Loop Quantum Gravity

Discussion in 'Politics & Religion' started by ShoeshineBoy, Dec 18, 2003.

  1. Just read a VERY interesting article in the Jan. Scientific American and it talked about Loop Quantum Gravity being a reasonable alternative to String Theory. It basically presented the idea that Space/Time comes in discrete units and not continuously as underlies relativity. Anybody know of any more articles/books/sites on this?

    I like the idea of string theory for a variety of reasons, but facts is facts. This article gave a few tests of this theory that will come forward in the next few years, esp. when a new satellite will be launched in 2006 to examine black hole radiation. Anybody else know of any other upcoming tests that will indicate whether string theory or loop quantum gravity will win the coveted prize as THE unified field theory?
  2. Well isn't that just great. When I was in elementary school, they taught us about nice little round balls called atoms with cool little circular orbiting things called electrons. Then when we got to highschool chemistry, they said forget what we taught you in elementary school, but those orbits are just probability rings where the electron "might be" or perhaps "might not be" -- think of it as a fuzzy cloud of chance surrounding the atom.

    Then in college they taught us to throw out Newtonian physics because it really only applies to things that go very slow (in relation to C) and things that exist on a macro-scale.

    After stomaching all of this, we were introduced to Einstein's theory of relativity. After severely struggling to understand how a spaceship would constantly need infinitely more energy as it approached the speed of light, we finally were able to grasp that time and space were actually related in a very unique and interesting way.

    THEN they spring quantum mechanics on us and teach us that a lot of the principles of quantum physics doesn't agree with relativity -- or that they cannot make a connection between the two. Suddenly we have terms like quarks, leptons and muons thrown at us, and we're then expected to accept the fact that, on a microscale, things are "kinda here, kinda there -- but could be anywhere -- we just can't measure it" (says Heisenberg). We must now accept the very real fact that Schroedinger's cat in a box is both alive and dead until our observation forces it into one of the two states. Protons are now going wherever we aren't looking and they somehow "know" we'll try and look and thus they will do everything they can to confuse the shit out of us (EPR Paradox).

    From this magic, hugh Everett III in 1957 said that, "hey, since on the quantum scale anything is possible, perhaps every nanosecond a somewhat less than infinite -- maybe half an infinite -- number of universes is spreading out in a tree-like fashion. Hence, we now have the "Quantum Many Worlds Theory."

    That was all well and good, but just when we thought we had reached the height of confusion, along came Dr. Michael Green and some of his stringed out Ivy-League buddies to give us 11 dimensional string theory (or was it 10? or does it really matter because I can't see much past 4 of them). Suddenly everything is really made up of a bunch of vibrating strings that oscillate, vibrate and whatever else 11 dimensional things do.

    Now they're getting into "loop quantum gravity?"

    We've gone from apples falling out of trees to discovering that everything is basically composed of a microscopic form of Ramen Noodles.

    When will this madness end?
  3. cartm


  4. Keep in mind that they're not throwing everything out. Relativity still applies to large scale objects and quantum mechanics to small scale. They're simply trying to figure out how to unify the two of them. Relativity and quantum mechanics are accurate to MANY significant decimal places and are highly applicable when applied appropriately. However, a "theory of everything" can have of course cosmological and maybe even theological applications. But, again, this is NOT a start from scratch scenario...We're dealing with stuff on the sub-Planck length level here and stuff that deals with the first 10^-43 seconds of the universe...There are some more implications mentioned in the article but I gotta run...Gotta go see Lord of the Rings III...
  5. omcate


    I am just wondering:

    How do these Ramen Noodles taste like ?

  6. That is where philosophy starts!
  7. PetaDollar

    PetaDollar Moderator

    Aphex, you got some bad info there. Look up the "Dirac equation" and "quantum field theory". Basically you can have a plain QM model, or a QM model with relativity. The latter explains everything the former does, plus lots more. It's much like super-sizing your extra value meal.
  8. DK_


  9. However, I do not understand if QLG theory compliments string theory or competes with it?


    This was as far as I got. Hope it helps. Makes a great background.

    #10     Dec 19, 2003