At Rest with our Hubble view

[Layman]

Did that help?

No it did not. You are still making up your own cosmology, take a look at Battle Point Astronomical Association : The Search for the Edge of the Universe

"The distance and characteristics of the remote galaxy may then be determined by spectral analysis of the received light. The most distant galaxy observed to date using this technique is receding at 95% of the speed of light, and is at a distance of eighty billion trillion miles. It takes light 13.5 billion years (13.5 bly) to travel this distance. The universe was approximately one billion years old when light left that galaxy."

"In summary, we can say that even a perfect telescope would be unable to observe objects beyond approximately 14 billion light years distance due to the redshift cutoff. This is very close to the time when stars and quasars were first formed after the Big Bang. Going back farther we would be in the dark period with no stars, only atoms of hydrogen, deuterium and lithium."

 

[AlexG]

The Battle Point Astronomical Association is an association of amateur skywatchers. If you're actually going to cite a source, you should find a better one.

 

[Layman]

The Battle Point Astronomical Association is an association of amateur skywatchers. If you're actually going to cite a source, you should find a better one.

Well, this is what I got from ask.com and it is the same as other things I have read from books written by Ph.D.'s. I cannot provide a source from those books if they are not on the internet, and they where written in a time when the universe was a billion years older, and when the age of the universe had already been lowered already to that point. (they had already taken the idea that it would keep getting younger into consideration) This source just proves that it is not my own personal opinions about how far we can see in the visible universe.

The fact that we can even see the CMB is a bit of an enigma of its own, and it is easy to just say that the results are wrong because of the person who did them, but then no one has really been able to generate the correct results. That is why there really isn't a widely accepted theory that explains all this, and people tend to think there is some other explanation beyond what we currently know in physics. I think all Grumpy is doing is just assuming that since we see the CMB than it is coming from a distance that is less than the speed of light. The calculations don't show this and implies that there is a missing piece of the puzzle that has not yet been considered.

I think this source actually comes from a time when we thought that the universe was about a billion years older, the fact that the universe keeps getting younger in theoretical physics would make any source very questionable. But, I don't think anyone has shown how the younger age of the universe would then translate into us being able to see further back in time with telescopes before the formation of stars and galaxies.

 

[AlexG]

The CMB is from 388,000 years after the initial expansion. They are the photons which were released at the time of the recombination, when charged ions and electrons were able to combine into neutral atoms.

The predicted black body spectrum of the CMB EXACTLY matches the observed values from the WMAP.

I think this source actually comes from a time when we thought that the universe was about a billion years older, the fact that the universe keeps getting younger in theoretical physics would make any source very questionable.

Do you have any evidence for this? A half remembered tech manual? An amateur astronomy club? Or have we already changed all the data on the internet?

 

[Markus Hanke]

Doesn't light of all frequencies travel at a common speed through the same conditioned bit of space?

Your question has been answered in post 258 by Tach. Basically it boils down to the fact that different frequencies get refracted by different angles in an inhomogeneous space such as Farsight suggests. This is contrary to what we observe, plain and simple.

 

[Layman]

Do you have any evidence for this? A half remembered tech manual? An amateur astronomy club? Or have we already changed all the data on the internet?

Just about every book that was ever written on the subject from the 80's and 90's, if you guys actually ever read popular physics you would know this stuff. I guess I should apologize for you not knowing something again, it seems to be really getting you agitated. The universe was thought to be about 14.4 billion years old and that was after they already adjusted it to make it even younger.

I must have slipped from an older universe that was identical to this one a billion years later, since you seem to know everything there is to know about everything, and I haven't seen anything on the net that reflects these older predicted ages. This is why I originally didn't know the correct age of the universe on the internet. I read that they where thinking it could be lower than that even, and it could drop still so I just went with it instead of denying it.

But now that it has been put on the internet as being 13.77 billion years, I am sure you will troll it hard enough to keep it from dropping even further than that, so then it could end up getting stuck at about this age.

 

[AlexG]

You should really confine your posting to the conspiracy section, with the rest of the woo-woos.

 

[PhysBang]

Just about every book that was ever written on the subject from the 80's and 90's, if you guys actually ever read popular physics you would know this stuff. I guess I should apologize for you not knowing something again, it seems to be really getting you agitated. The universe was thought to be about 14.4 billion years old and that was after they already adjusted it to make it even younger.

I've read quite a bit of academic histories of cosmologies and from that perspective it looks like you have things almost exactly backwards.

The problem of the age of the universe, from the 30s onwards, was that the age of the universe was very much too low. It is only from WMAP onwards that the age of the universe gets fixed at something within a billion years with any great confidence. Their first publication lists it at 13.4 +/- 0.3 and their last lists it at 13.77 +/- 0.13 billion years (13.76 +/- 0.11 billion years in combination with other observations).

On the other hand, at the very end of the 90s, the High-z Supernova Search Team and the Supernova Cosmology Project presented their first results, with estimates of the age to the universe of over 14. However, the confidence intervals on these measurements were almost 2 billion years.

So you are correct that the popular science media of the very end of the 90s was pushing an age of the universe that is about a billion years older than the current estimate. Yet it seems foolish to have taken this estimate as one that was definitive, given the challenges in performing supernovae observations and the large error bounds given by those reporting their results. However, this is how the popular science media tends to work.

 

[PhysBang]

The fact that we can even see the CMB is a bit of an enigma of its own, and it is easy to just say that the results are wrong because of the person who did them, but then no one has really been able to generate the correct results. That is why there really isn't a widely accepted theory that explains all this, and people tend to think there is some other explanation beyond what we currently know in physics. I think all Grumpy is doing is just assuming that since we see the CMB than it is coming from a distance that is less than the speed of light. The calculations don't show this and implies that there is a missing piece of the puzzle that has not yet been considered.

Now this is bizarre. The CMB has exactly the look that it should have if it is a blackbody spectrum of the given redshift and decidedly not the look it should have if it were an overlap of a number of sources of different redshifts. We have known this with good confidence for at least three decades. There are different ways to consider the distance to an object with a given redshift and thus different ways to consider the recession velocity of a given redshift.

 

[Grumpy]

Layman

"The distance and characteristics of the remote galaxy may then be determined by spectral analysis of the received light. The most distant galaxy observed to date using this technique is receding at 95% of the speed of light, and is at a distance of eighty billion trillion miles. It takes light 13.5 billion years (13.5 bly) to travel this distance. The universe was approximately one billion years old when light left that galaxy."

They need to update(as do I), the latest, most accurate measurements of the age of the Universe is 13.77 billion years. The first 300,000 after the Big Bang and milliseconds of inflation were dark because, just as in the atmosphere of a star, the plasma was opaque. It takes a photon generated by fusion in the core of a star thousands, tens of thousands or millions of years to work it's way outward to be released by the stars surface of last scattering(depending on the size of the star), most(by far)don't make it at all. It is this radiation pressure that holds the star from gravitational collapse. It has a lot in common with the first few hundred thousand years of the Universe, also a plasma. At something like 300,000 years(380,000 is the latest measurement, but the error margin is quite large IIRC)the plasma cooled throughout the amazingly homogenic early Universe until it became normal matter, like steam condenses to water at a certain pressure and temperature. At that point it became transparent to all those previously confined photons and they were released to transit space and time. Between that moment and around 300,000 million years, not much happened other than small variances in the original distribution caused lumpiness in the vast clouds of hydrogen that collapsed to light off the first stars or grow the local Black Hole(supermassive BHs existed very early, they are the seeds that grew the galaxies they reside in). As I said, the furthest galaxies are not at light speed, yet. 95% is not 100%. The CMB is going even faster, but it too is still visible. The CMB is the oldest thing it is possible to see, therefore every other point in space in the Universe is between us and it(at a distance in time). They are not saying anything different from anything I have said. They too are saying that the CMB and first galaxies will soon disappear over our light horizon.

I think all Grumpy is doing is just assuming that since we see the CMB than it is coming from a distance that is less than the speed of light. The calculations don't show this and implies that there is a missing piece of the puzzle that has not yet been considered.

In the visible dimension of time, the CMB has not reached lightspeed. In the realtime(present)Universe the calculations tell us that if we could see it today(we can't), that part of the Universe IS travelling above lightspeed. It IS over our light horizon, but it will be several billion years before we can see that.

There is the apparent, visible Universe, then there is the Universe that exists today. The apparent one is largely an illusion because everything we see is as it was, not as it is today. We see the CMB as it WAS 13.77 billion years in the past. The point where we see the CMB has experienced an additional 13.77 billion years of time today, it looks nothing like what we are seeing anymore, but if they point their telescopes at us they would see something very like what we see where they are, they would not see the Milky Way galaxy, as it doesn't exist yet in their visible Universe. This is what it really means that we cannot see the whole Universe. We cannot see the whole Universe as it is today(everywhere's now)in space, it's present actual size, condition or the positions of it's components. We can only see The Universe in the dimension of time. Looking out at a distance is looking back into time. And, since the CMB is still visible in time, so is the entire history of the Universe back until that point.

"In summary, we can say that even a perfect telescope would be unable to observe objects beyond approximately 14 billion light years distance due to the redshift cutoff. This is very close to the time when stars and quasars were first formed after the Big Bang. Going back farther we would be in the dark period with no stars, only atoms of hydrogen, deuterium and lithium."

Precisely what I have been saying(only I used the 13.77 billion years we now have measured the age of the Universe to be).

Grumpy

 

[Undefined]

Only in vacuum (index of refraction is independent of wavelength and equal to 1). In any refractive medium, the above is not true because the index of refraction is wavelength dependent, $$n=n(\lambda)$$ and he speed of light depends on the index of refraction, $$v=\frac{c}{n}$$ where $$c$$ is the speed of light in vacuum. The difference in light speeds in a refractive medium explains the dispersion according to wavelength.

Thankyou Tach, for your response. Yes, I was naively aware that it is only for vacuum conditions of space paths. That is why I specifically ignored effects from dust and gas scattering etc as part of my question. These ignorable/known scattering effects include those from diffracting/refractive "medium" of any kind, leaving only specified "space" (ie, free space paths in vacuum) as the only aspect my question required an answer for in the context of the discussion between Farsight and Markus Hanke so far on "variously conditioned space" paths [vacuum only] speed of light at various points along the "free space" portions of travel by the light "bunch" front of "white" light beam of multiple frequency light. Based on this further clarification of my question prompted by your kind response above, I will point this out when answering Markus Hanke's kind response. Thanks again.

 

[Undefined]

Your question has been answered in post 258 by Tach. Basically it boils down to the fact that different frequencies get refracted by different angles in an inhomogeneous space such as Farsight suggests. This is contrary to what we observe, plain and simple.

Please read my reply to Tach above. It clarifies that the inhomogeneity (variously conditioned vacuum "space only") I alluded to in my naive question is not due to effects of non-space media (particles/bodies). I ask only about the case of free space vacuum parts of the path traveled by the multiple frequency front of "white" light.

So, why would anyone expect frequency dependent diffraction in/by the vacuum-only free-space variously conditioned sections of the light at any speed whatever that speed may be constrained to during traversal of varying space path condition space locations it is moving through at the time?

Thanks again for your response. Will be back again tomorrow for your further reply on the basis of my further clarification following Tach's post above.

 

[Tach]

Hi guys, interesting discussion.

Markus, Farsight, can you explain naively to me why a proposed variable lightspeed and varying lightfrequency would result in a "rainbow" (frequency spectrum spread) effect along a variously conditioned space path?

Doesn't light of all frequencies travel at a common speed through the same conditioned bit of space?

I mean, even IF the speed of a white light "front" changes, the various light frequencies in the "front" are all changed to the same different "local" lightspeeds as the "front" passes each location along the whole path, doesn't it?

So, the answer is that your claim highlighted above in red is false, "light of all frequencies travel at a common speed through the same conditioned bit of space" does NOT travel at "a common speed" , it travels at DIFFERENT speeds, depending of the refraction index of the medium. The only exception is vacuum. I am glad that you realized the errors in your statement.

 

[Undefined]

So, the answer is that your claim highlighted above in red is false, "light of all frequencies travel at a common speed through the same conditioned bit of space" does NOT travel at "a common speed" , it travels at DIFFERENT speeds, depending of the refraction index of the medium. The only exception is vacuum. I am glad that you realized the errors in your statement.

Please note that they were questions, not statements. The questions were in a specific context of free space without any lightscattering (reflection, refraction) media. And the questions were asked of Markus Hanke and Farsight specifically in that context of their discussions/claims between them. Thank you for your interest, but your "corrections" are not necessary nor required at this juncture. Markus Hanke and Farsight have still to reply in context to my original question (as clarified since). I will be back tomorrow for their contextual replies. No need for you to reply further, Tach, until they have done so. Thanks anyway, Tach.

 

[Tach]

Please note that they were questions, not statements.

Actually , they were phrased as statements, see the red highlights.

The questions were in a specific context of free space without any lightscattering (reflection, refraction) media.

Actually, that was not the case, see the red highlights.

but your "corrections" are not necessary nor required at this juncture.

My corrections correct your misconceptions.

Markus Hanke and Farsight have still to reply in context to my original question (as clarified since).

Markus already made the same correction relative to your errors. As to Farsight, the two of you share the same misconceptions on the subject.

No need for you to reply further, Tach, until they have done so. Thanks anyway, Tach.

I am glad I could clear your misconceptions, though, from your follow-on posts it appears that some still persist.

 

[Undefined]

Actually , they were phrased as statements, see the red highlights.





Actually, that was not the case, see the red highlights.



My corrections correct your misconceptions.



Markus already made the same correction relative to your errors. As to Farsight, the two of you share the same misconceptions on the subject.



I am glad I could clear your misconceptions, though, from your follow-on posts it appears that some still persist.

Even Markus, in the post you link to, refers to my post to him as a question. He understood that it was a contextual posing of a question which was based on what is being claimed by Farsight and Markus, and their different takes on the matter, and NOT any statements of mine.

The only person so far who has tried to distort the question/context is you. Do you feel such a compulsive need to "correct", that you will even go so far as to twist other's questions/posts into a "strawman" of your own "construction" so that you can then proceed to "correct" something which doesn't require any "correction"?

Please stop muddying the waters so you can play more games, Tach. You've been warned by the moderators for doing that before. Be careful not to provoke further sanctions for doing the same again and again like this.

Please don't make any further response to me until the Farsight and Marcus have made their respective clear answer to my clarified question (for question it was, as Markus has already confirmed in your linked oost of his to me). Thanks in advance for your future co-operation in this matter, Tach.

 

[Tach]

The only person so far who has tried to distort the question/context is you.

I simply pointed out and I simply corrected your (many) errors. Markus did the same, actually he quoted my answer to you ad-literam. .

 

[Undefined]

I simply pointed out and I simply corrected your (many) errors. Markus did the same.

I have (regretfully, but unavoidably perforce of your disruptive "gameplaying") reported your game playing to the moderators. You keep ignoring the fact (as proved by Markus Hanke's post which you linked to) that I asked a question and provided context as part of the query process. Your games of "correcting" your OWN "strawman" misrepresentations only muddy the waters and spoil proper discourse between courteous members. I will have to ignore you until you have something worthwhile (legitimate comment/contribution IN CONTEXT) to make on my question/discussion with Farsight and Markus Hanke on this aspect as posed in my question to THEM. Please desist from commenting on same until THEY have a chance to clearly answer for themselves my question as clarified. Thankyou.

 

[Farsight]

For the third time now - I am talking about gravitational light deflection, as in us here on Earth watching a ray of light just grazing past the sun ( or any other massive body ). This has nothing to do with local measurements, but everything with us not seeing a frequency dependency over a global light ray trajectory.

It has everything to do with the fact that it's the Shapiro delay. The out-and-back signal duration increases when the light skims the Sun. Nine-tenths of this is because the light goes slower near the Sun. You can contrive a thought-experiment where light passes between two nearby stars wherein the beam doesn't bend at all. Then all of the delay is because the light goes slower near the stars.

The speed of light in glass is the same as the speed of light in vacuum only locally in any microscopically small neighbourhood, i.e. in the space between the atoms making up the glass. It is not however the same on scales much larger than these atoms. This is why a ( macroscopically large ) glass prism refracts a light ray, turning it into a pretty little rainbow. You can easily do this experiment at home.

And this tells you that refraction in a prism does not occur because c is reduced. So it tells you that your assertion that we should expect to see refraction when c varies, is a straw man argument.

Same in gravitational light deflection - if the speed of light varied with the radial coordinate from the massive body, then different frequencies would be deflected at different angles over the macroscopic distance the light ray travels ( e.g. from a distant source past the sun to an Earth-bound observer ).

You know full well that the coordinate speed of light varies in a non-inertial reference frame such as a gravitational field. The speed of light does vary with the radial coordinate from the massive body.

This is not what we observe, hence the speed of light never varies, neither locally nor globally. Light deflection is due to space-time curvature, nothing more and nothing less. The speed of light is always constant.

We observe the Shapiro delay. We observe optical clocks running slower when they're lower. Those clocks don't run slower because your plot of clock rates is curved.

This is not a strawman, this is physics.

It's a strawman. Refraction in a prism is not caused by a reduction in c, so claiming that a varying speed of light must result in rainbow gravitational lensing is specious.

Talking about physics - can you give us the equation which governs the values for permittivity and permeabiliy as a function of the radial coordinate. This should be interesting...

Please don't attempt to hide behind mathematical demands because you're losing the argument.

 

[Farsight]

Markus, Farsight, can you explain naively to me why a proposed variable lightspeed and varying lightfrequency would result in a "rainbow" (frequency spectrum spread) effect along a variously conditioned space path?

It wouldn't. As Markus has admitted, c in glass is the same as c in vacuo. An analogy I heard about is that you walk at 4mph, and on an empty street, you progress down that street at 4mph. However on a busy morning when the street is crowded, you have to go round people, and you bump into people too, so even though you're still walking at 4mph you don't make such good progress. But if you're a tall man with big strides your progress is hampered less than if you're a little lady with small steps.

Doesn't light of all frequencies travel at a common speed through the same conditioned bit of space?

Yes. When we look at a nova we don't see the red wavelengths before we see the blue wavelengths.

I mean, even IF the speed of a white light "front" changes, the various light frequencies in the "front" are all changed to the same different "local" lightspeeds as the "front" passes each location along the whole path, doesn't it?

Yes.

So I don't get why a spectrum-spread of that mixed frequency white light "front" should occur? The whole mixed-frequency light "front" just goes along as a "bunch" (allowing for intensity losses due to "scatter by "gas and dust etc" along the way) at whatever local lightspeed is applicable in any space condition it travels through, doesn't it; arriving at the target/observer as that undifferentiated bunch of white light even IF the speed of that bunch/front has (all together) varied by the same amount at any variation of speed due to space condition?

Like I said, it's a straw-man argument.

Thanks again to both of you for your very informative and interesting exchanges/contributions to discussions on this, and many other deep matters, Markus Hanke, Farsight. Have to go. Back tomorrow to read your responses to my respectful naive query.

Methinks you are not so naïve, Undefined.