Ok, so it's sort of a property of space that it has certain amount dark energy. Just wanted to clear that up, thanks!

:-k Now, if I would only know where that new space comes from...

I know this won't change snowflake's mind, but I was troubled that someone else said that the arguments against accelerated expansion are "compelling". They are not.

The observation, which snowflake does not dispute, is that supernovae at redshifts around one are dimmer than they would be if you assume linear expansion of the universe. The conclusion of acceleration comes from this observation simply and naturally: if the supernova is dimmer than you expect, it must be further away than you expect. If the supernova is further away than predicted by a constant rate of expansion, the true expansion rate must be accelerating.

Consider the following analogy. You are standing by the highway, and you observe two cars go by you at the same speed. You happen to know that one of the cars has cruise control turned on, and is moving at a constant speed of 60 km/h. However, one hour later, the driver of the second car calls you on his cell phone, and informs you that she is actually 100 km away. You *should* conclude that she must have accelerated, because at the initial speed of 60 km/h, she could not have traveled 100 km.

That's really all there is to it. The distant galaxies are dimmer, and hence further away, than constant expansion would predict. Hence the expansion must be accelerating.

I'm surprised no one has mentioned SN 1997ff. It was discovered in the Hubble Deep Field at a much higher redshift than the SNe used in Perlmutter's and Kirschner's observations, and although its light curve was not well-enough sampled to pin down its brightness completely, the lower limits demand that it is *brighter* than expected. This means that the universal expansion was *de*celerating at early times, and is now *ac*celerating. This supports the general picture of big bang cosmology, and rules out the most common alternate explanations, such as sn evolution or grey dust.

Finally, while it is true that galaxies are not pinned in place like pennies on a balloon, their local motion is only a few hundreds of km/s, at most. By the time you get out to a redshift of 0.1, the Doppler redshift caused by this motion is much smaller than the redshift caused by the universal expansion, so it may correctly be ignored. This is why we only see blueshifts in very nearby galaxies, that are gravitationally bound in our group.

Your whole argument (motion being faster in the past = deceleration) is based on a misconception.

But then, as a working astrophysicist, I guess I'm part of the Establishment. Again, I don't expect snowflake to be able to recognize his error, but I hope that others reading along will be able to see the difference.

Yours sincerely,

Don

I’m surprised you do not see the internal contradiction in this argument. The magnitude of SN 1997ff has been confirmed in a large number of ‘supernovae Ia’: The trend is real, the causal explanation is lacking. Because to shift gears between a period of 'deceleration' and 'acceleration requires not a 'cosmological constant', but 'variable acceleration'.

I just looked into the bag, and there is not one club in the General Relativity arsenal that can explain a change in acceleration in mid flight. It takes a variable tractor beam to do that, and that requires new physical laws.

There are other possible explanations for the switch between brighter and dimmer than expected supernova than this shell-shuffling that explains nothing. The simplest explanation is miss-identification of distant hypernova…

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jwj

It's a big universe out there...is it really unwinding, really burning out?

Thank you for that simple, straightforward explanation of the rationale for this conclusion.

I'm surprised you wrongly see this as an "internal contradiction." The explanation is not lacking. Here it is: The space in the universe has always been expanding. When the universe was younger, there was less space and everything was closer together. Since the negative pressure of the dark energy is proportional to the volume of space, there was less of it in the distant past, and this "expansion force" was overwhelmed by the slowing gravitational effect of all the mass in the universe. The universe continued to expand, but the expansion was slowing. At one point, space had expanded to a volume sufficient for the dark energy to overcome the domination of gravity, and the expansion began to accelerate.

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Everyone is entitled to his own opinion, but not his own facts.

If what you say is true, the acceleration rate should still be increasing as the density shrinks and the volume continues to expand, but this is not what the supernova data suggest: The peak in the supernova Ia attenuation factor occurs at z=0.5, then moving towards the current epic, the supernova attenuation rate falls into the predicted hubble curve. To fit this curve, the current acceleration rate must be less than it was in the past. If as you suggest, the net dark energy force is increasing, the accelation of the expansion should either peak at a constant or still be increasing. I think. Could we get a second opinion on this one? Alec? Adam?

I got beat up pretty bad for proporting in my paper the expansion rate was currently decreasing. My bad. The 'jerk' in the cosmic acceleration rate cannot be modeled with a simple linear acceleration factor, neither can the inflationary period, which hypothetically occurred before all of this other weird non-relativistic behavior.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

I think this is because as we move toward the current epoch, we are looking at a smaller volume of space, so the effect of the dark energy falls under the threshold of detection. It's just barely detectable at z=.5, and that's looking through A LOT of expanding space, so at shorter distances, there's not enough space between here and there for the acceleration to show itself.

Absolutely. I'm just expressing my understanding of the situation, which I believe is consistent with the astrophysical community. This also appears to be what Doctor Don - a working astrophysicist - said recently in this thread. Perhaps he could clarify or validate my explanation. Or Phil? Spiff? Tim Thompson? Heck, I'd even be interested in what dgruss' understanding is of the mainstream view on this matter.

It's possible that the cosmological constant isn't exactly constant, but I don't think there's any evidence (or need) at this point to say that it's NOT constant. What is highly variable is the volume of the universe and the overall density and the distance between galaxies, so it's the interplay of these variables with the cosm. constant that indeed produces a nonlinear effect.

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Everyone is entitled to his own opinion, but not his own facts.

This is correct. There are two competing effects. On smaller scales, the acceleration is unmeasurable. The larger scales you examine, the stronger the effect is (just like stretching a rubber band -- points near each other are stretched a lot less than the ends of the band). But on really large scales, we are looking so far back in time that we are looking back at a time when the acceleration was less (or even *de*celeration). Look too close, and the effect is small. Look too far away, and the acceleration is less. So there's a zone where the effect is at its strongest (z ~ 0.5 - 1.5), and we need to measure a lot more supernovae in this zone, with much smaller error bars, in order to determine the characteristics of the acceleration. This is what the proposed SNAP satellite mission hopes to do.

Right now we don't know much more than the fact that the expansion is accelerating, and in the early universe, the expansion was decelerating. There's no evidence that the acceleration is slowing down. If the cosmological constant model is correct and the acceleration is due to vacuum energy density, we would not expect the acceleration to slow down, once begun, because the energy density of empty space remains constant, so its contribution to Einstein's Field Equations remains constant. If that energy density were to change for some reason, then the rate of acceleration would change. Of course, that model may be wrong.

Yours,

Don

Right. I recall from Riess's et al 2004 paper that they specifically were not drawing any conclusions that were outside the range of their data. But their most distant Ia supernovae showed the expansion prior to ~6 billion years ago was decelerating. Since such supernovae were brighter than expected, this also ruled out any "tired light" models as well as a concern over a hypothetical "gray dust" that could have been affecting the earlier observations of dimmer-than-expected supernovae around z=.5 that indicates the dark energy then takes over from gravitation and begins to accelerate the expansion.

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Everyone is entitled to his own opinion, but not his own facts.

Hi Doctor Don

I know this will not change Doctor Don’s mind, but I was troubled by the idea that others may feel compelled to yield to authority rather than to logic. (I am usually not this terse, at least I try not, but I thought Doctor Don should listen to how his own words sound.)

Doctor Don, thank you for your response. You gave the following analogy as an attempt to refute my logical arguments.

Dr.Don
"Consider the following analogy. You are standing by the highway, and you observe two cars go by you at the same speed. You happen to know that one of the cars has cruise control turned on, and is moving at a constant speed of 60 km/h. However, one hour later, the driver of the second car calls you on his cell phone, and informs you that she is actually 100 km away. You *should* conclude that she must have accelerated, because at the initial speed of 60 km/h, she could not have traveled 100 km."

The analogy you give would indicate that the closer car would have a smaller red shift than the further car, but it totally fails to correspond to the cosmological description of an expanding space time. All “cars” have the same cosmological expansion rate at the same time, Your analogy of one car going a constant speed and another accelerating is contrived, artificial and false.

The expansion of the universe is like a compressed sponge with poppy seeds in it. When the sponge is allowed to expand, the rate of expansion is greatest when the sponge is first set free. All the poppy seed galaxies have the same intrinsic, “cosmological “ rate of expansion at the same time. When we view poppy seed galaxies far away, we are observing their motion as it was in the past. (The closer to the present a poppy seed galaxy is observed, the slower the motion. The further in the past a poppy seed galaxy is observe, the faster it’s observed or indicated motion. An object moving faster in the past than the present is decelerating).

You can prove me wrong in my assertion that space time is decelerating by simply by plotting a graph. Take the graph touted as proof of the “acceleration” of space ( http://www-supernova.lbl.gov/public/...ysicsToday.pdf ) and plot it on a piece of graph paper, just as if you were still in high school physics class. Velocity is on the Y axis, and Time is on the x axis. A positive slope indicates acceleration, and a negative slope indicates deceleration, assuming you stick with convention and have increasing velocity go up the y axis, and past events are to the left on the x axis, with future events to the right on the x axis.

You will have to translate the graph, the velocity of 1asn’s are presently indicated on the x axis, and the intensity, which is a measure of distance, is on the y axis. You will need to translate the distance measure to a temporal measure, but since you know the speed of light, this should be no problem.

When you get done translating the graph to a standard description, you will find that the slope is negative, indicating decelerating.

The surprising part about the type 1a sn data, is that the rate of deceleration should have been the greatest when the universe was younger since gravitational interaction should be the greatest then.

Thank you for your response, I look forward to seeing your graph.

Snowflake.

Snowflake, are you going to derive your time conversion for me like I asked, or are you going to ignore my request (which does not help your case). (Also, I'm sure that it would help Don with his plot.) I have asked you three times now. I contend that this plot is your "high-school" version (distance vs time, on the axes you desire them to be on). If it is not, please show me how. Otherwise, you can't prove anything and you're wasting our time.

On another note, is your conversion from distance to time just multiplying the distance to the object by the speed of light. That gives you the look-back time. That is not the correct quantity to be looking at in this regard. Was this specific galaxy moving away from us at that speed when the light was emitted? No. The unverse has expanded since then (causing the redshift), and the the galaxy has therefore moved away from us. The galaxy is at a farther distance, and therefore at a higher velocity by the Hubble law. The Hubble law gives us the expansion velocity of a galaxy in the universe *now,* not when the light was emitted. That's what v(t) = H(t) * d(t) means. If you don't understand this, or if you disagree, read the cosmology chapter in a basic textbook. That could also help you with the other arguments.

Dax

Sorry, this does not work. First, it is the close correlation between supernova magnitudes, after stretch factor corrections, and the Hubble curve that established what the Hubble value is. It was the deviation of SN 1a from this established value at high redshift, above z~0.35 that first indicated acceleration. All of the papers, Nugent, Goldhaber, Hamuy, Aldering, Garnavich, Perlmutter; they all plot this high inception of the deviation.

You can’t have it both ways – either the researchers were bending the data to fit the curve (as I contend) in the first place, or the acceleration rate is less now than it was at z=0.5. In EITHER case, the data did not agree with the BB prediction, and do not support the fundamental BB argument without a MAJOR revision in GR.

Meanwhile, more and more local supernova (such as 2001ba) are popping up with brighter, extended light curves, statistically beating Doppler expansion to death. The astrophysical community must quit ignoring this fact. Snowflake's contention the most distant observed supernova events are comparible to the brightest of the local events is statistically and empirically logical. If Riess is not switching tracks, where are these distant, brilliant hypernova?

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jwj

It's a big universe out there...is it really unwinding, really burning out?

I prefer "concise" to "terse", but whatever you like. I'm not sure what you mean by authority, since I have appealed to no authority beyond empirical data and reason. The beauty of science is that anyone can work these things out on their own, and results can be correctly called right or wrong. You are wrong. I bear you no ill will, I do not think less of you for being wrong, but that does not change the fact that you are, indeed, wrong. I confess I do think less of you for refusing to learn, but that's neither here nor there.

You are misunderstanding the analogy. The two cars do not map to two galaxies. One car (the more distant one) maps to a galaxy as observed. The other car (with cruise control) maps to a hypothetical galaxy you would observe if the expansion of the universe were not accelerating.

Um, closer galaxies *do* have smaller redshifts than further galaxies. That *is* the description of an expanding space time. I don't get what you're arguing here.

But as I keep trying to tell you (and clearly I was right in saying my last post was not going to change your mind, so I don't know what your complaint is, there), the "motion" observed (via the redshift), is not due to the intrinsic, local motion of the galaxy, but due to the expansion of the space between here and there. So if we see it, *now*, moving faster, then it must have accelerated in the meantime. That's the key that you're missing. The redshift is measured *now*; it has nothing to do with how the galaxy was moving when the light was first emitted.

Something moving faster now than in the past has accelerated.

Which time? In what reference frame? As measured by whom?

Usually, as Tobin Dax as pointed out, redshift, which is a measure of time, is plotted on the x-axis. You don't want to translate distance into time, because then you have time vs. time, which doesn't help you. Besides which, trying to translate distance into time runs you into the ambiguity of perspective and reference frame, as I alluded to, above.

Only if you do it wrong.

And it was! It was decelerating early, the rate of deceleration slowed down and then reversed itself, so that the expansion is now accelerating.

Yours,

Don

Hi Tobin Dax

I am sorry in not responding to your question on a timelier basis. I have been extremely busy.

You are already familiar with the plot of z verses distance and how it translates to velocity verses time. This is how Hubbell measured the red shift of distant galaxies, he presented his plot as velocity verses distance. Since distance corresponds to look back time, the plot can be drawn as velocity verses time, a simple graphical presentation of velocity verses time.

Some may be quick to jump on this reversion to Hubbell’s graphs as the source of my “confusion”. Hubbell never accepted the idea that the red shift was the result of the expansion of space-time, it had to be some measure of velocity or possibly some other explanation. By my insistence on describing things in a common sense straightforward manor, similar to how Hubbell originally presented the information, it appears that I am falling victim to an issue resolved in the 1920-30’s. This is not the case at all. It is just that I ascribe two causes for a red shift, one due to uniform expansion, the other is due to motion in an “unobserved” dimension. I will be posting my description of this effect soon in a separate thread.

(I should also mention that according to my uniform expansion theory the red shift caused by the expansion of space time is not locally observable since the energy lost due to expansion is equal to the extra energy the photon starts off with due to the increased curvature around atoms in the past when atoms were denser. Instead of stopping the expansion of space-time at the boundary of galaxies, as is presently assumed by the “mainstream”, matter itself is part of the expansion of space-time, according to my hypothetical model. The observed recessional shift is actually a Doppler like effect due to motion of three-dimensional space-time along an unobserved dimension that conforms to a specific geometric description. Thus the simple logic, an object moving faster in the past than the present is decelerating, the universe is decelerating. Not only is my model simple, it’s explanations are logical. Just wait until you see how complicated the explanation for an “accelerating “ universe gets based upon the “mainstream” models.)

Despite my hypothetical model yielding a different physical explanation for the cosmic red shift compared to the “establishment”, there still is my issue regarding how the mainstream describes the expansion as presently “accelerating”. Presently all measures indicate that the expansion is presently constant, it is only in the past that there is any indication that variation from a constant rate of expansion. Some discussion about correlating the red shift to rates of expansion is in order even if in my model the expansion of space-time red shifts are self-canceling. This will allow a brief introduction to the amount of complexity that becomes involved with the “standard” model.

First a note of clarification. There are a number of ways to describe the “motion” of galaxies as they are carried by the expansion of space time; these include: “recessional red shift”, red shift, recessional velocity, Hubbell flow, cosmological expansion, and expansive motion, to mention a few that come to mind. Older texts also use the word “Doppler” to describe the cosmological red shift.

According to the principals of general relativity, a photon will lose energy as a result of the expansion of space time. (General relativity appears to cause a “violation” of the conservation of energy principle, where did the energy go? The expansion of space-time comes at an energy cost. Why is there a differentiation between “global” events and “local” events?).

While the change in wavelength associated with the expansion of space-time is due to energy considerations, it is easiest to visualize the expansion of space-time as causing a “stretching” of the wavelength of light. As space-time expands, the energy of the photon diminishes and it’s wavelength increases, so the wavelength of a photon “stretches” with the expansion of space-time.

Since the recessional red shift is analogous to the stretching of space-time, it is possible to correlate this to expansive motion, but there are some precautions or considerations that should be realized first. The red shift records the result of historical events and does not necessarily record “current” rates of expansive motion. For example, let’s use a rubber band with the two ends separated a certain amount. The stretching of the rubber band represents the expansion of space-time and the two ends can represent the location of two galaxies. Initially, at t1, there is no expansion so the expansive motion between the two points on the rubber band is 0. As a “photon” moves across the “rubber band”, the rubber band is now stretched (t2), causing the wavelength of the “photon” to increase. Just before the “stretched” photon arrives at the end point,(t3) the stretching of the rubber band stops. The expansive motion relative to the two ends at t3 is currently 0, and started off as 0, yet a red shift is indicated. Some care has to be exercised in correlating red shift to expansive motion, it may not be indicating what is happening “now”. ( In your response to me you stated that the red shift indicates what is happening “now”, In the intervening time it took for the light to reach us, some big “black hole” could have passed near the source galaxy and altered the velocity of the source galaxy.) The red shift records the net energy loss or net “stretch” over an interval of time.

This does not mean that expansive motion cannot be deduced, just that one must be careful. If enough distance measures were available along with the red shift, then the proper description of events is perhaps possible.

The analogy to a rubber band is not quite complete in that in applications of the “standard model” also have to consider the rate of expansion while the photon is traveling through an expanding space time field. For example, two rubber bands are going to be stretched the same distance over the same time period but one is pulled quickly at first, and the other is pulled quickly at the very end of the time interval. A photon of light traveling across the two rubber bands will, depending upon the theoretical model one wants to apply, take longer to travel across the rubber band in the first example than the second. (If one allows the speed of light to vary with the rate of expansion things also get more “interesting”.)

The relationship the “establishment” uses to correlate the red shift to distance based upon expected rates of expansion is usually expressed as z = Ho x l + 1/2 (1 +qo) x (Ho x l)^2 + ….(power series expansion). Z is the red shift parameter, l is distance, Ho is the locally observed rate of expansion, qo is the anticipated deceleration parameter. If qo = 1/2 then the rate of expansion is “flat” ie poised between expansion and collapse, or “acceleration” and “deceleration”.

Note that the anticipated red shift is based upon the deceleration parameter qo or the anticipated rate for the deceleration of space-time based upon a specific model. It is based upon comparisons to this model to observations that the claims of an “accelerating” universe are made. If values of qo are greater than 1/2 than the universe is supposedly “accelerating” and if it is less, than the universe is “decelerating”. It is important to reiterate, the determinations of the qo is based upon specific applications expected from hypothetical models based upon principles of general relativity. Claims of the Universe “accelerating” or decelerating are based upon comparisons to the expected model.

There are many assumptions that the “establishment” has to make for their model predicting the expansion of space time. The expansion has to stop at the boundary of galaxies, the speed of light is constant, general relativity is responsible for determining the rate of expansion, and if it falls short, some other additional factor has to be added to preserve the general relativistic model, hence “dark energy”.

Also note that the claims that the universe is accelerating are based upon observations of the past, locally the rate of expansion is measured to be almost constant. If presently there is no observed variation, how can one be so confident that the universe is “accelerating”? Look at Hubbell’s graph yourself. Any claim of the effect of the expansion being cumulative so the evidence is more obvious in the past due to the compounding effect of the expansion must acknowledge that the assertion of a compounding effect is based upon the premise of a model that is now being forced to include additional fudge factors, such as “dark energy” in some kind of hypothetical distribution.

What really amazes me about the whole “acceleration” of space issue is how quickly and whole-heartedly so many have jumped on to the idea the universe is accelerating. Look at the statistical distribution of the voting. “Locally” there is no evidence of acceleration, the expansion appears to be constant. Also, just a few years ago every theoretical model describing cosmological expansion based upon a big bang, all described the deceleration parameter qo. While the extraction of information from exceedingly remote sections of space is truly amazing, we should not let ourselves get too convinced that our interpretation is correct. Particularly since the acceptance of the evidence on face value results in increasing complexity, now dark energy must be introduced and it must interact in some particular fashion.

Based upon the simplest explanations that are correlated to the simplest of theories, (my uniform expansion of space-time model), distant 1asn’s cannot be the same as those locally observed. They are smaller, and so they burn more quickly and do not produce as much light, so they are not as far away as assumed by those advocating that the universe is “now” accelerating.

The reason I believe they are smaller, is that the effect of gravity was greater in the past, as predicted by Dirac. The increased effect of gravity in the past means that it takes less mass and less time for a 1asn to “blow up”. Dirac was right about gravity varying with the passage of Cosmic time, he never derived a viable geometric model; I have.

Snowflake.

Hi Tobin Dax and Doctor Don

You guys still there? I answered or addressed your issues, any questions. Any defense for your position now Doctor Don or are you going to rest on your "authority" rather than logic?

Snowflake.

There is a reason for the silence: The first principle of cosmology states you can only use local observables: You can only assume gravity was greater in the past if you can point to evidence that it has continued to decrease in the present. Our understanding of the burning process of Ia's, and the metal peaks we observe indicate they are on average the same size today as they were in the past - there is no scientifically valid reason, given our observations of their spectra, to assume that they were smaller. Since there is no validation of this, and no logical argument to counter your assumption, there is nothing left to debate. You may be right, but how would anyone test the hypothesis?

And if you want to accuse the mainstream of using the same type of argument, as long as they can extrapolate to a BB, as long as they can stuff the Dark Energy in predictable holes, as long as they assume the tractor beam is always on and follows a predictable pattern of behavior, they have a shaky be testable theory. Almost.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

i dont really know but i HOPE its decellarting

Hi Jerry Jensen

Thanks for the response,

You made the following point regarding the effect of gravity being greater in the past.

“You may be right, but how would anyone test the hypothesis?”

You are absolutely right regarding the ability to test the hypothesis locally. According to the proposed hypothetical relationships there is no way to locally ever detect changes in the effect of gravity. All clocks will locally keep the same relative time, and all local rulers will keep their relative measure. A “year” will always be measured as a ‘year’, no matter if one uses a light clock, pendulum, vibrating crystal or chemical reactions. The effect of gravity will always be measured to be the same. When you do the algebra it is seems to be too cute to be real, but it is describing a specific geometric relationship of space-time.

If the effect of gravity is greater in the past, while it is locally unobservable, evidence of this should be indicated by observing objects in the past. Orbiting systems observed in the past should appear to be revolving around each other with velocities that are too fast to remain in stable orbits. This is observed but it is presently assumed that there must be more mass within the system than what can be seen, hence dark matter and black holes.

A quasar is the best example illustrating how the effect of gravity varies over the passage of time. A quasar is a young galaxy. Since quasars are observed in the past, according to the proposed uniform expansion theory, we are observing a galaxy when it was much smaller and denser than it presently is. Since the effect of gravity is so much greater in the past, the rate of energy production is dramatically increased. I presented a “paper” on this topic earlier on the BB (http://www.badastronomy.com/phpBB/viewtopic.php? ). It explains the energy production of a quasar without resorting to a “black hole”. One of the benefits of this model is that it also helps explain the lack of evidence of time dilation expected from quasars. (Although there is some variation in the correlation of time dilation due to red shift) Another benefit of the model is that it explains the lack of correlation of the observed image size of a quasar according to red shift.

According to the proposed model, the expansion of space-time is decelerating in absolute measures. In relative measures, there is no expansion whatsoever. This seems ambiguous but an expanding balloon can help explain the contradiction. If a series of circles are drawn on an expanding balloon, proportionally the circles keep the same relative measures, assuming all the local rulers are also expanded with the expanding balloon.

From an “absolute” perspective outside the expanding balloon it is possible to describe the expansion of the balloon. Relative measures remain the same, but absolute measures do not. The tricky part is that both measures of reality must conform to each other. Celestial systems must be stable, atoms must be stable, etc., for all objects as described by both frames of reference.

So how does one test the hypothesis? One explains what is observed with a simple set of consistent rules, without resorting to assumed cosmological constants, dark energy, dark matter, and other stuff dreamed up to keep the current model in accordance with observation.

Snowflake.

The devil is in the details. The rotational velocities are only out of wack at the edges of distant galaxies, not throughout the galactic plane. And the observed artifact is nonlinear, with respect to newtonian gravity. The rotational aberration is also nonlinear with respect to distance, and your theory would predict neither of these observations.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

This is probably a stupid question, but :
The mass gradient from core to edge will change, and as far as I know there is no reliable way to measure what it is. Without reliably knowing this, how can we say the rotational velocity is the aberration. I could just as easily claim that since the rotational velocity doesn't match theory then we can use it to calculate the mass gradient from core to edge of the galaxy in question. Or am I thinking off target?


Regards,

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MrObvious

MrObvious: As far as I know, that's how it's done. Look at star A, calculate its velocity. Figure out what orbital speed should be based on visible matter, note the difference. Solve for M (what the mass would have to be to retain the star in orbit about the galaxy). M is bigger than visible matter around star A, or even in the galaxy. So, we assume invisible matter. And from expected and determined velocities of stars we can build up a profile of the expected or required amount of matter necessary to cause the observed velocity.

That's how I understand it. You can also test gravitational lensing with distant galactic clusters.

Hi Jerry Jensen

Thank you for your response.

You said
“The rotational velocities are only out of wack at the edges of distant galaxies, not throughout the galactic plane.”

The rotational rate of stars within the core of a galaxy are also rotating “too fast”, so it is assumed within the cores of galaxies a black hole with the mass of millions of suns resides. This “discovery” of so much mass within the core of a galaxy is recent and has altered the light to mass ratio assumed within galaxies.

Your are also right regarding the rotational velocities of a galaxy at the edges, the effect of gravity would have to increase at a non linear rate with respect to the radial distance to keep the stars in a stable orbit. This effect is predicted. The effect of gravity is a function of Cosmic or Absolute time, (according to my uniform expansion model), which is a measure of ones location historically from the beginning of time. The gravitational relationship between two objects is therefore dependant upon when or where historically the two objects are observed.

In order for my model to account for the increasing effect of gravity with respect to radial distance there are “adjustments” that have to considered. The first is the time that separates the two objects; this determines how far back in time the gravitational relationship was established. A star 50,000 light years from the core has a gravitational relationship with respect to the core based upon the effect of gravity 50,000 years in the past.

This adjustment is not enough to account for the velocity profile observed within a galaxy unless the “absolute” age of the universe is decreased dramatically, something less than a billion years old. (Note, based upon “relative” measures of time, the universe is nearly infinitely aged). Such a reduction is highly unlikely, for a variety of reasons, so a second factor has to be considered.

There are two choices my model allows. The first is the “dark matter” option, the second is to consider special relativity.

The ‘dark matter’ option. While I tend to dismiss dark matter, my model does allow the existence of unobserved matter. It is my contention that galaxies start off as small rapidly rotating “threads” due to the 4th dimensional collapse of space. This influx of materializing matter from an “unobserved” dimension is observed within the cores of galaxies but it is attributed to other causes. Not all the matter from the unobserved dimension has ‘threaded through” to our universe, but the gravitational interaction of this ‘unobserved’ matter with our observed universe can be inferred.

The second option is to consider the effects of Special Relativity. This is my preferred option, but it too has issues resulting in assumptions that are untestable and assumed to make the model work. The rotational rates of galaxies, according to the proposed model, was much faster in the past, The speeds at the beginning of the universe are relativistic. The clocks within the cores of galaxies are slowed relative to the clocks of stars found on the “edge”. When this effect is added to the mix, it then becomes possible to explain the observed velocity profile of stars across a galaxy. Now the gravitational relationship between a star at the edge of a galaxy and the core are not determined by a 50,000 year separation in time, but hundreds of millions of years.

One of the “complifications” of this second option is that the spectra emitted from matter should be “bluer” as one approaches the core. This is because in my model even matter expands and a photon emitted form a denser atom would have a higher energy. In order to resolve this issue I have to assign physical attributes to the photon that forces it to conform to the location in time it finds itself in.

The trouble with dealing with the details, the details tend to get more complicated and take longer to explain and they take much more than a quick note to resolve. There has to be numbers cranked out that predict or conform to what is observed,

I must admit that regarding the velocity profile observed for stars within a galaxy, I find myself in a somewhat similar position as the advocates of dark matter. Those advocating dark matter state the matter must be there due to the observed velocities of stars in galaxies. For me, I have to adjust when the gravitational interaction between two bodies are historically determined. I have yet to do a good mapping, but “envelope” calculations indicate a velocity profile in accordance with observation with respect to the effects of special relativity. More over, my theory predicts that the cores of galaxies would be rotating ‘too fast’ and that the edges of galaxies would be also rotating too fast, based upon the inferred mass based upon luminosity, it is just that the magnitude of the effect has to be “massaged” into place.

Snowflake.

"Accelerating or decelerating?"

Neither!

Everything is static, and the differences between observed reality and reality are nothing more than smudges, smears, and lens abberrations...

And really large, high-velocity gas clouds transiting our parsec...

No, your questions are always a refreshing reality check. When the rotational abberation was first noted, and (this is based upon the luminosity to speed ratio and the assumption mass and brilliance are correlated,) the edges of galaxies had more burned out and therefore darker stars...Observations of nearby galaxies ruled this out, and everything from wimps to Cooper states have been thrown at the problem.

Personnally, I am torn between a Huygens effect (CREIL) and a second term in the proper equation for gravity. I tried for a long time to figure out whether the redshift function is intrinsic, gravametiric, cosmic non-Doppler, or Doppler before concluding it has to be all of the above. Perhaps this is true of this MOND effect as well.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

That's a scary thought, I threw in the mass gradient as an example of just how easy it is to take a non-sensical stance without enough information to begin with. If this is the basis for dark matter calculations then believing in BBT and dark matter are mutually exclusive or it's time to do some serious revising of the theories.


I don't know enough about these effects apart from doppler but would be interested in learning. I'd also be very interested in seeing some graphs of the non-linear mass/velocities.

Regards,

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MrObvious

Obviously!

But it is worse than that, Dark energy is delineated from dark matter because the anisotropy peaks in the CMB fall short the predicted values.

try http://arxiv.org/PS_cache/astro-ph/p...3/0403610.pdf] (Mcgaugh) the graphs are in the back.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

Excellent! Maybe we should rename this era the dark ages....

Thanks for the link too, be reading it at home tonight.

Got a question for you about spectography since it seems you spend some time in the feild. I've read on a few occasions that it uses the peaks to determine luminosity. I'd have thought it would be area. The other thing is, what is the seperation (resolution) for the varying frequencies, typical and best would be nice to know.

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MrObvious

I don't think this is correct: Yes, this is how 'they' interpret the data, but 'they' are bumping the observed luminosity up against the GR distance modulus. None of the standard candles are correctly mapping the predicted distance/attenuation function without fudge factors. A more reasonable interpretation is that the distance modulus is wrong and 'they' are underestimating the distance to and therefore the size - luminosity of the galaxies.

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jwj

It's a big universe out there...is it really unwinding, really burning out?

So you mean gravity depends on where we are in galaxy.
If this is true, then we are making huge errors by extrapolating "our" gravity to the whole universe, kuz "our" gravity depends on the position of solar system in the MW, our galaxy.

Either our laws of gravity are simply local. or these laws aren't the same all over the universe.

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Knowledge is Success ...............

I read the paper and something started bothering me. The core of a galaxy outputs a huge amount of energy directed outwards from the core. Surely this will affect the expected rotational velocity at a given radius and it would vary non-linearly. Without digging into the subject too deeply it occured to me that this force would appear as an acceleration on a body with a large surface area, eg a star.

Though I haven't done an exaustive search for such studies, all the ones I've read don't seem to mention this as a possible contributing factor in the expected rotational velocity for any given radius. This should be relatively simple to verify for anyone with access to the raw data.

Regards,

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MrObvious

Checking the poll, I see 60 % for accelerated vs. 20 § for decelerated.
Is this poll neutral ?
knowing that folk prefer an acceleration in pay increase, in economic growth, in job creation ... thus accelaeration has a postive image and decelaeration a negative one ?

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Knowledge is Success ...............