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Science project suggestions

  1. Sep 2, 2004 #1
    OK, some of you may know me, but for those who don't, I'm no expert in SST or LQG. I have read a decent amount of books, but I can't even fathom the mathematics (pretty much the real source) of either. My knowledge extends to The Elegant Universe, Carlo Rovelli's livingreview Quantum Gravity, Three Roads to Quantum Gravity, Hyperspace, and roaming around this site for a year and a half. My passion for physics started with Einstein (so I know basics of relativity) and then grew to Quantum physics (2-3 books). Also Scientific American for the past year, which has published some awesome articles.

    Well, now that we got that out of the way, some of you know that I have done some research on the comparisons and contrasts between LQG and ST and have wrote an essay. Now, I was planning on doing a science experiment this year on some bacteria that turned sugar into electricity. This is an awesome project, but I just don't have the passion for it like I do for LQG and ST. So.... I decided to basically turn my essay into a science fair project.

    1)Good, Bad idea?

    2) I need to put something out on display in front of my trifold. What I'm doing (of coarse) isn't an experiment, more like a demonstration. But I still need to put something out in front for display.

    For instance, When I was a freshman, I did a project on the Wave-Particle duality. It was a demonstration. But I still put a laser on display shooting through some slits showing diffraction patterns.

    I just need something simple like this. ANY IDEAS are welcome.

    What do ya think?

    Paden Roder
     
  2. jcsd
  3. Sep 2, 2004 #2

    marcus

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    Paden, as you are well aware I too am fascinated with the spectacle of current advances in quantum gravity. However if right now I was walking into a highschool gymnasium full of Science Projects I would make a bee-line for the one in which bacteria produce electricity.

    that sounds fantastic.

    the thing about science PROJECTS is that they involve some hands on working with something---in the empirical spirit we get from Galileo and all that. He used to roll balls down ramps. A project is different from reading and thinking and writing essays. Hands on is the essence.

    If I was a junior I would not make a project about QG (even tho I find it really exciting) I would take the opportunity to do something with real stuff. If I was confident of my ability to grow biovoltaic bugs I would be on that like a shot. wouldn't think twice. great project!

    the first decent tests of QG will not be until 2007, if then!
    and that involves observing tiny dispersion effects in gammaray bursts, which we cant even see
    down here on the ground----a satellite has to do it for us!
    what a dismally unempirical situation and how unlike a truly doable science project! bummer :frown:

    do you know about the phenomenon of "dispersion" of sound and radio waves. a long maybe 8 inch diameter PVC plastic pipe demonstrates this (maybe, unless I'm mistaken!)
    so if you make a sharp clap (many frequencies launched at once) it comes out at the other end as a dispersed poing or zow, because some frequencies travel faster and come out ahead of others, so the lower frequency part of the sound trails behind IIRC,
    well in 2007 if the GLAST goes up they will be looking for any sign of a very tiny dispersive effect in gammaray bursts (like the sharp clap with your hands) that have traveled on the order of a billion lightyears. so that some frequencies have had a chance to get a tiny bit ahead of others.

    I would not touch this kind of thing as a highschool science project! Too much that is dangerously novel and speculative and against all orthodox belief---everybody takes for granted that empty space is non-dispersive: all frequencies of light travel the same speed. No teacher I can imagine would want to contemplate that empty space might be dispersive especially since it is such a long-shot and hard to explain why.


    it is even hard to explain why sound traveling in a tunnel should be dispersive.maybe it isnt really! the whole thing is fraught with danger. better to grow the bugs that make electricity!

    BTW congratulations on writing that essay! that was a great project too!
    but writing an essay is one kind of job and constucting a science project is another IMHO
    --------------
    PS, demonstrating dispersion in sound waves is apt to be very expensive because the pipe might have to be 12 inch diameter (8 inch might not work) and it might have to be some 30 or 40 feet long

    maybe a sound reflector at the other end so that the echo would come back and that way you get to use the length of the tube twice
    and dont need such a long one.

    there has to be enough length so that the slightly faster traveling part of the sound mix has a chance to get detectably out ahead of the slower,
    so if it is too short you dont hear the zow effect.

    IIRC it is hard to explain too, why a pipe should do that.
    involves drawing pictures with soundwaves bouncing

    this whole idea could be invalid.

    should get more people's ideas (or stay with the biovoltaic bugs)
     
    Last edited: Sep 2, 2004
  4. Sep 2, 2004 #3
    Yes I too would have appreciate the hands on approach but quantum grvaity like Marcus said is a hard one.

    I say but, because looking for expeirments to reproduce might eventually help one to develope a deepr sense of relation to the topic of gravity. So why not determine what this rating would be in your location.

    What is the value of g in Claremont?
    http://kossi.physics.hmc.edu/Courses/p23a/Experiments/Gravity.html

    This experiment then directs you attention here because of the obvious points raised in list.

    I thought of another but I just do not know how you would apply geometrodynamics to bubbles using sound to change its shape? Can it be done?

    Just a thought.
     
  5. Sep 3, 2004 #4
    marcus,
    Thanks for your advice. I know exactly what you're saying about the hands on experiment. That's why I gave up a project on ST or LQG in the first place. I don't know what I'm gonna do. The Rhodoferax ferrireducens experiment, I do admit, is a cool one, but it just doesn't interest me like these other subjects. I do admit, however, that I am interested in atlernative energy resources.

    sol2,
    I appreciate your comments also. Also, was that a challenge you posted about the geometrodynamics and bubbles? Are you threatening me? :smile:

    Both,
    I'll give it a little more thought, see what comes up. Thanks for your input. You guys are great.

    Paden Roder

    P.S.- I know marcus already has one (congrats), but sol2!!!!!! You should be all over chroot for not giving you a medal!!

    I'm sure you're heartbroken :cry: lol
     
    Last edited: Sep 3, 2004
  6. Sep 4, 2004 #5

    marcus

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    on the internet sometimes when someone says thankyou the proper thing to do is stop :smile:

    I realized immediately I had nothing useful to say, but went ahead babbling.

    Its very hard. I know QG is fascinating and very timely (a kind of epocal change in physics in the making) but so hard to see in terms of concrete handson projects.

    do you know what the Newtonian gravitational constant G is?

    Do you know the story of how Henry Cavendish measured it circa 1795 IIRC?

    the planck units derive from this constant G (and c and planck's hbar)

    this constant G relates mass to gravitational attractivenss. It is the basic geometrical proporition in General Relativityh that relates curvature to energy density ( matter, as energy density, curves spacetime via this constant G)

    Amazingly, an experimental genius Cavendish, one of the greatest experimentalists who has ever lived, managed to measure this constant G around 1795 (check the date in Britannica)

    using very simple apparatus made of a dumbell shape thing suspended horizontal by a thread----socalled torsion pendulum.

    the horizontal dumbell would slowly rotate clockwise until the thread had twisted enough to resist and then it would slowly start to rotate back counter clockwise.

    this genius Cavendish realised that the natural frequency of the gentle oscillation revealed just the information about the inertia of the balls and the springiness or twistiness of the thread which he would need if he wanted to gauge the gravity pull exerted by placing a big lump of lead up near the dumbell to try to get it to twist towards the lead.

    for a contemporary of Mozart and Haydn he was really brilliant

    IIRC this G thing is
    6.673 x 10-11 cubic meter/sq. second per kilogram

    no one should be talking about gravity unless they know this quantity and have some understanding of it.

    the 1915 Einstein eqn, and all the cosmology eqns are made with this
    the planck length and planck time and planck mass are made with this G.
    this G is the soul of gravity and the index of the strength of gravity thru out the universe
    and this curious eccentric English of 18th Cent. a lifelong bachelor living at his club, perhaps slightly daft, he measured it.

    as a trivial consequence, knowing G lets one find out the mass of the earth in kilogram, so you could call measuring G the same as "weighing the earth" but this is a laugh because G is universal. it is also how you would weigh our galaxy by seeing the speed stars swirl along the rim of it.

    it is a powerful fundamental constant, like c, and like hbar.

    the device that is used to measure G is commonly called a 'cavendish device'

    a crazy australian has bought one which he takes down in submarines and old mineshafts and even lowers down oil wells because he thinks G might be different down there. G is the same everywhere in the universe, so that is how crazy this australian is. but of course he could be right, anybody could.

    the thread that supports the little horizontal dumbell is a QUARTZ thread.
    or it was the last time I looked. I do not know why. maybe quartz is strong and has a strong twisty springiness

    Could a highschool Junior in Sutherland Iowa build a Cavendish device?
    I do not know. buy, borrow? steal?
    to measure a fundamental constant like G or the speed of light is a great thing. I do not know if science projecters do this. anywy it is something to think about.

    Sol was talking about measuring little g, the earths grav. accel
    roughly 9.8 meters per second per second.
    the two are related-----big universal G and little terrestrial g----if you
    know the mass and radius of the earth.
    g is very easy to measure
    if you know radius of earth, and G, and g, then you can calculate mass of earth in kilograms
     
  7. Sep 4, 2004 #6

    marcus

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    Last edited: Sep 4, 2004
  8. Sep 4, 2004 #7
    Marcus,

    I created a network of posts today that are interlinked specifically done for you and your post above mine here.

    If you venture into the areas that are linked and you come back here, you must tell me if I have succeeded in incoporating gravity in a most subtle way.

    The experiments seem to ask us okay in the early universe, if microscopically look at the origins, how shall this compatible view take us to today? You had to understand that if the spacetime fabric is flat, then we have to realize the weakness in gravity with which we might look at our universe today. Back then the undertsanding of the Q<->Q measure helps you to orientate your thinking.

    Consider then the amplitude of that string. How would it look in the early universe and how would the amplitude look today? There are definitiely gravitational considerations to this perspective that many have failed to understand. It really is unfortunate, when it comes to understanding extra dimensions.


    The post you supplied are links that I had looked at 2 years ago to wrap my mind around the understandng of GR, and since then, quantizing this view to what we see "microscopically now". This information exists around us right now. Imagine :smile:

    If you were to ask me about the Mercuries orbital "oscillations," how would we ever percieve this at such quantum levels? I am speaking to that as well. :smile:

    Because we can look at this feature in one extreme of weakness( the experiment you showed), and I showed you the equation underneath the Q<->Q measure, so that you understand how Nima and Sava and Dvali approached this.
     
    Last edited: Sep 4, 2004
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