Interesting Article on General Relativity

Discussion in 'Physics' started by Sparky, Jul 15, 2008.

  1. Sparky

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  2. Dave

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  3. Distort10n

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    Not to people do not understand how science actually works and mock that nothing is 100% certain. Theories are just guesses, don't you know that Dave? :cool:

    *coughcreationistscough*
     
  4. Sparky

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    It has bugged me when I have had those "late-night" conversations and my friend responds with, "yes but that is JUST a THEORY"

    Ugh!!

    Most (including myself) don't know and understand how much goes into testing theories.

    Now there are crack-pot "theories" out there. (I'm afraid if I list any)
    Anybody can claim to have a theory or believe a theory.
    These may be giving the word "theory" and bad rap.

    Legitimate scientific theories have evidence, time and testings to back them up.

    As this article shows we are still testing relativity even though everybody accepts it.

    -Sparky.
     
  5. Wendy

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  6. Sparky

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    The link "has" worked.

    I think it is on scientific computing's site because this also doesn't work:

    http://www.scientificcomputing.com/

    I'll keep checking - if needed I can paste the entire article when I can get back to their site.

    -Sparky
     
  7. triggernum5

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    I'm not trying to be negative, but wouldn't GR actually failing a test actually make more interesting news?:)
    Honestly I wouldn't be too shocked if a mechanism was discovered that simply made it appear that the universe is expanding, making Einstein's original notions valid..:)
    That guy was intuitive on a whole other level..
     
  8. Dave

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    Link works here.

    In the interests of IP protection can I ask that you either get the copyright owners permission to do this and attribute source, or leave the story as a link and paraphrase content. Thanks :)

    GR failing would sure throw a few spanners in the works. Obviously failure of GR on one level may not invalidate the theory, more it may require modifications to be adopted into that level. Think how GR and quantum mechanics are contradictory.

    Dave
     
  9. Wendy

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    Worked this time, must have caught them while they were down.

    I suspect the link is enough, no need to post the article.
     
    Last edited: Jul 17, 2008
  10. triggernum5

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    Saying the theory of GR could, or could not be proven wrong gets really wishy-washy unless you strictly mind the literal definitions of aspects of the scientific method.. I don't mean to patronize anybody with the basics, but I'm going to toss them in..
    -Observation: What gets the ball rolling.. Does not need to be first hand..
    ---Guess: Just a guess regarding the observation.. Can be retarded or not, but is generally uneducated and loosely thought out, and usually annoying to the educated..
    ---Hypothesis: An educated guess that incorporates a non-trivial amount of logic and/or experience.. They can be either 'characterizational', or 'explanational'..
    ---Experimentation: Yields organized, ponderable observations/data..
    ***Beyond this point there is no necessary order.. Its more of a loose heirarchy..
    ---Laws: These are the 'characterizational component of a theory'..
    Laws typically define or quantify a relationship.. They don't explain 'why', they explain 'expectation'.. Think about how many laws are equations.. In GR, the Einstein Field Equations (EFE's) are laws..
    ---Models: These are often overlooked, and replaced with 'theory', which may just be the source of misconception.. They are the 'explanational component of a theory'..
    ---Theory: The collection of laws and models that describe the system and/or phenomena..
    ---Peer review/experimentation: Determines which science lunch table you eat at..:)
    Models are at risk of being proven wrong (sometimes wrong/unfairly).. Laws however are safe as long as they deserved to be called laws in the first place.. For example, early models of our solar system have been proven wrong, but Newton's law of gravity is still usually acceptable even though the EFE's yield more accurate results with alot of tensor calculus.. For that matter, the law that states that round rocks roll downhill is still valid..
    GR's models though are safe unless its determined that time is not a dimension.. Its important to realize that the rubber sheet is just an analogy that we can understand, and that it is valid for any 'field', and thus is more of an incorporated model from others..
    And the kicker is that the EFE's can work in n-dimensions, not just 4.. So GR doesn't need to fear new discovery.. Thats why so many ppl are trying to link relativity, and QFT's..
    And the double kicker is, even if we determine that time is not a dimenion linked with space, and the basis of the model comes crashing down, you still would have to admit that the EFE's still yield darned good results when you pretend..
    Modern science is full of the imaginary.. (Pun intended..)
     
  11. studiot

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    Perhaps those besotted with General Relativity should ponder Peratt's work.

    http://www.electric-cosmos.org/electricplasma.htm

    http://www.ieee.org/organizations/pubs/newsletters/npss/0306/peratt.html

    I have never seen a satisfactory proof/explanation for the statement' finite yet unbounded'

    The only way any Rieman Geometry works is to introduce an additional spatial dimension. The boundary is conviently shifted of into this extra dimension, but still exists.

    And if there is a boundary it begs the question 'What is on the other side?'
     
    Last edited: Jul 17, 2008
  12. Sparky

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    no problem,

    I'll leave it as a link and keep the same it in mind in the future.

    -Sparky
     
  13. triggernum5

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    A mobius strip is finite yet unbounded in 1 dimension..
    Perhaps it would help to consider the idea that every observer, no matter where they are can claim that they seem to be at the centre of the universe with equal validity, however if it was possible to observe the universe from its exterior, outside of our spacetime, a distinct centre would reveal itself..
    From a simpler POV, if the universe is expanding faster than c, and we can only travel slower than c, then to us the universe is unboundedeven if we start 1 inch from the edge trying to reach the edge..
    With expansion included, the most recent estimate for the diameterI have heard is ~156Billion ly..
     
  14. studiot

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    Please get your geometry right.

    A circle is finite, yet unbounded in one dimension, but requires a second dimension to exist in. The circle itself becomes the (one dimensional) boundary, which divides the two dimensional plane into two regions - the inside and outside of the circle.

    A mobius strip is two dimensional. Although the usual picture/construction shows a strip of twisted paper the actual mathematical strip extends the full space of two dimensions, twisted in a third dimension. Again the mobius plane is the boundary between two spaces in three dimensions.

    A Klein bottle ......possesses three dimensions but requires four dimensions to exist in well you get the picture. Again the bottle forms the boundary between two infinite four dimensional spaces.

    Well if our perceived universe is truly like this it gives the phrase

    'living on the edge'

    new meaning.
     
  15. triggernum5

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    But in 2D a mobius strip has boundaries just like a circle.. In 1D for that matter a mobius strip is also indistinguishable from a circle to any observer bound to its surface..
     
  16. studiot

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    A mobius strip cannot exist in 1 or 2 spatial dimensions so I have no idea what you mean by this.

    Perhaps if you were to expand on your statement I could help with your difficulty
     
  17. triggernum5

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    Neither can the earth, but we still map it in terms of 2D.. Why? Perhaps because they are the only relevant dimensions..
    In 2D the earth's surface is unbounded.. Then if you add another dimension voila, there is no longer any way to look at it as unbounded..
     
  18. theamber

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    It is necessary understand that we accommodate everything that we can perceive with our senses. Our brain receive stimulus from our senses by electrical signals, that do not represent what it is out there. It could be all an illusion. When we dream we can swear that we felt some real stimuli in our brain but when we wake up we discover that it was just a dream (unreal for our perception of reality).
    The reality is not what our senses can capture, for examples most animals have an imminent sense of danger in times of natural disasters. Even before our 'sophisticated devices' can perceive that.
    This is just a game we are just children entertaining ourselfs with limited illusions. There is no real facts we can sense. So far we found that besides neutrons, electrons, protons, neutrinos and quarks the rest is empty space....
    It was Newton that once said;
    "I was like a boy playing on the sea-shore, and diverting myself now and then finding a smoother pebble or a pretter shell than ordinary, whilst the great ocean of truth lay all undiscovered before me."


    I agree with him.
     
    Last edited: Jul 29, 2008
  19. studiot

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    Man does not need sensory stimuli to constuct complex mathematics or music, entirely in the mind.

    Bach was blind, Beethoven was deaf and Trachenberg was in chains at the end.
     
  20. theamber

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    I once saw a bunny with a pancake on it's head too.
    Are you just trying to prove me wrong?, well your are right I am Wrong.

    These people had senses at first Bach became blind at age 65. (even that does not have any effect on creating music). He had his son that wrote for him the music.
    Bethoven became deaf at a latter age too, but that was really an acomplisment. I can assume he could asociate the sounds because he knew how they where at first. Maybe he could also feel some vibrations with his hands or body. Actually he was in the proccess of becaming deaf when he wrote the last piece he wasn't totally deaf. Maybe it was not even true. Look know a lot of people make things up to impress or to try to sell more.
    But actually I played the violin as a hobby and even when I didn't heard anything I could think of new plays because I remember how things sounded. Then I could of just write the sounds and get the timming right.
    Actually the voyager probe recorded some sounds from Jupiter in bellow 20khz. Even there is no air out there the probe could feel the electrical vibrations from the planet. I think I heard that on Youtube.
    I don't know about the other person you mentioned.

    One thing is for sure; the brain cannot feel a thing by itself is mainly compose of fat.
    Certainly, people when missing a sense they have to use or develop the others more in order to compensate. Many things we assume because of our limited stimui.
     
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