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MY Thread - LQG and/or ST?

  1. Jan 21, 2004 #1

    Tsu

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    I think, pretty much - never mind. I tried to watch Integral's link to the PBS video, but I need to use Ivan's computer with the high-speed connection and that just isn't going to happen any time soon. I have so many questions, even I can't get them sorted out enough to make sensible posts. I can try to find more basic info about LQG and string theory somewhere on the net. Guess I'll first google "LQG for Dummies" first... Also probably "String Theory for Dolts". Once I have that all figured out, I'll be back with some questions. Maybe in my next life I'll be hard-wired for this stuff... :frown: (GOOD LORD! WHAT AM I WISHING FOR????)

    Can anyone guide me to some sites about these two theories where they don't speak Greek? (you know, Greek - like 'sumthinorother diffeomorphism' - What the h*** IS THAT?) :frown:

    Thanx anyway...

    i should seek professinal help... i marry a nerd and i hang out with him and all his friends who just scramble my brains... YOU'RE ALL OUT TO GET ME, AREN'T YOU???!!! IT'S A CONSPIRACY!!! hmm.... professional help it IS...:wink: Is there a 12-step group for physics wives?
     
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  3. Jan 21, 2004 #2

    Evo

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    Have you tried Brian Greene's Elegant Universe for string theory? Both the book and the TV show are perfect for laymen (like me). He explains things in a very simple and entertaining way.

    Hyperspace - A scientific odyssey through parallel universes, time warps & the 10th dimension - by Michio Kaku

    Other books -

    Not really related, but he's hot (and funny), so you might be interested. He wrote "Faster than the Speed of Light" Joao Magueijo. I saw him on C-SPAN a little over a year ago, after I read an article on VSL. His website is http://theory.ic.ac.uk/~magueijo

    Also, "The Fabric of Reality: The Science of Parallel Universes - And it's implications" by David Deutsch. He's more into multiverses and time travel, but an interesting read. http://www.qubit.org/people/david/David.html

    People here may have differing opinions, they, having actual knowledge of these things, may say they're not worth the time spent reading them, so you may want to take whatever advice someone here gives on these over mine.
     
    Last edited: Jan 23, 2004
  4. Jan 22, 2004 #3

    marcus

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    that's well written
    in a dramatic many-voiced spontaneous-sounding style
    and its quite funny
    the idea of a 12step group-----actually it should be
    what is called a "support group"----for physics wives is
    first rate. there should be.

    a friend of mine, solid state physicist, did a stint in holland at
    philips eidhoven and fell in love with a lovely dutch girl
    who lived in the town near the research labs, but
    she had no idea of physics----she was good with languages---and
    they moved to Los Alamos and lived completely among physicists
    and their wives in a kind of suburb. She could have used a support group for physics wives. Should have had one really.
    Finally she ran off with a geologist. He liked mountains,
    which she could understand.

    I dont think it is a very good idea for someone in your situation to try to learn LQG or string theory for that matter. Much rather learn German or sing in the campus glee club. Singing 4-part harmony is very useful---it makes people happy.

    You are good with one-liners, so I think you are handy with language. Do you know some other languages besides English? If thats not too personal a question.
     
  5. Jan 22, 2004 #4

    jeff

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    If you want to avoid wasting time on ideas that are popular in these sorts of low-brow public forums but not among physicists, forget about LQG.
     
  6. Jan 22, 2004 #5

    marcus

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    Re: Re: MY Thread - LQG and/or ST?

    Tsunami,

    As you have doubtless gathered, I am real lowbrow and you are welcome to waste time trying to discuss anything you want with me, popular or not among whomever. As for research "demographics", here are numbers from a Los Alamos archive database. This relates to "popularity among physicists".

    Numbers of scholarly preprints by year in Loop Gravity research topics
    (keywords "loop quantum gravity", "spin foam", or "loop quantum cosmology")

    2000 46
    2001 48
    2002 64
    2003 70


    --------------
    Numbers of scholarly preprints by year in String research topics (keywords "string", "brane", "M-theory"


    2000 1457
    2001 1496
    2002 1500
    2003 1265

    That is, those where the abstract summary of the paper has in it somewhere the word string, or the word brane, or the word M-theory.

    More about this, and links to sources in the "Rovelli's program" thread serving as a Loop Gravity link-basket for want of sticky.

    https://www.physicsforums.com/showthread.php?s=&postid=128448#post128448

    Anecdotal evidence, in my experience, tends to confirm what you see in the numbers. I have repeatedly come across papers by authors who formerly did string research and have largely or entirely switched over.
     
    Last edited: Jan 22, 2004
  7. Jan 22, 2004 #6

    Tsu

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    Evo,
    I've been watching the Elegant Universe on-line (the link that Integral posted). Actually listening would be more like it, as I don't have enough of something computer (ask Ivan) for the video to come through. I need to go down to his office to watch it on his system - except that he uses it for work, which he is ALWAYS doing! Listening is fine, but I'm a visual person, so I miss the visuals.

    Kaku is excellent. Hyperspace is what made me realize 'HEY! I CAN understand this stuff!' As long as I can stay away from the math and keep to the concepts (is that possible?) I'll be fine. I can't sit and read a lot of this stuff at one time beacause I end up with such a twisty-face trying to force an understanding that I end up with a headache! So I take it small chunks at a time - let it sink in and then go back for more. :wink: I know I'll never be able to understand it the way these folks do. They seem to be able to instinctively see, feel and understand it - like it's a PART of them. I've always envied that ability. I've always WANTED that ability! But... On the other hand, none of these folks are as good as I am at being ME, so...

    Marcus,
    Many-voiced? You mean, like - SCHIZOPHRENIC???!!! Funny you should use the word 'dramatic'. I was 'this close' (*shows miniscule space between fingers*) to auditioning for Tony and Tina's Wedding. And I do speak Spanish and love languages. I have MANY interests - including the directions that all sciences are heading - which is why I want to learn more about LQM & ST.

    Jeff,
    *blows raspberry* Killjoy. Then tell me, what ideas ARE popular among physicists these days? I'll google them, too! :smile: Might as well have a well-rounded perspective, right?

    Anyway, thank you all for your posts. I've started my own list of links to hit whenever I get the intense desire to get all twisty-faced, but feel free to post any others that you think might be excellent for non-nerds like me trying to exist amongst you genious types. It will take me awhile to get through it all, but I'll pop in at times with a question or 50. Ivan is really excellent with answering my questions, but lots of times I want a different perspective. Frequently, someone will come up with some off-the-wall phrase that just pulls it all together for me. Why am I even here, you ask? Don't ask ME!! Like I said, professional help is probably MORE than indicated here...
     
  8. Jan 22, 2004 #7

    Evo

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    I watched Elegant Universe when it originally aired & went online & ordered the video. It's also available on DVD now. Worth the few bucks. You can order it here http://shop.wgbh.org/webapp/wcs/sto...Id=-1&pageSize=20&searchText=elegant+universe

    Since I don't have a life (single & no desire to go hunting) I read at night in bed before I go to sleep, so I read a LOT! You're lucky to have Ivan, although he looks terribly pale... :wink:
     
  9. Jan 22, 2004 #8

    Nereid

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    Scientific American?

    SciAm has had quite a number of 'forefront of physics' articles in the past year or three, and there's nary a Greek letter or equation on any page. Furthermore, many of the articles are written by those regarded as leaders in their fields - Smolin, Greene, Tegmark, Kane (maybe not a leader?), Bekenstein, ... All articles have a "More to Explore" section too.

    Many local libraries carry subscriptions, your budget may stretch far enough for you to take out one of your own, and there's a (fee-based) online service too.
     
  10. Jan 22, 2004 #9

    Ivan Seeking

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    You all should feel honored!

    She won't talk to me about physics any more.

    well...only on rare occasion and only with her eyes closed and her face all scrunched up.

    ...sometimes she even makes funny sounds...like she's in pain...
     
  11. Jan 22, 2004 #10

    Tsu

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    Yer so funny, honey. BUT, I DO *TOO* TALK TO YOU ABOUT PHYSICS!! It's just that, after 20 years, I'm becoming a little weary of the direct-heat version of Scrambled-Eggs-For-Brains. I'd like to check out the microwave version for a bit. :wink:

    I don't know how 'honored' they should feel, either. I would think 'annoyed' would cover it better. I half expect that they're thinking as they post a few links for me "Here. Read these, kiddo, and come back when you can talk more than nonsense.":wink:

    Thanx for that link, Evo. I think that's probably the way for me to go. (*reaches for credit card* 'oh boy... more Hawaiian Miles!' )

    Nereid, with that on-line service of SciAm, I would have access to past issues, right? And I could run searches on different topics through their archives? (*reaches for credit card AGAIN* 'oh boy... even MORE Hawaiian Miles!' I go visit my cousin again!!!)

    THANX, EVERYONE! You can ignore me now if you want. (But if you don't want to, that's nice, too!)
     
  12. Jan 22, 2004 #11

    Nereid

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    That's true; or rather, it was the last time I looked (I now have my very own, personal subscription, which the mailman (oops! not PC - postperson? letterdeliverer??) kindly brings me every month.
    http://www.sciam.com/
    You'll have to put up with pop-up ads though.
     
  13. Jan 22, 2004 #12

    Tsu

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    Why do you choose hard copy over on-line service?

    edit: WAIT! OF COURSE! You don't have a computer in your bathroom?
     
  14. Jan 23, 2004 #13

    selfAdjoint

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    Mail carrier. In the US.
     
  15. Jan 23, 2004 #14

    Nereid

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    Trains and boats and planes (laptop batteries only last so long). The back patio, with a glass of Prosecco (laptop screens can't compete with the Sun). In bed (laptops don't take too kindly to hitting the parque if you drop them while falling asleep). Etc (Evo would understand, so would SelfAdjoint and marcus).
     
  16. Jan 23, 2004 #15

    Evo

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    Nereid, you're right about needing the paper copy. BTW, I got my first subscription to Scientific American when I was around 16. It's what got me interested in Quantum Physics. They sent me a free book one time called "Phenomena of Physics" or vice versa, and I got hooked.

    Actually, I do take my laptop to bed with me. I have a big bed and lots of empty space and I don't move around in my sleep, so...

    Sad huh?
     
  17. Jan 23, 2004 #16

    Tsu

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    I have questions.

    From this page by Smolin's site (I think that's where I am anyway )
    http://www.edge.org/3rd_culture/smolin03/smolin03_p3.html

    My questions are in red.

    "The key thing that Amelino-Camelia and others realized is that we can use the universe itself as an experimental device to probe the Planck scale. There are three different ways the universe gives us experimental probes of the Planck scale. First, there are accelerators in distant galaxies What accelerators? What causes them? that produce particles with energies much higher than we can produce in even the largest human-made accelerators. Some of these ultra-high-energy cosmic rays have been observed hitting our atmosphere with energies more than 10 million times those we have ever produced. These provide us with a set of ready-made experiments, because on their way to us they have traveled great distances through the radiation and matter that fill the universe. Indeed, there are already surprises in the data which, if they hold up, can be interpreted as due to effects of quantum gravity.

    Second, we detect light and particles that have traveled billions of light years on their way across the universe to us. During the billions of years they travel, very small effects due to quantum gravity can be amplified to the point that we can detect them."
    What do we use to detect them?
     
  18. Jan 23, 2004 #17

    Nereid

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    In the words of Stecker (p6)*: "In most theoretical work in cosmic ray astrophysics, it is generally assumed that the diffusive shock acceleration process is the most likely mechanism for accelerating particles to high energy. (See, e.g., Jones (2000) and references therein.) In this case, the maximum obtainable energy is given by Emax = keZ(u/c)BL, where u ≤ c is the shock speed, eZ is the charge of the particle being accelerated, B is the magnetic field strength, L is the size of the accelerating region and the numerical parameter k = O(1)
    (Drury 1994).
    " Very crudely, the same sort of thing that happens in accelerators at CERN, only over far, far larger distances, greater magnetic fields, or both (p7 has a good chart ("Hillas plot") showing the B-L relationship).

    *reference to the Stecker paper in this marcus thread: https://www.physicsforums.com/showthread.php?s=&threadid=11309
    CCDs at the focii of telescopes. Here's a thread - started by wolfram - on our very own PF on this topic:
    https://www.physicsforums.com/showthread.php?s=&threadid=9367

    I'm sorry to say that I've not followed up with an analysis of the HST images of distant supernovae (there are some excellent images, taken as part of the GOODS project: https://www.physicsforums.com/showthread.php?s=&threadid=11216)
     
  19. Jan 23, 2004 #18

    Tsu

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  20. Jan 23, 2004 #19

    selfAdjoint

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    Charge coupled device, I believe. Ultra sensitive electronic gizmo for detecting faint light "at the focus of large telescopes".
     
  21. Jan 23, 2004 #20

    Tsu

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    Excellent. Thank you.

    From above:
    "diffusive shock acceleration" - from a supernova? Are there other sources of cosmic rays that we measure?
     
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