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Thread: Is the universe leaking energy (Scientific American article)

  1. #1 Is the universe leaking energy (Scientific American article) 
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    Is the Universe Leaking Energy? by Tamara M. Davis in Scientific American July 2010.
    My background in applied thermodynamics and heat transfer and interest in cosmology were well served in this article. Too bad it cannot be seen completely in this URL.
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    Greetings again, pikbelady.

    I haven't seen that one, pikpobedy?
    Quote Originally Posted by pikpobedy View Post
    Is the Universe Leaking Energy? by Tamara M. Davis in Scientific American July 2010.
    My background in applied thermodynamics and heat transfer and interest in cosmology were well served in this article. Too bad it cannot be seen completely in this URL.
    But my question is: if the universe is leaking energy, what could this energy possibly be leaking into - unless it is another part of the universe????

    TFOLZO
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    The article was scanned or otherwise reproduced in http://www.physics.uq.edu.au/downloa...iAm_Energy.pdf.
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  4. #4 Energy Leakage??? 
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    Thank you pikpobedy; the article was very informative and clear.
    Quote Originally Posted by pikpobedy View Post
    The article was scanned or otherwise reproduced in http://www.physics.uq.edu.au/downloa...iAm_Energy.pdf.
    At first I thought it was going to be article which claimed that energy was being converted into mass. (Here of course this was not Einstein's discovery but a common observation about obese and energetic people made even in the ancient world - that the energy embodied in food would be converted into mass and that this mass could be lost through energy i.e. exercise!)

    But now I realize that the article was not of that type, but instead asks:-
    When light is redshifted by the expansion of the universe, where does its energy go? Is it lost, in violation of the conservation principle?
    The "cosmological redshift" is merely the Doppler Effect applied to galaxies. A few galaxies i.e. the Virgo Supercluster and Andromeda, are actually approaching us but other galaxies are receding from us in proportion to their distance from us.

    To speak of energy being lost by the redshift is merely to presume SR and GR's claims about "expanding space". This is the big problem about Einstein's relativity: it leads to impractical questions and the demand for impossible answers. If you want me to give an 'Einstein-compatible' answer I simply cannot - and if I did it would be bound to be wrong. Perhaps you could ask MoeYouAsked, TJLarryTJ or Curlyrob - it might help broaden their minds by diverting their attention from a frustratingly Relativistic Rolling Wheel!

    Instead, if you consider space to be infinite then galaxies are merely receding from us and from each other into space. At the Hubble distance they are receding from us at the speed of light. Beyond that distance they are receding even faster. When the strictures of Einstein's relativity are removed, the understanding of cosmology is radically altered. If you visit the Personal & Alternatives Section you will see how I have started a thread on Plasma Cosmology. Eric Lerner, writer of the Big Bang Never Happened still accepted SR but realized that GR was nonsense; get his book if you do not have it already.

    So thank you once again, pikpobedy, for providing the link to this revealing article.

    TFOLZO
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    Quote Originally Posted by TFOLZO View Post
    If you visit the Personal & Alternatives Section you will see how I have started a thread on Plasma Cosmology. Eric Lerner, writer of the Big Bang Never Happened still accepted SR but realized that GR was nonsense; get his book if you do not have it already.

    So thank you once again, pikpobedy, for providing the link to this revealing article.

    TFOLZO
    Lerner is a highly, ahem, unreliable source. For a brief overview of his many errors, see Errors in the "The Big Bang Never Happened". You'll see that the claim that he "realized that GR was nonsense" is based on a profound ignorance -- either incidental or intentional.
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    Quote Originally Posted by TFOLZO View Post
    The "cosmological redshift" is merely the Doppler Effect applied to galaxies. A few galaxies i.e. the Virgo Supercluster and Andromeda, are actually approaching us but other galaxies are receding from us in proportion to their distance from us.
    OK I'll bite... this time.
    The doppler red shift and blue shift has to do with the relative velocity between the source and the observer when the photons were emitted. The doppler shift occurs at the source relative to the observer. An observer behind, beside or in front will perceive the same shift regardless of distance as long as they have similar alignment. Works with radar, ladar, sonar and the sound of a car, siren or level crossing bell. The predominant redshift at cosmological distances including the microwave background needed another explanation than simple doppler effects.
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    Quote Originally Posted by pikpobedy View Post
    OK I'll bite... this time.
    The doppler red shift and blue shift has to do with the relative velocity between the source and the observer when the photons were emitted. The doppler shift occurs at the source relative to the observer. An observer behind, beside or in front will perceive the same shift regardless of distance as long as they have similar alignment. Works with radar, ladar, sonar and the sound of a car, siren or level crossing bell. The predominant redshift at cosmological distances including the microwave background needed another explanation than simple doppler effects.
    There is indeed a distinction to be made between cosmological redshift, and "ordinary" Doppler shift. The former is due to the metric expansion of space (and to that expansion alone), and the latter embeds motion of the source. For a clear, accessible discussion, see Cosmological Redshift | COSMOS
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    That still leaves open the question of how Cosmological Redshift is not a net loss of energy. If, for example, the number of photons in the CMBR is remaining the same, but each photon has less energy due to expansion lessening its frequency, then one is left to wonder: where did the energy go?

    Is increasing space between objects an increase in energy? Maybe potential energy due to gravity? I'm trying to find somewhere for it to balance.

    Dark energy isn't very satisfying, because it would require energy to be entering the system from outside the system. If energy can come from outside the system, then there must be something outside the system. That would mean the system doesn't actually contain the whole universe, but rather something exists beyond its boundaries.
    A mathematician and an engineer were at a party. An older colleague of theirs was there with his daughter. The two each asked if they could speak to her. He said it was ok, but they had to approach her by going half way across the room, then stop, then half way again and stop and proceed in that manner. The mathematician realized that he would never reach her and gave up. The engineer determined that he could get close enough to talk. --Approximate retelling of a joke by my math teacher.
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    Quote Originally Posted by Kojax View Post
    That still leaves open the question of how Cosmological Redshift is not a net loss of energy.
    That is indeed an excellent question, which is precisely why Dr. Davis chose to contribute her SciAm article on the topic.

    If, for example, the number of photons in the CMBR is remaining the same, but each photon has less energy due to expansion lessening its frequency, then one is left to wonder: where did the energy go?

    Is increasing space between objects an increase in energy? Maybe potential energy due to gravity? I'm trying to find somewhere for it to balance.
    It doesn't seem as if you got round to reading the article, for it addresses all of your questions. Here's my summary of the article:

    Energy is a frame-dependent quantity, so performing the bookkeeping correctly across different frames is fraught with traps for the unwary. It is by no means as straightforward as comparing wavelengths at source and destination. It is extremely important to recognize that you are talking here about distances between source and receiver that are truly vast. You cannot assume freely that the source and receiver are in the same frame. As such, you may not use that assumption in computing energy balances.

    The situation is even more subtle than that. Energy conservation is observed only locally, because the necessary Noether symmetries are generally absent over arbitrarily large distances.

    Dark energy isn't very satisfying, because it would require energy to be entering the system from outside the system. If energy can come from outside the system, then there must be something outside the system. That would mean the system doesn't actually contain the whole universe, but rather something exists beyond its boundaries.
    Dark energy has nothing to do with your question, nor with Dr. Davis' answer, so you needn't worry about that part, at least.
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    Quote Originally Posted by tk421 View Post

    It doesn't seem as if you got round to reading the article, for it addresses all of your questions. Here's my summary of the article:
    You caught me. I've read as far as until I'd actually have to subscribe. From the sounds of things it might not be a bad idea.


    Energy is a frame-dependent quantity, so performing the bookkeeping correctly across different frames is fraught with traps for the unwary. It is by no means as straightforward as comparing wavelengths at source and destination. It is extremely important to recognize that you are talking here about distances between source and receiver that are truly vast. You cannot assume freely that the source and receiver are in the same frame. As such, you may not use that assumption in computing energy balances.

    The situation is even more subtle than that. Energy conservation is observed only locally, because the necessary Noether symmetries are generally absent over arbitrarily large distances.
    That makes sense. Changing frames itself can be considered a form of stored energy or potential energy. Just like when you lift an object up in a gravitational field, it loses kinetic energy on the way up, but gains potential energy. Accounting for things in that manner, we should be able to restore energy conservation. No need to abandon it.


    But this raises an interesting issue. If energy conservation is tangled up in frame, and frame is altered by distance, then tired light is just as valid an explanation for hubble redshift again. (Not for the rest of the BBT's body of evidence, but at least for that one thing.)

    Sometimes I wonder if basic application of GR is sufficient to explain it. As an electron accelerates toward us, and then decelerates away from us, perhaps there is an "upstream downstream" effect present there? Distance is a component of time dilation when an object is accelerating, so if one or the other stage of acceleration is weighed just slightly heavier than the other, the net effect would be time dilation that depends on distance.
    A mathematician and an engineer were at a party. An older colleague of theirs was there with his daughter. The two each asked if they could speak to her. He said it was ok, but they had to approach her by going half way across the room, then stop, then half way again and stop and proceed in that manner. The mathematician realized that he would never reach her and gave up. The engineer determined that he could get close enough to talk. --Approximate retelling of a joke by my math teacher.
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    Quote Originally Posted by Kojax View Post
    You caught me. I've read as far as until I'd actually have to subscribe. From the sounds of things it might not be a bad idea.


    That makes sense.

    Changing frames itself can be considered a form of stored energy or potential energy.
    No.


    Just like when you lift an object up in a gravitational field, it loses kinetic energy on the way up, but gains potential energy. Accounting for things in that manner, we should be able to restore energy conservation. No need to abandon it.


    But this raises an interesting issue. If energy conservation is tangled up in frame, and frame is altered by distance, then tired light is just as valid an explanation for hubble redshift again. (Not for the rest of the BBT's body of evidence, but at least for that one thing.)
    No, it does not follow logically that tired light then suddenly re-emerges as viable. You would do well to read Ned Wright's summary on why tired light fails miserably. For example, what makes light tired is a loss of energy. But all known interactions that produce energy loss also causes momentum changes. That, in turn, implies blurring, which we do not observe. And that's in addition to the failure to explain time dilation of high-z supernovae light curves.

    Sometimes I wonder if basic application of GR is sufficient to explain it. As an electron accelerates toward us, and then decelerates away from us, perhaps there is an "upstream downstream" effect present there? Distance is a component of time dilation when an object is accelerating, so if one or the other stage of acceleration is weighed just slightly heavier than the other, the net effect would be time dilation that depends on distance.
    Sorry, you lost me. Could you try again?
    Last edited by tk421; 02-23-2014 at 09:25 AM. Reason: fixed quote tag
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    You are arguing over a non-problem. The cosmological redshift is simply due to galaxies receding into space. Beyond a certain distance they keep receding - but faster than light. That is all the understanding we, as Galileans where "all motion is relative", need (except for differential redshifts in quasar-galaxy complexes). It is only SR&GR which lead to these superadded and essentially unresolvable issues.

    TFOLZO
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    Quote Originally Posted by TFOLZO View Post
    You are arguing over a non-problem. The cosmological redshift is simply due to galaxies receding into space. Beyond a certain distance they keep receding - but faster than light. That is all the understanding we, as Galileans where "all motion is relative", need (except for differential redshifts in quasar-galaxy complexes). It is only SR&GR which lead to these superadded and essentially unresolvable issues.

    TFOLZO
    MODERATOR ACTION : I have warned you several times now to keep your personal opinions confined to the "Personal Theories" section, yet you keep posting this stuff in the hard science forums. I am giving you three days off to re-evaluate your approach here - when you come back, you will confine your opinions to the appropriate forums, or face a much longer suspension the next time.
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    Quote Originally Posted by tk421 View Post


    No, it does not follow logically that tired light then suddenly re-emerges as viable. You would do well to read Ned Wright's summary on why tired light fails miserably. For example, what makes light tired is a loss of energy. But all known interactions that produce energy loss also causes momentum changes. That, in turn, implies blurring, which we do not observe. And that's in addition to the failure to explain time dilation of high-z supernovae light curves.
    Red Shift due to Special Relativistic time dilation also does that, doesn't it?

    If a flashlight is shining toward you with two "AA" batteries powering it, and that flashlight is moving at a relativistic speed relative to you, then after you correct for Doppler red/blue shift, you're still left with some red shifting due to time dilation.

    The battery will appear to last longer, but the light also appears to be less energetic. In fact, the energy loss due to the relativistic red shifting of the light exceeds the energy gained by the batteries lasting longer. The batteries appear to you, the observer, to have contained less charge in the final analysis.

    In Special Relativity, you lose energy when you change frames of reference.
    A mathematician and an engineer were at a party. An older colleague of theirs was there with his daughter. The two each asked if they could speak to her. He said it was ok, but they had to approach her by going half way across the room, then stop, then half way again and stop and proceed in that manner. The mathematician realized that he would never reach her and gave up. The engineer determined that he could get close enough to talk. --Approximate retelling of a joke by my math teacher.
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