Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: Roy P on 11/06/2006 16:32:11
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I'm not a scientist (Neither am I a Creationist:-) but I do understand what redshift is and what the 'accepted' scientific reason is for it. I also understand why current evidence strongly supports the Big Bang theory. However, I've always had this gut-feeling that both of these theories rely on too limited and extrapolated 'evidence'.
I've tried a Google search for 'redshift controversy' but all I get are scientific papers which I do not understand -- acronyms and scientific formulas. Is there anyone out there who shares my doubt about the cause of redshift and who might give a simple explanation as to an alternative reason for it?
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Roy P
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The most commonly quoted alternative seems to be the tired light theory.
http://en.wikipedia.org/wiki/Tired_light_effect
quote:
Tired light mechanisms were first proposed in 1929 by Fritz Zwicky as an alternative explanation for the redshift-distance relationship. While the Big Bang and the Steady State cosmologies both proposed that the Hubble Law was associated with a metric expansion of space, tired-light cosmology was a proposal that photons slowly lose energy as they travel vast distances through a static universe (for example by an interaction between the photons and some sort of homogeneous and isotropic medium). Since a decrease in energy corresponds to an increase in light's wavelength, this effect would produce a redshift in spectral lines that increase proportionately with the distance of the source. The idea is still promulgated by a few proponents, but the vast majority of physicists and astronomers accept the conclusions of various studies that such an effect does not account for cosmological redshifts.
The term "tired light" was coined by Richard Tolman in the early 1930s
There are a number of different variations to explain why the light becomes tired.
George
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So light loses energy over time? If so, would light, traveling at our speed, quickly run out of energy, since it is no longer traveling at the speed of light, and therefore no longer having the benefit of relativity?
Would there be any way to take advantage of that fact? Could it be that what we see of the universe is how far the light travels before it dies, and we would see different stars and galaxies if we went to a different galaxy?
E=MC2... m=deg/360 X C... C= PiD
therefore E=deg/360 X 2(PiD)
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Light doesn’t lose energy if it is red shifted through expansion, its just stretched out more into a longer wavelength containing the same amount of energy.
I think its like this
Space is expanding so the wavelength of any photon travelling through it also has to expand but as the photons energy is conserved its extra length means its energy has to be spread over a longer wave length (its diluted) . but the photon still contains the same level of energy as it started out with in the beginning.
Just like Blue shifted light dosent contain extra energy as once again its energy is conserved all that is happening is the photons wavelength is being compressed so the energy contained within the wave length of the photon is squashed (concentrated)into a smaller wavelength.
All that has happened is the look of the photon has changed from what it was when it was emitted,the energy contained within the photon hasnt changed, its conserved.
Michael
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quote:
Originally posted by science_guy
So light loses energy over time? If so, would light, traveling at our speed, quickly run out of energy, since it is no longer traveling at the speed of light, and therefore no longer having the benefit of relativity?
It is not necessarily the case that light slows down as it loses energy (although this may be the case). The only thing that is certain is that light of a lower energy has a longer wavelength. For light to slow down to any speed below C would be a violation of the theory of special relativity. Ofcourse, it may be that as the universe ages, so C itself is changing.
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Would there be any way to take advantage of that fact? Could it be that what we see of the universe is how far the light travels before it dies, and we would see different stars and galaxies if we went to a different galaxy?
Even without the need for a tired light theory, the stars you would see from another galaxy would be different from that which you see from here. The universe is about 13 billion years (i.e. 13 x 10^9 years), so that everything that you can see in the sky must be closer than 13 billion light years away. If you move to a position that is 2 billion light years away from where we are here, then you would be able to see stars that are 15 billion light years away from here in one direction, but only 11 billion light years away from here in another direction. Ofcourse, the problem is that by the time you have moved 2 billion light years from here (which mist take you at least 2 billion years to do), the universe would have gotten at least 2 billion years older, and you would be able to see those stars anyway (excepting that those stars are, if the expanding universe theory is correct, moving away from you at the same time, so may well have disappeared from sight anyway).
George
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Many thanks for the link, George. Fascinating!
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Roy P