Could Dark Matter Possibly Be . . .

[apodman]

Thanks for the refresher. Sometimes all the stretching, moving, and radiating gets me disoriented and I lose my ability to visualize the setup.

[Chris Peterson]

Sorry about the (dumb) questions but are you saying that when the object originally formed it was already 13.7 billion Light Years away from us and, over the last 13.7 billion years, as its light has been traveling toward us, expansion has forced it to move away from us an additional 5 billion light years? This is the only explanation the seems to allow for both to be correct, that the object is 18 billion light years away and we are just seeing its light from 13.7 billion years ago.

No. When the object formed it may have only been a billion ly away, or a few hundred million. There's nothing that prevents space from expanding more than 13.7 billion ly in less than 13.7 billion years. You shouldn't confuse the maximum speed of an object through space (c) with the maximum rate that space can expand (no known limit).

The questions aren't dumb at all; this isn't something very easy to understand. I found this Wikipedia article which seems pretty well written. See if it helps.

[Sputnick]

The consensus is what it is. Nobody determines that; it is simply a recognition that a theory is accepted by a significant percentage of those expert in that field. Nobody thinks about whether they are "holding consensus", they simply decide what theories they accept as best.

Chris,
I'm encouraged by your use of the word "significant" instead of 'majority'. I do think that if Big Bang actually happened it could possibly be proved .. as nature reveals itself to us if we seek long enough.
By the way, I'm of the opinion that speed of light is not constant in space .. one example being when it is bent by gravitational fields .. that bending possibly necessitating speed up to reach the same point at the same time the light would have reached had it not been bent. Perhaps light travels in sync with those particles not affected by bending. Einstein said at one point that it was speculative that light travelled in space at a constant speed, then revised that saying 'the law of the speed would have to be raised to a principle', seemingly having said that so that the speed would have to fit comfortably into theories.
I really should have brought the quotes and contexts, though, so perhaps I should not even mention those things .. but can't bring myself to delete what I have written. Stubborn Pride? I suppose.

[Sputnick]

Sorry about the (dumb) questions but are you saying that when the object originally formed it was already 13.7 billion Light Years away from us and, over the last 13.7 billion years, as its light has been traveling toward us, expansion has forced it to move away from us an additional 5 billion light years? This is the only explanation the seems to allow for both to be correct, that the object is 18 billion light years away and we are just seeing its light from 13.7 billion years ago.

No. When the object formed it may have only been a billion ly away, or a few hundred million. There's nothing that prevents space from expanding more than 13.7 billion ly in less than 13.7 billion years. You shouldn't confuse the maximum speed of an object through space (c) with the maximum rate that space can expand (no known limit).

The questions aren't dumb at all; this isn't something very easy to understand. I found this Wikipedia article which seems pretty well written. See if it helps.

A question. The force behind Expansion must be considerably weaker than gravitational force or Andromeda and Milky Way would not be approaching each other. True or false?

Also - if the universe is flat, as some models suggest, 'Expansion' might be more 'Stretch' .. so there should be a difference between the rates of increasing distance between the galaxies 'ahead' of each other than 'above' each other. Could these measurements help determine the shape of the universe?

[Sputnick]

Hello Sputnick,

Sorry, but I need to weigh in here. Please try to not forget this point because, after well over 200 posts in this thread, I still hear the same refrain in your dialog after all the attemp I have personally made to clear up the errant argument that you persist in using WRT the BBT. For the last time, it is a THEORY and theories CANNOT be PROVEN. No one is trying to prove the Big Bang-IT IS NOT A FACT!!!!! No one has claimed that it is a fact so why do you keep basing your perception on that falsehood? I need say nothing more on the matter than that.

I,m trying to not allow this idea of yours that the theory is some misguided power trip by mainstream science to mislead us poor dumb lemmings over the cliff of ignorance by injecting the public with some hairbrained scheme concocted in some think tank and blind us to other opinions or ideas.

Don,t worry- other theories can,t be proved either. if observation and fact point in a certain direction then that's the direction one goes in. People in NY will will wear black UNTIL something darker comes along and the scientific community will continually test the BB idea until something irrefutable steps up to the plate. I can almost guarrantee if something better comes along it will be replete with a lot of the data that scientists already have with a twist. They are looking at everything everyday with new tools, more number crunching brilliant minds and the best of all a knowledge base from deep in the past all the way up to this morning.

So......after 216 posts or so and a plethora of repetition from both sides I have yet to see resolution, e.i. read first paragraph. Don't close off. Include.

Hi Astro,

I think my persistance has had some effect .. language has gone from subtly saying 'the Big Bang is fact' to clear admission it is not fact yet proven .. language in the forum also now reveals that the concensus is not necessarily a majority, etc. This is improvement in many ways.

I differ from your opinion that theories cannot be proven .. I believe even Big Bang if it is fact can be proven because nature reveals itself. Of course, if we adhere to a totalitarian definition of the word 'theory' as necessitating impossibility of proof, then I fail to see the sense in using the word, and cannot conceive as to how that definition arose, or why. If the loser definition of theory is used .. 'an idea' .. then ideas can be proven true.

[Sputnick]

You provide the weapon, and in this case you also provided the invitation. And you beat us to death with wine, wine, wine and whine, whine, whine. What do you expect? Live by the sword ...

You heard a whine when there was a buzz. You thought I was beating you when I was beating a different drum.

Some people consider this forum suitable matter for children to access on the internet. What social service does your signature line contribute to their education?

The education of reality .. that alcohol can have a sustaining effect .. relaxation .. enlightenment .. relief from stress .. an alternative to addictive prescription medication that dulls the mind and destroys creative processes .. and also it reflects the stresses children should prepare themselves for, tribal conflict which is at first mild then becomes threatening and injurious .. those stresses not taught in schools when they should be, leaving people unprepared as they enter adulthood. If it were not so, huge numbers of our 'progressive' population would not be addicted to prescription medication and 'recreational' drugs. Sad situation, the thought of which causes me to wish I had a shot of something relatively sweet.

And don't you know that, in response to your hideous viewpoints, the vast scientific conspiracy is playing "good cop, bad cop, crazy cop" on you? Guess which one I am. It's much more entertaining in this day and age than burning at the stake.

I did sense a conspiracy. Which cop are you? Well, if you consider my viewpoints 'hideous' I would say Crazy, man, real crazy.

[Chris Peterson]

I'm encouraged by your use of the word "significant" instead of 'majority'.

However, I can't think of any case where consensus doesn't mean a majority. Where there is no majority opinion, most would simply say that a consensus has not been reached. For example, there is a consensus that the BBT is correct (because a large majority of scientists accept the theory), but there is no consensus yet as to the nature of dark energy (because scientists are split into several factions with differing opinions).

By the way, I'm of the opinion that speed of light is not constant in space .. one example being when it is bent by gravitational fields .. that bending possibly necessitating speed up to reach the same point at the same time the light would have reached had it not been bent.

That the velocity of light is constant in space is well established experimentally. Light is not bent by gravity... that is a misconception. Space is distorted by gravity, which- in our limited 3D viewpoint- gives the impression that the light path is bent. But light always travels in straight lines, which are called geodesics (to distinguish them from "line", which is often interpreted in its Euclidean sense).

[Chris Peterson]

A question. The force behind Expansion must be considerably weaker than gravitational force or Andromeda and Milky Way would not be approaching each other. True or false?

That is a complex question, with no simple answer. First of all, their is no "force" behind the expansion of space. Whether the accelerating expansion that is related to dark energy operates via a force in unknown. We can't measure the expansion of space over such small distances as the separation of the Milky Way and Andromeda. There's no reason that space in that interval can't be expanding, and the galaxies still moving towards each other. It's a question of the rate of expansion (which is very small over a few million ly) versus the velocities of the two galaxies, which are very much higher.

It would be better to say that over non-cosmological distances, the effects of gravity dominate the effects of expansion.

Also - if the universe is flat, as some models suggest, 'Expansion' might be more 'Stretch' .. so there should be a difference between the rates of increasing distance between the galaxies 'ahead' of each other than 'above' each other. Could these measurements help determine the shape of the universe?

I don't understand the question.

[Chris Peterson]

I think my persistance has had some effect .. language has gone from subtly saying 'the Big Bang is fact' to clear admission it is not fact yet proven

I'm glad you are happy with what you are hearing. But I think you are the only one hearing it. Opinion on this doesn't seem to have changed over the course of any of these discussions, and I've never seen a hint that anybody actually considered the BBT (or any other theory) to be fact.

I differ from your opinion that theories cannot be proven ...

Most everyone who understands the process of science would disagree. In any case, to date no scientific theory has ever been proven.

[Sputnick]

I'm encouraged by your use of the word "significant" instead of 'majority'.

However, I can't think of any case where consensus doesn't mean a majority. Where there is no majority opinion, most would simply say that a consensus has not been reached. For example, there is a consensus that the BBT is correct (because a large majority of scientists accept the theory), but there is no consensus yet as to the nature of dark energy (because scientists are split into several factions with differing opinions).

A concensus can be made to appear to be a majority when members of concensus hold power of publication.

By the way, I'm of the opinion that speed of light is not constant in space .. one example being when it is bent by gravitational fields .. that bending possibly necessitating speed up to reach the same point at the same time the light would have reached had it not been bent.

That the velocity of light is constant in space is well established experimentally. Light is not bent by gravity... that is a misconception. Space is distorted by gravity, which- in our limited 3D viewpoint- gives the impression that the light path is bent. But light always travels in straight lines, which are called geodesics (to distinguish them from "line", which is often interpreted in its Euclidean sense).

So - you say light can be stretched (redshift) but not bent? I can't see why that should be possible. And I can't see how experiments with light done within the small range of solar system which they have been done in can prove anything about what happens in larger scales in which I have read normal physics seems to break down. If space is distored by gravity .. does it englarge itself? Does light have to travel a longer path because of the distortion of space? Anyway .. I will never be convinced that light's speed is unalterable because there seems no 'law' of science which is not subject to variance .. a primitive example of which is the Pioneer Anomaly throwing doubt on the persistance of gravity.

[bystander]

I think my persistance has had some effect ...

Indeed, if this were Survivor, I'm fairly certain you would be voted off the island.

I would like to ask you if you are being deliberately obtuse, or if you are genuinely that naive, but I realize it would do me no good. If the former, you would deny it, and if the latter, you wouldn't know it.

I would suggest that you clear your mind and carefully reread all three fora. People have been trying to inform you of the rules by which the game is played. If you want to play the game, you have to know the rules. You don't get to make them up as you go along.

[Sputnick]

A question. The force behind Expansion must be considerably weaker than gravitational force or Andromeda and Milky Way would not be approaching each other. True or false?

That is a complex question, with no simple answer. First of all, their is no "force" behind the expansion of space. Whether the accelerating expansion that is related to dark energy operates via a force in unknown. We can't measure the expansion of space over such small distances as the separation of the Milky Way and Andromeda. There's no reason that space in that interval can't be expanding, and the galaxies still moving towards each other. It's a question of the rate of expansion (which is very small over a few million ly) versus the velocities of the two galaxies, which are very much higher.

It would be better to say that over non-cosmological distances, the effects of gravity dominate the effects of expansion.

Which leads me to believe the speed of light could be effected by cosmological distances raher then the restrictive distance that speed has been tested in.

Also - if the universe is flat, as some models suggest, 'Expansion' might be more 'Stretch' .. so there should be a difference between the rates of increasing distance between the galaxies 'ahead' of each other than 'above' each other. Could these measurements help determine the shape of the universe?

I don't understand the question.

Picture a balloon being blown up as opposed to a flat sheet of rubber being stretched lengthwise. Actually .. the possibilities here could be significant .. because if the universe is a flat sheet being stretched lengthwise, it may be decreasing in width (as a flat sheeet of rubber would do) these effects should be measurable. Of course, the material of a flat universe may not be being stretched .. it may simply also be expanding from creation of more material .. but not inflating as a balloon - inflating lengthwise and possibly in its width.

[Sputnick]

I'm fairly certain you would be voted off the island.

Not an inaccurate portrayal. I have seriously considered voting myself off the island, and would not be on this island if weather permitted more pleasant time outdoors.

I would like to ask you if you are being deliberately obtuse, or if you are genuinely that naive, but I realize it would do me no good. If the former, you would deny it, and if the latter, you wouldn't know it.

I think I've been pretty straightforward .. and don't know how I deserve the reputation of not playing by the rules .. but I am happy to be in the concensus that Big Bang is not a proven fact. Naive, yes, as I have almost never joined in groups or clubs, btu I am enjoying the experience of seeing how power plays in this group.

I would suggest that you clear your mind and carefully reread all three fora.

My mind is fairly clear .. I can't afford to do as much drinking as I need to do to accept easily some of the dogma which has been evident here .. and I might profit by doing the reading you suggest, but I simply don't have enough time as I have no internet at home. No Whine there .. just fact.

People have been trying to inform you of the rules by which the game is played. If you want to play the game, you have to know the rules. You don't get to make them up as you go along.

Nereid has been performing her function faithfully. This is not a game for me .. recreation yes, education yes .. but not a game .. and while I fail to see how you could envision me as trying to make up rules I'm not offended as you have simply acquired a misconception.

[Martin]

I think it should be mentioned that it is only a theory that empty space is expanding. Observations clearly reveal that matter is moving and creating greater distances from other matter. However, the fabric of space itself -there is no direct evidence of it's expansion and this assumption is based merely on convenience.

Cris wrote:

In any case, to date no scientific theory has ever been proven.

Chris, there was once a theory that the sound barrier could be broken and it was proven correct

[Chris Peterson]

I think it should be mentioned that it is only a theory that empty space is expanding. Observations clearly reveal that matter is moving and creating greater distances from other matter. However, the fabric of space itself -there is no direct evidence of it's expansion and this assumption is based merely on convenience.

Of course, we use theory to interpret our observations. But there is, in fact, direct evidence that the expansion we observe is caused by the metric expansion of space, and not by the expansion of matter in a fixed metric. This direct evidence is in the form of temperature measurements of the CMB obtained at different ages of the Universe. What is observed is that the CMB was hotter in the past than it is now. This observation is predicted by a metric expansion of space, and contradicts a simple expansion of matter. So we have good reason to believe that space is actually expanding, as our models require.

In any case, to date no scientific theory has ever been proven.

Chris, there was once a theory that the sound barrier could be broken and it was proven correct :shock:

That wasn't a theory in the scientific sense, any more than it's a scientific theory if I say I can beat you in a 100m race. Remember that "theory" has a number of dictionary definitions, and in discussing science, we restrict ourselves to a fairly narrow one.

[Sputnick]

Of course, we use theory to interpret our observations. But there is, in fact, direct evidence that the expansion we observe is caused by the metric expansion of space, and not by the expansion of matter in a fixed metric. This direct evidence is in the form of temperature measurements of the CMB obtained at different ages of the Universe. What is observed is that the CMB was hotter in the past than it is now. This observation is predicted by a metric expansion of space, and contradicts a simple expansion of matter. So we have good reason to believe that space is actually expanding, as our models require.

Good reason perhaps but as you admit it is not proven fact. I see you have again fallen into the use of the royal "we" instead of speaking for yourself. Unfortunate. If I were a scientist with opposing views I would resent it even though I know you mean 'we the concensus. Not being a physicist, I ask if there is a possibility that the heat simply converted to another form of energy or matter?

Chris, there was once a theory that the sound barrier could be broken and it was proven correct

=Chris. That wasn't a theory in the scientific sense, any more than it's a scientific theory if I say I can beat you in a 100m race. Remember that "theory" has a number of dictionary definitions, and in discussing science, we restrict ourselves to a fairly narrow one.

"Narrow" or strangulating? Oops - there I go risking the wrath of our warm hearted moderator again.

[Chris Peterson]

Good reason perhaps but as you admit it is not proven fact.

Again, you seem to confuse fact and theory. We aren't talking about facts here, we are talking scientific theory. And of course, such theories cannot be proven. In this case, I simple provided an important piece of observational evidence that supports the theory that space is undergoing a metric expansion, and which argues against a simple material expansion.

I see you have again fallen into the use of the royal "we" instead of speaking for yourself. Unfortunate. If I were a scientist with opposing views I would resent it even though I know you mean 'we the concensus.

It is understood as "consensus". I don't know any scientist who would be offended. Those who pursue theories that lack consensus understand perfectly well what they are doing.

Not being a physicist, I ask if there is a possibility that the heat simply converted to another form of energy or matter?

I don't see how, or maybe I don't understand the question.

[Sputnick]

Good reason perhaps but as you admit it is not proven fact.

Again, you seem to confuse fact and theory. We aren't talking about facts here, we are talking scientific theory. And of course, such theories cannot be proven. In this case, I simply provided an important piece of observational evidence that supports the theory that space is undergoing a metric expansion, and which argues against a simple material expansion.

I see your language was correct.

I see you have again fallen into the use of the royal "we" instead of speaking for yourself. Unfortunate. If I were a scientist with opposing views I would resent it even though I know you mean 'we the consensus.

It is understood as "consensus". I don't know any scientist who would be offended. Those who pursue theories that lack consensus understand perfectly well what they are doing.

Agreed .. but it's still unfortunate that you can't present a stand alone opinion .. as your reader may not want to take your word for your view that your represent the consensus. Speaking for unknown others puts a person at risk of seeming to need to inflate their opinion.

Not being a physicist, I ask if there is a possibility that the heat simply converted to another form of energy or matter?

I don't see how, or maybe I don't understand the question.

Your first response indicated you understood the question - conversion from heat to other energy or matter being a possibility in physics or not. (?)

[Martin]

Chris, Thank you for your timely response. I stand corrected. It appears that observation does support a metric expansion as you kindly stated. Very interesting.

Back to the DM. As you already know, QM has identified the 3 messenger particles responsible for 3 of the 4 forces. Is it reasonable to think that the 4th will be found eventually? If so, how could it change our understanding of gravity. Could the Graviton change our theory on DM?

[astrolabe]

Hello Sputnick,

Nevermind all that other gobbledegook, did I read Einstein's quote incorrectly? I appeared in three posts that I know of and each one was worded the same.

[Chris Peterson]

Your first response indicated you understood the question - conversion from heat to other energy or matter being a possibility in physics or not. (?)

Heat is the entropic end-of-line for other energy processes. The CMB, even when it was hotter than today, was still only a few kelvin. I don't know of any mechanism that could result in that residual heat being converted to some other type of energy, or to matter.

[Chris Peterson]

Back to the DM. As you already know, QM has identified the 3 messenger particles responsible for 3 of the 4 forces. Is it reasonable to think that the 4th will be found eventually? If so, how could it change our understanding of gravity. Could the Graviton change our theory on DM?

I don't see the possible discovery of a graviton particle having any impact on DM at all. Neither do I see it changing our understanding of gravity as explained by GR. What it would do would be to tie GM and QM together, or at least to begin that process.

[Sputnick]

Hello Sputnick,

Nevermind all that other gobbledegook, did I read Einstein's quote incorrectly? I appeared in three posts that I know of and each one was worded the same.

I've become lost in the multiplicity of posts, Astro .. is this the quote you are referring to?

"It has often been said, and certainly not without justification, that the man of science is a poor philosopher. Why then should it not be the right thing for the physicist to let the philosopher do the philosophizing? Such might indeed be the right thing at a time when the physicist believes he has at his disposal a rigid system of fundamental concepts and fundamental laws which are so well established that waves of doubt can not reach them; but it cannot be right at a time when the very foundations of physics itself have become problematic as they are now."

Einstein: First paragraph of Physics and Reality

If you read it to understand that Einstein was saying physicists need to embrace philosophy to further understand physics, then that appears to me to be exactly what he was saying.

[Sputnick]

Everyone on the forum should know by now that I base my understanding of physics on instinct based on my minimal knowledge (although my knowledge is growing as I read three books in the past five days .. the last being The Shadows of Creation by Michael Riordan and David Schramm, copyright 1991 .. those books all telling me my instincts are not something to be ignored.

Einstein also depended on Instinct:
"To believe ( ) is logically possible without contradiction; but it is so very contrary to my scientific instinct that I cannot forgo the search for a more complete solution." (2cd paragraph on the Citadel Press Carol Publishing paperback 'The Theory of Relativity and Other Essays' by Einstein.

Applying instinct to Dark Matter - my instinct tells me that the 'universal' Cosmic Background Radiation is not Big Bang echo - but warmth emanating from Dark Matter .. that the ripples in CBR come from slight disturbances in the river-like flow of Dark Matter ('currents') - and that a radio search at frequencies just above CBR will find such a (Dark Matter) river carrying the group of 700 galaxy clusters south. The frequency would be higher because the river would be creating friction (or in another word interaction/exchange of particles) in its boundaries with non-flowing DM. Of course, as our galaxy and immediate neighbours, as well as the Virgo, Hydra and Centaurus superclusters appear to be 'racing' towards the Great Attractor which itself appears to be a conglomeration of superclusters, it is possible that we are being carried along by such a river, and that the CBR measurements are that of Dark Matter heated by the flow. Preposterous? My instinct says "No" and of course I have to rely on Nereid to point some discs towards the river containing the 700 clusters south to find the boundaries of their river.

[Sputnick]

I think it should be mentioned that it is only a theory that empty space is expanding. Observations clearly reveal that matter is moving and creating greater distances from other matter. However, the fabric of space itself -there is no direct evidence of it's expansion and this assumption is based merely on convenience.

Thank you, Martin.