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Does increasing velocity shrink matter?

  1. Jul 5, 2011 #1
    It seems that the ideal state for matter is for it to get compressed to a high degree or even to the point of infinity at the speed of light, just before it reaches the singularity in a black hole.
  2. jcsd
  3. Jul 5, 2011 #2
    Not sure what you mean by 'ideal state' nor am I sure why you refer to a black hole, as your question was about velocity, not gravity.

    Anyway, the quick answer is no. For you velocity does not cause matter to compress. Also, no matter (assuming you mean matter which has mass) can travel at the speed of light.

    As regards the singularity you mentioned, then yes, this can have an effect on matter.

    EDIT: Sorry, I just noticed your question was 'increasing velocity'. So I assume you meant does acceleration have an effect on matter. In which case the answer is yes.
  4. Jul 5, 2011 #3
    All objects falling into a black hole are constantly increasing in velocity.
  5. Jul 5, 2011 #4


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    I have the same questions as rede96 about the meaning of the OP, and for me, #3 didn't clear up those questions.
  6. Jul 5, 2011 #5


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    The Lorentz contractions, in SR, are matter of perspective (hence the word relativity).

    If you're standing on a small moon and I walk away from you, my vertical direction rotates relative to yours. You would see me (after I jump up to be visible over the horizon) appear shorter if you didn't realize I was leaning away from you.

    In a somewhat analogous fashion an object moving relative to you will appear foreshortened in the direction of motion since by virtue of it being in motion, its time axis is rotated relative to yours. Think of velocity as the slope of an object's world-line through space-time. A moving object relative to you has a world-line in a different direction from yours. Length's look different depending on the space-time angle at which you chose to define the length.
  7. Jul 5, 2011 #6
    Let me be the devil's advocate here.
    1) For a spaceship traveling at relativistic speed, we say the distance between the ship and the destination star shrinks because of speed as given by the contraction formula. What is actually shrinking here? The space, not any material.

    2) We find in all physics textbooks proof of length contraction by special relativy by using a rod laying on ground and measuring its length by 2 observers. Here they show 'the materials' of the rod is contracted.

    Isn't number (2) saying "space contracts, as in (1), but materials also contract because they are occupying space". Questions.
    (a) Is contraction of materials is caused by contraction of space?
    (b) Do materials contract, but space doesn't? [violates (1)]
    (c) Does only space contract, materials do not. [proof (2) fails].

    If (a) is right, then it violates the current assumption that universe (space) expands but matter does not.

    I may be thinking something out of line. Correct me please.
  8. Jul 5, 2011 #7


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    (d) None of the above.... but rather in unified space-time the line one draws saying "this is a spatial distance" and thence measures saying "and it is X meters." differs between observers moving at different speeds relative to each other.

    It is part and parcel with the fact that different observers also get different answers to the question of which events occur "at the same time".
  9. Jul 6, 2011 #8
    The reason I refer to a black hole is because it is constantly accelorating the objects that are locked in its orbit.
    For example, our solar system is locked in orbit around the black hole at the center of the Milky Way galaxy.

    Why is there a black hole at the center of our galaxy?

    It is because a super giant star exploded and created it, and all the matter in the galaxy-stars, planets, solar systems etc.

    Where did the super giant star come from?

    I believe it was formed from a black hole that was here before this one, and the black hole there now is swallowing up our galaxy so a new super giant star can be formed. The process being repeated over and over, unless something drastic happens to change it like a collision with another galaxy.

    You can look at images of galaxies and see the different stages from the huge whirl of the early stage, to the small glowing cloud of the nearly dead galaxy. And after all the matter passes the event horizon, we only see black.

    Here is where the compression from velocity would really come into play. It is at this point that the matter is compacted to the point where all moleculor and atomic activity ceases. Glowing objects no longer emit light. All we can see is a very black cloud of dust.

    It is at this point, I believe that all the matter is very close to the speed of light, where it eventually reaches the speed of light. And then everything keeps falling until it is a very, very compact spinning mass of matter at the center of the black hole.

    Since the mass is so compacted, and there is no empty space between the molecules, the mass should be near absolute zero.

    I believe that just before the matter is compacted to its final stage, it releases all its heat. We can see this release of this heat being spewed out at the poles of the black hole.

    After everything falls to the mass at the center of the black hole, the spinning sphere quits gathering energy, and begins to slow down over time. (maybe many billions of years).

    It is at this point when the spinning mass begins to expand and generate heat. The heat begins to separate the different elements and the hydrogen rises to the surface and eventually begins to glow. A super giant star is born.

    The mass keeps expanding and the star grows. When it reaches the final stages in the life of the star, I believe this is the point when the water, and other elements that are close to the center of the star, reach a temperature that causes the star to explode. (more billions of years).

    I believe that our galaxy is in the very early stages. Our solar system is very far from the black hole. However, this does not mean that we are not constantly accelorating toward the singularity. What it does mean though, is that the acceloration is very slight.

    So, if we had a stationary observer, outside our galaxy, that was observing our clocks and was comparing them to his stationary clock, he would see our clocks running slower than his, due to our velocity.

    This is relativity in play. There is a relative difference in the stationary clock and our moving clocks.

    What causes the relative difference?

    If our solar system is shrinking, and everything in it, then this could account for why we cannot perceive that we are constantly gaining velocity. All our measuring devices are shrinking too. Every properly done experiment will give the same results as experiments in the past when the measuring stick was a tiny amount longer, and our clock was slightly faster, relative to the stationary observer.

    There is no experiment that we can do to perceive that we are gradually shrinking. However, our view of the space around us would lead us to believe that the universe is expanding, when we are just shrinking.

    This is also the only reason I can see that our calendars stay on track. Since each orbit around the galaxy is faster than than the one before, we should have to constantly make adjustments to our calendars. (The adjustments we make to our calendar is because it is imperfect, not the cosmos). Relativity takes care of that problem too, with every orbit in our solar system equally shrinking.
  10. Jul 6, 2011 #9


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    Speed is relative and you are treating it here as if it were some absolute velocity. You are adopting a "preferred frame" point of view which is antithetical to the "relativity" of Special and General Relativity.

    Relativistically, no matter how close to the speed of light I am relative to you, I am still moving at speed 0 relative to me and I still have to boost an infinite amount to "reach" it.
    You speak about what relativity says but you demonstrate your lack of understanding with every sentence.Now let me mention some history which leads us to use "bad" terminology when describing relativistic effects.

    ---Prior to Einstein's theory it was thought (by many) that light waves traveled via a medium, the http://en.wikipedia.org/wiki/Luminiferous_aether" [Broken] just as does sound.

    ---The Michelson-Morley experiment failed to detect our planet's motion through the aether and many hypotheses were proposed to explain this negative result. One was that matter http://en.wikipedia.org/wiki/Aether_drag_hypothesis" [Broken] with it so that in the vicinity of the Earth, the aether is stationary.

    ---Lorentz proposed a http://en.wikipedia.org/wiki/Lorentz_ether_theory" [Broken], in which motion of clocks and rigid bodies through the aether caused slowing of the clocks and contracting of the bodies in just the right way to always yield a null result for a Michelson-Morly type experiment. This is from whence we get the terms "time dilation" and "length contraction" still used in relativity.

    ---Einstein's insight was that given Lorentz's dilation and contraction effects, the aether itself was impossible to observe. Applying Occam's razor he dispensed with the aether itself and developed SR. Wherein the time dilation and contraction effects, though still just as physically meaningful were not caused by absolute velocities of objects in some universal frame, but rather were relative effects of perspective when considering objects existing in time as collections of space-time events.

    So w.r.t. relativity theory. It is not that a moving object contracts, but that a moving object by virtue of its velocity relative to us the object's world-path is hyper-rotated in space-time relative to us so what we think of as a length (in the direction of motion) is for that object an interval through both (its) space and (its) time. In short one is looking at a different cross-section of the object's world line. Saying it contracts is saying the same quantity changes. The fact is that one is measuring something different, not that one is measuring a different value of the same thing.

    A Euclidean analogue would be if you were trying to measure the thickness of a telephone pole but you were using a level meter stick while the pole was leaning at an angle. You'd get a bigger number than the "proper thickness". This is a "Euclidean width expansion" analogous but opposite of the pseudo-Euclidean "length contraction" of relativity. (Picture the length of the telephone pole as its time axis so it is like a disk evolving over time, and your "straight up" direction as your own time axis. The pitch of the pole's lean (1/slope=run/rise = dx/dt) is the speed of the "disk" cross section.)

    Now the leaning pole is not "fatter" than the vertical pole any more than an object in relativistic motion is shorter than when it is stationary. What is true is that...

    * in the analogy the horizontal cross section of the pole is larger than its proper width, and
    *in relativity the cross section of simultaneous events of the moving objects world line is shorter than its proper length(simultaneous w.r.t. your time).

    The reason the behavior is of opposite type has to do with the metric structure of space-time. This you'll best understand by digging into the math of relativity.
    Last edited by a moderator: May 5, 2017
  11. Jul 6, 2011 #10
    Forgive me for shorting your quote, but there was a lot to take in!

    I got two fundamental questions out of that. (Please correct me if I am wrong.)

    1) As mater falls into a black hole, does it at any point accelerate to speed c?

    2) Is there any way to tell if our whole universe is shrinking.

    On number 1), the honest answer is I don't know. But if it did reach speed c at any point in would disprove a lot of well known physics. So I would say the answer is no.

    On number 2), I would say that Quantum physics could prove that the universe in not shrinking or if it was, we could detect it. (Quantum physics deals with discrete, indivisible units of energy called quanta as described by the Quantum Theory)
  12. Jul 6, 2011 #11


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