1st of all Nereid (or is it nereid? ), Thanks for staying with me. I see you all over the board, setting straight every imaginable misconception under the sun. And I just won’t give up on my ATM, although support (so far) has amounted to about several one-handed claps. But the DEILE idea was not dreamt up yesterday over beer. The main objections (so far) fall into the category of, “That’s not what the textbooks say…” Right. That is why it is in the ATM section.

Naturally, I’m suggesting there is something fundamentally flawed with BBT cosmology. This really should come as no surprise. For comparison, outside the scientific community, controversy rages over Evolution; but not within. Outside the scientific community, controversy rages over Global Warming; but not within. On the other hand, outside the scientific community, the BBT is blithely accepted; but not within. There is immense dissatisfaction with BB cosmology within the scientific community. Not so other mainstream scientific theories.

IMHO, the problem lies not in the theory of GR, but with the BB model. Newtonian gravity is a theory of gravity, but it is not a model of the solar system. Likewise, GR is a theory of gravity, but it is not a model of the universe. I believe the problem goes back to the FRW model, not GR.

Before I try to explain why the FRW model is not real (it is subtle), there are two key points I keep making and you keep ignoring, and both are utterly crucial to “getting the picture.” The first, the duality of the situation; the idea that contraction and expansion are both occurring at the same time, a la the wave-particle duality of quanta. Second, that there is another way to interpret the data, just as Copernicus showed there is another way to interpret planetary motion.

Please make clear where you stand with regard to these 2 assertions.
Okay...you asked for it.

The basic Hubble relation is that a remote source ("center of contraction"), at a distance of r > 5 Mpc, will be seen receding at a radial velocity v, proportional to its distance:

v = H*r (1)

So, we just assume, in our model, that H is constant. Since radial velocity is change-in-distance with time, we can write:

v = dr/dt = H*r (2)

To get acceleration, a, we just take the time-derivative of velocity:

a = dv/dt = H*dr/dt = H*v (3)

And this is exactly what is observed (ignoring small correction for GR): acceleration equals H-times-velocity, as in (3), which was arrived at by assuming that H is constant. QED: H is constant!

Furthermore (as if math doesn't count), a constant value of H solves the ancient galaxy problem once-and-for-all. Solving (2) for time, we get:

dt= (1/H)*dr/r (4)

To get elapsed time, we integrate (4):

t2 – t1 = 1/H*ln(r2/r1) (5)

where the subscripts 1 and 2 denote starting and ending time/distance. We can set t1 = 0 for convenience, but setting r1 = 0 results in a divide-by-zero, giving an infinite time. Implied is an infinite time back to zero size…plenty of time for galaxies and nucleotides to form. Again, the assumption—that the Hubble-constant is constant—fits the observations. As a bonus, there is no singularity problem, and no phase transition, so no missing magnetic monopoles.

But wait…that’s not all! If H is constant, the horizon problem completely disappears, because the rate of expansion has always been small, so there is plenty of time for uniformity to be established. Ergo, you do not have to invent new laws of physics (Inflation) to explain it. You do not have to invent an ad-hoc cause in the remote past (the Big Bang) to set it in motion. You do not have to postulate a mysterious energy field (Dark Energy) to expand it in the present.

You just have to explain why H, the rate of change, is a non-zero positive number.

And again, the reason H is a non-zero positive number (at distances > 5 Mpc) is because the rate-of-change at distances <5 Mpc is a non-zero negative number. The on-going contraction releases gravitational energy, driving the on-going expansion. And since space is expanding at the rate it is being driven (in the DEILE hypothesis), it should be perfectly flat. Again, exactly as observed.

So the flatness problem, the horizon problem, the singularity problem, the missing magnetic-monopole problem, the ancient galaxy problem, and the acceleration problem are all consistent with the hypothesis that the Hubble-constant is constant.

That’s a pretty full table, wouldn’t you say? I know you can name a theory (the BBT) that contradicts the constant-Hubble-constant hypothesis. But can you name an observation that contradicts it?

The heart of the DEILE thesis is energy balance: the energy being radiated away today is powering the expansion we’re seeing today. Stars supply the vast majority of the radiant power out there. The whisper of the CMB adds no support to the theory, and the theory says nothing about it.
The whole point of the DEILE idea is to explain the Hubble relationship…assuming H is constant (see yesterday’s post). The idea behind the idea is that the expansion rate is now and always has been very small, and is therefore easily explained.

Thanks, Bob
I'm not sure I understand the question.

I’m sure I don't understand the question.

At least we agree on something!

OK.OK, I'll discuss this further in my response to "yesterday’s post".Or, in my own words, the work to work out the extent to which DEILE matches observations on the abundance of elements and nuclides has not yet been done?Large-scale structure can be thought of (crudely) as the degree to which the universe is inhomogeneous, by size.

IOW, if you slice up a cube, 1 Mpc on a side, into 1000 smaller cubes, what is the variation in the content of each cube?

Repeat, with a cube 10 Mpc on a side.

Repeat, with a cube 100 Mpc on a side.

...

You can think of 'content of each cube' as 'how many galaxies are in this cube?'

(The P(k) in the Tegmark webpage has a precise, quantitative definition of these ideas; the data are from SDSS).

If the universe gets smoother, as you go up in scale, then the variation in content, among the 1000 cubes, gets smaller (as the cube from which they were made gets bigger).This is just Olbers' paradox (why is the night sky dark?).

The observations are that, no matter what waveband you observe in (other than those in which the CMB is detectable), the more carefully you observe, the less 'diffuse background radiation' you see ('the night sky is dark').

This is (or was) a paradox - if the universe is static, infinite, and homogeneous (on scales above~100 Mpc, say), then it should shine as brightly as the surface of the Sun.

So, to what extent can DEILE match the observations that the night sky is dark (that there is, apparently, no diffuse background radiation, other than the CMB)?

Not quite what I was asking about.

Let's make sure we have a common basis for discussion, shall we?

The "Hubble constant", H₀ is simply the slope of the line in the Hubble diagram - a plot of redshift against distance - at the present time (that's the subscript 0).

From a observational point of view, we can ask "to what extent do the data, when plotted in a Hubble diagram, fall on a straight line?" (within the limits of the errors, of course)

If the data do so fall, then the Hubble constant is constant. And one interpretation of such a straight line is that there has been no change in the rate of expansion of the universe, as far back/away as the furthest data points on the diagram.

If, on the other hand, the data show a clear ("above the noise") trend away from a straight line, then the Hubble constant is not constant.

A simple approach is then to see, in such a case, if the data fall on a line that can be described, so the residuals are "just noise", in terms of two parameters, H₀ (the Hubble constant 'now') and a deceleration parameter, q₀.

My question to you can now be rephrased as "Can you provide observational data showing that the deceleration parameter, in the Hubble diagram, is zero (within the limits of the noise in the data)?"

My assertion, way back in this thread, is that there are now hundreds (thousands?) of good, independent data to show that the deceleration parameter is not zero (here is a popular page showing this; here is a somewhat dated backgrounder; and here is the wiki page on the Hubble constant).So, if we're on a common wavelength now, the answer to this question is "Yes, and yes"

(I will address the first [snipped] part of your post later)

So let’s clear the waters.

Assuming the “standard” interpretation of red shift, the observation to-be-explained is the Hubble relation:

dr/dt = H*r > 0 (r > 5 Mpc) [1]

Initially, a hypothesis was put forward, that there was a big explosion in the past. But that didn’t work, due to the horizon and flatness problems. So a 2nd hypothesis, Inflation, was added to the 1st. But then, along came acceleration problem. So a 3rd hypothesis, Dark Energy, was added to the first two! And you can clearly see that the DEILE hypothesis does not jibe with these other 3 hypotheses, so you are assuming something must be wrong with it.

But the DEILE hypothesis is a different hypothesis. It must be judged on its own merits, not on its compatibility with the preexisting, convoluted conjectures it is intended to supplant! Consider just the Hubble relation [1], and compare it to an observation made long before Hubble’s:

dr/dt < 0 (on average, r < 5 Mpc) [2]

The DEILE hypothesis it that [2] explains [1]. [2] is associated with the release of energy, which we see as radiation. [1] is associated with a gain in energy, per the law of gravity. The energy released by [2] explains the energy required by [1]. It doesn’t work in a Newtonian universe with one fixed, absolute frame-of-reference, but in the everything-is-relative real universe, local contraction occurring simultaneously with non-local expansion is not a problem.

Or is it? You are continuing to ignore this assertion, that the universe is fundamentally bipolar or dualistic. Remember, the idea that light had to be either a particle or a wave was a stumbling block to progress for a long time. You cannot understand light until you accept that it is doing two things at once: waving and "particlizing." And you cannot understand the cosmos until you accept it is both expanding and contracting. Your statement, “The expansion of the universe is automatic…well, contraction is also a solution…” reflects an either-or prejudice.

If you do not see that the universe is contracting [2] even as it is expanding [1], then you are not seeing the forest for the trees. You could be literally missing half the picture, and my words befuddle you, because they describe the part you are not seeing.

But so far, you have not weighed-in decisively on either side of this key observation.

Yeah, you can put it like that. I’d say one step at a time.

That’s what I was thinking…

The important point is that DEILE is a theory of evolution. It aims to explain the instantaneous rate of change, the present 73 ppt/yr expansion for r > 5 Mpc, not the structure. Nonetheless, the DEILE belief that “H is constant until proven otherwise,” as we saw above in the math-section, translates to a much longer history. So there has been much more than 14 byr for the observed structure to form.

At the same time, central to the DEILE hypothesis is the assumption that the universe is “flat,” or uniform, from “large” scales off to infinity. The graphs seem to show that variation approaches zero at large scales. Is that a correct interpretation? If so, the DEILE hypothesis rests on this observed large-scale uniformity, on the one hand, while providing plenty of time for small-scale structures to form, on the other.
Just wanted to make sure...
This is covered in more depth in post 55, though not in terms of Olbers’ paradox.

What those results show is exactly what I am asserting, i.e. the expansion is accelerating at a rate equal to H*v. This follows immediately from the hypothesis that H is constant, as I showed in post 91. The reason this is not clear from their reports is that they are expressing their results in terms of the “holy trinity:” the Big Bang, Inflation and Dark Energy. But if you peel away the convoluted interpretation, and simply plot acceleration vs. velocity, the same way Hubble plotted velocity vs. distance, it’s a straight line with the same slope, i.e 73 ppt/yr.

Keep in mind, this is to a first approximation. When I say “constant-H,” I really mean “changes very slowly.” In the DEILE hypothesis, the expansion rate is related to the contraction rate, that is (approximately) the star formation rate. The star formation rate is known to be slowing down, so H should be slowly decreasing. But let us be clear on what the real bone of contention is here. The basic observation is: remote objects are (apparently) receding, and the remoter the object, the faster is the apparent recession. The question is this:

Was that recession velocity attained all-at-once, or was it attained gradually over billions of years?

In the BBT picture, the recession velocity is assumed to have been attained essentially all-at-once, during the Inflation era. In the DEILE picture, recession velocity is attained at an infinitesimal rate over cosmic time-scales.

The difference between these two ideas is the difference between Creationism and Evolution. In the Genesis story, life is created all-at-once. In one divinely inspired moment, God creates all the plants and animals (and disease-causing microbes…what was He thinking!?!). In the evolution story, these things take “billions and billions” of years. Now, there is nothing to say God could not have done it all-at-once, a la Genesis. But evolution is a much more natural explanation. Likewise, there is nothing to say that Inflation could not have accelerated an entire galaxy to half the speed of light in a trillionth of femtosecond, a la the BBT. But the DEILE hypothesis, that it took “billions and billions” of years to reach such velocity, is a much more natural explanation.

So the DEILE hypothesis explains one observation (on-going expansion) based on another observation (on-going contraction). It is simple and natural, and makes no ad-hoc conjectures. The BBT, on the other hand, attempts to explain the same observation by invoking 3 completely unnatural ad-hoc conjectures, while simultaneously completely ignoring the on-going contraction.

What the textbooks ignore is not a fault with my observation. The point is, you understand the earth-moon system (I’m assuming!), so it is a starting-point to understand the universe. Like the universe, the EMS is a gravitational system undergoing expansion. Earth’s rotational energy is being converted to gravitational energy, so the distance between earth & moon is increasing, i.e. the system is expanding. Conceptually, it is the same with the universe. The only difference being we are not certain of the source of energy in the case of the universe. The mainstream is saying this energy is dark. I’m saying it’s light.

But whether it is dark or light, something is supplying energy to remote objects, so the distance between remote objects is increasing, i.e. space is expanding.

The EMS is also the starting point of the observation that all gravitational systems are in flux. The moon is spiraling out; Phoebos and Charon are spiraling in. No gravitational system will hold perfectly still. Every system, when you examine it at the level of parts-per-trillion per year, is changing, plus or minus. So we should expect that the universe at-large is like every sub-system of which it is comprised: changing!


First, I have put the relevant Newtonian equations on the table, and no one has said, “Yes, that looks right,” or, “No, you forgot (fill in the blank), so your estimate is off by 36 OOMs.” If we cannot agree it looks right or wrong within 36 OOMs using Newtonian math, why bring in GR?

Second, I would say, isn’t it obvious something is wrong with the BB model? The math is only as good as the model it is based on, after all.

Part of the “wrongness” with the model, however, is the part you keep ignoring, so I can see how it would not be obvious to you.

And that part is the duality; the (net) contraction occurring at distances < 5 Mpc even as the (net) expansion is occurring at distance > 5 Mpc. It’s just completely absent from the models. It’s not to be found anywhere in the equations, which express but one distance scale, r. But there are two distance scales in the universe: r < 5 Mpc and r > 5 Mpc. In the former realm, dr/dt (net) is a negative number; in the latter, dr/dt = H*r, a positive number. If your model does not include these two different distance scales, it does not reflect reality. The math may be bullet-proof, but if the model does not take into account these two realms, it’s just a paper tiger.

The DEILE takes duality to heart. In fact, duality is the heart of the DEILE. The universe is doing both. The one (local contraction) explains the other (non-local expansion).

A Hubble diagram plots speed (or redshift) against distance. If the data fall (more or less) on a straight line on such a diagram, the slope of the line will be in units of <speed> over <distance>, which is just <frequency> (or <inverse time>).

If you are "asserting [...] the expansion is accelerating at a rate equal to H*v", then we need to look at a different diagram, one plotting acceleration against speed.

Can you provide a link to such a diagram?

Alternatively, can you confirm that you have, yourself, found the (acceleration, speed) data, plotted it, and could (in principle) share it with us?

But, as you say, nothing quantitative.

Or maybe not: "So there has been much more than 14 byr for the observed structure to form"

How much longer?

Why haven't we found galaxies or quasars (or GRBs) with redshifts of 10, 30, 100, ... 1 million?I re-read post 55, and apart from not being able to open Figure 1, I couldn't see how it addresses Olbers' paradox.

Specifically, there's nothing which tells me what the diffuse, background electromagnetic radiation should be, in the DEILE universe.

How bright would it be? How would that background brightness vary, across the various EM wavebands?

Right (except speed-over-distance is inverse time, not frequency). This is why I insisted at the beginning of this thread in expressing H in units of inverse time, 73 ppt/yr, instead of the highly-misleading km/sec/Mpc.

But the disconnect has a lot to do with interpretation. Technically, all we have are some spectrums of remote-looking points of light. So the question is, what are we looking at? What the observers do is characterize the spectrum in a certain, and say, “This looks like a type 1a SN, a standard-candle of known peak absolute magnitude X.” And they plot the observed magnitude against the observed red-shift on a graph. If the expansion is unchanging, and all the assumptions about the points-of-light are correct, you get a straight line, magnitude-vs-redshift. If the expansion is slowing down, however, as predicted by the BBT prior to 1998, the line will curve down at large redshift. If the expansion is accelerating, as “postdicted” by the DEILE, the line will curve up.

So how do we determine if the line is straight, curved up or curved down? This is very difficult, and was not done definitively until 1998. But why was this observation so hard to make?

First, as a point I have made repeatedly, the expansion does not really stand out from local variant motion until about 5 Mpc, so there is no “line” at all on the LHS of the graph, its just data points all over the place. Then when you get out past 5 Mpc, everything is pretty faint, and there are few good distance indicators, so it is very difficult to get rid of the noise, and make the data settle down into something clearly “trending up” or “trending down,” i.e. accelerating or decelerating.

Here’s the kicker: if you follow my math in post 91, you will recognize that I am arguing that the expansion is exponential:

r(t) = r(0)*e^(H*t) {r being distance; t being time}

This means that velocity-vs-time is an exponential curve (things go faster and faster). But when the value of the exponent is such a small number (0.0000000073/yr), it looks very much like a straight line, until you get to immense distances! And since the data points are all over the map, about all we can see is that the line curves up, and we can argue ‘til the cows come home whether it is an upward-curving exponential curve, as per the simple DEILE thesis, or some other kind of up-ward trending curve, per the fancy-dancy mainstream BB-plus-Inflation-plus-DE FRW universe with GR and tensor-matrix algebra. In the limited range where the data are clear, the simple DEILE model and the convoluted BBT are indistinguishable.

This is why I keep saying there are two ways to interpret the data. But precisely because there is not clear-cut observational distinction between the models, we must return to the more fundamental concept: duality.

At distance scales of less than 5 Mpc, the average distance between things is decreasing; at distance scales greater than 5 Mpc, the average distance between things is increasing. Mathematically:

dr(ave.)/dt < 0 for r > 5 Mpc
dr(ave.)/dt = H*r > 0 for r < 5 Mpc

In other words, there are two fundamental realms to consider: the near and the far. In the near, there is a net falling-in. Only when you go to immense distance is there a net falling away. Now consider this observation in the context of Einstein’s famous conclusion that GR showed the universe must “expand or contract.” What I am asserting is the universe is not doing one-or-the-other, but is in fact doing both. Agree? Disagree? Have no idea what I’m talking about? This should ring familiar: recall that light turned out to be neither particle nor wave, but both.

This duality is so fundamental to the DEILE picture, yet so “looked past” (i.e. ignored) by the BBT that we must come to an understanding on this. Is the universe doing one-or-the-other, or is it doing both? Are you in agreement with the Ground Observation of the DEILE thesis, that the universe is in fact doing both? If not, what are you picturing? If we are not in agreement on this most essential issue, I have no idea what “world view” you are subscribing to.

I can make neither head nor tail of what "H" is supposed to be, in your idea, Peter Wilson - the (local?) constant of proportionality between speed and distance? between the (local?) acceleration and speed? something to do with "expansion"*??

So, what "r > 5 Mpc" observational data leads (or could lead, if one were to do the number crunching) to a determination of the (local) value of H, in the DEILE idea?

*"r(t) = r(0)e^(H*t)", whatever "r" and "t" may be.

I have searched, but found no one else proposing that the expansion is exponential, so I cannot provide a link to such a diagram. I have done the graph by hand, with calculator in hand and the appropriate magnitude formula (Euclidean/Newtonian), and the graph looks like the observations (Figure 6, bottom of page) up to about z = 0.7 (solid line). Above z = 0.7, GR kicks in and the Newtonian/Euclidean 1st approximation no longer works, I believe. But below z = 0.7, if you just assume H is constant, then recession velocity must increases at a rate given by H*v, and this simple relation spits out the solid line on the above figure, which the data points appear to follow.

Unfortunately, I misplaced the graphs (did the exercise in 2003), and my graphic skills are wanting anyway (for those who haven’t noticed that my Figures 1 & 2 are no longer viewable on MySpace…phooey on them!), so I’m having difficulty sharing the graph showing that

a(dv/dt) = H*v

is a good fit with the observations, thus H-is-constant is a good starting assumption.

Nonetheless, with a little imagination you can see that this is so. Picture an exponential curve. Now look at the Hubble Diagram. You can see that there is a range over which the exponential curve fits the data points.
At this point, we are stretching the observations to the limit, so there is no definite answer. As I showed earlier, if you make the same assumptions about the CMB that the BBT makes, then the CMB has stretched some 1100 times its original length, which gives it an age of 98 byr! But I will be the first to admit that assuming H has been constant for the last 98 byr is going way over the extrapolation limit!
As I’ve tried to make clear above, the H-is-constant assumption fits the observations out to the point where GR significantly changes the picture, and I cannot say if it does or does not fit the observations beyond that point. So I can say something like, “The observations are consistent with a model in which H has been more-or-less constant for the last 5 byr,” but I can make no such statement going back 98 byr!
And again, because in the DEILE hypothesis the expansion rate, H, is proportional to the contraction rate (basically the rate of star formation and galaxy growth), it should decrease with time as star formation and galaxy merging slows down. So the only definitive answer to your question I can give at this point is:

Since the time of photonic decoupling (the formation of the CMB), structure in the universe has had much more than 14 byr to form, but probably substantially less than 98 byr.

This inability to give an exact reckoning of the time available for structure formation is not a deficiency in the theory, however. The DEILE is about the present, not the past. All statements about the past are ancillary to the hypothesis, that the present rate of local contraction (r < 5 Mpc) supplies more than enough energy to drive the observed rate (0.00000000073/yr) of non-local (r > 5 Mpc) expansion.

I'm not surprised (that you couldn't find such a proposal), so it comes down to the hard slog of making your own diagram.This highlights a shortcoming in my earlier post - one doesn't need graphing skills; what you really need is the data (anyone with even Microsoft's XL <shudder> can turn data into nice-looking plots).

What dataset(s) do you think would, if plotted, show a match with the (exponential?) relationship your idea predicts? Is it only the Berkeley SCP (Supernova Cosmology Project) data?That's what I was half-expecting you to write, and half-hoping that you wouldn't.

Sadly, for you, that's not how science works ... at least, not that part concerned with determining how well one's idea matches the (good, relevant) observations - and I don't know of any shortcut to proper data analysis (if what you are aiming to do is test how well your idea matches observations).And, as I've tried to point out, this post falls way short of making clear that the DEILE idea, as presented so far, fits the observations.

If anything, at most it shows that the DEILE idea and the concordance cosmological model are indistinguishable, when using one's eye to judge 'fits of theory to observation', for some low-z data, when plotted.

Telescopes haven’t gotten big enough.

I can only assume there are astronomers trying to do just that. It’s one of those projects that grows exponentially more difficult: the sources get fainter and the spectra more forested with absorption lines. It’s the bane of astronomers: fewer photons and fuzzier outlines.
When I look at the Hubble Deep Field , I can easily imagine that if we only looked even deeper, at wavelengths even longer, fainter objects even further away would continue to make their remote existence know.

I apologize for “the projector not working,” so to speak.

Try Figure 1 .

Regarding what the diffuse, background electromagnetic radiation should be, in the DEILE universe, I have no idea. It is like asking the evolutionist what the 1st life-form was. The evolutionist knows only that on-going selection processes should produce on-going evolutionary changes. The DEILE idea is that one observation (on-going contraction) explains another observation (on-going expansion). It says nothing about a 3rd observation, the CMB, which is in reality the SMB (solar microwave background), according to Jerry Jensen .

As caveated, Post 55 does not explain things in terms of Olbers' paradox. To see the connection, let me use the phrase “Olbers’ Scenario,” meaning the state of affairs Olbers reasoned that we ought to find ourselves in. In Olbers’ Scenario, the sky ought to be lit up in all directions, uniformly as bright as the surface of the sun.

Post 55 attempts to explain the expansion by building a universe that is static, then looking at the difference between this drawing-board universe that is static, and the real one that is in a state of expansion. The two key differences are: 1) the static universe is made entirely of dark matter; 2) the static universe is Newtonian.

The static universe is pretty boring. Its just a uniform fog of dark matter—whatever DM is—stretching to infinity at uniform temperature, pressure and density. Now in our drawing-board universe, we add back in just radiant matter, but maintain Newtonian gravity and Euclidean geometry. Now we get a uniform fog that is lit up. Still, not much happens. Suppose the radiant matter is hydrogen gas. It is radiating like a perfect black-body. A uniform fog of black-body radiation permeates this universe, as well as the uniform distribution of DM and hydrogen. Potentially, the hydrogen gas could contract to form stars, and then interesting things could begin to happen, but there is no way for a clump of gas to contract in such a universe, because it is in a state of Olbers’ Scenario.

The sky is uniformly lit up in this universe, at whatever temperature the hydrogen gas is at, just as the sky is uniformly lit up in Olbers’ Scenario. So we can build a static-universe “on paper” that is Newtonian/Euclidean, but it is still a very boring universe, and nothing like what we see happening in our universe can happen (stars forming and furiously radiating energy into space), because it exists in a perpetual state of Olbers’ Scenario, where there is uniform radiation in all directions, so nothing can ever heat up or cool down. In order for a clump of hydrogen gas to form a star, it must be able to “cool down,” so to speak, that is, radiate away gravitational energy. But it is impossible for a body to radiate away energy if the body is surrounded by a sky that is uniformly the same temperature as the body! (Thermodynamics again... )

To understand this, remember that I’m an engineer, so you have to think like an engineer to follow the reasoning. What I’ve done is designed a static universe: Then I’ve said, “Ok, this is too static. Let’s add some light matter to the dark matter.” Adding light (radiant) matter to the dark matter opens some possibilities, but then we run into Olbers’ Scenario: the sky is at a uniform temperature in all directions, nothing can heat up or cool down. Nothing can really happen. The design is still too staticky.

So then one of the other engineers, Al, says, “What if we give the radiation somewhere to go to? We’ll throw out the Conservation of Space paradigm of Newtonian gravity/Euclidean geometry, and allow the volume of space to increase with time. That way, there is somewhere for the radiation to go, and star formation can begin.” And I say, “Right. And we’re right back to an expanding universe. It’s no longer static. Brilliant idea, Al!”

But the point is to show why our universe is not static. A static universe can be built—on paper—but it looks nothing like ours: it is entirely dark and Euclidean. If we then “fiddle with the design” to make it more realistic, first by making it light, we then run into Olbers’ Scenario, where the universe essentially starts out in a “heat death,” and nothing happens. So then we fiddle with the design one more time to avoid Olbers’ Scenario—again, trying to create a more realistic model—and Oops!, by force of necessity, we are back to a non-static universe.

So the engineer announces, “I cannot design a static universe that looks anything like ours—Olbers’ Scenario being among the difficulties encountered in the design process—so that’s why the universe is expanding.” To the non-engineer, this sounds like a non-explanation, but to the engineer, it just logically follows that one requirement (avoiding Olbers’ Scenario so stars can form) dictates another requirement (space must be able to expand). And that is the tie-in to Olbers’ paradox…I just explained it differently the 1st time.

Nereid, you are making this way too difficult!

H is the Hubble-constant, for heaven’s sake! It is the observed rate of expansion of the universe at distances greater than 5 Mpc. It is the rate of change in distance with time, the 73 ppt/yr, that pops out from the observations using the “standard” interpretation of redshift.

The DEILE hypothesis is that the observed expansion of the universe, known as the Hubble relation*, can easily be explained…provided the “H” in the Hubble relation—the Hubble “constant”—is constant! That is all there is to it!

*mathematically, with r being radial distance and t being time, for r > 5 Mpc, the Hubble-relation is expressed as: dr/dt = Hr

Take an example: a galaxy at 10 Mpc; distance between us and it increasing at 720 km/s. Now if the-Hubble-constant-is-constant, then it is also accelerating away, increasing its velocity (v) at a rate given by:

dv/dt = Hv

So the acceleration is [73 x 10^(-12)/yr]* 720,000 m/s = 53 x 10^(-6) m/s/yr = 53 microns per second per year (53 um/s/yr)! Gaining velocity at a constant rate of 53 um/s/yr, the remote galaxy could go from 0 to 65 mph in half a million years flat! And if it had been accelerating like that for all-time, it would have taken it 13.7 billion years to go from 0 to 720 km/s. But of course, in the constant-Hubble-constant model, the rate of acceleration itself has been accelerating, so it has taken much longer. If H is constant, it takes about 10 byr for the velocity of that remote galaxy to double. So it took something like 10 byr to accelerate from 360 km/s to the present 720 km/sec, and who knows how long it has been accelerating altogether? “Billions and billions” of years.

It is just so much easier and natural to imagine this scenario, that of remote objects gradually gaining velocity over immense time periods, instead of them all being blasted forth instantaneously by some unknown supernatural force (Inflation). It’s an oak tree growing slowly and steadily, instead of a stick of dynamite going off. It is evolution, instead of creationism. But most important, the model "works," instead of producing one wrong prediction after another.

Well…to begin with, the DEILE has it the other way around. :sigh: The “local value of H” (that’s kind of confusing…I prefer the more general, “local contraction”) determines the non-local (r > 5 Mpc) value. The energy released as things fall together locally supplies the energy taken up by things moving apart non-locally. I’ve estimated the energy given up by local contraction (post 33), and estimated the energy taken up by non-local expansion (post 60), and the former is far in excess of the latter, thus it is perfectly reasonable to postulate that the former “is the cause” of the latter, i.e. the mysterious energy causing the expansion of the cosmos is none other than gravitational energy.

Good ‘ol Gravity is causing the moon’s orbit to expand, and Good ‘ol Gravity is causing the universe to expand, as well.

[Moderator Note] This post has been moved from the Big Bang Theory Whats wrong with it? thread. [/Moderator Note]That’s it, exactly!

In the 1920s, Hubble shook the astronomical world by announcing a simple relation characterizing the recession velocity of remote galaxies:

velocity = (a constant)*distance

The constant now bears his name, designated H, and we write:

v = Hr (1)

where v is velocity and r is radial distance. As I demonstrate in the DEILE thread, which explains the reason for the above relation, if you make the “perfectly good” assumption that the “constant” in the Hubble relation is indeed a constant(!), then a single differentiation and substitution leads to the conclusion that:

a = Hv (2)

where a is acceleration.

And indeed, in 1998, teams in the US and Australia shook the astronomical world by announcing that, based on observations of remote type 1a SN, the expansion is in fact accelerating, according to the above relation…except they did not express their results so clearly, as above manner. Instead, they expressed their results in the convoluted, Escher-esque BBT paradigm, and missed entirely this simple relation in their results. To this day, it goes unrecognized…except here and now by Yours Truly. Cosmologists will tell you the expansion is accelerating, but try to get a straight answer on what the acceleration actually is…

Well, there it is (2)...your straight answer. Acceleration is equal to a constant times velocity. And that constant “just happens” to be none other than Hubble’s!

Put these two relations side-by-side:

v = Hr (1)
a = Hv (2)

In the 8 decades since Hubble’s discovery, however, no mainstream cosmologists bothered to do the—as Sherlock Holmes would put it—“elementary” math required to take you from the Hubble velocity-distance relation (1) to the observed acceleration-velocity relation (2). Furthermore, 8 years after the discovery of what should have been totally obvious, this simple relationship, a = Hv, remains totally unappreciated. Extremely difficult observations have born out this finding, yet the BBT model is so tripped up and tangled in itself that this simple, elegant and most profound relation (2) remains buried in the models and completely unknown.

That is what is wrong with the BBT.

Yes. I did it in 2003, IIRC, and it matched what SCP had on-line at the time, up to the point where velocity becomes a substantial fraction of c, at about 5 bly, at which point I could see by looking at the graph that the simple Euclidean model was not working, and indeed the calculation diverged from the data. Nonetheless, the fact that the exponential model works in the sub-relativistic realm means it is worth taking a look at.

A difficult observation would settle it once and for all: a long-term, precision redshift survey of quasars from 5 Mpc out. Re-measure their redshifts every 10 years or so. If the expansion is exponential, as in the DEILE model, then sources beyond 5 Mpc will redden at a rate of H! (wavelengths of a particular line will grow at 73 ppt/yr). No complex supernova models and uncertain intervening media to cloud the data. If steady, known sources redden at a rate proportional to H, then that is that; its over; the expansion is exponential.

But we do not have to go that far. A perfectly reasonable assumption atop straight-forward math yields a prediction of acceleration proportional to H, and that is apparently what we are seeing.

In the 1920s, Hubble shook the astronomical world by announcing a simple relation among remote galaxies:

velocity = (a constant)*distance

In 1998, teams in the US and Australia shook the astronomical world by announcing a simple relation among remote type 1a SN:

acceleration = (the same constant)*velocity

Except, this simple, ought-to-look-familiar relation was completed missed by all involved, because they expressed their findings in the BBT paradigm.

In the 1920s, Hubble discovered that the observations show:

v = Hr (1)

In the 2000s, I discovered and have pointed out that the observations show:

a = Hv (2)

Relation (2) is probably the most profound discovery in all of astronomy since the discovery of (1). And you mock me for this? Nereid, you are throwing paper stones.

Thank you, Bob. Exactly. You cannot have one without the other.

Again, when we look at observation (1), we can surmise two basic scenarios regarding the origin/history of the velocity, v: 1) velocity was attained all at once; or 2) velocity was attained gradually over eons. The BBT is basically the former; the DEILE is basically the latter. I say “basically” because as we know, reality is seldom black-and-white, but these are the two poles of the spectrum of possibilities. Either the expansion began suddenly at a particular instant, a particular amount of time ago; or the expansion has been on-going and gradual for an indefinite, but immense, amount of time.

These are the two basic possible histories of the observed velocity. I understand both possibilities, have studied them, and have decided the latter is the more likely.

Think of some of the schemes to divert the killer asteroid: apply a small force to a huge object over a long time period, and it gets the job done. As I point out in the math section, it doesn’t take much energy to increase the distance between things on the order of 1 part in 14 billion per year. Apply a small constant force and…things gradually change.

Such an idea is totally in synch with our every experience. In particular, everything changes. Some things appear constant, but even the stars move in the sky, and mountains wear down. On long enough time scales, everything changes. And the universe is changing on truly immense time scales. You can hardly even see it…it takes huge telescopes, sophisticated instruments, and tons of analysis to even ferret it out. But slowly, ever so slowly, really far away regions are growing even farther away.

And that’s just the way it is; nothing stays the same.
It’s always been that way.

[Moderator Note] This post has been moved from the Big Bang Theory Whats wrong with it? thread. [/Moderator Note]

v = Hr (1)
a = Hv (2)

That's interesting, and I have to agree that I have never heard of this before, so if what you are saying is true it is very elegant.

Can you go into a little more detail showing that the numbers work as you say. I have the impression that this accelerated expansion is a relatively recent thing. Also, what other factors are you using and omitting?

Anyway thanks for pointing out this cool relationship.

__________________
Forming opinions as we speak

[Moderator note] This post was moved to this thread, from the How should we determine which of competing theories is most likely correct? thread, where it was originally a reply to this Peter Wilson post, as it is more pertinent to the Peter Wilson idea (DEILE) - in fact, a powerful challenge to it. [Moderator note]

When I look here, it looks like your idea is predicting that the rate of acceleration of the expansion should be about 17 orders of magnitude higher than it actually is. That doesn't actually sound like a good quantitative explanation to me.

__________________
Conserve energy. Commute with the Hamiltonian.

Let's use H = 72 km/s per Mpc, which is 2.3 x 10^-18 Hz.

Let's take an object at 10 Mpc ("A" - outside Peter Wilson's "5 Mpc" magic distance), one at 100 Mpc ("B"), and one at 1000 Mpc ("C").

Applying the classical Hubble relationship, we have, for the observed (expansion of the universe) recession velocity:
A: 720 km/s
B: 7,200 km/s
C: 72,000 km/s.

Plugging the above value of H into the "discovered in 2000 by Peter Wilson" relationship, we have, for the observed recession acceleration (to ~1 decimal place):
A: 1.7 x 10^-15 km/s² (= 1.7 x 10^-12 m/s²)
B: 1.7 x 10^-14 km/s² (= 1.7 x 10^-11 m/s²)
C: 1.7 x 10^-13 km/s² (= 1.7 x 10^-10 m/s²).

Have I understood the "Peter Wilson relationship" correctly?

[Moderator Note] This post has been moved from the Big Bang Theory Whats wrong with it? thread. [/Moderator Note]You're missing the point. Yes, if the velocity is proportional to distance, then as time goes on, and we see an object move farther away, we will also see its recessional velocity increase. That's not what cosmologists are talking about when they say the expansion is accelerating. When cosmologists say the expansion is accelerating, they mean that it appears that the Hubble parameter is specifically not constant, and that it was lower in the past than it is now. That is what the type Ia supernova data seem to indicate.

__________________
Conserve energy. Commute with the Hamiltonian.

[Moderator Note] This post has been moved from the Big Bang Theory Whats wrong with it? thread. [/Moderator Note]First, let me nominate that for the BAUT Understatement of the Month award

Look again at the Hubble relation:

v = Hr

Three easy pieces: velocity, v; the Hubble “constant,” H; and radial distance, r. Notice that one of these pieces, radial distance, changes with time. It follows that if one parameter in this relation changes, then at least one of the other two must change as well. As Spock would say, logically, there are only 3 possibilities:

A. H changes with time
B. v changes with time
C. Both H and v change as r changes with time

Of course, in the messy “real world,” we know the answer is C, both change with time, but to a first-approximation, to arrive at the “basic picture,” one assumption or the other, A or B, is “basically” true. The BBT glibly assumes A to be “true.” It seems reasonable, because the gravitational field is so weak at the immense distances involved, there is nothing to substantially slow anything down. So modelers just assume velocity is constant, forcing H to change with time.

But in science, when you make an assumption, you are supposed to test it. When facing the horns of a dilemma, either of which could be true, you are supposed to do a binary what-if scenario. You ask: If we looked at the picture more carefully, what would distinguish A from B? You create two models, see where they differ, and decide which one better fits the data. Instead, the mainstream has simply assumed A, and never even bothered with B.

When the assumption A proved troubling (horizon and flatness problems) BBers just added another assumption (Inflation). When acceleration crashed the Inflation party in 1998, they just added another assumption (Dark Energy). Now that DE is proving troubling, some say we have to assume extra dimensions exist. Pretty soon it will be “assumptions all the way down”!

In science, if your 1st assumption is not working, you are supposed to try another. And the 2nd possibility (B) is that the Hubble-constant is constant, i.e. velocity changes with time. In this scenario, you immediately conclude that:

a = Hv

The difficulty is that we cannot measure acceleration directly…at least, not yet. Eventually it will be done, with long-term, high-precision redshift surveys of quasars. These will (I predict) show directly the above relation to be true, that is, wavelengths of known lines from steady sources will be found to increase at a rate equal to H, i.e. 73 ppt/yr.

What we have today is redshift and luminosity measurements of remote type 1a SN, thought to be good “standard candles.” A plot of magnitude-vs-redshift is made, and compared to the curve predicted by the model. Until 1998, the model had predicted a downward-trending curve, as per assumption A. But the data did not “trend downward,” as expected. Instead, the data points trended upward, indicating acceleration.

The vanguard was caught off-guard, and scrambling for an explanation, experts dusted off Einstein’s infamous “greatest blunder,” and gave it a new name. Lost in the whole affair was what, exactly, the acceleration is.

Naturally, it is very difficult to say, “what exactly” the acceleration is. Acceleration is not measured in the type 1a SN observations; it is inferred. Straight off, the only thing immediately apparent was that the expansion was not decelerating, as had been expected, but accelerating. To “measure” it, you have to construct a model with acceleration in it, and see if it fits the data. The mainstream simply took the model they had, which did not fit the data, and added DE until it did. (With a big enough hammer, a square peg can be made to fit a round hole.)

Nonetheless, I have built my own (round) model, using, a = Hv, did the calculations to convert from that beguilingly simple formula to the expected magnitude-redshift curve that ought to result, and it produced an upward-trending curve that fit the data points like a glove…until GR kicks in, at about half the speed of light. But failing to account for GR at truly immense velocities and distance is not a failure of the basic concept, as you will see.

If the large-scale universe is expanding in a manner given by a = Hv, then the distance between remote things grows at an exponential rate. Thus, the exponential curve represents a generalized time-distance curve of all remote objects, with the vertical axis representing distance, and the horizontal axis representing time.

The zero-point (0,0) is the here and the now. The distance between the time-line (y=0) and the curve is the distance between us and any remote (> 5 Mpc) object. To the left of center is the distance to it in times past; to the right is distance in times future. So you can see that remote object recede faster and faster with time, i.e. accelerate. The shape of the curve is always the same, whether the object is 50 Mpc away or 500 Mpc; only the vertical scale changes.

If we draw a line tangent to the curve at any point, the slope of that line represents recession velocity at that instant in time. If you draw the tangent line from “now” back to zero distance, you find that it intersects it (the time axis) at minus 14 billion years. That is, if a galaxy at 50 Mpc had been receding at its present velocity for the last 14 by (per assumption A), then it would have been right next door 14 by ago, per the BBT interpretation. But in the exponential model, a galaxy’s velocity has not been constant; it has been accelerating. If the expansion is exponential (assumption B), then 14 Billion years ago, it was receding at about 1/3 the velocity it has today, and it was about 1/3 the distance away, but still quite remote by earthly standards, at 17 Mpc.

Because the exponential curve always looks the same at all scales, the above result applies to all cosmic distances (> 5 Mpc). Everything “appears” as if it set out from the same point of origin 14 by ago! That is, a “snap shot” of the universe expanding according to assumption B looks exactly like the universe expanding according to assumption A! Except it is not; it is completely different.

When you appreciate that the two basic assumptions, A & B, diverge by only 1 part in 14,000,000,000 per year, you see why it is so blessedly difficult to tell them apart. If we could fast-forward the universe a billion years, it would be readily apparent. But lacking a time-machine, we have to infer difference from other evidence. And the “other evidence” (the flatness, horizon & acceleration problems) point to the latter assumption, that H is constant.

Finally, when you consider the exponential model, and appreciate that the steepness of the curve represents velocity, you realize that at some point the curve becomes steeper than the speed of light, and simple Euclidean geometry cannot work. This is where the 1st-approximation, a = Hr, no longer produces the observed magnitude-redshift relation. So what? It works half-way to infinity. It gets us on the right track. It fits the observations from 5 Mpc to 3 - 4 bly, and it does not suffer the Big 3 defects of the BBT.

It does not jump out, but it is there it in the type 1a SN data if you look for it:

a = Hv

Interesting, agreed. Very interesting.

[Moderator Note] This post has been moved from the Big Bang Theory Whats wrong with it? thread. [/Moderator Note]Again, this is simply false. The assumption is the reverse, that H is mostly constant. But the supernova data shows that a constant H doesn't work; instead H has to change over time to explain the observations.

As I've already said (and you seem to have ignored), when astronomers talk about the expansion accelerating, they are not talking about the increasing relative velocity between us and some distant object. Instead they are specifically talking about a change in the Hubble parameter in addition to that increasing velocity.

__________________
Conserve energy. Commute with the Hamiltonian.

No...I'm not sure where you get that from.

The estimate is not showing that the expansion should be 17 OOMs greater than it is; it is showing that there is plenty of energy availble to drive the expansion. The estimate is showing that the energy available to drive the expansion is many OOMs greater than the energy taken up by expansion.

Yes, except technically, H is not in units of Hz, which is "cycles" per second, but plain 'ol inverse time; and 5 Mpc is not a "magic" distance, it is a fundamental distance. Its like geo-synchronus orbit (GSO): below GSO (about 24,000 miles), satelites spiral in; above GSO, they spiral away. There is nothing "magical" about 24,000 miles; its just a fundamental distance, related to earth's mass and rotation rate. Likewise with 5 Mpc: it is not a magic distance, just a fundamental one, related to the universe's contraction rate and density. Within 5 Mpc, there is net contraction; beyond 5 Mpc, net there is net expansion. Nothing magical; just the way things are.

Thanks for the confirmation, and clarification*, Peter Wilson.

What is the recession velocity predicted by this Peter Wilson idea, for objects at distance of:
A) 10 Mpc,
B) 100 Mpc, and
C) 1,000 Mpc?

I note that it cannot be 720 km/s, 7,200 km/s, and 72,000 km/s (respectively), because there is, in the Peter Wilson idea, an acceleration term.

*I'm afraid that I don't "get" the distinction between frequency and 'inverse time' - they both have units of T^-1, don't they?

Secondly, how precisely can "5 Mpc" be specified/determined - in principle?
For example, could it be 4 Mpc? 8 Mpc? or only 5.1 Mpc or 4.9999 Mpc??
Does it vary, throughout the universe? throughout its history?

If you're postulating that this is the energy used to drive the expansion, then you'll need to explain why almost none of it is used to do so, and the rest goes somewhere else. This is the same problem that particle physics has when they try to predict vacuum energy from first principles, and come up with a number that's orders of magnitude too high. Even if I take your numbers as accurate, having a billion billion times too much energy is as much of a problem for a theory as not having enough.

__________________
Conserve energy. Commute with the Hamiltonian.

Okay, I guess its clear by now that the Light Energy of the DEILE hypothesis is not the Dark Energy of the BBT, even though I confused everyone at the start with the title of the thread, declaring that they are the same: Dark E. is Light E.

In the DEILE hypothesis, radiant energy is the driving force for expansion, but of a completely different model of expansion, i.e. exponential expansion, not linear. Yeah, yeah, I can hear the boos and hisses. Why didn’t you tell us that?

Basically, because you gotta’ start somewhere. :shrug: I can’t just say, The whole BBT is completely wrong. Well, actually, I just said it, but its not a good starting point, shall we say? I’m taking the same input data that the BBT uses, and painting a completely different picture. And I can only paint one brush stroke at a time.

As explained at some length in the BBTWWWI? thread, when we look at the Hubble relation, v = Hr, we realize r, radial distance, changes with time, so something else must as well, either H, v, or both. Basically, the BBT assumes that v is constant, and H decreases as r increases; basically, the DEILE assumes the opposite, that H is constant, and v increases as r increases. The kicker, however, is that observationally, these two fundamentally different “assumptions” diverge by only 1 part in 14,000,000,000 per year, so you have to look to immense distances to see any difference at all. And thus, direct evidence regarding which of these two basic scenarios is correct was completely non-existent until 1998.

Nonetheless, the evidence is now in, and it looks like the expansion is exponential. Some argue with this, obviously, but it is the starting point of the DEILE hypothesis: the expansion is and always has been (to a 1st approximation, again) the same, small, infinitesimal rate we observe today—as you put it, 2.3 x 10^(-18)/sec—and all that’s needed to explain this observation is a source of energy that will increase the distance between remote objects at a rate of 2.3 x 10^(-18)/s. Explain H—why it has a non-zero value—and you’ve explained the whole thing, acceleration and all.

To summarize, here are the key elements of the DEILE picture, so different from the BBT:

1. It is observed: v = Hr (the Hubble relation)
2. It is hypothesized that H in this relation is constant, i.e. a = Hv (exponential expansion/the Wilson relation)
3. In 1998, type 1a SN observations showed that velocity is accelerating, in a manner akin to the above relation (there is scatter in the data, so there is room for quibbling, but it’s a good fit)
4. It is therefore assumed that hypothesis (2) is correct
5. It is hypothesized that radiant energy supplies the energy needed to explain observation (1), the Hubble relation

Thus, light energy in the DEILE hypothesis is not supplying the dark energy of the BBT model—it is supplying the energy of a completely different model, i.e. the exponential expansion model. And in that model, the expansion rate is and always has been small; the energy required to drive the expansion is and always has been small; therefore, there is and always has been plenty of radiant energy available to do the work.

While I work on answering the most recent questions, here is a Pop Quiz:

Q. A quasar at 1,000 Mpc is accelerating—per the Peter Wilson relation—at 1.3 x 10^(-13) km/s^2. How long would it take it to go from 0 to 72,000 km/s, its present velocity, at that rate of acceleration?

As I've said twice now in that thread, which you seem to be ignoring, this claim of yours (that the big bang assumes v is constant) is false. That is, the starting point for the big bang theory is precisely the opposite, that the Hubble constant is constant. It's been well known for a long time that this leads to an exponential rate of expansion. The great idea that you have here is actually just the simplest possible starting model for an expanding universe. It's where you start with the math when working on cosmology, because it's the easiest case. I've done the work myself in an intro to cosmology class. Since the results of that simple model don't match what we see perfectly (though it is a good starting point), you start adding in the possibility that H might change over time. In fact, if there's any matter or radiation in the universe at all, it's easy to see that the Hubble parameter would decrease.

When astronomers talk about an accelerating expansion, they do not mean simply that a given object will increase in its rate of recession over time. Astronomers all know that, and it's a straightforward result. What they mean is that the evidence suggests that the Hubble parameter has increased over time, contrary to expectation that it should decrease.

This is one of the problems when you criticize a theory without really understanding what it's saying. It's great that you realized that a constant Hubble parameter leads to exponential expansion, but with just a relativity small amount of study, you would have realized that the mainstream already knows that, that this is a good starting point for a simple model, but that (as is typical of very simplified models), it doesn't match the data perfectly, and (also as is typical), we need to make the model a little more sophisticated. It's like working out ballistic trajectories without air resistance: it's a good start, but there's much still to be done. The sad thing is that you've somehow assumed that all the people that have spent their lives working on this are too clueless to have figured this out, when in fact they did so many years ago.

__________________
Conserve energy. Commute with the Hamiltonian.

Grey, I have absolutely no idea what you are talking about. Every
mainstream source states that H changes with time. If you run exponential expansion backwards, there is no beginning. But in the BBT, there is a most-definite beginning, some 13.7 bya. If it is "well known" the expansion is exponential, then why is this such a well-kept secret? Why aren't astronomers telling us the universe is of an infinite age, if they "all know" the expansion to be exponential?