Cosmological Redshift and Expansion of Space

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by tvanflandern</i>
<br /><blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Jim</i>
<br />The use of E=hf is not intended for use on spectral lines is it?-And that is not a measured item.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">The energy of lightwaves can be a directly measured item, even though it is not measured by spectrographs.

Specifically, Baum and his team measured the energy, frequency, and wavelength (independently) of photons arriving from a high-redshift quasar to test the possibility that their energy violated the E=hf law, or even the possibility that the speed of light (fw=c, where w = wavelength and c = speed of light) might be different for those lightwaves. The results of the experiment showed no differences from the accepted laboratory relationships. -|Tom|-
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The 'E' in E=h*f should not be interpreted as the energy of the 'photons'. It is the energy difference between the atomic levels that emits/absorbs light waves with frequency f if an electron goes from one level to another (the Planck constant h is the proportionality factor between both). As mentioned a few posts above already, light has no energy (no classical wave energy either) as 'energy' is a concept from classical mechanics (i.e applicable to particles in force fields, but not to electromagnetic waves).

Thomas

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Mikey</i>
<br />Well, it seems to me that expansion theories are based primarily on redshift observations, and that seems to be a major flaw to me. Expanding space (making something from nothing) that push galaxies apart just seems absurd. Lilly pads in a pond may move this way, but water as opposed to space, has substance.

My understanding of red shift as it applies to relativity, is that light coming at you is at a higher frequency (tight bandwidth) than light going away from you (longer bandwidth). But in actuality, the frequency of that light never changed. It is only our perception of it coming and going.

But then we can take light, run it through a prism, and it is obvious that the resistance within the prism produces different colors of light; each with a different frequency. So light "can" be affected by obstacles along the route.

So isn't it just our perception of incoming light incorrect? We are basing our observations from our own relative point of view, which obviously is not the point of origin. Therefore I would suspect space is not expanding, Stars are closer than they appear, the BBT is a false fabrication, and gravational forces are constant in the Universe based soley on mass and distance. Whay make it so difficult?

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My original point was not primarily directed at questioning the interpretation of the redshifts as recession velocities, but at the concept of an expanding space. Cosmologists argue that the usual Doppler interpretation and the 'expanding space' interpretation are equivalent and just a matter of choice of the coordinate system. However, bound physical systems (like our solar system) do evidently not expand, and cosmologists thus argue that these are exempt from the overall space expansion. But this should actually mean that redshifted light entering our solar system should be blueshifted back again to its original wavelength (as locally the space is unexpanded) so no redshift should be observed at all, which obviously contradicts observations (and the statement that the 'expanding space' model would be equivalent to the Doppler assumption).

Thomas

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Thomas</i>
<br />The 'E' in E=h*f should not be interpreted as the energy of the 'photons'.<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">All waves carry energy and momentum. When they collide with matter, they transfer some of that energy and momentum to the matter, creating a push. For example, sunlight produces a pushing force on artificial satellites, which can be quite large for balloon satellites.

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">light has no energy (no classical wave energy either) as 'energy' is a concept from classical mechanics<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Your conjecture is wrong, as many astronomical applications show. Every lightwave ("photon") has an energy that depends on its frequency. And that applies to lightwaves propagating through space, not just to lightwaves freshly released from atoms where an electron has changed orbitals. -|Tom|-

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Thomas</i>
My original point was not primarily directed at questioning the interpretation of the redshifts as recession velocities, but at the concept of an expanding space. Cosmologists argue that the usual Doppler interpretation and the 'expanding space' interpretation are equivalent and just a matter of choice of the coordinate system. However, bound physical systems (like our solar system) do evidently not expand, and cosmologists thus argue that these are exempt from the overall space expansion. But this should actually mean that redshifted light entering our solar system should be blueshifted back again to its original wavelength (as locally the space is unexpanded) so no redshift should be observed at all, which obviously contradicts observations (and the statement that the 'expanding space' model would be equivalent to the Doppler assumption).

Thomas
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This is indeed a very good point!

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Thomas</i>
<br />My original point was not primarily directed at questioning the interpretation of the redshifts as recession velocities, but at the concept of an expanding space. Cosmologists argue that the usual Doppler interpretation and the 'expanding space' interpretation are equivalent and just a matter of choice of the coordinate system. However, bound physical systems (like our solar system) do evidently not expand, and cosmologists thus argue that these are exempt from the overall space expansion. But this should actually mean that redshifted light entering our solar system should be blueshifted back again to its original wavelength (as locally the space is unexpanded) so no redshift should be observed at all, which obviously contradicts observations (and the statement that the 'expanding space' model would be equivalent to the Doppler assumption).

Thomas
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Thomas, why should the light be blueshifted upon encountering unexpanded space? If the redshift is caused by the light wave propagating through expanding space, then blueshift would be the result of light propagating through <i>contracting</i> space. However, as you state the local space of the solar system has neither expanded nor contracted but has been unchanged. Therefore, light entering the solar system would simply cease to be further redshifted, it would not be blueshifted.

JR

<blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by jrich</i>
<br /><blockquote id="quote"><font size="2" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by Thomas</i>
<br />My original point was not primarily directed at questioning the interpretation of the redshifts as recession velocities, but at the concept of an expanding space. Cosmologists argue that the usual Doppler interpretation and the 'expanding space' interpretation are equivalent and just a matter of choice of the coordinate system. However, bound physical systems (like our solar system) do evidently not expand, and cosmologists thus argue that these are exempt from the overall space expansion. But this should actually mean that redshifted light entering our solar system should be blueshifted back again to its original wavelength (as locally the space is unexpanded) so no redshift should be observed at all, which obviously contradicts observations (and the statement that the 'expanding space' model would be equivalent to the Doppler assumption).

Thomas
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">Thomas, why should the light be blueshifted upon encountering unexpanded space? If the redshift is caused by the light wave propagating through expanding space, then blueshift would be the result of light propagating through <i>contracting</i> space. However, as you state the local space of the solar system has neither expanded nor contracted but has been unchanged. Therefore, light entering the solar system would simply cease to be further redshifted, it would not be blueshifted.

JR
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Hi JR,

For the 'photon', space <i>would</i> effectively contract when going from expanded into unexpanded space.

As an analogy, consider for instance the change of wavelength of light in a refracting medium: whether the refractive index is changed by lets say continuously changing the density of the medium by a certain amount, or simply by the photon going from a region with one density in one with another, doesn't make any difference. The wavelength will always adjust to the present refractive index (i.e. after the light leaves a refractive medium, its wavelength is the same again as before entering it).

Thomas