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Is light 'static'?

  1. Apr 4, 2004 #1
    since light is the only unchanging and irrelative motion in the universe, wouldn't it be fair to say that in 4-dimensional space all light is static and that the cosmos is expanding upwards in 4d at the speed of light c? and light is cosmic drag?
     
  2. jcsd
  3. Apr 5, 2004 #2
    Well actually 4-space would be expanding ana-wards, but close enough. :wink:
     
  4. Apr 5, 2004 #3

    selfAdjoint

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    You sure it's not kata-wards? And how do you determine which is which?
     
  5. Apr 6, 2004 #4
    really? :confused: i thought that was a crazy idea...lol...

    how would this translate into 3d? wouldn't this imply that the cosmic expansion is proceeding at the speed of light c and that the value of c fluctuates with H, Hubble constant?
     
  6. Apr 14, 2004 #5
    hey, this is probably a stupid question and there's something i'm missing - but could someone please help me out!!
     
  7. Apr 14, 2004 #6

    selfAdjoint

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    In 4-dimensional (or better 3+1-dimensional) spacetime, all motion becomes geometric. The world line of anything is a curve comprising the succession of positions and moments in the thing's history. In this way light is static in the same way Jesus in present in the Lutheran sacrament, by ubiquity. Jesus is present everywhere, so also in the bread and wine. And everything is static in Minkowski geometry so light is also.
     
  8. Apr 14, 2004 #7
    but how does 4 dimensional expansion affect the 3 dimensional universe???
     
  9. Apr 15, 2004 #8
    Hi Billy Boy - I have pondered the same question myself - but have not been able to geometrize it so that it makes sense. As you know, I have a different approach to relativity than the conventional relativists - My thinking on this stems from an idea suggested by Stephen Hawking - that every frame is actually moving at the velocity of light - but the motion is a composite of space squared and time squared - where the time increment is mulltiplied by c squared - so using this simple idea we plot time on the vertical axis and space on the horizontal - if the object of interest is not moving with respect to the plotted frame - then all motion is in the direction of the vertical - that is, ageing occurs at the maximum rate - but if the object is moving wrt the frame - there is a space component and the actual motion is a composite of the two. From this you can quickly derive the Einstein Lorentz transformations.

    Now suppose instead that we construct a potential coordinate system in three spatial dimensional, and that we postulate that each axis is distending at the velocity c; a point at the origin representing light will generate a sphere as the axis grow in length - the distention of the three coordinate axis at rate c represents the expansion of space - now the problem with this metaphore is that the fractional increase in the size of the universe at a local level is insignificant from the standpoint of v= Hr (the local change in distance due to the total change in the Hubble radius) - in order to make some sense out of this expansion hyperbole, you would have to believe that every point in the universe is deemed to be locally expanding at the velocity c. It isn't as bad as it first sounds because you do not have to add the individual expansions together to get some huge total volume rate - rather you have to buy the idea that each point is at the geocenter of its own Hubble sphere and it expands at a rate that exacly matches its Hubble manifold (an expanding bubble at each Hubble center)- and likewise for every other point - so there is an overlap of the distensions with the net result that the amount of change becomes locally undetectable -

    Anyway - its fanciful, but I wouldn't bet on it.
     
  10. Apr 20, 2004 #9
    Hey Billy Boy - seems we got snuffed on the other forum - this frequently]happens because physics is dominated by persons who have no tolerance for ideas that might undermine SR. Too bad - it was a lively interesting exchange - your initial question was not at all improper and your analogy to sound waves was appropriate - there is of course reason why waves are limited in velocity - in a plucked string it is the mass per unit length that determines velocity, in water, air or other mediums it is the bulk modulus (a factor that relates the properties of the medium to its inertial contents). Anyway, the deprecation of your question was totally unfounded - do not let the SR bigots destroy your curosity. SR is a religeon - those that attack legitimate inquiries that question SR are not only arrogant, they are a disgrace to true science,
     
  11. Apr 27, 2004 #10
    yogi - i really appreciate your willingness to speculate on these things...i for one am hoping that these new orbiting experiments prove something definitive about relativity, it would be nice if sr and gr were established facts so we could then proceed to explore their limits with less inhibition...

    your image of all frames moving at c is nice, can you point me to where hawking writes something about this? i am not a huge fan of his writing actually, i think feynman always explains things better (too bad he kicked the bucket)...

    it's interesting to consider that an object that doesn't move on the horizontal axis then travels singularly at c - time without motion moves at the speed of light, and since no mass = no motion, massless particles like photons must travel at c...photons are without rest mass or relativistic mass no matter what the reference frame, but an object with mass is still at rest in relation to its own coordinate system so then, yes everything can be said to be locally expanding through time/space at the c velocity...but then, of course, if it has mass it has motion relative to another coordinate system which is why not everything appears to move away from us at c...the farther away the object, the more eccentric the reference frame...otherwise everything expands through time and space at a uniform rate of c, thus doesn't appear to expand at all....
     
  12. Apr 28, 2004 #11
    Hi Billy Boy. It is not always possible to visualize such things as expansion - we don't know much about what space is - but for me it is the ultimate intrigue. I think it was for Einstien also. Here is a quote:

    In his 1929 tribute to Newton and Faraday, Einstein commented:

    “..every attempt to deny the physical reality of space collapses in the face of the law of inertia. For if acceleration is to be taken as real, then space must also be real within which bodies are conceived as accelerated. Newton saw this with perfect clarity and consequently he called space ‘absolute” ..the forces between particles were regarded as unconditionally associated with the particles themselves. ...Mere empty space was not admitted as a carrier for physical changes and processes. It was only ..the stage on which the drama of material happenings was played.”

    “...The ether was invented, penetrating everything, filling the whole of space, and admitted as a new kind of matter. ... it was overlooked that by this procedure, space itself had been brought to life...It (the ether) was thus to some degree identical with space itself.... In this way the field theory was born as a illegitimate child of Newtonian physics.”

    I take every opportunity to engage discussants about the subject. As you have found, many of the folks on these forums have already reached unshakeable conclusions about these subjects. This is to be expected - those that invest the time and effort in acquiring a scientific education do not like to consider that some of the fundamentals upon which that fabric is based may yet be flawed.

    I will check to see if I can find the Hawking reference

    Regards

    Yogi
     
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