Dark Energy is Light Energy - Page 3

Jerry · #61 (**permalink**) 01-May-2006, 04:05 AM

Quote:

Originally Posted by Peter Wilson

The expansion of the universe is a manifestation of the principle of Conservation of Energy.

Space expands in GR as naturally as water flows downhill.

You lose me here, because space should be defined as that which is nothing. Yes, I know Einstein's mathematicians came up with abstractions that give space dynamic properties, but rationally, these are absurbities on the same order as the emporers naked robe.

The fact is, Newton's calculations don't properly predict orbits. Einstein took a page from Aristotle and told us that is because it is the nature of space to expand and contract.

Peter Wilson · #62 (**permalink**) 01-May-2006, 06:17 PM

The odd thing is, the cause-effect relation between expansion and contraction is perfectly obvious in all non-infinite systems.

Take a core-collapse supernova. We think of these as explosions, but in fact, they are more intrinsically implosions. We would say the "cause" is gravitational contraction, and the "effect" is the observed expansion.

Take another example: NASA using Jupiter to sling-shot a space probe to Saturn. The space-probe's orbit expands, while Jupiter's orbit contracts. Again, straight-forward cause-effect: the contaction of Jupiter's orbit "causes" the expansion of the space-probe's orbit.

Another example: "Evaporation" of globular clusters. What happens in a crowded globular cluster is a sort-of random gravitational interaction among stars. And in these interactions, low-mass stars tend to pick up high velocity, whereas massive stars tend not to. So occasionally, a low-mass star will pick up enough velocity to escape, and it will "evaporate" (expand)from the cluster. The result, when you do the energy balance, is that some massive star must have lost gravitational energy, and is now closer to the center of the cluster. Again, it is straight-forward cause-effect: the contraction of the orbits of massive stars in the cluster "causes" the expansion of the orbits of low-mass stars.

In all these examples, gravitational contraction of one part of the system "causes" expansion in another part. Gravity causes the SN to explode (expand); gravity causes the orbit of NASA's space probe to expand; gravity causes globular clusters to expand; gravity is causing the moon's orbit to expand. Gravity causes expansion in all these systems.

All I am saying is this same cause-effect (action/reaction) principle applies to the universe at-large: On-going local contraction everywhere causes residual on-going cosmic expansion, "as naturally" as water flows down-hill.

Jerry · #63 (**permalink**) 02-May-2006, 07:54 PM

Quote:

Originally Posted by Peter Wilson

The odd thing is, the cause-effect relation between expansion and contraction is perfectly obvious in all non-infinite systems.

Take a core-collapse supernova. We think of these as explosions, but in fact, they are more intrinsically implosions. We would say the "cause" is gravitational contraction, and the "effect" is the observed expansion.

Not a good argument - if we understand the SN Ia process: To create the same type of explosion, we use high (conventional) explosives to trigger the same chain of events. The source of the initial energy - gravity or high energy explosives - is irrelevant.

Quote:

Take another example: NASA using Jupiter to sling-shot a space probe to Saturn. The space-probe's orbit expands, while Jupiter's orbit contracts. Again, straight-forward cause-effect: the contaction of Jupiter's orbit "causes" the expansion of the space-probe's orbit.

Another poor example - here, the gravitational assist is exactly akin to tacking a sailboat into the wind. Planets can just as easily be used to provide gravitational braking - I think the Messinger probe uses both Mercury and Venus to help it slow down.

Quote:

All I am saying is this same cause-effect (action/reaction) principle applies to the universe at-large: On-going local contraction everywhere causes residual on-going cosmic expansion, "as naturally" as water flows down-hill.

If you want to argue that gravitational squeezing of matter eventually leads to the release of primal energy in some cases, that may be true, but it is difficult to argue that all bodies that are contracting are causing expansion somewhere else. Since with these examples, general energy sources can be substituted for gravity, these examples are not definitive.

Nereid · #64 (**permalink**) 02-May-2006, 08:39 PM

Quote:

Originally Posted by Peter Wilson

[snip]

Interestingly, for a body of a given ATM, the expansion velocity does not depend on the distance from the source. Suppose the radiation pressure from the sun is pushing an asteroid-belt asteroid of a given ATM outward at 1 m/yr, and there is a Kuiper-belt object with the same ATM, only 10 times more distant. Ten times farther away, solar radiation pressure is 100 times weaker, due to the inverse-square law. But the gravitational field is also 100 times less, for the same reason. Because the driving force—radiation pressure—and the opposing force—gravitation—decrease in exactly the same proportion with distance, the net effect does not change with distance. The KBO of the same ATM will also recede at 1 m/yr. In the general 2-body radiant system, expansion velocity does not change with distance.

In summary: a radiant, two-body system expands at a rate that depends on the radiant power of the system, and the “Coupling-Parameter” of the 2nd body, which depends primarily on its area-to-mass ratio. Recession velocity for a given ATM does not change with distance.

[snip]

What is "ATM" (my bold)?

Peter Wilson · #65 (**permalink**) 02-May-2006, 11:29 PM

Sorry. ATM = Area-to-mass ratio

Nereid · #66 (**permalink**) 03-May-2006, 12:48 AM

Quote:

Originally Posted by Peter Wilson

Sorry. ATM = Area-to-mass ratio

Is it the same as "surface-to-mass ratio (STM)"?

If not, then how does it differ?

If so, then why two terms for the same thing?

Peter Wilson · #67 (**permalink**) 03-May-2006, 12:58 AM

Quote:

Originally Posted by Jerry Jensen

Not a good argument - if we understand the SN Ia process:

The example I used is a core-collapse SN. In the core-collapse SN, all of the expansion energy is gravitational. Gravitational contraction supplies the energy of the observed expansion.

Quote:

Another poor example - here, the gravitational assist is exactly akin to tacking a sailboat into the wind. Planets can just as easily be used to provide gravitational braking - I think the Messinger probe uses both Mercury and Venus to help it slow down.

Your counter-example just proves my point, that expansion and contraction always go hand-in-hand. The Messinger probe's orbit contracts, in this case, and the orbits of Mercury and Venus expand. It's the same conservation-of-energy principle: if one part of the system contracts, another part must expand. If you generalize this principle to the universe-at-large, you find that local contraction everywhere must result in cosmic expansion. The universe is expanding because the universe is contracting.

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If you want to argue that gravitational squeezing of matter eventually leads to the release of primal energy in some cases, that may be true, but it is difficult to argue that all bodies that are contracting are causing expansion somewhere else.

It is not an argument, it is an observation, and it is not "primal energy," it is gravitational energy that is released. Consider a mereroid careening through the solar system. As it approaches a body, it loses potential energy (PE), while gaining kinetic energy (KE); as it moves away from a body, it gains potential energy while losing kinetic. The whole time, the total energy (PE + KE) = constant. However, if that meteroid skims earth's atmosphere, then it begins to radiate away energy. That is why you can see it. When it finally falls to earth, all the gravitational energy that it had (wrt earth) has been radiated away. The earth-meteroid system has contracted, while the universe over-all has expanded. Granted, the contribution from one meteor is infinitesimal, but when you sum the contributions from all radiant sources in the universe, it adds up. As I argue in post 60, the total energy radiated away due to gravitational contraction in the universe is far, far greater than the energy taken up by expansion. Gravitational systems lose energy in the form of radiation as they contract, and some of this energy shows up in the expansion of the universe.

bigsplit · #68 (**permalink**) 09-May-2006, 07:40 PM

that dark energy represented over 70% of the total energy of the Universe with dark matter in the 20s and ordinary matter the least. If the local contration (dark matter and ordinary matter) produce the dark energy...it does not add up....or am I missing something?

Peter Wilson · #69 (**permalink**) 10-May-2006, 05:22 PM

It is evident the readers are having some difficulty figuring out just what it is I am trying to say. That is to be expected, because I am talking in a completely different paradigm.

I recently came across a draft of the idea I wrote in 1987, titled simply, “Why the Universe is Expanding”. Threw it in a drawer and forgot about it. In reading something I’d written nearly 2 decades earlier, I found myself saying a lot: “Huh?” The seed of the idea was there, but the explanation was convoluted and not at all convincing. So I kinda’ know how ya’ll are feeling.

Needless to say, this project to explain why the universe is expanding got side-tracked. I got interested again in 1998 when it was announced that the expansion was accelerating—which I already knew. Then when I got laid off in 2003, and with a lot of spare time, I began to consider in earnest: How in god’s name do I explain this? I’ve tried explaining it six million ways to sideways. I’ve looked at it from every possible angle, plus seven. It’s perfectly clear to me, but I’m still trying to figure out how to explain it to you.

An important first key is to understand the paradigm shift. It is like the shift from the Ptolemaic to the Copernican model of the solar system. To understand why the planets move in the sky the way they do, you have to abandon the in-born notion that the earth is stationary. And to understand the expansion of the universe, you have to abandon the idea that has been fixed in mainstream for eight decades: the explanation for expansion is to be found in the past. The mainstream has been barking up the wrong tree, because the answer lies in the present.

The explanation for the expansion of the moon’s orbit is in the present: the earth is spinning. The explanation for the expansion of the sun is in the present: nuclear reactions are taking place in its core. The explanation for the expansion of the universe lies in the ever present: the universe is contracting.

And when trying to follow the math, keep in mind that in an infinite universe, the amount of energy and matter is infinite, so you cannot do a “total.” You can only talk about “energy-per-unit-something.” In my accounting, I do the math in joules-per-kilogram. The mainstream uses energy-per-volume, which is equivalent to energy-per-mass, so long as you include the density. My approach may be unfamiliar, but it is more intuitive and straight-forward. Energy-per-unit-mass is less confusing than energy-per-unit-volume-at-such-and-such-density. So make the switch.

Quote:

Originally Posted by bigsplit

I thought that dark energy represented over 70% of the total energy of the Universe with dark matter in the 20s and ordinary matter the least. If the local contraction (dark matter and ordinary matter) produce the dark energy...it does not add up....or am I missing something?

No, you’re right. This is where it gets confusing, because I have no idea where the mainstream gets their numbers. In my estimate (post 60), the observed radiant energy is many, many OOMs greater than the energy required to produce the observed expansion (instead of OOMs less). In other words, in my estimate it does add up! Which is my point. The expansion makes perfect sense, and is to be expected, based on the observed contraction, without any additional energy besides that given up by local contraction. There is dark and light matter, radiation, local contraction, and cosmic expansion. It all adds up.

Quote:

Originally Posted by north

i agree to a point, but; the thing is though is that both can cause the opposite to happen. it depends on position of both relative to each other. explain further. i'm not quite sure what you mean.

Well, you’ve nearly explained it yourself. Its reciprocity, like the yin-yang principle, like the wave-particle duality, like north-and-south. You cannot have one without the other; cannot have contraction without expansion.

Quote:

Originally Posted by andyschlei

This implies action at a distance. The two skaters only spin faster as they move together because they are holding on to each other. There is no innate connection between largely separated bodies…

Well, you’re “almost right.” There is a connection…a very, very, very weak gravitational connection. And that is why it takes so little energy to expand it! (According to my estimates, anyway.) That is why I cannot figure out how the mainstream gets their IMMENSE(!) expansion energy. Your comment drives right to the heart of what I’m trying to say: the “connection” between remote objects is “almost zero.” There’s very little force between objects 5 megaparsecs apart! It takes very little energy to overcome it.

Quote:

Originally Posted by Nereid

And if you work with Newtonian physics, you can write down equations, showing that A = B; observational data can be plugged in, and indeed A = B.

Okay, let A = energy radiated by matter undergoing local gravitational contraction; let B = gravitational energy gained by matter due to the expansion. If A explains B (as I’m contending), then A > B (as bigsplit points out).

In post 33, I estimate A to be 1 j/kg/yr; in post 60, I estimate B to be < 10^(-20) j/kg/yr (almost zero, as andyschlei would have it). I have explained both of these estimates to the best of my abilities. If I’ve lost you somewhere or made a mistake (you already found one, thanks), please say specifically where in post 33 or 60, and we’ll go from there.

Nereid · #70 (**permalink**) 10-May-2006, 07:37 PM

Quote:

Originally Posted by Peter Wilson

The expansion estimate will just about wrap up the present presentation of DEILE. In one sentence: The on-going expansion of the universe on cosmic scales is a natural, to-be-expected consequence of the on-going contraction occurring on local scales.
[snip]

Consider that the expansion of the moon’s orbit is driven by the spinning earth. [snip]

The earth-moon system is a two-body affair, of course, while the expansion of the universe involves an infinite number of bodies. The calculation is a little more difficult. This is where the “tensor-matrix algebra” comes in, I believe. Nonetheless, the two-body system and the infinite-body system share some characteristics, which we can use to get a feel for the answer.

First, in both the two-body system and the infinite-body universe, the rate of expansion determines the power. [snip]

Secondly, the power of expansion for both the two-body system and infinite-body universe depends on the density. [snip]

Lastly, recall that the starting assumption for the two-body system is that the 2nd body is in a stable orbit around the 1st, and we are considering only the rate-of-change. [snip]

We now look at how a radiant two-body system behaves. Take the solar-system. Technically, it’s a multi-body system, but for the OOM est., the two-body model is a good approximation. The power output of the sun is roughly 4 x 10^26 watts (post 33). This radiation produces a net outward force of about 70 trillion pounds. But how “efficiently” does this 70 trillion lb-f of outward pressure “couple” to the two-body system under consideration?

The efficiency of coupling, or coupling-parameter (CP), depends on the albedo of the 2nd body, and its surface-to-mass ratio (for larger than molecular-scale systems). [snip]

What this means is that sub-micron dust gets “coupled” efficiently to the solar wind and expanded right out of the solar system on the order of years (think comet tails); 10-micron-sized dust gets expelled on the order of centuries; 100um dust is driven out in millennia, etc. For a Jupiter-sized body, however, the sun will burn out before expelling it. The point is, the sun has plenty of expansion energy available, but the “coupling” of this energy to bodies in orbit is very small, except for the very smallest.

[snip]

In summary: a radiant, two-body system expands at a rate that depends on the radiant power of the system, and the “Coupling-Parameter” of the 2nd body, which depends primarily on its area-to-mass ratio. Recession velocity for a given STM does not change with distance.

[snip]

As to the effect of distance: In the two-body radiant system, we saw that expansion velocity is constant with distance. When you go from 2-bodies in 2-dimensions, to an infinite number in 3-dimensions, the expansion velocity increases with distance, instead of remaining constant. When you add one dimension, velocity multiplies by one dimension. Another way to look at it is to picture the 3D infinite system as a bunch of 2-body systems “added up.” So instead of recession velocity being constant, it keeps “adding up,” that is, it increases with distance. In other words, Hubble’s law: expansion proportional to distance.

As noted above, expansion energy is proportional to density. The density of the universe is about 3 x 10^-27 kg/m^3. source The density of earth-moon system is about 0.1 kg/m^3. The earth-moon system is expanding at roughly 100 ppt/yr, “the same” OOM as the universe. The universe is 26 OOMs less dense than the earth-moon system, however. Making a wild guess, I would say the expansion energy of the universe at-large is 26 OOMs less than in the energy involved in the earth-moon system, i.e. about 10^(-29) j/kg/yr.

This seems impossibly small.

But when I look at the numbers, it seems the answer must be very small, whatever it is. The density of the universe is said to be something like 1 hydrogen atom per cubic meter. Over the course of a year, the distance between each atom increases from 1.0m to 1.000000000073m. How much force is there between hydrogen atoms 1 meter apart? How much energy can it take to move them apart by 10^-10 per year? It has to be a small number, whatever it is.

Summarizing the parameters that are known with confidence:
1) Expansion rate of universe: 73 ppt/yr
2) Expansion rate of earth-moon system: same OOM as universe
3) Energy of expansion of earth-moon system: <0.001 j/kg/yr
4) Density of earth-moon system: 0.1 kg/m^3
5) Density of universe: 3 x 10^-27 kg/m^3

Maybe my math is off a little.

To hedge, I’ll split the difference. I’ll add 9 OOMs to the energy estimate, and knock 8 OOMs off the CP guess.

Final estimates:

1) Power output, P, of visible matter: 1 j/kg/yr
2) Coupling parameter (CP): 10^(-20)
3) Resulting power of expansion (P*CP): 10^(-20) j/kg/yr
4) Resulting expansion rate, H:10^(-10)/yr

In layman’s terms: Density of the universe is not mathematically zero, but close to it. Expansio rate is almost zero. Energy of expansion is almost zero. Energy available to drive expansion? 1.0 (j/kg/yr). Conclusion? Expansion easily explained in terms of radiant energy available.

According to The Mainstream, however:

1. The expansion energy is immense, and can only be accounted for by dark energy.
2. The quantity of DE required to explain the expansion is so large it makes up 74% of the universe.
3. Radiant energy plays no significant roll in expansion.

How could my back-of-the-envelope calculation be so different?

The infinite-body system is not an exact analog of the two-body system. Maybe energy in the infinite body goes at the square-root of density, instead of linearly. That would bring it up from 10^(-29) to 10^(-15) j/kg/yr. GR complexifies things, and maybe that changes it by an OOM or two. Maybe I have to multiply it by the age of the universe, 10^10 years. That is still only 10^(-3) j/kg. It’s a mystery to me.

When I look at the numbers, everything seems to add up. Thin universe; slowly contracting; expanding even more slowly. Just another ordinary universe. No Inflation. No Dark Energy. No elephant in the chicken coop. :yawn: Just a thin soup—3 x 10^(-27) kg/m^3 thin—on a budget of 1 j/kg/yr, becoming even thinner, at a sub-glacial 10^(-10) per year. Really, not much happening…well, Old-man Rigley died last year.

But the mainstream insists, No, it doesn’t add up. You’ve got the math all wrong, and don’t understand GR. In a 2-body system, sure, radiation pressure causes expansion. But in GR, in an infinite universe, positive pressure produces contraction, not expansion. Here, post 7 Only DE, which produces negative pressure, can overcome the positive pressure of radiation.

According to TM, the universe is crazy. In the beginning, there was this huge explosion. Crazy. But that didn’t work. Bangless BBT So we added inflation. Crazy. But it worked. For a while. Then we found the expansion was accelerating. Crazy. Dark energy was added to explain that, but it takes a lot of it. Crazy. The universe is crazy, and if you think otherwise…

I don’t know. Maybe it is. The expansion seems rational to me. 73 ppt/yr? It’s like almost nothing is happening. What is wrong with this picture? I can’t tell. I’ve gone over the numbers again and again. Extremely thin universe; contracting locally at a moderate clip; radiating energy as it does so; resulting in infinitesimal expansion over-all. Looks right on paper. Everything appears in order, exactly as it should be. All I can say in conclusion is that if TM is right on all this, and the universe is crazy after all…at least I got something to blame it on!

There seem to be a number of confusing aspects to this presentation, due to the analogies used (well, confusing to me anyway):

-> the increasing size of the Moon's orbit: I can't see how this relates to the expansion of the universe. The driver (for the Moon) is angular momentum and the difference between the rotation period of the Earth (1 day) and the revolution period of the Moon (1 month); the coupling is a function of the properties of the Earth - its radius, the size of the Moon-induced tides, etc. If the Earth were rotating more slowly than the Moon is orbiting (say, once a decade), then the Moon would be spiralling in.

-> solar system bodies: only very small objects are blown out of the solar system by the Sun's radiation pressure; the rest will eventually spiral in to the Sun, due to the Poynting-Roberton effect (it's more complicated than this - there's also the Yarkovsky effect, for example). How does this illustrate DEILE? If we're going to work with analogies, at the very least it shows the importance of considering rotation, and (more generally) the complexity of calculating radiation pressure induced motion (there will always be motion transverse to direction of the radiation, and Poynting-Robertson type effects must be at least considered).

So where does DEILE stand? Even without looking for other shortcomings (than just some simple considerations of other effects of 'radiation pressure'), I'd say there's at least a great deal more work to be done.

Peter Wilson · #71 (**permalink**) 11-May-2006, 12:57 AM

Quote:

Originally Posted by Nereid

There seem to be a number of confusing aspects to this presentation, due to the analogies used (well, confusing to me anyway):

-> the increasing size of the Moon's orbit: I can't see how this relates to the expansion of the universe.

The earth-moon sytem is a reference point. It is expanding at the same rate as the universe. And because there is conversion factor between foot-pounds and joules, it is easy to convert its expansion energy into joules/kg/yr.

Quote:

-> solar system bodies: only very small objects are blown out of the solar system by the Sun's radiation pressure; the rest will eventually spiral in to the Sun, due to the Poynting-Roberton effect (it's more complicated than this - there's also the Yarkovsky effect, for example).

This is an oft repeated misconception. Like on an airplane, there are lift-forces to consider, and drag forces. Radiation pressure produces the equivalent of lift, and the PR effect produces drag. The net effect, however, is lift, or expansion. You can cite a counter-example, a body spinning in a certain way, for exmple, that spirals in, but the net effect is always expansion. Comet tails aways point away from the sun. This is not an analogy, but erosion/sedimentation is. You can find erosion and sedimentation occuring all over the earth, but above sea-level, the net effect is erosion, and below sea-level, the net effect is sedimentation. In like manner, the net effect of solar radiation pressure is expansion.

Quote:

Originally Posted by Nereid

So where does DEILE stand? Even without looking for other shortcomings (than just some simple considerations of other effects of 'radiation pressure'), I'd say there's at least a great deal more work to be done

Follow the energy. I'm on vacation thru the 15th, so the discussion will have to wait for awhile. But in the mean time, consider this: The universe has a density of 3 x 10^(-27) kg/m^3; it is expanding at a rate of 10^(-10)/yr.

How much energy can it take to expand something with such a low density at such a low rate? It is expanding at the same rate as the earth-moon system, but it is roughly 25 OOMs less dense. How much energy can that take?

Nereid · #72 (**permalink**) 11-May-2006, 06:09 PM

Quote:

Originally Posted by Peter Wilson

The earth-moon sytem is a reference point.

A "reference point" for what?

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It is expanding at the same rate as the universe.

It is?
Has it always?
So what?

Quote:

And because there is conversion factor between foot-pounds and joules, it is easy to convert its expansion energy into joules/kg/yr.

So?

Quote:

Originally Posted by Nereid

-> solar system bodies: only very small objects are blown out of the solar system by the Sun's radiation pressure; the rest will eventually spiral in to the Sun, due to the Poynting-Roberton effect (it's more complicated than this - there's also the Yarkovsky effect, for example).

This is an oft repeated misconception. Like on an airplane, there are lift-forces to consider, and drag forces. Radiation pressure produces the equivalent of lift, and the PR effect produces drag. The net effect, however, is lift, or expansion.

More (confusing) analogies.

In the case of bodies in the solar system, above a certain size, the net effect is (nearly always) in-spiralling.

For real objects, these effects are quite real - you can't turn one off and leave another on, at your whim.

Quote:

You can cite a counter-example, a body spinning in a certain way, for exmple, that spirals in, but the net effect is always expansion. Comet tails aways point away from the sun.

They do indeeed ... and dust streams abound in the solar system (producing meteor showers), the particles responsible for zodiacal light are spiralling in to the Sun, ...

But, since you made the claim ("the net effect is always expansion"), let's see you defend it - show that the net effect is always expansion.

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This is not an analogy, but erosion/sedimentation is. You can find erosion and sedimentation occuring all over the earth, but above sea-level, the net effect is erosion, and below sea-level, the net effect is sedimentation. In like manner, the net effect of solar radiation pressure is expansion.

Quote:

So where does DEILE stand? Even without looking for other shortcomings (than just some simple considerations of other effects of 'radiation pressure'), I'd say there's at least a great deal more work to be done

Follow the energy. I'm on vacation thru the 15th, so the discussion will have to wait for awhile. But in the mean time, consider this: The universe has a density of 3 x 10^(-27) kg/m^3; it is expanding at a rate of 10^(-10)/yr.

How much energy can it take to expand something with such a low density at such a low rate? It is expanding at the same rate as the earth-moon system, but it is roughly 25 OOMs less dense. How much energy can that take?

OK, we'll wait until you're back.

If you read this before you go, perhaps you could consider this:
- the orbit of Phobos is decaying (it's inspiralling, not expanding)
- binary pulsars are in orbits that are decaying (not expanding)
- China's energy production is expanding at a much faster rate than the universe is expanding.

Perhaps the causes of China's expanding energy production have as much to do with the expansion of the universe as changes in the Moon's orbit?

Peter Wilson · #73 (**permalink**) 17-May-2006, 10:37 PM

Quote:

Originally Posted by nereid

A "reference point" for what? … Has it always? So what?… So?

Good! Good! Now I can begin to see where I’m losing you.

What I’m trying to do with the moon analogy is to put the Hubble expansion in perspective. In the popular image, the universe is “flying apart.” But in reality, the universe is expanding at an infinitesimal rate…slower than the moon’s orbit is expanding. And everyone understands that the moon is not “rushing away.” Likewise, remote galaxies are not “rushing away.” Yes, the distance between remote objects is increasing, but so what? The distance between them is already immense.

Nothing is going anywhere.

All that is happening is the distance between remote things is increasing. Associated with this increase in distance is an increase in energy. It takes so-much energy to increase the distance between the earth and the moon, at the observed rate of expansion of 10^(-10)/yr. And it takes so-much energy to increase the distance between remote objects (> 5 Mpc) at the observed rate, which for an OOM estimate is the same 10^(-10)/yr.

As for the foot-pounds…again, I’m trying to put the expansion/contraction into familiar terms. What is one joule? What is 1 j/kg/yr? Think of something weighing about 1 kilo; now imagine lifting it 2”. You have imparted 1 joule of energy to it. Now you "know" how much energy 1 joule is. Lower the kilo back down, and you have “a feel” for how much energy is lost in proportion to mass each year. So by expressing the expansion energy in terms of elevation-change-at-earth’s-surface, we can get “a feel” for the energy involved that is intuitive. The intent of all this information is not to confuse, but to help the reader "get the picture."

And the earth-moon analogy is not intended to show that all orbiting bodies spiral away, but simply to make the point that expansion points to an energy flow. Since the earth spins faster than the moon orbits, energy flows from the earth to the moon. The expansion is rotational energy transmogrifying into gravitational energy. The expansion of the universe is likewise: gravitational energy is flowing from local to non-local regions, carried by radiation, and manifested as increasing distance between things.

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More (confusing) analogies. In the case of bodies in the solar system, above a certain size, the net effect is (nearly always) in-spiraling. For real objects, these effects are quite real - you can't turn one off and leave another on, at your whim…Show that the net effect is always expansion.

I’m not turning off the drag effect by whim. The drag effect of light only applies in a stationary radiation field (read the wikipedia entry carefully). The sun’s radiation field is not stationary. It rotates at 1 rpm (month…not minute

). Most solar system objects have a rotation rate much slower, so the radiation field is transferring angular momentum to the particles, not the other way around. Very close to the sun, orbiting bodies will orbit faster than the radiation field rotates, and hence will transfer momentum to the field, and spiral in to their doom.

I am arguing that it is not particle size that determines “spirality,” but instead it is rotational velocity of the orbiting body wrt the rotational velocity of the radiating body. Nonetheless, let us not get side-tracked debating when and when not particles spiral in or out. We both agree there is "a line." On one side of the line is contraction; on the other is expansion. You’re arguing that in the solar system “the line” is particle size; I’m arguing that “the line” is radial velocity. But we both agree that there is a line.

We’ll assume you’re correct, for the sake of argument, that “dust” (what we see in comet tails) spirals away from the sun, but that larger particles spiral in. If so, it’s just another example of the contraction/expansion motif that I keep hammering on. Earth satellites below geosynchronous orbit spiral in; above, they spiral away. “Hot” globs of gas expand; “cold” globs of gas contract. Massive stars in a globular cluster tend to “sink” towards the center; less-massive stars tend to “float” away. Virtually all gravitational systems have inflection points, “a line,” of one kind or another, with contraction on one side, and expansion on the other: size; temperature; spin; distance…whatever. With regard to the universe over-all, “the line” is distance. There is net contraction below 5 Mpc; net expansion beyond it.

The energy of expansion beyond 5 Mpc is much less than the energy of contraction generated within 5 Mpc, so Hubble the expansion is not a mystery at all, but a natural and to-be-expected phenomenon.

Peter Wilson · #74 (**permalink**) 18-May-2006, 10:14 PM

In calculating the energy of expansion of a given system, there are 3 basic variables: expansion rate, density and configuration. Calculating the expansion energy of the earth-moon system is trivial (answer= 10^(-4) j/kg/yr, see post 60) and since the rate is the same as the universe over-all, we use the 10^(-4) j/kg/yr expansion energy of the earth-moon (EM) system as a “reference point” to get rid of one variable, the expansion rate.

Next we consider density. If the density of the EM were halved, that is if each body weighed half as much, the force between them would be halved, and the energy-per kilogram would be halved, given the same rate of expansion. Applying this same principle: if the density of the EM was 25 OOMs less, then the expansion energy would 25 OOMs less. What we would be left with is something like a dust mote being orbited by an even smaller dust mote, 250,000 miles away. Intuitively, the expansion energy of such a system is very, very small. Specifically, such a 2-body system, with the same density as the universe, and expanding at the same rate, would have an energy of expansion of some 10^(-29) j/kg/yr.

Last, we consider configuration. The EM is 2-body, 2-dimensional system, and the universe is an infinite-body,3D fractal affair. So how do you compare an apple to an orange? Admittedly, this math lies over my head, but by getting rid of 2 variables—rate and density—we are down to just 1 variable: configuration. Obviously, it takes more energy to expand an infinite-body 3D system at a given rate-and-density than a 2-body system of the same parameters, but it is not infinitely more. It is just some factor, call it X, that comes out in the math. You multiply the 10^(-29) j/kg/yr by X, whatever it is, and you get the expansion energy of the universe. And 10^(-29) j/kg/yr multiplied by almost anything is a still a small number.

The expansion rate of the universe is very small: 10^(-10)/yr. The density of the universe is extremely small: 10^(-27) kg/m^3. Just looking at these two numbers, it seems the expansion energy must be very small.

Does this clarify why I believe the expansion energy of the universe is so small? Can anyone explain how the mainstream comes up with an expansion energy that is so huge?

Nereid · #75 (**permalink**) 19-May-2006, 07:17 PM

Quote:

Originally Posted by Peter Wilson

Good! Good! Now I can begin to see where I’m losing you.

What I’m trying to do with the moon analogy is to put the Hubble expansion in perspective. In the popular image, the universe is “flying apart.” But in reality, the universe is expanding at an infinitesimal rate…slower than the moon’s orbit is expanding. And everyone understands that the moon is not “rushing away.” Likewise, remote galaxies are not “rushing away.” Yes, the distance between remote objects is increasing, but so what? The distance between them is already immense.

OK; personally, I find these analogies to be quite distracting (not to mention confusing).

From now on, I will ignore them.

Quote:

Nothing is going anywhere.

All that is happening is the distance between remote things is increasing. Associated with this increase in distance is an increase in energy.

Is this a Peter Wilson claim? Or a (Peter Wilson) summary of modern, mainstream cosmology? (or something else entirely)

Perhaps you could clarify this please? If it's your own claim, then BAUT members can challenge it; if it's your summary of mainstream cosmology, then BAUT members may ask you for a reference which shows such 'an increase in energy# (leaving aside Dark Energy - accelerated expansion - I thought that the Hubble expansion was an inevitable consequence of a GR universe ... one without any increase or decrease in 'energy').

Quote:

It takes so-much energy to increase the distance between the earth and the moon, at the observed rate of expansion of 10^(-10)/yr. And it takes so-much energy to increase the distance between remote objects (> 5 Mpc) at the observed rate, which for an OOM estimate is the same 10^(-10)/yr.

Can you show this is so, in a GR universe? I don't doubt that you may be able to show such in a Newtonian universe, but we know that we live in a universe in which GR better accounts for what we have observed (so far) than Newtonian physics, so either you are claiming you can show GR is wrong, or you have misunderstood modern cosmology (or, once again, I have misunderstood your idea).

Quote:

As for the foot-pounds…again, I’m trying to put the expansion/contraction into familiar terms. What is one joule? What is 1 j/kg/yr? Think of something weighing about 1 kilo; now imagine lifting it 2”. You have imparted 1 joule of energy to it. Now you "know" how much energy 1 joule is. Lower the kilo back down, and you have “a feel” for how much energy is lost in proportion to mass each year. So by expressing the expansion energy in terms of elevation-change-at-earth’s-surface, we can get “a feel” for the energy involved that is intuitive. The intent of all this information is not to confuse, but to help the reader "get the picture."

And the earth-moon analogy is not intended to show that all orbiting bodies spiral away, but simply to make the point that expansion points to an energy flow. Since the earth spins faster than the moon orbits, energy flows from the earth to the moon. The expansion is rotational energy transmogrifying into gravitational energy. The expansion of the universe is likewise: gravitational energy is flowing from local to non-local regions, carried by radiation, and manifested as increasing distance between things.

Except that, as I have mentioned, you seem to be working with classical physics, not GR.

Quote:

I’m not turning off the drag effect by whim. The drag effect of light only applies in a stationary radiation field (read the wikipedia entry carefully). The sun’s radiation field is not stationary. It rotates at 1 rpm (month…not minute

). Most solar system objects have a rotation rate much slower, so the radiation field is transferring angular momentum to the particles, not the other way around. Very close to the sun, orbiting bodies will orbit faster than the radiation field rotates, and hence will transfer momentum to the field, and spiral in to their doom.

I am arguing that it is not particle size that determines “spirality,” but instead it is rotational velocity of the orbiting body wrt the rotational velocity of the radiating body. Nonetheless, let us not get side-tracked debating when and when not particles spiral in or out. We both agree there is "a line." On one side of the line is contraction; on the other is expansion. You’re arguing that in the solar system “the line” is particle size; I’m arguing that “the line” is radial velocity. But we both agree that there is a line.

We’ll assume you’re correct, for the sake of argument, that “dust” (what we see in comet tails) spirals away from the sun, but that larger particles spiral in. If so, it’s just another example of the contraction/expansion motif that I keep hammering on. Earth satellites below geosynchronous orbit spiral in; above, they spiral away. “Hot” globs of gas expand; “cold” globs of gas contract. Massive stars in a globular cluster tend to “sink” towards the center; less-massive stars tend to “float” away. Virtually all gravitational systems have inflection points, “a line,” of one kind or another, with contraction on one side, and expansion on the other: size; temperature; spin; distance…whatever. With regard to the universe over-all, “the line” is distance. There is net contraction below 5 Mpc; net expansion beyond it.

Are you still working within your analogy? Or have you switched to some (emergent?) property of your idea (5 Mpc)?

Quote:

The energy of expansion beyond 5 Mpc is much less than the energy of contraction generated within 5 Mpc, so Hubble the expansion is not a mystery at all, but a natural and to-be-expected phenomenon.

Does this vary with local environment, or is it some 'universal' effect?

If the latter, then it should be easy to test (e.g. see if there are any clusters, bigger than 5 Mpc, which are 'flying apart', if only in their outer parts).

buzgz · #76 (**permalink**) 21-May-2006, 07:49 PM

The Hubble constant seems to be increasing with time. I assume your "light energy" also increases with time. Have you discussed this ?

Peter Wilson · #77 (**permalink**) 22-May-2006, 06:15 PM

Quote:

Originally Posted by Nereid

OK; personally, I find these analogies to be quite distracting (not to mention confusing). From now on, I will ignore them.

I’m not sure how else to explain it. What is happening on the largest scales in the universe is the same thing that is happening on smaller scales. It’s the same principle at work: No gravitational system is static (excepting the cold-collapsed body). Change is the only constant. That which is not in the process of contracting is in the process of expanding. The change may be geologic, or it may be cataclysmic, but no gravitational system is changeless. Pick any system—your binary pulsar—it’s slowly changing. The universe, likewise, is “almost” static, but not quite. As everything within it slowly, ever so slowly contracts, the universe slowly, ever so slowly, expands.

Quote:

Is this a Peter Wilson claim? Or a (Peter Wilson) summary of modern, mainstream cosmology? (or something else entirely) Perhaps you could clarify this please?

Its me describing the picture in my own words. To use The Mainstream’s words: “In reality, however, the "motion" of distant galaxies is not genuine movement like stars orbiting the center of our galaxy, Earth orbiting the Sun or even someone walking across the room. Rather, space is expanding and taking the galaxies along for the ride.”

Even this “along for the ride” phrasing, however, suggests motion. Fact is, our brains aren’t built to picture space itself expanding. We can only talk about it. All gravitational equations involve “distance-between,” so it is a natural way to express it. The distance-between all remote objects is increasing. This means all remote objects are gaining gravitational energy wrt all others. And in my estimate, this gain in energy is infinitesimal, because the expansion rate is so small (10^(-10)/yr), and the density is so close to 0.0 (10^(-27) kg/m^3).

Quote:

Leaving aside Dark Energy - accelerated expansion - I thought that the Hubble expansion was an inevitable consequence of a GR universe ... one without any increase or decrease in 'energy'.

That’s what I’ve always thought! (emphasis added). I try to explain in post 55 why a static universe cannot exist, given radiant matter and GR (that is, only a Newtonian universe composed entirely of dark matter can be made to hold still, i.e. not expand). I had always assumed that GR just took all this into account, and predicted accelerating expansion.

I think the confusion is over the acceleration. Acceleration is the natural result of infinitesimal expansion repeated to ever larger scales. Acceleration is the principle of compounding, like interest on a loan. The more there is, the faster it grows.

Quote:

Can you show this is so, in a GR universe? I don't doubt that you may be able to show such in a Newtonian universe, but we know that we live in a universe in which GR better accounts for what we have observed (so far) than Newtonian physics, so either you are claiming you can show GR is wrong, or you have misunderstood modern cosmology (or, once again, I have misunderstood your idea).

That’s an interesting question. In my energy estimate, I use Newtonian Gravity, but the central observation—that space itself is expanding—is “outside” the absolute frame-of-reference of NG.

I’m not saying GR is wrong, but something in BBT is in error.

A while back in a thread on Dark Matter, Ken G and I had a discussion regarding a purported calculation showing that GR accounted for DM, at least in galaxy rotation. Ken G argued—apparently successfully—that there could be “small” differences between NG and GR, but not the observed 1 OOM difference, so as to account for dark matter. I would use Ken G’s same argument here: there may be small differences between NG and GR, but not many, many OOMs of difference!

In my estimation, the expansion energy is infinitesimal, and the acceleration is exactly as it should be. In modern cosmology, the expansion energy is fantastic—much more than light and dark matter combined—and there is no accounting for it. The mainstream has come to a fantastic conclusion; I have come to a quite ordinary one.

Perhaps I’m hard to understand, but stay with me, because maybe, just maybe, I’m onto something. Think about it: the mainstream is saying, “The expansion cannot be explained in terms of present observations.” I am saying the exact opposite, “The expansion is easily explained in terms of present observations.”

At some point a little voice inside you should pipe up, “Maybe Peter is right. Maybe the expansion of the universe does make sense…”

Quote:

Are you still working within your analogy? Or have you switched to some (emergent?) property of your idea (5 Mpc)?

Again, I’m just describing well-known phenomenon in terms of a repeating pattern: contraction of one part, expansion of another. I can give you countless examples: matter spirals in around the equator of a blackhole (contraction), and shoots out its poles (expansion). Virtually all gravitational systems have this duality. It is nothing new or unfamiliar. I’m just pointing to this well-worn pattern as the key to understanding. On the largest scales, this pattern converges as: Net Contraction between objects < 5 Mpc apart; Net Expansion between objects > 5 Mpc apart.

Quote:

Originally Posted by Peter

The energy of expansion beyond 5 Mpc is much less than the energy of contraction generated within 5 Mpc, so Hubble the expansion is not a mystery at all, but a natural and to-be-expected phenomenon.

Does this vary with local environment, or is it some 'universal' effect?

Assuming the Cosmological Principle, it’s the same everywhere.

Nereid · #78 (**permalink**) 22-May-2006, 09:24 PM

Quote:

Originally Posted by Peter Wilson

I’m not sure how else to explain it. What is happening on the largest scales in the universe is the same thing that is happening on smaller scales. It’s the same principle at work: No gravitational system is static (excepting the cold-collapsed body). Change is the only constant. That which is not in the process of contracting is in the process of expanding. The change may be geologic, or it may be cataclysmic, but no gravitational system is changeless. Pick any system—your binary pulsar—it’s slowly changing. The universe, likewise, is “almost” static, but not quite. As everything within it slowly, ever so slowly contracts, the universe slowly, ever so slowly, expands.

This is one reason why I get confused ... 'the same principle at work'. In each of your examples (or analogies), the mechanism for expansion or contraction is an interplay of factors (radiation, gravity, angular momentum, etc) - there is (to me) no unifying 'principle'.

Another source of confusion is 'No gravitational system is static' - that's pure GR (or, it would be if static were replaced by stable, plus some 'reasonable' assumptions about the distribution of mass-energy), and the discovery of this conclusion, within any GR universe, was revolutionary.

Yet later in this very same post you seem to resile from the (GR) conclusions!

Quote:

Its me describing the picture in my own words. To use The Mainstream’s words: “In reality, however, the "motion" of distant galaxies is not genuine movement like stars orbiting the center of our galaxy, Earth orbiting the Sun or even someone walking across the room. Rather, space is expanding and taking the galaxies along for the ride.”

Even this “along for the ride” phrasing, however, suggests motion. Fact is, our brains aren’t built to picture space itself expanding. We can only talk about it. All gravitational equations involve “distance-between,” so it is a natural way to express it. The distance-between all remote objects is increasing. This means all remote objects are gaining gravitational energy wrt all others. And in my estimate, this gain in energy is infinitesimal, because the expansion rate is so small (10^(-10)/yr), and the density is so close to 0.0 (10^(-27) kg/m^3).

Perhaps it might be a good use of your time to learn how, in detail, the Friedmann-Robertson-Walker solutions to the (GR) field equations are derived.

I may be completely wrong, but your use of popsci summaries, and the logic of your idea (in this last para), suggest to me that there are some basics about modern cosmology that you may not have grasped.

Quote:

That’s what I’ve always thought! (emphasis added). I try to explain in post 55 why a static universe cannot exist, given radiant matter and GR (that is, only a Newtonian universe composed entirely of dark matter can be made to hold still, i.e. not expand). I had always assumed that GR just took all this into account, and predicted accelerating expansion.

I think the confusion is over the acceleration. Acceleration is the natural result of infinitesimal expansion repeated to ever larger scales. Acceleration is the principle of compounding, like interest on a loan. The more there is, the faster it grows.

Another reason to spend time getting to grips with what the modern theories of cosmology actually say (i.e. the math).

The FRW solutions do not contain an acceleration, unless you add something like a cosmological constant. The observations of acceleration lead to the addition of a new term 'dark energy' to the equations; the latest WMAP results, when combined with other data, suggest that this 'dark energy' has the form of a constant (just like Einstein's 'greatest blunder'), at least for the time probed by the CMB (and since).

As I said earlier, my impression is that your idea may be viable only in a Newtonian (or other classical) universe.

Quote:

That’s an interesting question. In my energy estimate, I use Newtonian Gravity, but the central observation—that space itself is expanding—is “outside” the absolute frame-of-reference of NG.

I’m not saying GR is wrong, but something in BBT is in error.

A while back in a thread on Dark Matter, Ken G and I had a discussion regarding a purported calculation showing that GR accounted for DM, at least in galaxy rotation. Ken G argued—apparently successfully—that there could be “small” differences between NG and GR, but not the observed 1 OOM difference, so as to account for dark matter. I would use Ken G’s same argument here: there may be small differences between NG and GR, but not many, many OOMs of difference!

In my estimation, the expansion energy is infinitesimal, and the acceleration is exactly as it should be. In modern cosmology, the expansion energy is fantastic—much more than light and dark matter combined—and there is no accounting for it. The mainstream has come to a fantastic conclusion; I have come to a quite ordinary one.

Perhaps I’m hard to understand, but stay with me, because maybe, just maybe, I’m onto something. Think about it: the mainstream is saying, “The expansion cannot be explained in terms of present observations.” I am saying the exact opposite, “The expansion is easily explained in terms of present observations.”

At some point a little voice inside you should pipe up, “Maybe Peter is right. Maybe the expansion of the universe does make sense…”

Well, it looks like you've either just talked yourself into a 'GR must be wrong' stance, or at least a 'GR needs considerable modification' one!

In any case, I think you have it backwards; 'there are good observations which are inconsistent with predictions from GR applied to the whole universe, unless there is an additional term (dark energy, of a 'cosmological constant' kind)'. And 'Peter Wilson has an idea, in which the observed expansion of the universe, including its acceleration, can be accounted for by {insert a summary of how you arrive at the consistency between your equations and the observations here}'

Quote:

Again, I’m just describing well-known phenomenon in terms of a repeating pattern: contraction of one part, expansion of another. I can give you countless examples: matter spirals in around the equator of a blackhole (contraction), and shoots out its poles (expansion). Virtually all gravitational systems have this duality. It is nothing new or unfamiliar. I’m just pointing to this well-worn pattern as the key to understanding. On the largest scales, this pattern converges as: Net Contraction between objects < 5 Mpc apart; Net Expansion between objects > 5 Mpc apart.
[snip]

Have you attempted to quantify this 'well-worn pattern'?

For example, within our immediate 100 Mpc neighbourhood, what regions are contracting and what are expanding? What is the distribution of the contracting regions, by size (I imagine you'll need to make a usable, consistent definition of 'size')?

Peter Wilson · #79 (**permalink**) 23-May-2006, 01:03 AM

Quote:

Originally Posted by buzgz

The Hubble constant seems to be increasing with time. I assume your "light energy" also increases with time. Have you discussed this ?

Actually, the mainstream assumes that H decreases linearly with time. I am assuming it decreases with time, only very slowly. So I am not sure where you get the idea it is increasing.

Nonetheless, your question raises an issue I am bumping into with Nereid. The above source claims (in line with the mainstream), "(The Hubble-constant) value must vary with time..."

The truth is, H "must vary with time," in order to fit the BBT model to the observations. But what if the Hubble-constant is constant? The the Friedmann-Robertson-Walker solutions to the (GR) field equations that Nereid would have me "get familiar with" make this highly questionable assumption that the Hubble-"constant" is not constant!

Nereid: what happens to the Friedmann-Robertson-Walker solutions to the (GR) field equations if you assume the Hubble-constant is constant?

Nereid · #80 (**permalink**) 23-May-2006, 02:22 PM

Quote:

Originally Posted by Peter Wilson

Actually, the mainstream assumes that H decreases linearly with time. I am assuming it decreases with time, only very slowly. So I am not sure where you get the idea it is increasing.

Nonetheless, your question raises an issue I am bumping into with Nereid. The above source claims (in line with the mainstream), "(The Hubble-constant) value must vary with time..."

The truth is, H "must vary with time," in order to fit the BBT model to the observations. But what if the Hubble-constant is constant? The the Friedmann-Robertson-Walker solutions to the (GR) field equations that Nereid would have me "get familiar with" make this highly questionable assumption that the Hubble-"constant" is not constant!

Nereid: what happens to the Friedmann-Robertson-Walker solutions to the (GR) field equations if you assume the Hubble-constant is constant?

My impression, reading this post, is that there is a great deal of confusion about modern cosmology.

For example, there is very good observational data showing that the Hubble constant is not constant, and that the way it seems to have changed fits the concordance model well.

Perhaps a good place to start would be those observations? The primary ones are 'just' an extension of the kind of observations Hubble made, way back in the 1920's - distance vs redshift. Today these include objects with redshifts of up to ~6, and fairly reliable distances for objects with redshifts up to ~2, via supernovae (I'm going from memory here; I don't have access to resources that would enable me to confirm this).

The really astonishing observation is the CMB - if it is cosmological in origin (and no one, AFAIK, has come remotely close to presenting a case that it's not), then it has a redshift that it consistent with standard cosmological models ... which incorporate a changing H (though not one which varies linearly with time, pace Peter Wilson).

On the theoretical side, H is not an arbitrary input in the FRW solution, it is an output ... so to get a constant H, you have to change the basic assumptions of GR. Off the top of my head, I'd guess that one way to get a 'constant H' solution would be to plug in a time varying energy field ('PW Energy'?). But I can't see why you'd want to do that; as I said, there is very good observational data showing that H is not, in fact, constant!

Peter Wilson · #81 (**permalink**) 24-May-2006, 12:25 AM

Quote:

Originally Posted by Nereid

This is one reason why I get confused ... 'the same principle at work'. In each of your examples (or analogies), the mechanism for expansion or contraction is an interplay of factors (radiation, gravity, angular momentum, etc) - there is (to me) no unifying 'principle'.

The unifying principle is “on-going.” To understand why any one of these systems is either expanding or contracting, you have to look at what is happening in the present. Ditto for the universe. The answer lies in the present, not the past; the expansion is on-going, not the result of some event in the remote past.

And the key word is “net.” The universe is fantastically complex; a jillion things are going on at every scale from quarks to intergalactic voids. But when you add it all up, there is a net loss of energy, from local “centers of gravity.” The net loss of energy is the amount radiated away. Beyond the “local neighborhood” (5 Mpc), however, there is net gain in energy, proportional to H. And in my Newtonian estimate, the net loss of energy due to local contraction is far greater than the net gain due to non-local expansion.

Quote:

Another source of confusion is 'No gravitational system is static' - that's pure GR...

Right. That’s why I’m not saying GR is wrong…I think the model is wrong.

Quote:

Perhaps it might be a good use of your time to learn how, in detail, the Friedmann-Robertson-Walker solutions to the (GR) field equations are derived. I may be completely wrong, but your use of popsci summaries, and the logic of your idea (in this last para), suggest to me that there are some basics about modern cosmology that you may not have grasped.

I have learned how he FRW model is derived, and as far as I'm concerned, it is dead-wrong. The FRW is a finite-model universe in an infinite-model’s clothing. FRW takes a sphere somewhat bigger than 5 Mpc, say 50 Mpc, and asks: What would happen if suddenly nothing existed in the universe beyond 50 Mpc? And FRW takes no account that all the galaxies within this arbitrary sphere are crashing and colliding (contracting), and furiously radiating away energy all the while. In other words, FRW treats galaxies as if they are dark. Well, of course, such a sphere of dark matter expanding into empty space will slow down! But that does not reflect reality. FRW is not real.

But rather than quibbling over starting assumptions of FRW and the handling of infinity, the point is, the picture can be interpreted in 2 completely different ways. Like the Copernican vs Ptolemaic: same data; different interpretation. I think this is where we are talking past each other. I am looking at the picture one way; you (and plenty of good company) are looking at it another way.

It is possible to look at a 2-dimensional picture, and get a completely wrong impression of the 3rd dimension. In this Mars photo, I see a series of mounds. NASA reports it’s a series of craters. I trust NASA more than my eyes, in this case. I go through this all the time with pictures of Mars. When there are no unambiguous 3-dimensional cues, I see craters as mounds and mounds as craters. With a magazine in hand, I can “fool myself” by closing my eyes, turning the picture upside-down, then opening them. Then I can "see" the picture correctly, and the caption makes sense.

Likewise, when we look at the cosmos, we are looking at an image of the universe in which the dimension of time has been removed. We are only seeing the universe in one instant in time. History has been "flattened," like the 3rd dimension in the Mars photo.

All remote things are receding. That much we agree on. We do not know the history of that recession, however. The BBT posits: “The recession velocity was attained all-at-once (during the period of Inflation).” I’m saying, “The recession velocity is attained gradually, and continuously, over immense time periods.” Two completely different interpretations, based on the exact same set of data.

But you have to see it both ways before you decide which is which! You have to 1) understand there are 2 ways of interpreting the picture; and 2) make an effort to “see it” the 2nd way. But it is worth the effort. Once you “see” the picture the way I am describing it, it will all make sense! You will understand "the caption" to my theory: The universe is expanding because the universe is contacting.

Peter Wilson · #82 (**permalink**) 25-May-2006, 12:30 AM

Quote:

Originally Posted by Nereid

Have you attempted to quantify this 'well-worn pattern'?

For example, within our immediate 100 Mpc neighborhood, what regions are contracting and what are expanding? What is the distribution of the contracting regions, by size (I imagine you'll need to make a usable, consistent definition of 'size')?

I'm not sure how to quantify a pattern. The laws of conservation just “are.” Two galaxies collide, light up with star formation, and merge. But in the process, some parts get flung away, in order to conserve angular momentum of the original pair. All real (i.e. complex) gravitational exhibit this same, general pattern: contraction of one part; expansion of another.

The distribution by size is fractal.

The “shape” of the pattern that repeats at every scale is the tendency for dense regions to become more dense (contract), and sparser regions to become even more sparse (expand). This pattern—contraction of the dense regions, accompanied by expansion of the outer parts—ends on the largest scale. We live in an over-dense region of the universe, and it is becoming denser. Yet beyond some distance (+/- 5 Mpc), the universe is very empty, and these sparse regions are becoming even emptier.

Quote:

My impression, reading this post, is that there is a great deal of confusion about modern cosmology. For example, there is very good observational data showing that the Hubble constant is not constant, and that the way it seems to have changed fits the concordance model well.

I’ll agree about there being a lot of confusion regarding modern cosmology. The flatness and horizon problems were saying that H is constant. But instead of throwing out the assumption that H decreases, Inflation was invented to “fix” the problems caused by the assumption! Likewise, the acceleration is saying that H is constant. But instead of throwing out the assumption that H decrease, Dark Energy was invented to “fix” the problem created by the starting assumption.

All the evidence is pointing to a constant Hubble-constant…but it doesn’t fit the BBT, so the possibility of a constant-constant just gets ignored, and the mainstream just keeps adding one ad-hoc “fix” after another. The changing-constant in the BBT is being used to fit the observations to the model, instead of fitting the model to the observations.

Quote:

On the theoretical side, H is not an arbitrary input in the FRW solution, it is an output ... so to get a constant H, you have to change the basic assumptions of GR. Off the top of my head, I'd guess that one way to get a 'constant H' solution would be to plug in a time varying energy field ('PW Energy'?). But I can't see why you'd want to do that; as I said, there is very good observational data showing that H is not, in fact, constant!

Whoa! Wait a minute…time out. H is an observable. It must be “plugged into” the model…the model does not tell us what H is! And before you name an ad-hoc time-varying energy field after me, remember, I am trying to dispel the ad-hoc time-varying energy field! It is gravitational energy that is supplying the expansion energy. Like a teeter-totter or balance-scale, one side goes down; the other up. On the local side, things “fall down;” on the cosmic side, things “fall up.”

Nereid · #83 (**permalink**) 25-May-2006, 10:08 AM

Quote:

Originally Posted by Peter Wilson

[snip]
Whoa! Wait a minute…time out. H is an observable. It must be “plugged into” the model…the model does not tell us what H is! And before you name an ad-hoc time-varying energy field after me, remember, I am trying to dispel the ad-hoc time-varying energy field! It is gravitational energy that is supplying the expansion energy. Like a teeter-totter or balance-scale, one side goes down; the other up. On the local side, things “fall down;” on the cosmic side, things “fall up.”

Just quickly (more later this week, or next): H is not built into GR, the theory.

You can define the instantaneous time rate of expansion, in your equations, and call it H. In general, it will be a function of t (the comoving time); the value of H at 'the present time', in a cosmological model, is H₀. To test your model, you compare the value of H₀ (an output) with H₀, the observation (e.g. from the Key Hubble Project).

More realistically, you have a whole lot of observations, and some parameters in your model that you can't derive 'from first principles'. You use a variety of techniques to find solutions that are consistent, and which give you estimates of parameters (with 'error bars'). There are several ways to do this, such as constraining some parameters (e.g. H), to estimate others.

There are many traps to be avoided ('degeneracy' is one), but ultimately you have a consistent model (crudely, it fits all the good observational data, within the error bars) or you don't.

Peter Wilson · #84 (**permalink**) 26-May-2006, 08:38 PM

There are several areas, “paradigms,” where we seem to be talking past each other, and it might be in order to separate them out, and look at them one-at-a-time.

1. Rate-of-Change in energy vs. Total Dark Energy
2. How Infinity influences the picture
3. What Acceleration means
4. The Effect of Radiation

The first “paradigm” problem—Rate vs. Total—is the most mysterious to me. When I look at the expansion problem, it is a rate-of-change problem. If I want to explain how an elevator goes against gravity at a certain rate, say 10 ft/s, then the answer must take the form of a rate of energy input. I.e. “The counter-weight falls at the same rate the elevator rises, supplying some of the energy, while the motor supplies the balance.” Notice that both the counter-weight and the motor supply energy at some rate. Likewise with the expansion of the moon’s orbit. To explain that phenomenon, I have to explain it in terms of a rate of energy change: “The earth’s rotational energy is being converted into gravitational energy at such-and-such rate.” And when it comes to expansion of the universe at-large, I am looking at the problem in the same way: in order to explain the phenomenon, I have to account for energy input at some rate.

The mainstream (TM) paradigm, however, is one of total energy. We read that dark energy, in totality, makes up some 70% of our universe.

Somehow, a rate-of-change problerm has been turned into a sum.

What we have here is a collision of paradigms, and I am baffled by it.

I think we can all agree that if the rate-of-change was 0.0, then there would be no problem. That is, if the light from distant galaxies faded in luminosity with distance, but not wavelength, then we would be living in a static universe, and we would be discussing some other poser. But the universe is not static: the distance between remote objects is increasing, at an observable, non-zero rate (per standard red-shift interpretation). And since this rate is a positive number (0.00000000073/yr…as it happens), it demands an explanation in terms of a rate, which is how I have done my estimate. In my estimate, the power (rate of energy) required to drive the expansion at the observed rate is much less than the power (rate of energy) output of visible matter.

TM, however, provides an explanation in terms of total energy (after a lot of math). I have no idea how TM turns this rate-of-change problem into a total problem.

It is as if the teacher asks, “Ok class, how fast must a train travel to get from Chicago to Detroit in 3 hours?” And I answer, “90 mph.” And the teacher says No, then points to the brainy kid in the back, who says smugly, “700 miles.” And the teacher says, “Thank you Johnny, that is correct.” And I’m thinking, But, but…the problem was how fast, not how far!

In like manner, I am vexed by TM's "answer," which is total energy, rather than rate-of-change of energy.

Obviously, before we can agree whether my answer explains it or not, we have to agree on what it is that needs explaining: a rate-of-change, or a total?

Comments?

Nereid · #85 (**permalink**) 28-May-2006, 12:25 AM

Quote:

Originally Posted by Peter Wilson

There are several areas, “paradigms,” where we seem to be talking past each other, and it might be in order to separate them out, and look at them one-at-a-time.

1. Rate-of-Change in energy vs. Total Dark Energy
2. How Infinity influences the picture
3. What Acceleration means
4. The Effect of Radiation

The first “paradigm” problem—Rate vs. Total—is the most mysterious to me. When I look at the expansion problem, it is a rate-of-change problem. If I want to explain how an elevator goes against gravity at a certain rate, say 10 ft/s, then the answer must take the form of a rate of energy input. I.e. “The counter-weight falls at the same rate the elevator rises, supplying some of the energy, while the motor supplies the balance.” Notice that both the counter-weight and the motor supply energy at some rate. Likewise with the expansion of the moon’s orbit. To explain that phenomenon, I have to explain it in terms of a rate of energy change: “The earth’s rotational energy is being converted into gravitational energy at such-and-such rate.” And when it comes to expansion of the universe at-large, I am looking at the problem in the same way: in order to explain the phenomenon, I have to account for energy input at some rate.

The mainstream (TM) paradigm, however, is one of total energy. We read that dark energy, in totality, makes up some 70% of our universe.

Somehow, a rate-of-change problerm has been turned into a sum.

What we have here is a collision of paradigms, and I am baffled by it.

I think we can all agree that if the rate-of-change was 0.0, then there would be no problem. That is, if the light from distant galaxies faded in luminosity with distance, but not wavelength, then we would be living in a static universe, and we would be discussing some other poser. But the universe is not static: the distance between remote objects is increasing, at an observable, non-zero rate (per standard red-shift interpretation). And since this rate is a positive number (0.00000000073/yr…as it happens), it demands an explanation in terms of a rate, which is how I have done my estimate. In my estimate, the power (rate of energy) required to drive the expansion at the observed rate is much less than the power (rate of energy) output of visible matter.

TM, however, provides an explanation in terms of total energy (after a lot of math). I have no idea how TM turns this rate-of-change problem into a total problem.

It is as if the teacher asks, “Ok class, how fast must a train travel to get from Chicago to Detroit in 3 hours?” And I answer, “90 mph.” And the teacher says No, then points to the brainy kid in the back, who says smugly, “700 miles.” And the teacher says, “Thank you Johnny, that is correct.” And I’m thinking, But, but…the problem was how fast, not how far!

In like manner, I am vexed by TM's "answer," which is total energy, rather than rate-of-change of energy.

Obviously, before we can agree whether my answer explains it or not, we have to agree on what it is that needs explaining: a rate-of-change, or a total?

Comments?

I suggest that you start a thread, in the Q&A section, with a question such as "I've read that Dark Energy (DE) has been added to modern cosmological models, to account for observational data on distant supernovae, the large-scale structure of the universe, and the WMAP observations of the CMB. I've also read that this DE "makes up some 70% of our universe", and that it is somehow related to the rate which the universe is (or was) expanding ... there is some kind of acceleration.

If the universe is expanding, does that mean it is gaining energy (overall)?

If the rate of expansion is accelerating, does that mean that energy is being added to the universe, at an increasing rate?

And what role does the Hubble constant (H₀) play in this (accelerated) expansion?"

There's little to be gained discussing your ATM idea until the basics of GR-based modern cosmological models are understood.

Peter Wilson · #86 (**permalink**) 31-May-2006, 11:51 PM

Quote:

Originally Posted by Nereid

There's little to be gained discussing your ATM idea until the basics of GR-based modern cosmological models are understood.

First, there is a lot to be gained: understanding.

There is no accepted theory as to why the expansion of the universe is accelerating. It has been given a name, but it remains an enigma, a mystery.

I’m offering an explanation.

What I hear you saying is, “Peter, you don’t understand the picture correctly, and we cannot talk about your theory until you do.” But I do understand “modern cosmological models.”

What I am apparently “failing to get across” is that there are two ways to interpret the picture, just as there are two ways to interpret the face/vase; two ways to interpret depth in a 2-D image; two ways to interpret planetary motion (the sky moves/the earth moves). So, too, there are two ways to interpret the expansion.

What I am saying is, “Look at the picture another way. Then, the expansion will make sense.”

Nereid · #87 (**permalink**) 02-June-2006, 08:42 PM

Quote:

Originally Posted by Peter Wilson

There are several areas, “paradigms,” where we seem to be talking past each other, and it might be in order to separate them out, and look at them one-at-a-time.

1. Rate-of-Change in energy vs. Total Dark Energy
2. How Infinity influences the picture
3. What Acceleration means
4. The Effect of Radiation

The first “paradigm” problem—Rate vs. Total—is the most mysterious to me. When I look at the expansion problem, it is a rate-of-change problem. If I want to explain how an elevator goes against gravity at a certain rate, say 10 ft/s, then the answer must take the form of a rate of energy input. I.e. “The counter-weight falls at the same rate the elevator rises, supplying some of the energy, while the motor supplies the balance.” Notice that both the counter-weight and the motor supply energy at some rate. Likewise with the expansion of the moon’s orbit. To explain that phenomenon, I have to explain it in terms of a rate of energy change: “The earth’s rotational energy is being converted into gravitational energy at such-and-such rate.” And when it comes to expansion of the universe at-large, I am looking at the problem in the same way: in order to explain the phenomenon, I have to account for energy input at some rate.

The mainstream (TM) paradigm, however, is one of total energy. We read that dark energy, in totality, makes up some 70% of our universe.

Somehow, a rate-of-change problerm has been turned into a sum.

What we have here is a collision of paradigms, and I am baffled by it.

I think we can all agree that if the rate-of-change was 0.0, then there would be no problem. That is, if the light from distant galaxies faded in luminosity with distance, but not wavelength, then we would be living in a static universe, and we would be discussing some other poser. But the universe is not static: the distance between remote objects is increasing, at an observable, non-zero rate (per standard red-shift interpretation).

If you've not already done so, why not read through Ned Wright's Cosmology Tutorial? Or, if you're OK with somewhat more math, the Cosmology section in Sean Carroll's Relativity lecture notes?

Maybe I will start a thread, in Astronomy, on this; I think it will clear up much of your confusion and bafflement.

(The Carroll webpage rather neatly addresses H, its change with time, energy, acceleration, dark energy, the equation of state, the cosmological constant, and ties all these to observables! But if you can't follow the math, it might cause some eye-glazing).

Quote:

And since this rate is a positive number (0.00000000073/yr…as it happens), it demands an explanation in terms of a rate, which is how I have done my estimate. In my estimate, the power (rate of energy) required to drive the expansion at the observed rate is much less than the power (rate of energy) output of visible matter.

Part of the problem might be that, in GR, "energy" doesn't have quite the same meaning as it does in everyday language.

For example, mass is 'merely' one form of energy, from the GR perspective.

Quote:

TM, however, provides an explanation in terms of total energy (after a lot of math). I have no idea how TM turns this rate-of-change problem into a total problem.

The Carroll webpage gives you the gist (for details, you may need to find a treatment that doesn't go quite so fast).

Quote:

It is as if the teacher asks, “Ok class, how fast must a train travel to get from Chicago to Detroit in 3 hours?” And I answer, “90 mph.” And the teacher says No, then points to the brainy kid in the back, who says smugly, “700 miles.” And the teacher says, “Thank you Johnny, that is correct.” And I’m thinking, But, but…the problem was how fast, not how far!

In like manner, I am vexed by TM's "answer," which is total energy, rather than rate-of-change of energy.

Obviously, before we can agree whether my answer explains it or not, we have to agree on what it is that needs explaining: a rate-of-change, or a total?

If I could put this another way, if you're seeking to use just the physics of GR and electromagnetism (you can't measure redshift if you don't know what to do with photons), to construct your ATM idea, then how could you answer questions of the kind "how does your idea fit with the normal big bang cosmologies?"?

Nereid · #88 (**permalink**) 03-June-2006, 11:41 AM

In this DEILE, what is the CMB? How does it arise?

How well does this DEILE idea match the following sets of observations? I'm particularly interested in detailed matches.

1) observations of the CMB, particularly those from WMAP, but also from the observations of the CMB such as summarised here.

2) observations underlying the Hubble relationship, especially wrt galaxies.

3) observations of the abundance of elements and nuclides.

4) observations that were used to determine the large scale structure of the universe, such as those referenced here.

5) observations that the night sky is dark - that the upper limits on diffuse background EM radiation, in all bands is {X} (the CMB excepted, of course).

Peter Wilson · #89 (**permalink**) 05-June-2006, 11:37 PM

Quote:

Originally Posted by Nereid

Maybe I will start a thread, in Astronomy, on this; I think it will clear up much of your confusion and bafflement.

My dear Nereid! I’m just not making myself understood.

The phenomenon the DEILE hypothesis purports to explain is one of change. The mainstream, however, gives their answer in terms of a total! The mainstream has performed a conceptual hijacking, and now has everyone befuddled!

If we ask, Why is the moon’s orbit expanding?, the answer cannot be, “70 trillion joules.” You do not have to “check the math” to know that 70 trillion joules does not “explain” why the moon’s orbit is expanding! The “problem” is given in terms of change-per-unit-time, so the answer must be in the form of some-kind-of-change-per-unit-time, not a total.

Q. The moon’s orbit expands so-much per-year; where does the energy come from?
A. The earth’s rotation slows down so-much per-year (supplying the energy).

Notice that the answer—a rate of change—is in the same form as the question.

It is the same with the Hubble expansion. If we ask, Why is the distance between remote objects changing at the rate of 73 ppt/yr?, the answer must be in the form of change. I am clear on this. The mainstream is not. My only point of confusion is how the mainstream has become so confused.

Quote:

If you're seeking to use just the physics of GR and electromagnetism to construct your ATM idea, then how could you answer questions of the kind "how does your idea fit with the normal big bang cosmologies?"?

You see, it doesn’t fit within BB cosmology! To understand it, you have to make another starting assumption. Assume the Hubble-constant is constant. Make that assumption, and the observations make sense. Things start to add up.

In my idea, there is only one idea: the increasing distance between things occurring at > 5 Mpc is due to the decreasing distance between things occurring at < 5 Mpc. Because the decrease in distance is occurring at a more-or-less constant rate, the increase should be occurring at a more-or-less constant rate, as well. That is what is observed. The acceleration observations are saying that the Hubble-constant is constant!

Unlike the BBT, the DEILE hypothesis contains no ad-hoc conjectures, no artificial flavors: no Big Bang; no Inflation; no Dark Energy; no BBT cosmology; nothing but the known laws of physics. One observed phenomenon (contraction) explains another (expansion).

That is it.

Nereid · #90 (**permalink**) 05-June-2006, 11:53 PM

Quote:

Originally Posted by Peter Wilson

My dear Nereid! I’m just not making myself understood.

The phenomenon the DEILE hypothesis purports to explain is one of change. The mainstream, however, gives their answer in terms of a total! The mainstream has performed a conceptual hijacking, and now has everyone befuddled!

I'm even more befuddled ... by DEILE.

The expansion of the universe is automatic, once you have a universe with mass-energy in it (well, a contraction is also a solution), it follows from GR.

So asking for an explanation of expansion, in terms of what drives the change, is a little like asking for an explanation of (electrical) charges (or, if you prefer a 20th century question, the explanation for the EM force).

Quote:

If we ask, Why is the moon’s orbit expanding?, the answer cannot be, “70 trillion joules.” You do not have to “check the math” to know that 70 trillion joules does not “explain” why the moon’s orbit is expanding! The “problem” is given in terms of change-per-unit-time, so the answer must be in the form of some-kind-of-change-per-unit-time, not a total.

Q. The moon’s orbit expands so-much per-year; where does the energy come from?
A. The earth’s rotation slows down so-much per-year (supplying the energy).

Notice that the answer—a rate of change—is in the same form as the question.

It is the same with the Hubble expansion.

Perhaps this this the disconnect - you seem to see some connection between the Moon's orbit and the universe's expansion, in terms of similarities of underlying processes.

Textbook astrophysics doesn't, other than that gravity is at work in both cases.

Quote:

If we ask, Why is the distance between remote objects changing at the rate of 73 ppt/yr?, the answer must be in the form of change.

Or, the answer falls out of GR equations, end of story (unless you are seeking something deeper, such as what 'explains' GR. However, I don't think that's what you're trying to do).

Quote:

I am clear on this. The mainstream is not. My only point of confusion is how the mainstream has become so confused.

And, from my POV, it's odd that you haven't put the relevant GR equations on the table, to show how (and where) 'change', per DEILE, is the same (conceptually) for the Hubble expansion as for the Moon's orbit.

I mean, isn't it obvious, when you read the Sean Carroll webpage, that an expanding universe follows, automatically, from the math (the only thing in doubt is its rate, and our present time)?

Quote:

You see, it doesn’t fit within BB cosmology! To understand it, you have to make another starting assumption. Assume the Hubble-constant is constant. Make that assumption, and the observations make sense.

Pretend I'm from Missouri (? The "show me" state); show me.

Please put the observations on the table which are consistent with "the Hubble-constant is constant".

Quote:

Things start to add up.

In my idea, there is only one idea: the increasing distance between things occurring at > 5 Mpc is due to the decreasing distance between things occurring at < 5 Mpc. Because the decrease in distance is occurring at a more-or-less constant rate, the increase should be occurring at a more-or-less constant rate, as well. That is what is observed.

I think I asked you about this before (I need to check) - is this what is actually observed?

Quote:

The acceleration observations are saying that the Hubble-constant is constant!

Unlike the BBT, the DEILE hypothesis contains no ad-hoc conjectures, no artificial flavors: no Big Bang; no Inflation; no Dark Energy; no BBT cosmology; nothing but the known laws of physics. One observed phenomenon (contraction) explains another (expansion).

That is it.

Good. When can we expect that you will answer the questions about the five categories of observations?

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