke a lot. Diamonds are extremely hard. His post above mine is also a pun.
  18. Dec 27, 2012 #17
    How and if an inverse tangent function "jumps" from positive infinity to negative infinity.
  19. Dec 27, 2012 #18

    How tiny chemical reactions and electrical signals can conjure up such vivid memories from 20+ years ago amazes me. Occasionally I have a dream that has been recurring since I was 7-8 years old (currently 27 years old), and it just fascinates me to think about what all is stored in our brain and how some of it surfaces when you least expect it.
  20. Dec 28, 2012 #19
    The problem is you're using infinity as if it's a number. You added infinity with infinity. That makes no sense if infinity isn't a number.
  21. Dec 28, 2012 #20
    It makes plenty of sense. For every number in the 0-1 set, there is a corresponding number in the 1-2 set. In my example, x is not necessarily infinity, it's the number of numbers in between 0-1.

    The concept of infinities cancelling out, and one infinity being "bigger" than the other, is used ALL THE TIME in calculus when dealing with limits. For example, consider (2^x)/(x!) As x goes to infinity, the top and bottom are both infinity. However, the bottom infinity is "larger" so the limit as it goes to infinity is zero.
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