Expanding Universe and the Red Shift

[ynot]

The expanding universe concept is usually presented as the main evidence to support the validity of The Big Bang Theory. Or at least it gives great weight to the Theory. Personally, I don’t support in the Big Bang Theory regardless of whether or not the universe is expanding (but would be more likely to if it indeed is).

That an expanding universe would cause a “red shift” in distant stars makes perfect sense to me so there is no problem there. I guess the main concern I have is that that an observable effect of an expanding universe should be that distant stars would be fading out and disappearing (maybe this is happening and I’m simply ignorant of the fact). The Hubble telescope was aimed at a “blank“ area of space and set with a long exposure. Surprise, surprise, it was found that the “blank” space in fact contained a wealth of galaxies etc. So it is possible for things to move beyond our current view.

I believe that there are possible alternatives to the concept that an expanding universe causes the “red shift and offer a few below“. Will try to keep things brief.

Cosmic Sunset - I don’t believe this one is very likely, but throw it in anyway. When there are a lot of dust or smoke particles in the atmosphere you get a lovely orange/red sunset. Perhaps space contains a type of “space dust” that causes an observable reddening effect of distant stars. The greater the distance, the greater the effect.

Degrading Light - Perhaps light degrades as it travels over great distances and the infrared end of the spectrum simply survives the longest.

Multi-Speed Light - This is my favoured concept. Perhaps different parts of the light spectrum travel at different speeds, and the infrared end of the spectrum travels faster than the ultraviolet. If this were so, it would cause a “red shift” effect. The greater the distance, the greater the effect.

I’m not an academic so hope my half-baked ideas aren’t too simplistically naïve. If you’re not rolling around the floor with laughter, I would appreciate any feedback anyone cares to offer.

 

[KingMerv00]

The expanding universe concept is usually presented as the main evidence to support the validity of The Big Bang Theory. Or at least it gives great weight to the Theory. Personally, I don’t support in the Big Bang Theory regardless of whether or not the universe is expanding (but would be more likely to if it indeed is).

That an expanding universe would cause a “red shift” in distant stars makes perfect sense to me so there is no problem there. I guess the main concern I have is that that an observable effect of an expanding universe should be that distant stars would be fading out and disappearing (maybe this is happening and I’m simply ignorant of the fact). The Hubble telescope was aimed at a “blank“ area of space and set with a long exposure. Surprise, surprise, it was found that the “blank” space in fact contained a wealth of galaxies etc. So it is possible for things to move beyond our current view.

I believe that there are possible alternatives to the concept that an expanding universe causes the “red shift and offer a few below“. Will try to keep things brief.

Cosmic Sunset - I don’t believe this one is very likely, but throw it in anyway. When there are a lot of dust or smoke particles in the atmosphere you get a lovely orange/red sunset. Perhaps space contains a type of “space dust” that causes an observable reddening effect of distant stars. The greater the distance, the greater the effect.

Degrading Light - Perhaps light degrades as it travels over great distances and the infrared end of the spectrum simply survives the longest.

Multi-Speed Light - This is my favoured concept. Perhaps different parts of the light spectrum travel at different speeds, and the infrared end of the spectrum travels faster than the ultraviolet. If this were so, it would cause a “red shift” effect. The greater the distance, the greater the effect.

I’m not an academic so hope my half-baked ideas aren’t too simplistically naïve. If you’re not rolling around the floor with laughter, I would appreciate any feedback anyone cares to offer.

Actually my answer is the same to all three:

Not all stars/galaxies are red shifting, only the majority. Some are blue shifting towards us. This is to be expected because some stars/galaxies may be under the influence of other forces like gravity. All three hypothesis above fail to explain the existance of any blue shift.


I now have a question for the forum in general:

Has anyone measured rotating galaxies for the red shift? The portions of a galaxy rotating away from us should be more red shifted than the portions rotating towards us. Can we measure the red shift this precisely? If so, it would pretty much prove that the shifts are caused by movement.

 

[Dragon]

ynot,

Have a look at this wikipedia article on the redshift. It should make you understand why all three of your ideas are non-starters. For instance the diagram on the right shows how the whole spectrum of a distant star is redshifted, red bits, blue bits, blank bits, the lot.

 

[KingMerv00]

I now have a question for the forum in general:

Has anyone measured rotating galaxies for the red shift? The portions of a galaxy rotating away from us should be more red shifted than the portions rotating towards us. Can we measure the red shift this precisely? If so, it would pretty much prove that the shifts are caused by movement.

I looked it up, so I guess I'll answer my own question.

From our good friends at wikipedia:

Redshifts have also been used to measure the velocity of gas of interstellar clouds, the rotation of galaxies, and the dynamics of accretion onto neutron stars and black holes which exhibit both Doppler and gravitational redshifts.

Emphasis mine.

Check out the link. It helps alot.

 

[KingMerv00]

ynot,

Have a look at this wikipedia article on the redshift. It should make you understand why all three of your ideas are non-starters. For instance the diagram on the right shows how the whole spectrum of a distant star is redshifted, red bits, blue bits, blank bits, the lot.

NO! It was MY link! Mine!

 

[KingMerv00]

ynot,

Just thought I say that all of your questions were reasonable. You don't have to label yourself "naive" or call your ideas "half-baked" just because they aren't in the majority. Doubt is very healthy.

Heck, I just learned that astronomers have this red shift measurement down more accurately than I had thought before. Yay for me.

 

[CurtC]

...regardless of whether or not the universe is expanding...

The universe is undoubtedly expanding.

I guess the main concern I have is that that an observable effect of an expanding universe should be that distant stars would be fading out and disappearing (maybe this is happening and I’m simply ignorant of the fact).

I don't understand your reasoning here. Fading out and disappearing? You mean getting more and more dim because they are now farther away? If that's what you're saying, then I guess if you lived for a few hundred million years and compared how bright the stars are now versus when you were younger (if you have a good memory), then just maybe you might notice a difference. But in time spans less than that, such as our <80 years of making extra-galactic observations, the remote galaxies will be hardly at all further than they were 80 years ago. This reminds me of the janitor at a museum telling a visitor that a particular fossil is 15 million and 20 years old: "When I first started working here 20 years ago, they told me it was 15 million years old then."

The Hubble telescope was aimed at a “blank“ area of space and set with a long exposure. Surprise, surprise, it was found that the “blank” space in fact contained a wealth of galaxies etc. So it is possible for things to move beyond our current view.

I don't see how your last sentence follows from the first two. Yes, there are galaxies every which way we look. What was that about moving beyond our current view?

Cosmic Sunset - I don’t believe this one is very likely, but throw it in anyway. When there are a lot of dust or smoke particles in the atmosphere you get a lovely orange/red sunset. Perhaps space contains a type of “space dust” that causes an observable reddening effect of distant stars. The greater the distance, the greater the effect.

With the sunset, we start with a full spectrum of white light, and remove some of the blue light, so the remaining light tends to have more red photons. But with receding galaxies, the individual photons have been shifted down in frequency. There are speficic frequencies of light that stars emit, which can be measured extremely accurately, and are due to the nature of the sub-atomic processes that created a photon. Those specific frequencies are shifted down in frequency with distant galaxies, not just that the higher-frequency ones have been weeded out.

Degrading Light - Perhaps light degrades as it travels over great distances and the infrared end of the spectrum simply survives the longest.

Again, this wouldn't explain the red shift I duscuss above.

Multi-Speed Light - This is my favoured concept. Perhaps different parts of the light spectrum travel at different speeds, and the infrared end of the spectrum travels faster than the ultraviolet. If this were so, it would cause a “red shift” effect. The greater the distance, the greater the effect.

Well, we have a pretty good handle on the speed of light, plus even if infrared travels faster, we'd also by now be seeing the bluer colors, which even though they're younger, would still be getting to us in the right proportion. Plus, it doesn't explain the red shift as discussed above.

Sorry to burst your bubble, but the facts falsify your different hypotheses. If you can come up with others that fit the observed facts, that would be great. So far, no one has come up with anything other than the Big Bang/Inflation model that works.

 

[cbish]

Cosmic Sunset - I don’t believe this one is very likely, but throw it in anyway. When there are a lot of dust or smoke particles in the atmosphere you get a lovely orange/red sunset. Perhaps space contains a type of “space dust” that causes an observable reddening effect of distant stars. The greater the distance, the greater the effect.

Degrading Light - Perhaps light degrades as it travels over great distances and the infrared end of the spectrum simply survives the longest.

Multi-Speed Light - This is my favoured concept. Perhaps different parts of the light spectrum travel at different speeds, and the infrared end of the spectrum travels faster than the ultraviolet. If this were so, it would cause a “red shift” effect. The greater the distance, the greater the effect.

I'll simplify

1) And this cosmic dust would be what?
2) Degrading light. Any study or demonstration of this phenomena?
3) Multi-speed. See #2

 

[chipmunk stew]

ynot,

Just thought I say that all of your questions were reasonable. You don't have to label yourself "naive" or call your ideas "half-baked" just because they aren't in the majority. Doubt is very healthy.

Heck, I just learned that astronomers have this red shift measurement down more accurately than I had thought before. Yay for me.

Also, a fine brainstorm of possible alternative explanations. Sometimes, the good ideas that don't bear out in reality are the most interesting ones to explore. You're doing what scientists do.

I had a lousy science program in high school. We studied almost exclusively correct hypotheses. We rarely formulated our own. This was the cram your head with facts philosophy of teaching. It would have been much more engaging and enlightening had we brainstormed possible alternative explanations and then explored their viability. Science is actually better at eliminating ideas than confirming them. You can often disprove a hypothesis absolutely, but you can never prove one absolutely.

 

[Dr. Fendetestas]

Has anyone measured rotating galaxies for the red shift? The portions of a galaxy rotating away from us should be more red shifted than the portions rotating towards us. Can we measure the red shift this precisely? If so, it would pretty much prove that the shifts are caused by movement.

Yes, it has been done. Actually, one of the secondary distance indicators is the Tully Fischer relation:

Light from galaxies has spectra formed by narrow lines. But, as you pointed out, if a galaxy rotates, part of it is coming towards us and part is getting away. This causes part of the light to be blue-shifted and part to be red-shifted. The net result is a broadening of the initially narrow lines. By measuring the spectra of these galaxies, we can infer their rotation speed from the width of the lines. The faster a galaxy spins, the bigger its luminosity is and from this we can estimate the distance (by comparing its luminosity to the brightness we perceive).

 

[bjb]

Wow, you guys didn't miss anything, even the redshift of a spinning galaxy! I would like to add further evidence for the Big Bang theory, the presence cosmic microwave background. The observation that the universe is expanding was made first and the Big Bang theory was developed to explain the expansion. Soon afterwards , some sort of cosmic background radiation was predicted to exist as an 'echo' of the big bang, but it was not measured until the 60's.

It's fine to come up with alternatives to accpeted theories, however, redshift and cosmic background radiation are real and measurable phenomenon, not theoretical abstractions, so your theory had better have a good explanation for them.

 

[Grounded]

<...snip...> Soon afterwards , some sort of cosmic background radiation was predicted to exist as an 'echo' of the big bang, but it was not measured until the 60's.
<snip>

What is this 'echo', and what did it reflect from. If the answer is other objects floating in space, it seems the 'signal' would be very small. Any references would be great!

 

[Art Vandelay]

Cosmic Sunset - I don’t believe this one is very likely, but throw it in anyway. When there are a lot of dust or smoke particles in the atmosphere you get a lovely orange/red sunset. Perhaps space contains a type of “space dust” that causes an observable reddening effect of distant stars. The greater the distance, the greater the effect.

The sun looks yellow because the blue part of the spectrum is scattered. Note that the blue doesn't disappear, it's just scattered. That's why the rest of the sky looks blue. If there were space dust scattering blue light, we should see a blue sky, even at night.

Multi-Speed Light - This is my favoured concept. Perhaps different parts of the light spectrum travel at different speeds, and the infrared end of the spectrum travels faster than the ultraviolet. If this were so, it would cause a “red shift” effect. The greater the distance, the greater the effect.

If this were the case, the different parts of the spectrum wouldn't synch up. If we see a star get eclipsed by a planet, we should see the red part of the spectrum eclipsed at a different time from when the blue part gets eclipsed.

Good brainstorming, though.

 

[KingMerv00]

What is this 'echo', and what did it reflect from. If the answer is other objects floating in space, it seems the 'signal' would be very small. Any references would be great!

"Echo" probably wasn't the right analogy. "Afterglow" is more appropriate. The CMBR is energy left over from the Big Bang and it is found everywhere with astonishing uniformity. I'll just give you the link since it will undoubtedly explain it better than I could.

http://en.wikipedia.org/wiki/Cosmic_microwave_background_radiation

 

[Melendwyr]

The universe undoubtedly has a redshift. It's not clear that it's actually expanding.

The Big Bang is the best explanation yet for the sum of evidence. That doesn't mean it's a good explanation...

 

[KingMerv00]

The universe undoubtedly has a redshift. It's not clear that it's actually expanding.

The Big Bang is the best explanation yet for the sum of evidence. That doesn't mean it's a good explanation...

I'd say it is a very reasonable one. I think you are being kind of harsh. Eh, who knows, maybe the red shift is a glitch in the matrix.

 

[Melendwyr]

Don't get me wrong, the expansion hypothesis explains Olbers' Paradox, the Cosmic Microwave Backround, the redshifting... it's just that it also requires some very, very odd assertions, among which is the idea that matter-energy is independent of the space it moves through.

If our meager exploration of space as taught us anything, it's that our ideas about the universe rarely survive close examination of the things we're speculating about. Our ability to draw conclusions about the structure of the universe as a whole is questionable.

 

[Grounded]

"Echo" probably wasn't the right analogy. "Afterglow" is more appropriate. The CMBR is energy left over from the Big Bang and it is found everywhere with astonishing uniformity. I'll just give you the link since it will undoubtedly explain it better than I could.

h_t_t_p://en.wikipedia.org/wiki/Cosmic_microwave_background_radiation

Sorry if this is out of scope for this discussion.

It is curious to me that this microwave background is described as having density (only "5x10^-5 of the total density of the universe"). Doesn't density imply mass? Can the expansion of the universe be quantified in real terms that even I could understand? Maybe this should be a separate thread - I don't want to hold anyone up.

Thanks for the link KingMerv00. I've got more homework to do.

 

[Grounded]

The universe undoubtedly has a redshift. It's not clear that it's actually expanding.

The Big Bang is the best explanation yet for the sum of evidence. That doesn't mean it's a good explanation...

Is there proof that the universe is cooling? If so, expansion is required - where/how else would the energy be dissipated.... (wait, fusion and intense gravity - that's it. The universe will become a huge black hole )

I'm serious about the cooling/expansion - I admit I got carried away in the parenthesis. It's hard to demonstrate emotion/joking on the keyboard.

 

[cbish]

The universe undoubtedly has a redshift. It's not clear that it's actually expanding.

The Big Bang is the best explanation yet for the sum of evidence. That doesn't mean it's a good explanation...

Go on! What would be?