Redshift & Expansion: What Else Is There?

[shrumeo]

Redshift = expansion??

I'm not a physicist so I'll probably be laughed at for asking this.

I understand the concepts of redshift and the Doppler effect being used to substantiate the hypothesis that the universe is expanding, indeed accelerating, since the farther an object is the higher its redshift.

This fits.

But, please tell me there is more than this to say that the universe is expanding and accelerating.

I mean, there may be some undiscovered property of space that shifts the wavelength of light proportional to the distance traveled. I'm not invoking any ether theories or anything. I just mean, there has to be other data besides redshifting to confirm the expansion of the universe. I'd hate to know that so much theory is built on one type of data point.

Can someone educate me?

 

[LURCH]

The Cosmic Background Radiation is also taken by many to be evidence of universal expansion. CBR is a radio signal that comes from everywhere in space at once. Back when radio comunication was in its early stages, some guys were setting up a cone-shaped antenna for some purpose (telephone signals I think) when they found that the antenna picked up a low-energy interference. The signal seemed to come from everywhere, no matter what direction they pointed the antenna. At first, they thought it was radation from the decay of bird-droppings inside the horn. But after cleaning, the signal persisted.

It was eventually determined that the signal was coming from space. Later someone found that just such a signal was predicted by the Big Bang Theory, as a left-over "glow" from the heat of the original explosion.

Personally, I'm a bit suspicious of the BB theory, for the same reasons you mentioned. From my cinical perspective, the CBR would not be seen as support of the BBT if that theory were not already established.

 

[marcus]

Originally posted by shrumeo
...I understand the concepts of redshift and the Doppler effect being used to substantiate the hypothesis that the universe is expanding, indeed accelerating, since the farther an object is the higher its redshift...

But, please tell me there is more than this to say that the universe is expanding and accelerating.
...I'd hate to know that so much theory is built on one type of data point.

There is more than just observed redshifts that supports the idea that the U is expanding.

It is good to be skeptical and question prevailing ideas and ask for more than one kind of evidence---so seem like very fair questions you are asking.

The main equation of Relativity has two kinds of stable solutions---space expanding and space contracting----and it goes back to 1915, well before extragalactic redshifts were systematically observed.

The first test of General Relativity (GR) was in 1919, measuring the bending of light as it passed the sun. It passed that test and thereafter it has passed every test anyone could think of performing. Recently two pulsars (radiosource neutron stars) were found orbiting each other and this provided a stringent test which the theory passed ("with flying colors", said Ned Wright, who posted the news on his "News of the Universe" page)

The first reason IMHO to think that the universe is expanding is that GR has been tested now for over 80 years in a lot of different cases and it works really well. The GPS system depends on using GR formulas to adjust the time signal from the satellite---if those formulas weren't right the system would give the wrong coordinates. So the main equation of GR has been confirmed in many ways over 80 years.
And this main equation says the universe should be expanding (unless it is collapsing).

So far nothing here about redshifts or about the CMB.

You can see that the evidence for expansion is not ONLY redshifts.
Because of GR one would expect to see either a whole bunch of redshifts (meaning expansion) or a whole bunch of blueshifts (meaning contraction). Well, as it happens, we see redshifts rather than the reverse. So since expansion was one of the two possibilities it seems reasonable to put two and two together and explain the redshifts by the expansion.

The CMB was an extra bonus. It was first predicted in 1945 IIRC, based on the General Relativity idea that the universe is expanding.
If you follow that expansion back you come to a time when a flash of light is released. Since things are sparse enough that there is not much to stop the light, it must still be flying in all directions thru space. The 1945 guys (Alpher and Gamow?) predicted that the wavelength of the original flash of light would have been STRETCHED OUT by the expansion of space by a factor of around 1000 and therefore that the light would now be radiowaves.

(if you start with visible light and stretch the wavelength out by 1000-fold you get microwave/infrared.) They predicted a certain frequency band or wavelength band to look in.

This was a pretty radical thing to predict. It was a bold test of General Relativity and the expanding space idea----nobody had detected those Background Microwaves. They would only be expected to be there if the expanding picture was correct----no other theory had predicted anything like the CMB.
If the astronomers looked for signal in the band that those guys predicted from GR considerations and the signal HAD NOT BEEN FOUND that would have been discrediting for GR. Scientific theories have to risk falsification---make predictions that could prove them wrong---in order to be meaningful. GR was meaningful and said look for the CMB, and the CMB was found: they found the signal right where predicted.

I guess what I am saying is that the expansion thing is just one aspect of GR----one facet of what GR predicts. That one equation can be applied to a lot of things and used to predict different kinds of things (timechange, lightbending, spaceexpansion, neutron star orbits,...)
By now that one equation (the GR equation) has been thru so many tests and predicted so many things that have turned out that it would be difficult to replace it with a substitute that would handle all that stuff anywhere near as well.

(People try to develop alternatives but so far it hasnt worked out too well. Someday no doubt.)

So ultimately I tend to believe in space expanding because it is part of what that model of gravity predicts---and the model works---AS WELL as because a whole bunch of foreign galaxies have redshifts that increase with distance. It isn't just the redshifts.

 

[Nereid]

IIRC, the full story of the CMB and the Big Bang is somewhat richer than either LURCH or marcus have described; yes it was predicted, but the theorists didn't know how to look (or was it that they didn't really believe their predictions?); the engineers (let's hear it for engineers!) who found it worked for AT&T, and were completely unaware of the cosmic implications of their data - 'a sticky white substance of uncertain dialectric constant' seemed a more likely explanation.

The BB has a third pillar of evidence - the primordial abundance of nuclides. It's not only that the amount of H and He in the universe is just what the BB theory says it ought to be, but also ⁷Li, ⁴He, ³He, and ²H (and the absence of anything else primordial - apart from the hydrogen we're completely a star-made product).

The acceleration of the expansion was a surprise, and isn't well characterised yet. AFAIK, the signal is seen only from distant Type 1 supernova data, though it can be seen in the CMB (through models).

 

[Mr. Robin Parsons]

Shurmeo, all of the light that is used in all of these measurements, is light that has traveled the distance, and arrived here, at the Face of the Earth, that is why we can observe/see it, hence, what is really happening "out there" no one really knows...the Universe could have turned back upon itself (contraction) several thousands, or millions, or (1 or 2 or more) billion years ago, and we would/will not know that till that light arrives here at the face (or 'near' face...satellites) of the planet...

But don't think that that really means anything with respect to it happeneing today, or tomorrow, the 'evidence' (the light record) would get here before anything else happened, so we are eminantly safe!

 

[shrumeo]

well, I think they can safely assume that it will NOT turn back on itself if it is accelerating instead of decelerating.

Also, I've been told that the "expansion" of the universe is expansion of space itself, not simply objects of matter moving away from each other, although it has that effect. The effect of space expanding is basically that objects will move farther apart. I guess the expansion of space has NO effect on the location of a photon with respect to another photon, since they have no mass. But, maybe it does, maybe "separating" photons, or at least stretching the wave, could have an effect of increasing the wavelength (redshifting) of the light. So maybe the double effect of Doppler and stretching light by expanding space makes it look like the universe is accelerating?

Also, if space itself is expanding, every particle of matter would have to expand as well(?) since, say, a proton takes up some volume, then it would also have to be expanding along with the space it occupies(?). If it didn't would electronic orbitals destabilize or something? since, the electron can be visualized to be "moving" with some momentum with respect to the proton.

You see why I'm so confused by this seemingly simple concept.
I think if I took some classes on GR then this might all make sense to me.

 

[shrumeo]

a whole bunch of foreign galaxies have redshifts that increase with distance

that's kind of what i was saying, maybe there is some other undiscovered property of space (stupid aether theory) that stretches light more the farther it travels.

I think the CBR is from the annihilation of matter/antimatter when the U was cool enough for that to happen, I think it was about 1 second old. I assume the CBR is mixture of similar wavelengths. That would mean that the annihilation event "released" a mixture of very simlilar wavelength photons? Does this mean that there was pretty much ONE type of matter particle and ONE type of antimatter particle. If there were a mixture of different kinds of particles, wouldn't the energy of their annihilation vary? Wouldn't we see a broad background spectrum or at least a few different regions of the EM spectrum to look at?

 

[Mr. Robin Parsons]

shrumeo gravitational redshift, our local star does it...the farther away a luminous gravitational object is, the more time/distance the gravity of the source star would have to work on stretching out the emitted light, or the space in which the emitted light is traveling, in...

 

[clicky]

Redshift created aging light!

The redshift results from expansion of the structure of light as it travels for a long time from the distant galaxies, according to Eugene Savov’s theory of interaction. It is all one interaction that occurs at different scales and thus accounts for the great puzzles of our time.

 

[Mr. Robin Parsons]

Originally posted by clicky
The redshift results from expansion of the structure of light as it travels for a long time from the distant galaxies, according to Eugene Savov’s theory of interaction. It is all one interaction that occurs at different scales and thus accounts for the great puzzles of our time.

Sounds (really) nice, but there isn't any available proof...nor disproof, sooo...sounds nice...

 

[clicky]

Proof

A complete picture of "firework universe" that nicely explains many big puzzles, presented in Eugene Savov's book Theory of Interaction,
looks like a convincing proof.

 

[Mr. Robin Parsons]

Originally posted by clicky
A complete picture of "firework universe" that nicely explains many big puzzles, presented in Eugene Savov's book Theory of Interaction,
looks like a convincing proof.

Your other post mentions;

(SNIP)[/color] The redshift results from expansion of the structure of light as it travels for a long time from the distant galaxies, (SNoP)[/color]

so, inasmuch as no one has been anywhere nears the outside of this solar system, to take MEASUREMENTS, or this galaxy, no one knows that with any kind of EVIDENCE, hence NO PROOF... but it sounds good...understand?

 

[shrumeo]

The BB has a third pillar of evidence - the primordial abundance of nuclides. It's not only that the amount of H and He in the universe is just what the BB theory says it ought to be, but also ⁷Li, ⁴He, ³He, and ²H (and the absence of anything else primordial - apart from the hydrogen we're completely a star-made product).

<<I realize that this is an old thread that may get no responses.>>

I've heard this before, that at first when atoms started to form in the early universe that the only atoms were hydgrogen atoms, period. Where were all the neutrons? So stars are making He from H, where are these neutrons coming from? I think this can be simply answered if I just had an intro nuclear physics course, something about electron capture or something like this. O wait, der!, just read it quickly. Electron capture is one electron plus one proton makes a neutron and a neutrino. Got it.

Well, another thing that's puzzling, that just came to mind as I type this. Unless I'm wrong, which may very well be the case, according to Electric Charge Theory, all charge should be balanced. There can't be an excess of electrons to protons in the universe, or vise versa. Isn't that strange? So, the universe has EXACTLY the same number of protons and electrons?? Every proton that formed from the quark-gluon soup, if you will, had an electron associated with it presumably. Were the formation of protons and electrons coupled somehow?

 

[Chronos]

just to drift further from the point, the net energy of the universe must be assumed to be zero [entropy rules]. positive energy [matter] must be balanced by negative energy [force] to maintain equilibrium. but matter is so dense [m=e/c^2], it takes a huge amount of negative energy [think dark energy] to balance the equation. dark energy, therefore, is actually potential energy [like a rock on top of a mountain]. that is why we cannot directly observe it. predictions regarding dark matter and dark energy are merely an attempt to balance the equation using gravity as currency, imho.

 

[Mike2]

just to drift further from the point, the net energy of the universe must be assumed to be zero [entropy rules]. positive energy [matter] must be balanced by negative energy [force] to maintain equilibrium. but matter is so dense [m=e/c^2], it takes a huge amount of negative energy [think dark energy] to balance the equation. dark energy, therefore, is actually potential energy [like a rock on top of a mountain]. that is why we cannot directly observe it. predictions regarding dark matter and dark energy are merely an attempt to balance the equation using gravity as currency, imho.

I find this extremely interesting. If there is no alternative but that a universe exist, then the probability of its existence is 100%. There is zero Shannon information contained in the universe. Furthermore, that the universe exists is always a 100% certainty. Whatelse is the case after that may be subject to some doubt, but we know that the universe does exist with 100% certainty. So we might suppose that the change in entropy is zero for the entire universe.

But even if there were a less than 100% probability of this particular universe to exist, wouldn't that still remain the case throughout all of time? So isn't it the case that at least there is no change in information/entropy of the universe throughout all of time.

I'm trying to convince myself of this. Do you know of any more official studies in this regard?

It could be that this is the key to understanding many aspects of reality.

First, it may be that some information involved with the curvature of space may need to equate to the information contained in the sum of particles. So the expansion of space may be linked to the creation of particles.

Secondly, it may be possible to link the expansion of the universe with the creation of life. The expansion may represent a increase in entropy, and life may be a mechnism to decrease entropy as a balance.

Third, you may even be able to calculate whether there is life on other planets if you could calculate the decrease in entropy associated with life, even intelligent life.

 

[shrumeo]

But even if there were a less than 100% probability of this particular universe to exist, wouldn't that still remain the case throughout all of time? So isn't it the case that at least there is no change in information/entropy of the universe throughout all of time.

What is Shannon information? And why do you somehow equate or relate entropy to "information"?

First, it may be that some information involved with the curvature of space may need to equate to the information contained in the sum of particles. So the expansion of space may be linked to the creation of particles.

Do you mean the creation of particles from nothing, or from "dark energy"?

Secondly, it may be possible to link the expansion of the universe with the creation of life. The expansion may represent a increase in entropy, and life may be a mechnism to decrease entropy as a balance.

This kills me every time I see it. LIFE IN NO WAY DECREASES ENTROPY! Nor does it involve a decrease in total entropy (maybe in some cases for open systems like anything else, but not in any special "life" kind of way.) People think this because the hear in school that entropy = disorder, which is absolutely does not. Here is a nice website: http://www.entropysite.com/

 

[shrumeo]

Aha!

I reead up on it. The "entropy" in Information Theory would not necessarily, or probably not at all, the same "entropy" of thermodynamics. Maybe one could analogize them somehow, but I don't think the 2 words really mean the same thing.

Looking "entropy" up at Dictionary.com you get:

1. Symbol S For a closed thermodynamic system, a quantitative measure of the amount of thermal energy not available to do work.
2. A measure of the disorder or randomness in a closed system.
3. A measure of the loss of information in a transmitted message.
4. The tendency for all matter and energy in the universe to evolve toward a state of inert uniformity.
5. Inevitable and steady deterioration of a system or society.

#2 is totally misleading BTW, but I kinda like #4, but it's more the effect of entropy than entropy itself.

 

[Chronos]

Mark2, a very elegant and profound insight into the implications of a zero net energy state universe. the fact it cannot standstill [quantum theory] and must also be expanding or contracting [GR] requires a universe that is doomed to become increasing complex as well as simple. i especially like the apparent need for sentient life in the universe. expansion created additional entropy burdens that could not be 'burned off'. by conventional random creation and annihilation of particles. so the universe was forced to evolve and create more efficient 'entropy dumps'. that is sentient life, and the more aware it becomes, the more efficient is serves as an entropy 'exhaust'.

you may be amused by some papers written by Cahill of Flinders U. i think process physics is more intuitive than scientific [at this time, anyhow]. but it does inspire a more comprehensive view of why there is force and counter force, as well as matter and anti-matter. btw, information is the densest form of entropy in the known universe.

clarification. entropy is commonly thought of as disorder.. randomness. i prefer to think of it as balance, hence entropy has a plus [order] and a negative [disorder] quality. information is a very highly ordered state [+ energy]. we need a new description of reality to equate that. i don't object to the thermodynamic explanation. i just think it is inadequate. if this universe must exist [and i believe it is forced to exist under quantum theory], then it must become increasingly complex and simple over time. expansion is therefore required. sentience is an unavoidable consequence in such a universe.

is this particular universe necessary? no. but it is absolutely required for a universe to exist. pure non-existence would violate quantum physics. such a universe would have a perfectly fixed position and velocity [0,0], and this is forbidden. therefore, it is 100% necessary for a universe to exist. it is also necessary for it to behave in a causal manner.

for a universe to exist, it must be closed in the sense that it forbids observable features that would prohibit it from existing [infinity being one]. it must also include causality and be perfectly balanced [zero state] to have space-time dimensions. [i could elaborate on that but i am tired] quantum theory places a lower limit and GR places an upper limit on how such a universe must behave in order to meet these restraints.

why do we only perceive 3 spatial dimensions and one time dimension? because that is the minimum required to explain it. there is a probability the universe has many more dimensions than we can perceive. but they are not necessary or important enough to predicate our existence.

any reality beyond our ability to observe has no consequences in this universe. all the universe demands is that we exist to wonder why it does. [btw, i have a rough idea how to calculate the life form density necessary to perpetuate this universe].

 

[Mike2]

Mike2, a very elegant and profound insight into the implications of a zero net energy state universe. the fact it cannot standstill [quantum theory] and must also be expanding or contracting [GR] requires a universe that is doomed to become increasing complex as well as simple. i especially like the apparent need for sentient life in the universe. expansion created additional entropy burdens that could not be 'burned off'. by conventional random creation and annihilation of particles. so the universe was forced to evolve and create more efficient 'entropy dumps'. that is sentient life, and the more aware it becomes, the more efficient is serves as an entropy 'exhaust'.

I suppose that at some point efficiency requires a deliberate and purposeful effort, which requires beings aware of their surrounding and mindful of that purpose who can manipulate matter to that end.

is this particular universe necessary? no. but it is absolutely required for a universe to exist. pure non-existence would violate quantum physics. such a universe would have a perfectly fixed position and velocity [0,0], and this is forbidden. therefore, it is 100% necessary for a universe to exist. it is also necessary for it to behave in a causal manner.

I'm not sure that you can impose quantum mechanics on the universe as a whole. Perhaps that is a phenomena that can only be described within a universe. If the universe must absolutely exist, and there is no uncertainty about that, then the uncertainty principle would seem not to apply. Otherwise, you would be presupposing alternative times and sites where space-time itself first began. If it hadn't begun yet, then there are no alternatives as to where and when it can begin.

for a universe to exist, it must be closed in the sense that it forbids observable features that would prohibit it from existing [infinity being one].

Right, everything must be consistent with everything else.

it must also include causality

I'm comfortable with that on an intuitive level. For if the first point of space-time can arise out of nothing, then this proves that it is possible for other points to arises as well, and there you have causality (or at least logic) producing expansion.

and be perfectly balanced [zero state] to have space-time dimensions. [i could elaborate on that but i am tired] quantum theory places a lower limit and GR places an upper limit on how such a universe must behave in order to meet these restraints.

I'm presently reading a book by Eric J. Chaisson, Cosmic Evolution, where he expounds on how ordered states can be created only as a means of more efficient ways to dump entropy. This got me thinking about how entropy fits into quantum mechanics where one state is chosen from a superposition of many. So the nature of quantum interactions or observation reduces the number of available states and would therefore reduce entropy. Does that sound right?

[btw, i have a rough idea how to calculate the life form density necessary to perpetuate this universe].

I'd like to see that.

 

[shrumeo]

I know you two aren't listening to me but I don't care:

I see where you are getting this anthropomorphic view of this.
I have not read Cosmic Evolution. But I read the cliff's notes. or at least someone who read it and sounds like they know what they are talking about.
Here are a few clips from: http://www.2think.org/cosmicevolution.shtml

"I'm not sure if I buy everything in Cosmic Evolution. The author may be trying to use a hammer for everything and not just for the nails they were intended for."

In another book review, on the same site:

"Many of us already know that "we habitually inflate the impressiveness of coincidence in order to make a good story" (p. 149)."

It sounds like you are trying to use the tendency of all heat (thermal energy) to disperse into more places than it started in (entropy) to build that into "order" and "complexity" which are not too much more than conceptual constructs in most circumstances. If he is using entropy to MEASURE complexity, or somehow detect it, well that's nice if he spells out how he does this scientifically, as opposed to just comparing 2 things, making a judgment, and saying Thing 1 is more complex Thing 2 because it sure looks that way to me.

Here is an exerpt from the cover blurb in Cosmic Evolution:
"Guided by notions of beauty and symmetry, by the search for simplicity and elegance, by the ambition to explain the widest range of phenomena with the fewest possible principles, Chaisson designs for us an expansive yet intricate model depicting the origin and and evolution of all material structures."

Sounds great except to Einstein who said: "Elegance is for tailors."

 

[Mike2]

If he is using entropy to MEASURE complexity, or somehow detect it, well that's nice if he spells out how he does this scientifically, as opposed to just comparing 2 things, making a judgment, and saying Thing 1 is more complex Thing 2 because it sure looks that way to me.

Chaisson uses energy rate density to measure complexity. Table 2, page 139, he rates the varying degrees of structured complexity:

Milky Way galaxies____0.5 erg/sec/grams
the Sun_____________2.0 erg/sec/grams
planets(Earth)_______75.0 erg/sec/grams
Bioshere(plants)____900.0 erg/sec/grams
human body_______20,000 erg/sec/grams
human brains_____150,000 erg/sec/grams
modern society___500,000 erg/sec/grams.

But so far his observations are interesting, but he does not explained why it is this way. His theory is contrived, not derived. He explains that complexity can emerge due to non-equilibrium flows of energy. But nothing he says implies that complexity is necessary. Thus I am not satisfied. As far as the author is concerned, we are all still accedents. I would prefer a theory that states that at least complexity IS necessary, not just possible.

 

[energia]

there are other interpretations for stellar redshift
including the Compton Effect and Shapiro Effect

there is no conclusive evidence that the Doppler Effect is the correct interpretation, although it was the initial interpretation of Edwin Hubble in 1929
and it remains the accepted and core interpretation of Big Bang Theory

the standard model of cosmology is currently BBT - other competing models also exist (Superstring model for example)

Cosmologists are not quick to embrace new models - in fact the prevailing policy is to reject all steady state models as crank models - whether the theory fits the data or not - or whether the mathematical argument is sound or not

some theoretical cosmologists have proposed that the visible universe is a local light bubble in a universe of infinite numbers of light bubbles

there are so many theories in fact that it would be impossible for one person to study them all in a human lifetime

 

[Chronos]

i think the energy density concept is a good approach. i too, however, question how chaisson arrived at the values quoted. i think it would be sounder to start with matter density, which can be estimated. we have a fair notion of how much total mass there is in the observable universe [most estimates are around 10^55 grams]. we also have a fair notion of its size [about 13.5 billion light years]. this gives a basis to approximate the average matter density per unit volume over time. we could then break it down into spherical shells of equal volume and compare the more local densities to the more remote densities. if we, as we assume, all matter was created as a result of the big bang and the universe has expanded since then, we should find the density has decreased over time in a manner consistent with the rate of expansion. if, however, we find it is approximately the same over time, it is difficult to avoid revisiting steady state theory. this approach does not directly include the radiation density, but, this component must be small compared to matter density [an e=mc^2 thing] and limited by the CBR temperature. i would be fascinated to see the numbers.

 

[shrumeo]

Yes! Thank You!

there are other interpretations for stellar redshift
including the Compton Effect and Shapiro Effect

there is no conclusive evidence that the Doppler Effect is the correct interpretation, although it was the initial interpretation of Edwin Hubble in 1929
and it remains the accepted and core interpretation of Big Bang Theory

the standard model of cosmology is currently BBT - other competing models also exist (Superstring model for example)

Cosmologists are not quick to embrace new models - in fact the prevailing policy is to reject all steady state models as crank models - whether the theory fits the data or not - or whether the mathematical argument is sound or not

some theoretical cosmologists have proposed that the visible universe is a local light bubble in a universe of infinite numbers of light bubbles

there are so many theories in fact that it would be impossible for one person to study them all in a human lifetime

Thank the heavens that someone out there agrees with me. I have looked around with my limited knowledge and intellect and have seen more than a handful of theories that explain the way the universe looks and behaves VERY WELL, sometimes better than relativity and quantum mechanics, and make much more common sense and are much more logical. I just think these were the first two models that came out that really started to fit the data (mostly) and through some kind of zeitgeist were hailed as being the grand solutions.

The fact that there are so many valid solutions to the problems of "what's really happening" shows me the limits of human consciousness. The fact that the establishment rejects so many alternate theories outright without giving them a chance in peer review, despite some of them being quite robust toward scrutiny, shows me the limits of the human backbone.


PS:

i think the energy density concept is a good approach. i too, however, question how chaisson arrived at the values quoted .

sounds like he made them up. BTW my arse has an energy density rate of 1b erg/s/g during flatulence. How does yours measure up?

 

[Mike2]

i think the energy density concept is a good approach. i too, however, question how chaisson arrived at the values quoted.

Whatever his numbers, they don't even tell us how likely it is that complexity will arise.

The universe expands, and then particles arise. Particles represent structure. So it should be possible to calculate the emount of information contained in their structure. We see expansion as a dissipative process; even before particles are formed, expansion disperses space and creates more possible states/places. But then we find particles which represent structure. So is there a counter balance to the increased entropy of dissipative expansion? Is there a conservation of information?

 

[Mike2]

We see expansion as a dissipative process; even before particles are formed, expansion disperses space and creates more possible states/places. But then we find particles which represent structure. So is there a counter balance to the increased entropy of dissipative expansion? Is there a conservation of information?

So, I wonder, can an entropy difference be calculated for the expansion of space-time before particles of any kind appeared? I suppose that means that the universe was smaller than the smallest particle at that point so that it was not yet possible for particles to appear. So before particles, how would one calculate the entropy change from one point of expansion to the next? Would that simply be the ratio of volumes? Or perhaps curvature is a better measure since we still would not know the shape in order to calculate volume.

I suppose that expansion causing large imbalances in entropy is what causes a potential for particles to appear. Or maybe the selection of all the possible places the particle could appear in itself adds information to the universe that would otherwise only dissipate.

Any comments or interest? Thanks.

 

[Chronos]

So, I wonder, can an entropy difference be calculated for the expansion of space-time before particles of any kind appeared? I suppose that means that the universe was smaller than the smallest particle at that point so that it was not yet possible for particles to appear. So before particles, how would one calculate the entropy change from one point of expansion to the next? Would that simply be the ratio of volumes? Or perhaps curvature is a better measure since we still would not know the shape in order to calculate volume.

I suppose that expansion causing large imbalances in entropy is what causes a potential for particles to appear. Or maybe the selection of all the possible places the particle could appear in itself adds information to the universe that would otherwise only dissipate.

Any comments or interest? Thanks.

all energy transactions, so far as i am aware, require matter to have observable consequences. i therefore doubt any observable space-time dimensions are necessary, or could exist, in the absence of either component. we are therefore forced to assume both aspects must be included in any predictive models.

we only know, with certainty, a few things about the universe. one, it does exist, and two, we are aware that it does. i also suspect both conditions must be the most probable of any possible states required for any universe to exist. explaining it is more complicated.

expansion of the universe, which is on sound footing, requires an energetic component to offset the known effect of gravitational attraction. every shred of evidence points to a universe that has expanded over time, but may eventually collapse. however, the preponderence of evidence suggests we live in a universe that is perfectly balanced between expansion and collapse. coincidence? i find that highly improbable.

 

[Mike2]

all energy transactions, so far as i am aware, require matter to have observable consequences. i therefore doubt any observable space-time dimensions are necessary, or could exist, in the absence of either component. we are therefore forced to assume both aspects must be included in any predictive models.

All this is saying is that your models pre-supposes the existence of particles, and therefore do not explain the existence of particles. The question is whether particles are a form of structure or not; I think it is quite obvious that they do represent a form of structure. Did particles always exist in the universe? If not, then the creation of particles is a decrease in entropy, an increase in information. So if entropy must always increase, or at least remain constant, then what represents an increase in entropy to offset the decrease that comes from the creation of particles? Without particles there is only empty space. So it seems that there is no alternative but that the expansion of space must represent a dissipative process that (more than) offsets the decrease in entropy associated with the "formation" of particles?

If the size of particles in not arbitrary, then the expansion of space can be measured with respect to some characteristics required before particles can appear. If space alone can be describe as a function of inherent properities, such as curvature or elasticity, etc, then one can calculate the information/entropy of such a function as is done for functions that serve as signals along a wire.

 

[selfAdjoint]

Mike, if the earlier state of the universe was some kind of condensation, then it would be for entropy purposes one particle, and breaking up into many particles would be a loss if information, aka a growth of entropy.

 

[Mike2]

Mike, if the earlier state of the universe was some kind of condensation, then it would be for entropy purposes one particle, and breaking up into many particles would be a loss if information, aka a growth of entropy.

That was interesting, thanks for the comment. So the question seems to be do particles represent a breaking up of some more primaitve state? Or do particles represent added structure?

I don't suppose it is possible to actually break up the original particle of space-time into separate sub-sections of space-time that drift apart from one another. For then you would have to have some other space-time/coordinate system to measure the separation of the break-up of the original space-time. Then the same question would be asked of this new space-time that we are asking about the first space-time.

So I think we are looking at particles as representing added structure to space-time. If particles are sub-manifolds of the original, then they cannot represent a break-up of the original manifold. For a true break-up of a manifold would consist of separate sections of the same dimensionality as the orginal (thus, not sub-manifolds of it). Again, it would not be possible to have unconnected subsection of space-time and still propagate a signal through the absolute nothing between these unconnected sub-sections.

Though I could be wrong, your comments are always appreciated. Thanks.

 

[selfAdjoint]

I tend to think more of fields, with particles appearing as localizations of the fields. So my vague idea is first, high enough temperature that all the forces converge and there is only one uniform field that fills the whole, small, universe. Then as the universe expands and the temperature falls, the forces separate out, and the field transitions to multiple fields, and then the fields develop localizations. At each step the number of posibilities goes up.

 

[Mike2]

essence of particles

I tend to think more of fields, with particles appearing as localizations of the fields. So my vague idea is first, high enough temperature that all the forces converge and there is only one uniform field that fills the whole, small, universe. Then as the universe expands and the temperature falls, the forces separate out, and the field transitions to multiple fields, and then the fields develop localizations. At each step the number of posibilities goes up.

That would be the traditional view, but it begs the question as to where these fields come from. In fact, that would be the Standard Model perspective, wouldn't it? Doesn't String theory model QED and QCD and gravitation all as different modes of the same kind of String? Wouldn't that seem to eliminate any reference to separate quantum fields in favor of one "String field" theory?

I'm trying to develop an intuition about quantum fields. It seems to me that a quantum field cannot be anything like a classical field. If the field is connected and continuous, then any disturbance would have to propagate in all directions and thus any "particle" would have to almost immediately dissipate, right? Or if a field were a piecewise linear thing, where disturbances are discrete, then wouldn't that still require disturbances to dissipate. In fact it would dissipate more quickly since there would come a point where the dissipating wave would not have enough of an effect on its neighborhood to change the next portion by the minimum discrete value. So it would cease to propagate at that point.

So I'm thinking that particles cannot be disturbances of any kind of connected field, since that would require that particles dissipate. And unconnected fields cannot propagate through absolutely nothing. So instead I'm thinking that particles must therefore be the absence of a connected field, places where the field (or spacetime) no longer exists. These are places where spacetime (or at least the field) comes to a boundary. A boundary does not dissipate. Am I right on that point? Then the field only describes the average density of such particles, the probability of finding a particle at a given point.

Furthermore, I am beginning to wonder if strings are a natural choice to describe particles. Why not higher dimensional objects like surfaces? I can certainly visualize how a 3D field can converge on a 2D object; it just stops there. But I'm not sure how a 3D field would converge on a 1D object. It would seem as though one of the dimensions of 3D would have to shrink to zero to fit on a string. Wouldn't that give the same troubles as 3D converging to a point? I would think that if something (particle) actually "exists" inside at least 3D, then you'd have to bump into it no matter which way you approach it. If it exists for all observers, then there can be no possible observer that could not preceive it. But with a 1D string, with no width, it cannot be precieved when viewed on its side. So I think this means that particle must have a 2D surface.

 

[Chronos]

... it may be possible to link the expansion of the universe with the creation of life. The expansion may represent a increase in entropy, and life may be a mechnism to decrease entropy as a balance.

... you may even be able to calculate whether there is life on other planets if you could calculate the decrease in entropy associated with life, even intelligent life.

You might find this interesting [link below]. Harrison's calculations, as he points out, do not yield very satisfying results. The concept and approach, however, is very appealing.

http://www.upscale.utoronto.ca/GeneralInterest/Harrison/BlackHoleThermo/BlackHoleThermo.html