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Red and blue shift interpretation

gray28
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3/10/2014 11:53:04 PM
Posted: 2 years ago
I get the feeling that theists are trying to cast aspersion on traditional red and blue shift interpretation, and so as to prevent the conclusion that this (local) universe is doomed. Why would they do such a thing if a physical plane of finite breadth and duration seemingly supports their claim of the physical plane passing away? Doom of our (local) universe is a strong basis for logically arguing that there are an infinite number of universes separated by space-time (a multiverse). This news is horribly damaging to their position!

Anyways, are there any scientists out there who can perfectly argue that the present interpretation of red and blue shifts is correct? it's important to prove that this is so.
Sswdwm
Posts: 1,398
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3/11/2014 3:00:59 AM
Posted: 2 years ago
At 3/10/2014 11:53:04 PM, gray28 wrote:
I get the feeling that theists are trying to cast aspersion on traditional red and blue shift interpretation, and so as to prevent the conclusion that this (local) universe is doomed. Why would they do such a thing if a physical plane of finite breadth and duration seemingly supports their claim of the physical plane passing away? Doom of our (local) universe is a strong basis for logically arguing that there are an infinite number of universes separated by space-time (a multiverse). This news is horribly damaging to their position!

Anyways, are there any scientists out there who can perfectly argue that the present interpretation of red and blue shifts is correct? it's important to prove that this is so.

I'm no cosmologist (I don't know of any here in DDO either) but I'll give this a go.

There are multiple things redshift tells us:
1. Speed of recession
2. Expansion of space
3. Distance
4. Angular velocities
5. Gravitational Distortions

1,2 & 5 are independent things that can affect redshift. In cosmology as far as I understand, remote objects such as other galaxy clusters is mostly due as a result of #2, the expansion of space. We know this because assuming #1 alone means there are galaxies with high redshifts apparently travelling at relativistic speeds (>.9c), which would require stupendous amounts of energy.

#5 is a result of light leaving dense, Hugh gravity objects such as near a black hole or very dense star, the light from such an object would become more redshifted as the gravitational well it needs to crawl out of is very deep. This is mostly irrelevant for galaxies as a whole however.

Creationists, especially YEC's have issue with #3. Indeed in the days of Hubble, it was naively taken as an assumption that galaxy distance increased linearly with red shift. Hubble didn't have the today's data to work from but a layman can see that almost all high redshift galaxies were fainter, and simpler in structure. The assumption that the universe was together at one point and therefore the rate of recession being proportional assumption was not a reasonable one.

Nowadays we have a number of 'standard candles' to work with to correlate distance and redshift. One of the best examples are type 1a supernova, which explode with uniform brightness and with a very characteristic spectra ( making it easy to tell apart from other supernova) not to mention they are exceptionally bright - allowing precise measurements of its maximum brightness for even faraway galaxies. Correlating the peak brightness yields a near-linear plotwhicj is positively curved towards the present, which is where the bombshell that the universe is expanding at an increasing rate originally came from. But the experiment did do it's job to confirm and fine-tune the interpretation that higher redshift = further away.

Another independent check is to look at the broadening of the spectral absorption lines. The further away/higher redshift a galaxy is, the more intergalactic dust & gas light must pass through to reach us, which will broaden the spectral features. This pretty much occurs with increasing intensity without fail in all cases of higher and higher redshift.

Hope I got that all right...
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Iredia
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3/11/2014 4:55:13 PM
Posted: 2 years ago
At 3/11/2014 10:11:11 AM, gray28 wrote:
Thanks Sswdwm for the capable explanation. Can anyone top this?

Space expansion is a bogus concept. Space is not material it can't expand. The Doppler effect interpretation of redshift is okay enough. But at this moment I am unsure if its the correct one. Googling the subject though I have seen two other proposals. One is the Wolf effect, the other is that the redshift is intrinsic to stars and/or galaxies themselves.
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Sswdwm
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3/11/2014 5:07:01 PM
Posted: 2 years ago
At 3/11/2014 4:55:13 PM, Iredia wrote:
At 3/11/2014 10:11:11 AM, gray28 wrote:
Thanks Sswdwm for the capable explanation. Can anyone top this?

Space expansion is a bogus concept. Space is not material it can't expand. The Doppler effect interpretation of redshift is okay enough. But at this moment I am unsure if its the correct one. Googling the subject though I have seen two other proposals. One is the Wolf effect, the other is that the redshift is intrinsic to stars and/or galaxies themselves.

Perhaps you should do more research into spacetime before just asserting it cannot expand because you declare it to be immaterial.
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Iredia
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3/11/2014 5:46:44 PM
Posted: 2 years ago
At 3/11/2014 5:07:01 PM, Sswdwm wrote:
At 3/11/2014 4:55:13 PM, Iredia wrote:
At 3/11/2014 10:11:11 AM, gray28 wrote:
Thanks Sswdwm for the capable explanation. Can anyone top this?

Space expansion is a bogus concept. Space is not material it can't expand. The Doppler effect interpretation of redshift is okay enough.
But at this moment I am unsure if its the correct one. Googling the subject though I have seen two other proposals. One is the Wolf effect, the other is that the redshift is intrinsic to stars and/or galaxies themselves.

Perhaps you should do more research into spacetime before just asserting it cannot expand because you declare it to be immaterial.

I don't declare it is immaterial, it is so. Assuming they are correct, I don't know what particle space is made of ? And trust me, space being a fabric doesn't make things easier. Try spinning a top around another spinning one on spandex as against a sturdy table; the former is much harder than the latter.
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gray28
Posts: 16
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3/11/2014 11:52:20 PM
Posted: 2 years ago
I have no personal objection to the idea of spatial expansion. It's another way of looking at things, and is based on the proposition of space not being as empty as we once thought. If this is true it would certainly solve a lot of the problems associated with gravity. Einstein being on the right track about this comes to mind. I admit that I'm no scientist, but spatial expansion is far more promising a hypothesis than seeing the creation of our (local) universe as being a 'big bang' explosion.

Yet the main point remains that the components of this universe are distancing themselves from another. Inflation theory is upheld, and there is no problem with red versus blue shift interpretation.
RoyLatham
Posts: 4,488
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3/12/2014 2:16:42 PM
Posted: 2 years ago
Galaxies can be flying apart without space expanding. They could just be going further apart as a result of continuing the expansion of the Big Bang into existing space. However, we happen to know that space is also expanding.

I separately posted the Krauss lecture on cosmology http://www.debate.org... It explains the concepts curved space and expansion quite well. The curvature of space can actually be measured. It turns out that space is flat overall; it is curved locally by gravity.
Iredia
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3/12/2014 4:48:25 PM
Posted: 2 years ago
At 3/12/2014 2:16:42 PM, RoyLatham wrote:
Galaxies can be flying apart without space expanding. They could just be going further apart as a result of continuing the expansion of the Big Bang into existing space. However, we happen to know that space is also expanding.

No, it doesn't and I hope one day people will see it for the absurdity it is.


I separately posted the Krauss lecture on cosmology http://www.debate.org... It explains the concepts curved space and expansion quite well. The curvature of space can actually be measured. It turns out that space is flat overall; it is curved locally by gravity.

I will watch the video. But I happen to have watched a number of Krauss videos and read his book 'A Universe From Nothing'. I don't think the substance of his argument will be different. Put simply, it will be same old story of how light speed being constant, quasar redshifts suggesting they surpass the speed of light etc being evidence for the inference that quasars don't move and space expands between them. It's a pathetic cop-out. Ask a physicist to do the necessary calculations and establish the daily rate of metric expansion of space (as it applies to earth).

Even before being tested for, do you expect any layman to take seriously the idea that the area of his house can increase without any movement of any kind occuring ?
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RoyLatham
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3/12/2014 9:58:26 PM
Posted: 2 years ago
At 3/12/2014 4:48:25 PM, Iredia wrote:
At 3/12/2014 2:16:42 PM, RoyLatham wrote:
Galaxies can be flying apart without space expanding. They could just be going further apart as a result of continuing the expansion of the Big Bang into existing space. However, we happen to know that space is also expanding.

No, it doesn't and I hope one day people will see it for the absurdity it is.

So why don't you write it up and collect your Nobel prize.

I will watch the video. But I happen to have watched a number of Krauss videos and read his book 'A Universe From Nothing'. I don't think the substance of his argument will be different. Put simply, it will be same old story of how light speed being constant, quasar redshifts suggesting they surpass the speed of light etc being evidence for the inference that quasars don't move and space expands between them. It's a pathetic cop-out.

That's not the theory. Not even close. If you cannot parse the book or lectures, I suggest giving up and moving to a different subject.

Ask a physicist to do the necessary calculations and establish the daily rate of metric expansion of space (as it applies to earth).

Krauss is, of course, a distinguished physicist.

Even before being tested for, do you expect any layman to take seriously the idea that the area of his house can increase without any movement of any kind occuring ?

Having an expanding house is not part of any theory. The expansion is entirely at the edges. Galaxies are moving apart, so they go into the new space and get further apart from each other. However, the galaxies themselves don't change size. Krauss says this explicitly near the end of the video. It's like blowing up a balloon with objects inside the balloon.

But you make a good point about expecting a layman to understand modern cosmology. No, I don't expect that. Much of well-established science is well beyond the understanding of the average person. Quantum physics, for example, is so far outside of ordinary experience that it defies "common sense." Scientists accept it because it agrees with observation.
Iredia
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3/12/2014 10:24:09 PM
Posted: 2 years ago
At 3/12/2014 9:58:26 PM, RoyLatham wrote:

So why don't you write it up and collect your Nobel prize.

I won't even bother. In time, whether or not I try, whether or not you like, the theory will crack under what is obvious and true.


That's not the theory. Not even close. If you cannot parse the book or lectures, I suggest giving up and moving to a different subject.

I said the substance of his arguments, not the theory. Did Krauss make mention of what I wrote in the video ? In any case, as I said, I'll watch it.


Krauss is, of course, a distinguished physicist.

I know. I strive to judge ideas by themselves and not by the person.


Having an expanding house is not part of any theory. The expansion is entirely at the edges. Galaxies are moving apart, so they go into the new space and get further apart from each other. However, the galaxies themselves don't change size. Krauss says this explicitly near the end of the video. It's like blowing up a balloon with objects inside the balloon.

I didn't say it's a part of the theory. And the expansion being at the edges will have effects discernable at a local scale, which is why I said a physicist should do the calculations for that.

Metric expansion due to galaxies moving apart from themselves in space is understandable. If they don't change size while doing so, fine. Brainwashing students into believing space itself (that objects exist in) expands isn't. And BTW blown up balloons expand IN space. At least I agree with the opinion that the popular balloon analogy doesn't make sense.


But you make a good point about expecting a layman to understand modern cosmology. No, I don't expect that. Much of well-established science is well beyond the understanding of the average person. Quantum physics, for example, is so far outside of ordinary experience that it defies "common sense." Scientists accept it because it agrees with observation.

Read properly. I was referring to their understanding of an absurd idea. In any case, all scientists were once average people so don't push your luck too far. At a base level, scientists can and do explain concepts to laymen: in fact, laymen have concepts that preempt scientists. A good example would be a universe with a beginning, although this understanding is being revised in light of a new hypothesis. That said, I myself believe in stuff that defies 'common sense', as I think, or as inspired by scientists or philosophers. The same applies to many common folks.

So, don't use the excuse that concepts in science are far outside the ability of laymen to grasp. That one annoys me_seriously. Especially when a scientist is talking nonsense_like metric space expansion.
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RoyLatham
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3/12/2014 11:04:52 PM
Posted: 2 years ago
At 3/12/2014 10:24:09 PM, Iredia wrote:
At 3/12/2014 9:58:26 PM, RoyLatham wrote:

So why don't you write it up and collect your Nobel prize.

I won't even bother. In time, whether or not I try, whether or not you like, the theory will crack under what is obvious and true.

You understand that the theory has been around for quite some times, and it has withstood assaults from the best physicists. If it cracks, it won't be because it is obviously absurd. It will be because there is a better explanation for the observations. That's likely to be even more "absurd."

I said the substance of his arguments, not the theory.

Nope, not close.

Krauss is, of course, a distinguished physicist.

I know. I strive to judge ideas by themselves and not by the person.

You claimed a physicist could do calculations that disprove the theory. Not so.



Having an expanding house is not part of any theory. The expansion is entirely at the edges. Galaxies are moving apart, so they go into the new space and get further apart from each other. However, the galaxies themselves don't change size. Krauss says this explicitly near the end of the video. It's like blowing up a balloon with objects inside the balloon.

I didn't say it's a part of the theory.

Then why did you cite an expanding house as being absurd? If you want to discuss the theory, don't say things utterly unrelated to the theory.

And the expansion being at the edges will have effects discernable at a local scale, which is why I said a physicist should do the calculations for that.

What is discernible it that the universe is expanding at an accelerating rate, rather than expanding at a constant rate, staying the same, or contracting.

Metric expansion due to galaxies moving apart from themselves in space is understandable. If they don't change size while doing so, fine. Brainwashing students into believing space itself (that objects exist in) expands isn't. And BTW blown up balloons expand IN space. At least I agree with the opinion that the popular balloon analogy doesn't make sense.

What is observable as "space" has energy as an inherent property. I've heard what is outside of the observable universe as "zero energy state vacuum." But it is irrelevant what is outside since it can never be observed. Whether something that can never be detected exists or not is metaphysical question not a scientific one. The balloon analogy is readily understandable because the interior of the balloon is analogous to the known universe and what is outside is unknowable.

But you make a good point about expecting a layman to understand modern cosmology. No, I don't expect that. ...

Read properly. I was referring to their understanding of an absurd idea. In any case, all scientists were once average people so don't push your luck too far. At a base level, scientists can and do explain concepts to laymen: in fact, laymen have concepts that preempt scientists. A good example would be a universe with a beginning, although this understanding is being revised in light of a new hypothesis. That said, I myself believe in stuff that defies 'common sense', as I think, or as inspired by scientists or philosophers. The same applies to many common folks.

You first say that laymen understand absurd ideas, those things that defy common sense. Then you go on to say that you entertain such ideas and and you think other people do too. Do you mean that common people can accept absurdities that you like, but not absurdities that science likes?

I think that people can accept magic performed by gods, but not understand how it is done. The whole idea is that it is not explicable at any finer level. Scientific theories provide understanding as precise mathematical descriptions of what the laws of nature require. That's the scientific concept of "understanding." However, there is no relation of things like common sense to everyday experience

So, don't use the excuse that concepts in science are far outside the ability of laymen to grasp. That one annoys me_seriously. Especially when a scientist is talking nonsense_like metric space expansion.

Scientific understanding of cosmology is solely by mathematics, which scientists then try to relate by analogy. Since the average person has little understanding of math, they are going to miss out. They can understand some of the analogies, but you go out of your way to dismiss any analogy that doesn't match you concepts derived from everyday experience. So that makes the understanding impossible.