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a reply to: Arbitrageur

Thanks.

blackcrowe, I can't agree with a lot of what you said, but if I had to make a choice of whether hypothesized luminiferous aether was more like dark matter or dark energy, I would have to go with dark energy, not so much for the reason you mention which I don't understand, but because I would imagine that if such an aether existed it would probably be distributed somewhat uniformly and with our limited understanding of dark energy so far, it seems to be uniformly distributed. In contrast, dark matter is certainly not uniformly distributed. Scientists have even mapped the density variations using gravitational lensing observations: Unprecedentedly wide and sharp dark matter map So as that map shows we see dramatic variations in apparent dark matter density.

In the diagram in your reply.

It is a section of the Universe.

The D/M clumps are highlighted. The DE/Aether is not highlighted. But is still there, everywhere and uniformed. Occupying all the area of the diagram. With D/M represented within it.

These are only opinions of course.

a reply to: Arbitrageur

Thanks, blackcrowe and arbitrageur for the comments.

blackcrowe - I will stick to the term quantum luminiferous aether in my work, because that is what it is. It is what Maxwell sought. I agree with you that certain terms and ideas are presently disadvantageous politically, but that shouldn't sway us. Legitimate criticism is one thing; what is presently "in" is another.

arbitrageur - I am a novice in matters related to dark energy and dark matter, and value your comments. Is it possible that dark matter and dark energy are the same thing, with dark matter being the clumping of an otherwise continuous substance now called dark energy? With a postulated massive aether, it could make sense that visible matter would attract the aether leading to higher aetherial densities within and near galaxies.

I have given thought to the change in light propagation due to a change in aetherial density. In my work there are some fittable parameters, such as: 1) the force constant associated with the tension; 2) the aetherial mass density; 3) constants associated with flow forces. To get to Maxwell's Equations (ME) and the Lorentz Force Equation (LFE) these constants must be set. One of the setting relationships is T0 = m0c^2, where T0 is the tension per unit area and m0 is the mass per unit volume under nominal conditions. If we alter T0 and m0, possibly because of an increase in density due to the gravitational pull near and within galaxies, then ME and LFE remain provided we keep T0 = m0c^2 as well as the other fitted constant relationships. Please note that there aren't many free parameters, but there are some.

originally posted by: delbertlarson
arbitrageur - I am a novice in matters related to dark energy and dark matter, and value your comments. Is it possible that dark matter and dark energy are the same thing, with dark matter being the clumping of an otherwise continuous substance now called dark energy? With a postulated massive aether, it could make sense that visible matter would attract the aether leading to higher aetherial densities within and near galaxies.

When you start reading theoretical physics papers, you can find all sorts of ideas proposed that "thing A" might be related to "thing B", even things which other sources say probably aren't related. I don't really have the time or the interest to evaluate all those ideas, though I might spend some time looking into those I find more plausible.

There are several reasons I don't find dark matter and dark energy being the same thing as a plausible idea, because in one important respect they have opposite properties, not exactly, but sort of.

Dark matter seems to interact gravitationally, that is it's the placeholder for why masses clump together with more gravitational attraction than can be accounted for by visible light, and other observations like gravitational lensing support that idea.

In contrast, dark energy seems to have the opposite effect of pulling masses toward each other, it seems to push them apart, a sort of "anti-gravity" though that's not precisely correct.

So a scheme to make those contrasting effects part of the same thing would require some sort of unlikely scenario which I can't say is impossible but it seems so unlikely that I haven't really entertained the idea. Remember the negative mass idea in your aether model which I didn't like because of the theoretical problems with negative mass? I think you finally decided you didn't like the negative mass idea too much either, but apparently a physicist thinks if we can hypothesize negative mass among other things, it could be possible for them to be related. I can't get past the negative mass idea personally, but here's a video by physicist Matt O'Dowd explaining the idea:

Are Dark Matter And Dark Energy The Same?


There's an even worse idea than negative mass to get the theory to work, mentioned at 7:20 in the video, which is not quite unfathomable as in this definition of kluge but close and is certainly inelegant and contrived:

In modern computing terminology, a "kludge" (or often a ""hack"") is a solution to a problem, doing a task, or fixing a system that is inefficient, inelegant or even unfathomable, but which nevertheless (more or less) works.

It may not be the most contrived solution ever, but it's close.

Matt explains the idea then gives his own thoughts on why the biggest problem is even with the multiple kluges, he still thinks the equations don't result in predictions that will match observation. He also links to some of his other videos on dark energy and dark matter which explain them in more detail if you're interested in getting his thoughts on those. He seems to understand them as well as anybody which isn't that well because there's a reason we call them "dark", but what we can understand are the data and observations that forced us to create those. I don't think the data are disputed, but people have tried to make various models to explain the data, and some of them are a lot more plausible than the problematic idea described in the video above.

Even the mainstream Lambda-CDM model (which treats dark matter and dark energy as different things in the equations) doesn't seem to be perfect and has some tension, but I suppose the reason it's still the mainstream model is the alternatives proposed so far seem to be worse.

a reply to: Arbitrageur

Thanks for the response. For the record, I never liked negative mass. I put it in because it was a simple way to make Maxwell's Equations (ME) work out. I now have a better way to make things work out for ME, and the new approach gets the Lorentz force equation too, so we can thankfully bid adieu to negative mass.

I watched the video. The big kluge was something not too different from an approach I looked into briefly regarding the origin of Poisson's Equation when I was just getting started on the aether. (Poisson's Equation involves sources and sinks, which could be from a continuous production of something. Instead I settled on displacements sourced by an extra substance embedded within the aether.) I rejected the continuous production idea back then and wish to reject it now, but one should always keep an open mind about possibilities. Just because we don't like it doesn't mean its wrong. I was also amused by the video's discussion about things moving toward you when you push if the mass is negative. I've been down that path too, and as mentioned, really didn't like it.

Early in my education, nearly 40 years ago now, I made the decision that this astrophysics stuff just couldn't be trusted. Who is to say that the conditions local to earth stay the same, even remotely the same, as we get to the scales of galaxies? I see in the video a heavy reliance on general relativity, and I was convinced long ago (from EPR results) that relativity isn't correct. So I guess I should perhaps just wrap up my aetherial derivation as it is and leave the dark arts to others.

I am thankful for the quick and clearly incomplete education. I should look at Matt's other videos on these matters as well.

originally posted by: delbertlarson
I am thankful for the quick and clearly incomplete education. I should look at Matt's other videos on these matters as well.

Here's a link to his dark matter and dark energy playlist. It contains 9 videos: 6 explaining videos and 3 that look at specific papers or ideas, one of which you recently watched (#7):

www.youtube.com...

They get a little technical but that's good for someone like you who has the training and background for understanding the technical aspects.

This Crisis in Cosmology video isn't on that playlist and is more related to cosmological models than dark energy specifically, but it's one clue that our existing models may have some bugs to work out, at least:

The Crisis in Cosmology

The search for a single number: the hubble constant, which is the rate of expansion of our universe, has consumed astronomers for generations. Finally, two powerful and independent methods have refined its measurement to unprecedented precision. The only problem is that they don’t agree. This calls into question some of our most basic assumptions about the universe.

a reply to: Arbitrageur

nice...

the only thing !
there was no Big Bang and the Universe is not expanding.
the so called background radiation ( from the big nonsense ) is a measurement or better said instrument and calculation failure.
Dark Matter and Dark Energy is a mathematical calculation error correction in a week theory and do not physically exist, just on paper of a flow math theory

that being said, good luck in wasting time on things that do not exist !

a reply to: KrzYma

Wow... so ignorant, the CMB has been measured by many different independent instruments, all have measured the same features in the maps in the same places to different levels of detail.

To wish it away as instrument noise is to frankly be... both arrogant, ignorant and to prove you know absolutely nothing about any of the experiments, measurements or science behind it.

but sure, keep wasting your time with Electric universe stuff... which so far has zero calculations.

originally posted by: Arbitrageur
Here's a link to his dark matter and dark energy playlist. It contains 9 videos: 6 explaining videos and 3 that look at specific papers or ideas, one of which you recently watched (#7):

www.youtube.com...

I watched all nine videos. Thanks for the link.

When it comes to cosmology, a first problem arises by analogy, if we consider a virus living inside of an amoeba. The earth's orbit occupies a sphere roughly 8 light-minutes in radius, while the whole universe is roughly 40 billion light-years in radius in a present estimate. Hence, the radius of the universe is roughly 2.5x10^15 times larger than what we inhabit. If our amoeba is 0.6 mm in radius, a scaling of 2.5x10^15 becomes 1.5x10^12 meters, or 1.5 billion km, roughly ten times the radius of earth's orbit. Within the amoeba, the ambient conditions are considerably different than conditions elsewhere in the 1.5 billion km radius. Within the latter, we have ice, mountains, oceans, lava, a molten core, an atmosphere, a near-vacuum, planets, moons, and one star with extreme pressures and temperatures inside. So what a virus living inside of an amoeba would see locally would be far different from what exists elsewhere, and by analogy, what we experience may be far different than what occurs at the edges of the universe.

A second problem with cosmology is that we can't do controlled experiments. All we can do is observe. So it makes it difficult to test our theories.

A third problem with cosmology is that within general relativity it is almost always stated that "if the special theory is wrong, the general theory is also wrong". Due to EPR results, and more generally in order to make sense of quantum mechanics, I came to the conclusion long ago that the special theory was wrong. So for all of these reasons I never until recently studied cosmology and I retain my skepticism.

Nonetheless, from the videos it appears that my first two objections are well known by cosmologists and it must be admitted that a lot of smart people have spent a lot of time, even careers, on these issues. It appears there is indeed some evidence for dark matter and dark energy. We should be mindful, especially in the case of very distant objects, that we are being quite speculative to think that nothing happens to the light between there and here, and also keep in mind that far distant regions may be vastly different from our own, but I will admit that the prevailing assumptions are at least possible.

On the third problem, that of general relativity, for the purposes of this post let's assume the equations are somehow right, but without the underlying philosophy. Let's just say for now that the equations describe a tensor field within, and intrinsic to, an aether. This is a huge leap of faith, and requires substantial detailed future work, but let's take that leap for now.

From the videos I learned that dark energy could be caused by tension.

Importantly, the aether has a tension. The tension is required for the derivation of Maxwell's Equations, as described here. Without the presence of normal matter, the aether has a nominal uniform mass density and a nominal uniform tension, and my upcoming publication will show how this leads to both Maxwell's Equations and the Lorentz Force Equation (provided I don't find yet another problem or error during careful checking).

Given the above, dark energy could be the aetherial-tension-energy minus the aetherial-mass-energy, provided that the magnitude of the aetherial-tension-energy density (which is gravitationally repulsive) exceeds the aetherial-mass-energy density (which is gravitationally attractive). That way, the repulsive effect wins out, even though we have two background effects, one repulsive and the other attractive.

Since the tension has a repulsive (or anti-gravity) effect, normal matter will repulse the aether: it repulses the tension and attracts the mass, but with a fixed relationship between tension and mass, the overall effect is to push the aether away. Less aether within a galaxy will have the same effect as additional mass within a galaxy, and that then gives the effect which is now postulated to be caused by dark mass.

So it appears that an aether containing both mass and tension could possibly be used to explain observations now attributed to dark energy and dark mass.

Thoughts?

originally posted by: KrzYma
a reply to: Arbitrageur

nice...

the only thing !
there was no Big Bang and the Universe is not expanding.
the so called background radiation ( from the big nonsense ) is a measurement or better said instrument and calculation failure.

If you're open-minded, the title of the video describes the content:

Why the Big Bang Definitely Happened | Space Time | PBS Digital Studios

Dark Matter and Dark Energy is a mathematical calculation error correction in a week theory and do not physically exist, just on paper of a flow math theory

that being said, good luck in wasting time on things that do not exist !

This is one of the videos from the playlist that asks if Dark Energy just disappeared.

Did Dark Energy Just Disappear? | Space Time | PBS Digital Studios


If you look at one set of data, there's only a 3 sigma confidence in the existence of dark matter, not the 5 sigma that physicists usually aim for to declare an important discovery. The problem with 3 sigma is if you read 10,000 papers with 3 sigma confidence, only 9973 will be right and 27 will be wrong, not that many chances of being wrong but still too many for something important. So this is the basis for the question if dark energy disappeared, could it be one of those 27 papers out of 10,000 that declares a wrong result based on only 3 sigma confidence.

Then the video explains that there are multiple lines of evidence, and when those are combined the effective result is over 5 sigma so confidence is still high. But you don't mention any specifics, and probably don't understand the multiple lines of evidence.

originally posted by: ErosA433
a reply to: KrzYma

Wow... so ignorant, the CMB has been measured by many different independent instruments, all have measured the same features in the maps in the same places to different levels of detail.

To wish it away as instrument noise is to frankly be... both arrogant, ignorant and to prove you know absolutely nothing about any of the experiments, measurements or science behind it.

but sure, keep wasting your time with Electric universe stuff... which so far has zero calculations.

The Thunderbolts (Electric Universe) folks have a newish video out discussing the same thing as the "Crisis in Cosmology" video I posted about two contradictory measurements for the Hubble constant, which says historically the measurements were not that precise and it was thought to be between 50-100 km/s/Mpc.

But now the two more precise measurements are about 67 and 73 and the error bars don't overlap which is a problem for mainstream models that needs to be solved. However, the electric universe followers must be absolutely brain dead if they believe Walt Thornhill saying that the discrepancy between 67 and 73 proves the big bang theory is wrong, since both numbers are consistent with an expanding universe and aren't that far apart considering the old estimate was 50-100.

So it's an old trick of Thornhill's to use maintream findings to claim mainstream science is wrong, which is especially ludicrous in this case since both the 67 and 73 numbers support a big bang theory, making a claim that they somehow disprove the big bang completely nonsensical. But as long as no math is involved, apparently people like agreeing with Thornhill and getting the ego boost that they are now smarter than all the smartest scientists on Earth who think there was a big bang. Reading the comments on the EU videos reflects this mindset.

originally posted by: delbertlarson
the whole universe is roughly 40 billion light-years in radius in a present estimate.

That's observable universe, not whole universe, which size is unknown, could be infinite.

what we experience may be far different than what occurs at the edges of the universe.

At one point we thought the Milky Way was the universe, before we realized those fuzzy things were other galaxies about 90 years ago. But an interesting observation of a galaxy which has rotation curves close to what can be explained without dark matter shows that indeed galaxy compositions can vary and not all galaxies contain 80% dark matter. Interestingly the failure to find much dark matter in that galaxy poses a bigger problem for some alternate models like MOND than it does for the dark matter model, though any model needs some explanation of the big difference. I made a thread about that:

Does the Failure to Find Dark Matter Prove the Existence of Dark Matter?

A second problem with cosmology is that we can't do controlled experiments. All we can do is observe. So it makes it difficult to test our theories.

True, but we can make so many observations that I think the plentiful supply of data tends to compensate for the lack of control. The advances in astronomical technology lately are mind blowing, in the pure vastness of the number of observations that can be made quickly with more advanced telescopes and sensors.

We're lucky we can observe the observable universe though. If our models are correct, at some time in the distant future our galaxy and Andromeda and possibly a few others in the local group will merge into a larger galaxy and the rest of the universe will be so far away eventually future observers won't be able to see the rest of the universe anymore.

A third problem with cosmology is that within general relativity it is almost always stated that "if the special theory is wrong, the general theory is also wrong". Due to EPR results, and more generally in order to make sense of quantum mechanics, I came to the conclusion long ago that the special theory was wrong. So for all of these reasons I never until recently studied cosmology and I retain my skepticism.

Could be but as Matt says in the video you watched that I reposted above about the possibility of dark energy disappearing, science always has to re-examine itself and admit the old ideas could be wrong in light of new evidence. The multiple lines of evidence for both dark matter and dark energy make them a lot more credible than if just a single fudge factor was inserted to balance a mismatched equation. This is why the leading alternative to the "dark matter" model called "MOND" is not taken very seriously, because it isn't well supported by multiple lines of evidence and just ignores some of the other lines of evidence that support dark matter, like the large scale structure of the universe, and it doesn't do very well with the bullet cluster or the example I made the thread about.

we are being quite speculative to think that nothing happens to the light between there and here, and also keep in mind that far distant regions may be vastly different from our own, but I will admit that the prevailing assumptions are at least possible.

I wouldn't phrase it that way, rather we surmise from spectroscopic shifts that something has happened to the light between there and here, the wavelengths got longer. And we have formulated several different hypotheses on how such a thing might happen, and have ruled out some of those explanations until we are left with the expanding universe idea in our model.

Less aether within a galaxy will have the same effect as additional mass within a galaxy, and that then gives the effect which is now postulated to be caused by dark mass.

As I said, any model will need to explain the result discussed in my thread where we found a galaxy without the extra mass. So if this leads to the idea that the aether is varying in amount or density, then I get lost on the purpose of or supposed properties of the aether which I explained to some degree in my prior post. Specifically, if the aether is a medium for the propagation of EM radiation, the origin of that idea is that waves need a medium to propagate, such as water waves in water, and sound waves in air and other materials. But if applying that type of thinking, as the properties of the medium change so does the speed of the waves traveling through the medium.

For example, Einstein wrote a "paper" on the luminiferous aether, but I put "paper" in quotes since it was just a letter to his uncle from about 1895 with his thoughts, reflecting some thinking of that time, that it was being compared to other waves in other media. For example he proposes a specific relationship:

Einstein's First "Paper"

Einstein says "The velocity of a wave is proportional to the square root of the elastic forces which cause its propagation, and inversely proportional to the mass of the aether moved by those forces". He is defining a supposed relationship between the velocity of the wave and the mass of the aether moved by those forces. If the density of the aether varies under such assumptions would that not imply a variation in the speed of light? Einstein continues by proposing some tests to determine the properties of the luminiferous aether by making precision measurements of how much the speed of light varies when the aether is subjected to things like various magnetic fields.

Or perhaps such simplistic assumptions about the speed of light varying with the density of the aether etc are wrong, but as the assumptions for luminiferous aether get more complicated, the Occam's razor preference for the relativity explanation of no luminiferous aether becomes more pronounced (which doesn't necessarily mean it's right, but I understand that logic which results in current mainstream thinking).

a reply to: ErosA433

YEAH.. plz come back to me if you have found the Dark Matter

in the mean time searching you should maybe listen to real experts

"Pierre-Marie Robitaille, Ph.D., is a professor of radiology at The Ohio State University. He also holds an appointment in the Chemical Physics Program. In 1998, he led the design and assembly of the world’s first Ultra High Field MRI System. This brought on the need to question fundamental aspects of thermal physics, including ideas related to Kirchhoff’s Law of thermal emission, and more. These presentations are not endorsed by The Ohio State University."

Gravitational Thermodynamics - Is it Science?


Dr. Pierre-Marie Robitaille: The Cosmic Microwave Background | EU2014


...but maybe you should start with some simple basic ideas



but well, be my guest, what exactly was there before the Big Bang ??
Big Bang created space and time, right ??
Is time a real physical thing, what is time ??
How do you understand the Einsteins's concept of space-time ?


one more on Blask Holes.. prove me he is wrong


good luck !!

a reply to: Arbitrageur

Sometimes what I write in posts does not convey my thoughts as well as I would like, and so I thank you for the suggested improvements. It adds clarity to the discussion. 1) My reference to a specific size of the universe is of course just one present-day estimate and not definitive; I question any such estimates myself and also believe the universe might be infinite; my point was how little of the universe we live in. 2) What I meant by photons changing from there to here was not the red-shift at their origin, but rather, once the red shift has occurred, it is my understanding that cosmologists assume no change from that point on occurs until they arrive at our telescopes, even though they have traveled for billions of years over billions of light-years of space. I believe you posted concerning "tired light" in the past, but I did not follow up on the link at that time. If you have it handy, I'd appreciate a link to the tired light analysis.

any model will need to explain the result discussed in my thread where we found a galaxy without the extra mass.

From Matt's videos I understand that all galaxies have the extra mass, but it is a large gas and dust cloud that is missing the extra mass. That cloud had most of the mass of two colliding galactic clusters, but the dark matter is found in the galaxies, not the cloud. Correct? Also, he says "gas", but it is my understanding* it would be gas and dust.

An explanation of the lack of dark matter in the gas and dust cloud could be that any accumulation of extra mass (or less aether, which could give the same effect) is non-linear. If so, the extra mass would accrue into the center of stars far more than into the gas and dust cloud. The problem with that, is what about the central black hole? If the dark-mass-confinement is non-linear, a central black hole would dominate all dark matter calculations, and my understanding* is that the evidence does not support that. But from an aether approach, where the effect comes from aetherial repulsion, we eventually get to a point where less aether becomes no aether at all - and once we get to zero aether we can go no lower, putting a ceiling on how much dark matter a black hole can have.

This line of thinking could also address the objection you raise regarding the speed of light in the aetherial medium. If the dark matter effect (aetherial density change) only exists within deep gravitational potentials of very massive objects such as the center of stars and black holes, then we will have no real observation of any light speed change, since when light goes through the center of such objects it will 1) often be absorbed or scattered and 2) the solid angle occupied by those objects is very small in comparison to where the effect does not exist.

^Again, please correct any misunderstandings on my part - I am very new to this. My main goal of raising this discussion is that it is clear that my derivation of Maxwell's Equations and the Lorentz Equation will rather obviously touch on these matters and I'd like to add an appropriate comment to my upcoming paper concerning this.

originally posted by: delbertlarson
What I meant by photons changing from there to here was not the red-shift at their origin, but rather, once the red shift has occurred, it is my understanding that cosmologists assume no change from that point on occurs until they arrive at our telescopes, even though they have traveled for billions of years over billions of light-years of space.

"not the red-shift at their origin"...I have no idea what you're referring to here. Astronomers assume the stars have spectral output based on their size, composition, and evolution on the Hertzsprung-Russell diagram like the stars in the milky way even if the stars are elsewhere. So they don't assume any red-shift at the origin that I know of.

"once the red shift has occurred, it is my understanding that cosmologists assume no change from that point on occurs until they arrive at our telescopes"...This makes even less sense to me. I have no idea what you're talking about with "from that point on", what point? The model in my head is that we have the local group of galaxies with a diameter of roughly 10 mega light years, or about 3 megaparsecs, and there's probably not any significant stretching from where the light travels from the outskirts of the local group to our telescopes on earth because the local group is gravitationally bound, which tends to counteract the tendency for space to stretch, so gravity overpowers dark energy in the local group. But the edge of the local group (doesn't have an exact "edge" anyway) is not a point I've ever heard anybody talk about in such a context.

For example, Hubble's law applies to distances of 10 megaparsecs or more, so we don't expect it to apply at distances shorter than that, and in fact Andromeda galaxy light isn't red-shifted, it's blue shifted, which isn't a contradiction to Hubble's law which isn't expected to apply to galaxies that close.

The mainstream model as I understand it is that for distances over 10 Mpc, the entirety of the space between origin and destination is stretched, at rates which vary over time according to dark energy observations, with only small exceptions in gravitationally bound regions like the 3 Mpc diameter of the local group which is small compared to some galaxies hundreds of Mpc away. Whether light from very distant galaxies stretches more or not during another up to 3 Mpc in the local group doesn't seem too relevant for general discussion, though it might be a factor if trying to make some precision measurements on dark energy.

I believe you posted concerning "tired light" in the past, but I did not follow up on the link at that time. If you have it handy, I'd appreciate a link to the tired light analysis.

Ned Wright's page on the topic was last updated 11 years ago and I think it still applies though astronomy is a fast moving field so there could be some more up-to-date papers out there, but it's still probably a good starting place for some fundamentals.

Errors in Tired Light Cosmology

From Matt's videos I understand that all galaxies have the extra mass, but it is a large gas and dust cloud that is missing the extra mass. That cloud had most of the mass of two colliding galactic clusters, but the dark matter is found in the galaxies, not the cloud. Correct?

I would say incorrect. Are you talking about the video called "No Dark Matter = Proof of Dark Matter?"? If so I think you got confused between the bullet cluster which is based on observations over a decade ago in 2006 and involves some gas, and the more recent observations written up in 2019 about a galaxy that Matt nicknamed "Fritz" since it's easier to say than NGC1052-DS2, which is composed of stars. The only mention of gas I heard him make for current observations was for the bullet cluster, while in reference to Fritz when he mentions gas he's talking about theories or hypotheses for how Fritz might have formed from various sources of gas a long time ago, not commenting on how much gas it appears to have in the images reaching our telescopes.

^Again, please correct any misunderstandings on my part - I am very new to this.

I think Eros said he was a professional astronomer at one point which I've never been so maybe he can correct me too if I said anything wrong, but as Matt O'Dowd says the real experts on NGC1052-DS2 are the ones writing papers about it, so my recommendation is to cut out the middlemen like me and Matt who might be misinterpreting something and read direct from the source papers (and see what they say about gas):

A second galaxy missing dark matter in the NGC1052 group
Still Missing Dark Matter: KCWI High-Resolution Stellar Kinematics of NGC1052-DF2
There's a rebuttal paper out now too saying MOND can explain the "Fritz" observations if you consider neighboring galaxies, but again what dark matter can explain that MOND can't is a larger cosmological model including explaining the large scale structure of the universe.

Here's an article on the "Bullet Cluster" with the gas, from 2006, not the same as "Fritz" (NGC1052-DS2):

NASA Finds Direct Proof of Dark Matter

The source paper that article is based on (I think):

A direct empirical proof of the existence of dark matter

There was at least one MOND rebuttal paper for that too, but apparently it wasn't very influential or convincing, since astronomers still seem to think MOND doesn't do a very good job of explaining those observations.

originally posted by: KrzYma
a reply to: ErosA433
"Pierre-Marie Robitaille, Ph.D., is a professor of radiology

.. prove me he is wrong

He is or was a professor of radiology, not astronomy yet he apparently doesn't know much about astronomy according to astronomers like Dr. Andrew Gould who have reviewed his proposals.

Ripples in Ohio From Ad on the Big Bang

Colleagues describe Dr. Robitaille as a biomedical researcher whose credentials were unquestioned until two years ago, when he drifted outside his field and began proposing radical revisions to some basic laws of physics.

About that time, Dr. Spigos said, Dr. Robitaille resigned as director of magnetic resonance imaging research there.

''At this time,'' Dr. Spigos said, ''there was this controversy between him and the scientific community'' over the physics theories. ''And I believe that they are outside the realm of his expertise.''

On a purely scientific level, the theories appear to be harmlessly if totally incorrect, said Dr. Andrew Gould, an astronomy professor at Ohio State.

Rumor has it he was asked to resign. Not only is he way outside his field of expertise talking about astronomy, but that article talks about how he's apparently aligned with evolution deniers and evolution is considered a scientific fact.

Hello science ladies and science gentlemen.

About gravity, The big bang, and identical, pulsating motions

If i have anything right about this, the scientific community has a fairly strong consensus that the universe is constantly expanding. And that the Big bang theory is very likely a correct theory but has not been proven 100%, at least yet. Here we assume that both of those factors, expanding universe and the big bang, are facts. And they serve as the foundations of my question.

As the galaxies expand and expand into the emptiness (or whatever there is...) that must mean that the gravity between objects decrease and sometimes is zero. But could gravity or some other force make everything eventually condense back into a "thing" which is everything in the universe? Let's say something wild... like the size of a melon? Planets expanding is the result of the explosion (Big bang) and the force that was behind that event.

So, now the planets are expanding, eventually get pulled back together into a melon size object consisting of all matter there is in the universe. Then it blows up (big bang), expands, gets pulled back together, eventually blows up again (big bang again) and same scientific laws always apply. Those planets and matter would always expand in the 100% exact same way. Life would evolve the same way. That would implicate that you have already read this post an endless number of times and in the future, you are going to read this post an endless number of times. If you decide to reply, it has been already done and will be done again.

a reply to: Finspiracy

sometimes is zero

Never zero.

But could gravity or some other force make everything eventually condense back into a "thing" which is everything in the universe?

Yes. If there is enough mass to produce enough gravity to do so.

Life would evolve the same way.

The theory of evolution is based on mutation. Mutation involves random occurrences (things like radiation impacts and other molecular mistranslations of DNA replication). So unless you think that a new Universe means everything would happen exactly the same way, neither life or the Universe would be the same the next time around.

originally posted by: Finspiracy
As the galaxies expand and expand into the emptiness (or whatever there is...) that must mean that the gravity between objects decrease and sometimes is zero. But could gravity or some other force make everything eventually condense back into a "thing" which is everything in the universe?

originally posted by: Phage
Yes. If there is enough mass to produce enough gravity to do so.

It doesn't look like there is enough mass to do that, does it?

It looks like gravity won't make everything collapse, assuming the "cosmological constant" is constant. Not only is the universe expanding, but the expansion is accelerating, as first announced in 1998 and now two decades later we have more data on this accelerating expansion, and still need to collect more data to get a handle on the cosmological constant.

However something besides gravity cmight cause a collapse though I wouldn't call it a "force", maybe a quantum effect? One which I don't understand very well and I'm not sure anybody does, but Neil Turok talks about it at the hour and a half point in this video, where he's asked how can the universe be cyclic given the observations of accelerating expansion/dark energy:

Neil Turok Public Lecture: The Astonishing Simplicity of Everything


His answer is that LHC measurements show the vacuum of our universe will be stable for 10 to the power of 500 years, and after that the vacuum might become unstable and that could cause some type of collapse, based on what we know about the Higgs. It sounds speculative to me, but he's not the only scientist I've heard say that so there must be a paper out there saying something like that but I haven't read it. I mentioned a few other thoughts on this back on page 367.

originally posted by: Phage
The theory of evolution is based on mutation. Mutation involves random occurrences (things like radiation impacts and other molecular mistranslations of DNA replication). So unless you think that a new Universe means everything would happen exactly the same way, neither life or the Universe would be the same the next time around.

Yes, the chances of the new universe happening the same way as the last one are some tiny chance, I don't know if it is one in a googolplex, but it's pretty small. But if the chances were one in a googolplex of the same universe occurring and you had a googolplex new universes, then one time out of that googolplex of new universes there might be another universe like this one. Maybe, or maybe not.

a reply to: Arbitrageur

Too many monkeys with too many typewriters.

(Typewriter? What?)

a reply to: Phage
I tend to agree with that but this idea of a cyclic universe comes up over and over and some people seem to want our universe to repeat, so I was trying concede some remote possibility to give those people a sliver of hope, though there isn't enough mass in the universe to make enough books to even print the number 1/googolplex, so chances are beyond remote. Even the mass in a trillion trillion trillion observable universes still wouldn't be enough to print enough books to write out how small the chance of 1/googolplex is.

Even if you get all the monkeys on the typewriters to type the exact same genetic code, say in identical twins, identical twins don't end up being identical, like they don't have moles in the same places and their fingerprints are different, for example. Sometimes even their genes aren't identical though it seems like they would be. So yes, it's really hard to get biology to happen the same way, even in the same universe.

Apparently maternity wards and funeral homes still use typewriters to fill in pre-printed forms, but outside applications like that, a lot of younger people probably don't know what a typewriter is.

a reply to: Arbitrageur
Got a couple of identical nephews. When they were small it was "Hey! KevinMichael." But it didn't take long to be able to tell them apart. Physically and otherwise.

originally posted by: KrzYma
a reply to: ErosA433

YEAH.. plz come back to me if you have found the Dark Matter

in the mean time searching you should maybe listen to real experts

"Pierre-Marie Robitaille, Ph.D., is a professor of radiology at The Ohio State University.

Ah... great a real expert on the subject of Astronomy and Dark matter, from a man who appears to have an obsession that thermal physics has the answers to everything and completely throws out whole areas of knowledge because hey doesn't like them... Such as for example in the black hole video there "Objects don't radiate internally" he is bastardisaing the meaning of what is being said, what he is kind of trying to claim there is that light inside a liquid doesn't exist, and radiation pressure doesn't exist... yet... that is absolutely not the case.

There are many issues with his videos and how he explains things... in one video he says that the sun cannot be a gas, because the ideal gas law cant be used since you need a real surface for their to be pressure... which is, blatantly quite incorrect, he also states that radiation doesn't transfer energy within objects... also proven to be an incorrect statement.

He then goes on to say that the sun is made of metallic hydrogen... because it is at high pressure.

Sooooo yeah, this guy, i don't have to prove anything really, he has his ideas and is arguments for arguing against what the accepted models say, are largely equation picking rather than well motivated, something he trips up over so so often.

SO i think Ill stick with the actual experts... you know... the people who have been working on useful things for the last few years rather someone who got fame years ago and clearly lost their mind. Ad Hominim attack? maybe, but his videos are quite problematic in just how ignorantly he brushes aside so many measurements. I almost wanted him at some-point in his videos to claim that fusion isn't the energy source of the sun.... which again would be to ignore so so so many measurements.

Funny too given his disproval of blackholes is "You cant see it, so you cant prove it exists" Id say the same for his motivation for his solar model, "you cant see the core of the sun mate, so you cant say anything about it"

works both ways.