Galaxy clusters offer clues to dark matter and dark energy

August 28, 2017 by Kate Becker
A massive, young galaxy cluster seen in X-rays (blue), visible light (green), and infrared light (red). Credit: X-ray: NASA/CXC/Univ of Missouri/M.Brodwin et al.; optical: NASA/STScI; infrared: JPL/CalTech

It's a cosmic irony: the biggest things in the universe can also be the hardest to find.

Elizabeth Blanton, a Boston University associate professor of astronomy, started hunting for distant galaxy clusters more than 20 years ago. A single can be as massive as a quadrillion suns, yet faraway clusters are so faint that they are practically invisible to all but the biggest Earth-bound telescopes. Distant clusters hold pieces of the story of how the web-like structure of the universe first emerged and could help illuminate the true nature of dark energy and dark matter. Now, her team's search is delivering its biggest return yet: a catalog of about 200 candidate galaxy clusters which, if confirmed, may include some of the most distant clusters ever found. The new results, which will be a useful tool for astronomers worldwide, were published in the July 26, 2017, edition of the Astrophysical Journal by a team that includes Rachel Paterno-Mahler (GRS'15), PhD candidate Emmet Golden-Marx (GRS'16,'19), Gagandeep Anand (GRS'17), Joshua Wing (GRS'07,'13), and colleagues at the University of Missouri-Kansas City and the Harvard-Smithsonian Center for Astrophysics.

Galaxy clusters can contain thousands of galaxies and many trillions of stars—and that's just what astronomers can see with ordinary telescopes. Hot gas between the galaxies glows with X-rays, and astronomers suspect that more than 85 percent of every 's mass is hidden in the form of dark matter. Mapped in three dimensions, the universe is a web of bright filaments and dark voids, with galaxy clusters occupying the spots where the filaments intersect.

Woven into this cosmic web are clues to two major cosmic mysteries: dark matter, the invisible stuff that permeates galaxies and the spaces between them, and dark energy, which is driving the accelerating expansion of the universe. Together, dark matter and dark energy make up some 95 percent of our universe, scientists suspect, but astrophysicists know of dark matter and dark energy's existence only indirectly, by their influence on the stars and galaxies that light up the sky.

The new cache of distant galaxy cluster candidates may help researchers pin down the properties of dark matter and dark energy, says Paterno-Mahler, first author on the new paper, one of a series forthcoming from Blanton's team. "Galaxy clusters are really good test-beds for learning about the cosmological parameters of our universe, like how much there is and how much there is."

By comparing faraway clusters with their local counterparts, researchers can also assemble a timetable of how galaxy clusters formed and grew. That's because light from the most distant clusters had to travel billions of years before reaching Earth, so astronomers see those clusters as they were long ago. "If we want to learn how clusters—the most massive collapsed structures in the universe—form and evolve, we need to study them over a range of distances, going all the way back," says coauthor Mark Brodwin, assistant professor of physics and astronomy at the University of Missouri-Kansas City. And because galaxy clusters give astronomers access to a large sample of galaxies that are similar in age, they also provide a laboratory in which to study how individual galaxies have changed over time. "You have a bunch of galaxies at the same epoch, together in space, to compare to more nearby galaxies," says Blanton.

Galaxy clusters offer clues to dark matter and dark energy
A visual-light image from the Sloan Digital Sky Survey (left) looks almost empty, but an image from the Spitzer Space Telescope (right) reveals dozens of faraway galaxies. An overlaid radio-wave map (green lines) reveals the telltale “C” of a galaxy moving relative to cluster gas. Credit: Blanton et al.

But the farther a galaxy cluster is from Earth, the fainter it appears. Traditional optical telescopes must stare at a single spot in the sky for a long time to collect enough light to reveal a distant cluster, and surveying the whole sky this way is time-prohibitive. So, to create the new catalog, Blanton and her team scoured archived data for clues to where clusters might be, and then followed up with targeted telescope observations. Their search, dubbed COBRA (Clusters Occupied by Bent Radio AGN, or active galactic nuclei), was supported by grants from the National Science Foundation and NASA.

Their trail of clues starts with the fact that almost every large galaxy has a supermassive black hole at its center. These black holes are notoriously messy eaters, and when they are feasting, some of the dust and gas plunging inward gets splashed out in enormous, spiraling jets. These jets can stretch the width of the galaxy and beyond, and they produce a radio-wave roar that astronomers can pick up with radio telescopes on Earth. If the galaxy also happens to be zooming through hot cluster gas (or if the gas is zooming past the galaxy), the jets flex into a characteristic "C" shape—"like your hair blowing in the wind," says Blanton. This "C" shape is the first clue to a possible cluster.

Blanton's team pored over existing sky surveys and found almost 2,000 of these peculiar objects. Then Wing, as part of his dissertation work, compared those suspected clusters to visual-light images from the archives of the Sloan Digital Sky Survey. The most exciting candidates, says Blanton, are those for which the Sloan pictures look dark, hinting that the radio signal could be coming from a cluster so distant that the Sloan Survey telescope can't see it at all.

With the possibilities narrowed down further, they then used the Spitzer Space Telescope to zero in on about 650 possible clusters, one by one. (Spitzer is most sensitive to infrared light, radiation that can't be seen by the human eye but is ideal for observing distant galaxies.) With a computer's help, they counted up the number of galaxies in each Spitzer frame and compared it to the typical number of galaxies in a comparable area of the sky. An unusually high number of galaxies—called an "overdensity"—suggests a galaxy cluster.

An overdensity is not definitive proof of a galaxy cluster, though. "You're seeing a 2-D image of a 3-D distribution of objects," explains Blanton. "Some of them could be way in the foreground, or way in the background." These "projection effects" can create the illusion of a cluster where none really exists. The group's next step, underway now, is to measure the distance to each galaxy in the apparent cluster to confirm that the grouping is real, not an optical illusion.

Golden-Marx is already pinning down distances to some of the using the 4.3-meter Discovery Channel Telescope, where BU is a partner institution, and Blanton hopes to secure time on the Hubble Space Telescope and one of the twin 10-meter Keck telescopes in Hawaii to get even more precise measurements. Once the distances are confirmed, the team will be able to properly order the clusters by age and also confirm whether their catalog really includes the most distant clusters yet found.

Explore further: Mapping dark matter

More information: R. Paterno-Mahler et al. The High-redshift Clusters Occupied by Bent Radio AGN (COBRA) Survey: The Spitzer Catalog, The Astrophysical Journal (2017). DOI: 10.3847/1538-4357/aa7b89

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rrwillsj
2 / 5 (4) Aug 28, 2017
Despite the gushing headline.

My impression after reading this article, is that these researchers are trying to explain what they hope to eventually discover. To provide the empirical evidence needed to prove their theoretical suppositions.

To be able to craft a definitive description of a T/S/G reality.

Which will result in directly contradicting the claims of empirical evidence for the Electrical Universe hypothesis.

And thereby offering the opportunity for both antithetical sets of scientists to accidentally wind up bolstering my Superior Theory.

That the BB and EU theories are correct dependent upon your POV. Each theory only describing one facet of reality. That Time/Space/Gravity and the Electrical (Quantum) exist with only minimal interaction.

And, who knows? May eventually go their separate ways?
Dingbone
Aug 28, 2017
This comment has been removed by a moderator.
baudrunner
3 / 5 (2) Aug 28, 2017
Puzzled about "dark matter"? Here it is:

1. astronomers are studying the farthest objects in the universe, in this case galaxy clusters, to come to their DM and DE theories, and have gotten nowhere, which is puzzling because the explanation for the observed gravitational anomalies that led to DM and DE theories is quite logical.
2. the universe continues beyond our observable range - there are a) objects out there so far away that their light will never ever reach us in the entire history of this galaxy, and between them and the limits of our observability lie b) objects whose light will eventually reach us.
3. the objects in b) are simply closer to the objects we are observing than the objects that we are observing are to us, but we can't see them, and they are the matter that is acting gravitationally on the objects that we can see. Enthusiasts create "dark matter" theory.

Simple.
Solon
1.8 / 5 (5) Aug 28, 2017
"Galaxy clusters offer clues.."

Thats good, as most astronomers are, for the most part, completely clueless.
Benni
1 / 5 (7) Aug 28, 2017
When Dark Matter Enthusiasts look in a mirror, I wonder how many of them are relieved that they're unable to see the remaining 95% of themselves?
Whydening Gyre
5 / 5 (8) Aug 28, 2017
When Dark Matter Enthusiasts look in a mirror, I wonder how many of them are relieved that they're unable to see the remaining 95% of themselves?

Yeah, but...
Do you see all the space between atoms in your body?
Benni
1 / 5 (7) Aug 28, 2017
When Dark Matter Enthusiasts look in a mirror, I wonder how many of them are relieved that they're unable to see the remaining 95% of themselves?

Yeah, but...
Do you see all the space between atoms in your body?


"Yeah but".......are you one of those "relieved" ones?
SlartiBartfast
3.8 / 5 (10) Aug 28, 2017
When Dark Matter Enthusiasts look in a mirror, I wonder how many of them are relieved that they're unable to see the remaining 95% of themselves?


Why do you keep repeating the same tired straw man? It's old. Just stop.
Benni
1 / 5 (7) Aug 28, 2017
When Dark Matter Enthusiasts look in a mirror, I wonder how many of them are relieved that they're unable to see the remaining 95% of themselves?


Why do you keep repeating the same tired straw man? It's old. Just stop.


August 28, 2017, 8:23 pm 1 SlartiBartfast

Because it gets the Trekkies like you all riled up that someone could have so much fun with such overt displays of fantasy. Just using a bit of sharply focused in trying to keep people like you focused in the real Universe where ENTROPY rules. Capiche?
SlartiBartfast
4.1 / 5 (9) Aug 28, 2017
Because it gets the Trekkies like you all riled up that someone could have so much fun with such overt displays of fantasy. Just using a bit of sharply focused in trying to keep people like you focused in the real Universe where ENTROPY rules. Capiche?


No, I don't. Nothing in that made any sense to me. Maybe it did in your own head, but for someone else, it didn't.

"Just using a bit of sharply focused in trying to keep..." That's not even comprehensible English.

"the real Universe where ENTROPY rules." You're trying to change the subject. We're talking about your use of the same old tired straw man (the bit about the mirror). And it _is_ a straw man, and you know it. And it's old, and you know it. So again, just stop already. It's pointless. It's annoying. It's tiresome. If you really have anything to say about the article, then say it. Stop trotting out the same old straw man over and over.
Whydening Gyre
5 / 5 (8) Aug 28, 2017
When Dark Matter Enthusiasts look in a mirror, I wonder how many of them are relieved that they're unable to see the remaining 95% of themselves?

Yeah, but...
Do you see all the space between atoms in your body?


"Yeah but".......are you one of those "relieved" ones?

I'm a more or less a loosely connected conglomeration of trillions of loosely connected systems bound together by strong force, weak force, electromagnetism and gravity.
Slarti is right. Your mirror schtick is pretty old and - lame...
Not to mention - inaccurate.
thingumbobesquire
1 / 5 (1) Aug 29, 2017
The most powerful force in the universe is not entropy. It is not even a purely physical force... It is the uniquely human creative drive to do the good for the benefit of unborn generations.This is why "artificial intelligence' is a fraud and why humanity must revolutionize its practice to continuously inhabit and conquer "outer space."
Benni
1.7 / 5 (6) Aug 29, 2017
And it _is_ a straw man, and you know it. And it's old, and you know it. So again, just stop already. It's pointless. It's annoying. It's tiresome. If you really have anything to say about the article, then say it.
.......and I did, i stated very clearly in unambiguous comprehensible language that the concept of 95% of the universe being missing is a fantasy, learn to read.

Stop trotting out the same old straw man over and over.
..........exactly right, it's exactly what the DM Enthusiasts should stop doing until they can prove 95% of the Universe is MISSING. So until you overage Trekkies can prove your fantasies are real, and you keep posting this inane slop & swill that 95% of the Universe is missing, then I will continue challenging you to prove it. SO JUST STOP IT WITH INFERRED SCIENCE.

This is entertaining & fun, I know how to do it & you don't & that's what so deeply galls you.

Benni
1.7 / 5 (6) Aug 29, 2017
Slarti is right. Your mirror schtick is pretty old and - lame...
Not to mention - inaccurate.


You know, you guys with your dark matter schtick is pretty old-lame......not to mention -inaccurate.

You DM Enthusiasts started this slop & swill DM stuff way back in the 1930's with Zany Zwicky, don't you think it's time to simply get over it? I mean hell's bells man, you've only been reading about the "mirror analogy" for a couple of years. But one thing you can say about Zwicky, he too was entertaining with this DM stuff, just like me & that's what galls you so deeply.
dnatwork
1 / 5 (3) Aug 29, 2017
If I understand correctly, both dark matter and dark energy have gotten stronger over time. Dark matter made up only 10% of bright galaxies 10 billion years ago; similarly, dark energy was not a major force then. Why, then, are they seeking answers in the amount of matter or energy at any one time, rather than seeking answers in the changes in structure over time?

Physicists seem to think in static terms: once an object is left alone, it just sits there on their rubber-sheet analogy, quietly pushing down into its little bowl of bent space. What is pushing back up against it?

If there is no upward force, then it must keep bending space indefinitely.

Perforce, over time, a galaxy will fall into a tighter and tighter bowl (frame of reference, needs no bottom), and the radius of orbiting stars will be more limited over time. Dark matter.

Perforce, the voids between galaxies will appear to expand ever more quickly as the galaxies themselves "shrink" inward. Dark energy.
Zzzzzzzz
4 / 5 (4) Aug 29, 2017
"If I understand correctly,"

Apparently you do not.
dnatwork
1 / 5 (1) Aug 29, 2017
"If I understand correctly,"

Apparently you do not.


So dark matter and dark energy have not gotten stronger over time? Or they have, but you just find my thoughts stupid and annoying?
Whydening Gyre
4.3 / 5 (6) Aug 29, 2017
Slarti is right. Your mirror schtick is pretty old and - lame...
Not to mention - inaccurate.


You know, you guys with your dark matter schtick is pretty old-lame......not to mention -inaccurate.

You really should find your own words... You plagiarist, you...

You DM Enthusiasts started this slop & swill DM stuff way back in the 1930's with Zany Zwicky, don't you think it's time to simply get over it? I mean hell's bells man, you've only been reading about the "mirror analogy" for a couple of years. But one thing you can say about Zwicky, he too was entertaining with this DM stuff, just like me & that's what galls you so deeply.

It's been 2 years too long...
"Missing" is quite different than "unseen".
Math is derived from reality, not the other way 'round. Ergo, it's pretty common sense to realize it has limits...
Benni
1.7 / 5 (6) Aug 29, 2017
It's been 2 years too long...
"Missing" is quite different than "unseen".
Math is derived from reality, not the other way 'round. Ergo, it's pretty common sense to realize it has limits


What? Only 2 years since I started my DM Mirror Analogy? Zany Zwicky started this mumbo jumbo cosmic fairy dust tale 90 years ago. And you're complaining about..........? My mere 2 years? Wait'll it gets to be 90.

You should be complaining about the 90 year guys who have yet to come up with some real science so as to actually prove 95% of the Universe is missing.

By default, if 95% of the Universe is missing, then so also is 95% of our local solar system, but where is the evidence for that? Einstein's Field Equations for Gravity as used in the Photon Deflection of General Relativity is proof positive our solar system is not 95% missing, but you don't know why his math was correct do you?
Da Schneib
3 / 5 (6) Aug 29, 2017
If I understand correctly, both dark matter and dark energy have gotten stronger over time.
Hmmm. Not really. The very first thing to understand is that the terms "dark matter" and "dark energy" refer to phenomena that have little or nothing to do with one another. Just because they're both called "dark" doesn't mean they're associated.

When inflation was over and the inflaton underwent vacuum decay, it dumped all its excess energy into the entire cosmos everywhere. This is called the "Big Bang." All the matter in the universe came from that energy. The vacuum decay was not to zero; it was to a level that was much lower than it had been but not to zero. So there was some inflaton left, but not enough to overcome the gravity of all that mass.

Most of the mass (4/5) became dark matter; but around 1/5 of it became all the matter we see in the universe around us. The remaining inflaton was dark energy.
[contd]
Da Schneib
3 / 5 (6) Aug 29, 2017
[contd]
So dark matter and ordinary matter share a common origin, and it's different from the origin of dark energy.

Now, the Big Bang wasn't smooth; it was lumpy. Some places got more of the inflaton energy than others. These are called "primordial density fluctuations," and we can see their effects in the Cosmic Microwave Background (with WMAP, and the Planck satellite, among other things), and in the density fluctuations indicated by the existence of galaxy clusters and cosmic voids, and in the filaments of the "cosmic web." So that's three very strong pieces of evidence for this lumpiness.

The matter fell together by gravity; this created the galaxy clusters and the cosmic web, and vacated the cosmic voids. Remember, this is both dark matter and ordinary matter.

I suppose you can think of this as "dark matter getting stronger," but it's only a local effect. In the cosmic voids, along this same line, you'd think of "dark matter getting weaker."
[contd]
Da Schneib
3 / 5 (6) Aug 29, 2017
[contd]
As the cosmic voids became larger and lost their matter, they also lost their gravity; and this meant that the inflaton left in the voids became stronger. So the voids expanded. Now, the thing about the inflaton is that it's not matter, and it's not energy; it's an intrinsic property of space. So when the voids expanded, not only did the inflaton (which is usually called "cosmological constant," and is a term in the Einstein Field Equations of General Relativity Theory, the field theory of gravity; I'll call it that from now on, but remember that it's the same thing as the inflaton) get stronger because there wasn't much gravity opposing it, but it also got stronger because it's an intrinsic property of spacetime, and when space expands, there's more cosmological constant.

So you can say, if you like, that "dark energy got stronger." Actually it didn't; for any given amount of space, there's a set amount of cosmological constant, it's just that space grew.
[contd]
Da Schneib
3 / 5 (6) Aug 29, 2017
[contd]
If you think about this, you will realize that this inflaton, this cosmological constant, is dark energy. It's not like matter; it's a property of spacetime that's always the same everywhere. Where there's a lot of matter, there's a lot of gravity and it overwhelms the cosmological constant; in those places space is contracting. But in the big cosmic voids, there's not a lot of matter, and therefore not a lot of gravity, and the cosmological constant works unopposed. In those places, space is expanding.

If you look at maps of the universe that we've been making, you'll see that there is a lot more void than filaments and galaxy clusters. Therefore, we say the universe is expanding, and the rate is increasing because the voids keep getting bigger and the filaments and galaxy clusters keep getting farther apart.

This is called the ΛCDM theory, or the Standard Model of Cosmology. Λ is the symbol in the EFE for cosmological constant.
[contd]
Benni
1.7 / 5 (6) Aug 29, 2017
Schneibo........take a breath.
Da Schneib
3.3 / 5 (7) Aug 29, 2017
[contd]
CDM stands for Cold Dark Matter.

The evidence is extensive and varied, including redshift and supernova observations of galaxies and galaxy clusters, gravitational lensing observations of the galaxies, galaxy clusters, and filaments, CMBR observations from the WMAP and Planck satellites and about seventy years of radio astronomy, and observations of galaxies and galaxy clusters behaving in ways that they could not if the matter we see were all there was (and by a lot; the matter we see can only be 1/5 of the matter that's there).

Now for the rest of your post.

Dark matter made up only 10% of bright galaxies 10 billion years ago
No. There is no evidence that the amount of matter has changed since the Big Bang.

similarly, dark energy was not a major force then.
It wasn't, but that's not "similar" to anything about matter of either kind, dark or ordinary.
[contd]
Da Schneib
3.3 / 5 (7) Aug 29, 2017
[contd]
Why, then, are they seeking answers in the amount of matter or energy at any one time, rather than seeking answers in the changes in structure over time?
Ummm, you do realize that by checking the amount of dark energy at one time, and then at another, you can find the rate of change, right? So looking for changes in the structure over time is, in fact, exactly what they are doing.

I'm not going to answer the rest; from the above you can figure out the answers to your questions, and figure out why what you are claiming is wrong. If you don't care enough to bother then I won't waste my time. But if you absorb this information, and ask more questions, then it won't be wasted. So getting more information is up to you now.
Benni
2.1 / 5 (7) Aug 29, 2017
Schneibo........if you don't take a deep breath soon, you're gonna turn blue, then what am I gonna do for entertainment if you're no longer around for me to sound offf on?
Benni
1.7 / 5 (6) Aug 29, 2017
Most of the mass (4/5) became dark matter; but around 1/5 of it became all the matter we see in the universe around us. The remaining inflaton was dark energy.


Yes Schneibo, we know you were there to watch it all happen. The Gospel According to Schneibo.
Whydening Gyre
4 / 5 (8) Aug 29, 2017
Most of the mass (4/5) became dark matter; but around 1/5 of it became all the matter we see in the universe around us. The remaining inflaton was dark energy.


Yes Schneibo, we know you were there to watch it all happen. The Gospel According to Schneibo.

You realize, of course, that the info DS just relayed is a composite of info gained by 10's of thousands of scientists, including Nuclear physicists... (Of which you seem to consider yourself one...)
RealityCheck
1 / 5 (4) Aug 30, 2017
@Benni, @Da Schneib

Really, you're BOTH as bad as each other. Don't EITHER of you ever LISTEN?

@Benni, Zwicky NEVER said 'exotic' DM, only then-'unseeable' ORDINARY material....which we NOW FINDING all over! So Zwicky was RIGHT; it was mainstream 'theorists' coming AFTER Zwicky invented 'exotic' DM. So there WAS ORDINARY matter; NOW found more of with every new telescope/instrument observation. ALSO: GR was being MISAPPLIED by those who 'expected' Keplerian dynamics instead of the severely NON-Keplerian dynamics (due to NON-Keplerian ORDINARY mass distribution/orbital regimes). So QUIT badmouthing Zwicky; it's 'modern theorists' to blame for the 'dark exotic matter' silliness. OK? :)

@Da Schneib, you CAN'T HAVE IT BOTH WAYS. Alleged 'expansion' is (claimed to be) LOCALLY SAME RATE EVERYWHERE; while matter can be gravitationally/electromagnetically 'bound' together as the 'expansion' MOVES THROUGH it. The FLAW is: NO MECHANISM to CONSISTENTLY explain BOTH 'claims'.

Ok? :)
Ojorf
3.9 / 5 (7) Aug 30, 2017
By default, if 95% of the Universe is missing, then so also is 95% of our local solar system, but where is the evidence for that?


Not at all, that makes no sense.
Could you please explain why you think that.
antialias_physorg
4 / 5 (8) Aug 30, 2017
By default, if 95% of the Universe is missing, then so also is 95% of our local solar system

Erm..whut? That's like saying: "Because our solar system doesn't contain a neutron star there are no neutron stars in the universe."
Benni
1.7 / 5 (6) Aug 30, 2017
You realize, of course, that the info DS just relayed is a composite of info gained by 10's of thousands of scientists, including Nuclear physicists... (Of which you seem to consider yourself one...)


No WhyGuy, it isn't "10's of thousands of scientists, including Nuclear physicists", it's a very small cadre of of Astro-Physicists who want to be thought of as being Nuclear Physicists, big difference. It's the reason Zany Zwicky often referred to Einstein as a "Spherical Bastard", simply because Einstein actually was a Nuclear Physicist & Zwicky wanted to be looked on as Einstein's equal but unable to attain it due to lack of intellect, so Zwicky went on his versions of name calling rants doing the same thing the present day cadre of Funny Farm Scientists do here. The consensus among real Nuclear Physicists was always against Zwicky just as it is today, all this other stuff is just NOISE from a tiny irrelevant cadre of wannabes.

Benni
1.7 / 5 (6) Aug 30, 2017
By default, if 95% of the Universe is missing, then so also is 95% of our local solar system, but where is the evidence for that?


Not at all, that makes no sense.
Could you please explain why you think that.


When Einstein calculated Photon Deflection in General Relativity, he calculated the deflection of a photon just grazing the peripheral disc of the Sun to within 0.02% of error. If the Universe were composed of 80-90% Missing Matter/Energy, that means so also is the Sun missing it's share of the 80-95%. This quantity of missing Mass/Energy would be exhibited in an unexplained gravity field from the Sun that would have so severely altered Einstein's calculations as to make them irrelevant.

In other words, Einstein's Field Equations should have included a CONSTANT for 5 times the amount of gravity that he used for calculating photon deflection, but he didn't & was dead on accurate in calculating the mass of the Sun from it's Visible Mass.

Benni
1.7 / 5 (6) Aug 30, 2017
By default, if 95% of the Universe is missing, then so also is 95% of our local solar system


Erm..whut? That's like saying: "Because our solar system doesn't contain a neutron star there are no neutron stars in the universe."


.......about the kind of response one could expect from a Biologist such as yourself.
dnatwork
3.5 / 5 (4) Aug 30, 2017
Dark matter made up only 10% of bright galaxies 10 billion years ago

No. There is no evidence that the amount of matter has changed since the Big Bang.


https://www.scien...alaxies/

This article is about a recent study showing that dark matter was only about 10% of galactic mass 10 billion years ago. They go on to state that that does not prove there is no dark matter. Fair. But then they assume that dark matter was there, it was just somewhere else. Not fair. The only reason we talk about dark matter is because we see its effects, not the matter itself. If the effects are not visible, either, then there is no reason to assume the dark matter is still there. That's circular and non-falsifiable, closer to religion than science.

dnatwork
3.8 / 5 (4) Aug 30, 2017
similarly, dark energy was not a major force then.

It wasn't, but that's not "similar" to anything about matter of either kind, dark or ordinary.


The whole mystery of dark energy is why it gets stronger over time. No one can explain why there should be a cosmological constant. Einstein regarded it as his biggest mistake.

Research shows that dark matter became more dominant over the past ten billion years. Research shows that dark energy became more dominant over the past ten billion years. When two things happen on the same timescale in the same place (ten billion years, affecting entire universe simultaneously), Occam's Razor says to look for one common explanation first, not several different explanations. If you have to make pretzels to preserve your theory (almost everything is stuff we can't find and can't interact with, but all of it constantly interacts with us), maybe the theory needs straigthtening out.
dnatwork
3 / 5 (3) Aug 30, 2017
The standard theory has to be mostly correct (calculating photon detection within .02% sounds pretty good). What could be missing is a dynamic concept of the effect of matter and energy on spacetime.

The presence of mass causes spacetime to curve. Does it reach a degree of curvature and stop? If so, then a static view of the universe is good enough.

But what would cause the curvature to stop increasing? Is there a force pushing back? Does spacetime have some structure, a rigidity that mass has to overcome, like a spring, so it stops when it bends far enough to produce a countervailing force? Where is either of those in the standard theory? If it's not there, then there is nothing to stop spacetime from curving infinitely in the presence of mass.

If a system defines its own frame of reference, then within that frame you could never see the curvature happening. You would only see it by looking at different reference frames. Like galaxies and voids over billions of years.
dnatwork
3 / 5 (3) Aug 30, 2017
So I'm saying, what if there's nothing much to explain? If spacetime is doing what it does in the presence of mass, then what they're trying to explain with dark matter and dark energy are just the emergent effects of spacetime continuing to curve indefinitely, causing reference frames to drift farther apart. Voids seem to be expanding at an accerating rate--or maybe all the matter is falling into smaller and smaller reference frames at a constant rate. Galaxies seem to be gathering more invisible mass over time--or maybe the spacetime they're sitting in is collecting in smaller and smaller reference frames at a constant rate.
dnatwork
3.7 / 5 (3) Aug 30, 2017
Don't ding me for the obvious typos: photon deflection, not detection. And "spacetime from curving indefinitely," not infinitely.

Which leads to another thing: if space curves indefinitely in the normal case, then black holes would not be a special case. The frame of reference inside would just be shrinking very fast, such that everything inside would be beyond the Hubble distance.
Benni
1.8 / 5 (5) Aug 30, 2017
The presence of mass causes spacetime to curve. Does it reach a degree of curvature and stop?


When Einstein calculated photon deflection at the immediate peripheral disc of the Sun, the result was 1.75 arcseconds, or 0.000486 degrees from the original path of the photon.

The maximum deflection of a photon of any wavelength by any stellar body in the Universe is always less than 90°, and always a lot less than this.

A photon cannot reach some hypothetical "degree of curvature and stop". Photons exist & travel only at one velocity, speed of light (c). The only thing that can happen to a photon to "stop" it dead in it's tracks is transformation to mass.

There is no quantity of gravity that can "stop" a photon so as to reduce it's velocity below lightspeed whereby resulting in transformation to mass.
RealityCheck
1 / 5 (3) Aug 30, 2017
An FYI to ALL. :)

https://phys.org/...lent.htm

See? Yet MORE discoveries of Normal 'previously unseen' Matter; and MORE 'RE-interpretations' of what IS 'seen' from 'here'.

On Feb 23 in BELOW linked thread, I said:
It's COMPLEX and involves plasmic states/processes in the form of an EVOLVING 'cloud' MIX of constituents: ie, hydrogen/other atoms/ions, molecules, dust AND INTERMEDIATE SPECIES produced by high energy/radiation going through it all (from whatever source).
Further on in BELOW linked thread, on Feb 25, I said to @Da Schneib:
There are boundary regions (where Hydrogen may be neutral/non-energized/cooler etc); shock regions (which may be highly ionized/energetic/hotter); and TRANSITIONAL STATES etc which will all interfere/produce some resultant-effects re what radiation leaves whole 'mess' there/finally detected 'here'. :)
https://phys.org/...mic.html

Spot on, hey? :)
Whydening Gyre
5 / 5 (2) Aug 30, 2017
There is no quantity of gravity that can "stop" a photon so as to reduce it's velocity below lightspeed whereby resulting in transformation to mass.

Finally. An interesting statement from Benni. Can you provide further reference?
Can you provide a mechanical explanation of photons transforming into mass?
Its my own conjecture it wouldn't "stop", but rather, continually change direction (in an ever tightening vortex). Eventually becoming just "spin".
How many photons does it take to make an electron or proton or neutron?
Da Schneib
2.3 / 5 (3) Aug 31, 2017
Dark matter made up only 10% of bright galaxies 10 billion years ago

No. There is no evidence that the amount of matter has changed since the Big Bang.


https://www.scien...alaxies/

This article is about a recent study showing that dark matter was only about 10% of galactic mass 10 billion years ago. They go on to state that that does not prove there is no dark matter. Fair. But then they assume that dark matter was there, it was just somewhere else. Not fair.
I don't think you're following this. Matter took time to collapse; it didn't just appear in filaments. It says so right in the article, and there's even a link at the end of the article that describes it just that way.

Sorry man, your article doesn't say what you claim it does. You have to read the whole article, not just the first paragraph.
Da Schneib
2.3 / 5 (3) Aug 31, 2017
similarly, dark energy was not a major force then.

It wasn't, but that's not "similar" to anything about matter of either kind, dark or ordinary.


The whole mystery of dark energy is why it gets stronger over time. No one can explain why there should be a cosmological constant. Einstein regarded it as his biggest mistake.
This is often misinterpreted; he said that when Hubble discovered the Hubble Constant and he realized its implications.

Again, you're not getting it; cosmological constant is a property of spacetime. We already know that from the Casimir Effect. Vacuum exerts pressure; this is proven in the lab on Earth. If it pushes in, it can't help but push out. It's not mysterious at all; it's the pressure of the vacuum's virtual particles, which are excluded from the short distance between a pair of plates in a vacuum in the lab.

You can't pay attention to half the evidence and expect to get a clear picture of what's going on.
Da Schneib
2.3 / 5 (3) Aug 31, 2017
The standard theory has to be mostly correct (calculating photon detection within .02% sounds pretty good). What could be missing is a dynamic concept of the effect of matter and energy on spacetime.
The dynamic concept of the effect of matter and energy on spacetime is called "gravity." Our best theory of gravity is a field theory called GRT (General Relativity Theory) and its mathematical representation is the EFE (Einstein Field Equations). It's probably worth looking it over if you're going to make conjectures about spacetime since it's been tested many times both in astrophysics and in the laboratory, and even in satellites, and hasn't failed a test yet. The most stringent recent tests included Gravity Probe B, which detected an effect predicted by GRT called frame dragging, and LIGO, which detected gravity waves, another effect predicted by GRT.

When we detect such subtle effects of a theory, it's not very smart to throw it out.
Da Schneib
2.3 / 5 (3) Aug 31, 2017
@dnat, I can't make much sense of your other two posts. You'll need to ask some questions. But at least you are asking good questions so far.

All I can tell you is what GRT says, and that given GRT has been tested carefully and extensively, you're going to need a subtle and powerful theory to extend it; it doesn't seem possible at this time to overthrow it. It's worth noting that although GRT is often misrepresented as "overthrowing" Newton's Theory of Universal Gravitation, that's actually not the case in reality. It's an extension of the TUG; for short times and distances, and weak gravity, TUG is good enough to navigate space probes and make pretty good ephemerides. For ultimate accuracy you need GRT, but only Mercury (in the strong gravity field of the Sun) show inaccuracies in it in times shorter than millenia, and only studies over millions of years show it for the other planets. GRT extends TUG. It doesn't "prove it's wrong."
Da Schneib
2.3 / 5 (3) Aug 31, 2017
Most physicists believe that there is a more accurate theory of gravity called "quantum gravity" that will eventually be discovered. But uniting quantum physics with the GRT field theory has proven incredibly mathematically complex, so complex that no one has done it so far. Most physicists believe that someone, likely a mathematical genius like Einstein, will figure out how to do it, but until someone does, we have to go with our field theory, GRT. Given the enormous amount of evidence that supports it, we have to expect that whatever the quantum gravity theory is, it will predict all the same results GRT does until we hit some limit in strong gravity or enormous spans of time. Given we've only had a hundred years or so to study it, it's no surprise we haven't figured it out yet.

And you will note I haven't dinged you for typos. Keep asking the good questions.
Da Schneib
2.3 / 5 (3) Aug 31, 2017
If you want to understand where science is at with respect to gravity right now, we are in the same place electromagnetic theory was after Maxwell wrote his equations and before Planck, Dirac, and Einstein wrote theirs. We have a field theory; we don't have a quantum theory, and we aren't anywhere near a quantum field theory. We are in the Confusion; after Newton wrote TUG and the Laws of Motion, and before Einstein wrote SRT and GRT. There are enormous discoveries waiting for us; they are all dependent upon quantum gravity theory. There are other theories waiting out there too; we don't yet have a fully computable theory of the Color Force either, nor one of the Navier-Stokes equations of fluid dynamics. Many physicists are searching for these theories. The ones who find them will be as famous as Newton and Einstein. But no one has found them yet.

Patience is a virtue.
RealityCheck
1 / 5 (2) Aug 31, 2017
ERRATA; BROKEN LINK: The FIRST thread LINKED in my previous post is missing the "l" in "html" suffix); hereby remedied ...

An FYI to ALL. :)

https://phys.org/...ent.html

See? Yet MORE discoveries of Normal 'previously unseen' Matter; and MORE 'RE-interpretations' of what IS 'seen' from 'here'.
....
....
....
....


Apologies for any inconvenience. Thanks.
Benni
1.8 / 5 (5) Aug 31, 2017
There is no quantity of gravity that can "stop" a photon so as to reduce it's velocity below lightspeed whereby resulting in transformation to mass.


Finally. An interesting statement from Benni. Can you provide further reference?
.........there exists no data that exhibits the use of gravity to transform energy to mass by exerting a gravitational field so strong that it can "stop" the movement of a photon. You want a "reference"? If such a condition for transforming energy to mass existed you would read about it in every book or journal in every college classroom, but you don't read about it because it is such a ridiculous question to ask and you asked it.

Can you provide a mechanical explanation of photons transforming into mass?
It can't be observed, it can only be measured during the process of electron-positron pair production as one means of measuring transformation of energy to mass.

Ojorf
3.4 / 5 (5) Aug 31, 2017
If the Universe were composed of 80-90% Missing Matter/Energy, that means so also is the Sun missing it's share of the 80-95%. This quantity of missing Mass/Energy would be exhibited in an unexplained gravity field from the Sun that would have so severely altered Einstein's calculations as to make them irrelevant.


No, you have it totally wrong!
Go read up on dark matter, just try wikipedia s a start. If you understood the concept you would not come up with such arguments.
DM only interacts via gravity, it cannot clump into stars & planets, it can't even slow down, except for gravity, it's all around.
There is no gravity at the center of the earth even though there is a lot of mass all around.
Same concept.
Benni
1.7 / 5 (6) Aug 31, 2017
Its my own conjecture it wouldn't "stop", but rather, continually change direction (in an ever tightening vortex). Eventually becoming just "spin".
How does a photon or EM Wave "just spin"?

How many photons does it take to make an electron or proton or neutron?


As in electron pair production as I pointed already, Nuclear Physicists only know that energy to mass transformation takes place, but the mechanisms by which this occurs are without a doubt way more numerous & complicated than will ever be understood. Electron pair production is one method that is well understood & is used as the most frequent real model of a transformation process.

How many more transformation processes exist other than electron pair production is a reasonable question to ask, but for which there is no answer, but it is not unreasonable to use a number like gazillions.

Ojorf
3.7 / 5 (3) Aug 31, 2017
Let me ask you a simple question Benni, you are so into Einstein.

Do you believe the basics of GR, that matter 'tells' space how to 'bend' and space 'tells' matter how to 'move'?

If yes, then:
Space without matter would bend 'out' and be open.
Space with a lot of matter would bend in and be closed.
Space with just the right amount of matter would be flat.

Do you agree?

If so, could you calculate for us how much matter you need for it to be flat?

Please.
Benni
1 / 5 (5) Aug 31, 2017
No, you have it totally wrong!
Go read up on dark matter, just try wikipedia s a start. If you understood the concept you would not come up with such arguments.
DM only interacts via gravity, it cannot clump into stars & planets, it can't even slow down, except for gravity, it's all around.


Ojorf, just you repeating the same old, tired, & worn out psycho-babble.

I don't care about WikiPsychoBabble, I got my science education from attending 6 years in Engineering school studying Nuclear/Electrical Engineering in addition to almost two years of continuing education credits beyond that.

I know how to sort fact from fiction, you simply don't know how to recognize perpetual motion pscho-babble when you see it, in the meantime it's smacking you so hard up against the side of your head that it's caused you to go punch drunk into believing slop & swill like this DM cosmic fairy dust created by Fritz Zwicky whose peers always referred to him as "zany".

Benni
1.7 / 5 (6) Aug 31, 2017
Do you believe the basics of GR


Here's Einstein's response quoted directly from GR, I agree with every word of it:

Part III: Considerations on the Universe as a Whole- the structure of Space
Albert Einstein – General Relativity 1916

If we are to have in the universe an average density of matter which differs from zero, however small may be that difference, then the universe cannot be quasi-Euclidean. On the contrary, the results of calculation indicate that if matter be distributed uniformly, the universe would necessarily be spherical (or elliptical). Since in reality the detailed distribution of matter is not uniform, the real universe will deviate in individual parts from the spherical, i.e. the universe will be quasi-spherical. But it will be necessarily finite. In fact, the theory supplies us with a simple connection between the space-expanse of the universe and the average density of matter in it.
Ojorf
4 / 5 (4) Aug 31, 2017
Nice, but you did not answer the question.

You don't have to calculate anything, don't worry.
Ojorf
4 / 5 (4) Aug 31, 2017
Ojorf, just you repeating the same old, tired, & worn out psycho-babble.

I don't care about WikiPsychoBabble, I got my science education from attending 6 years in Engineering school...


If you don't care about it, you must have your reasons.
Care to give your criticisms point for point in your own words?
What do you disagree with and why?
Benni
1.7 / 5 (6) Aug 31, 2017
Nice, but you did not answer the question.


........and you seem to have a reading comprehension problem:
Here's Einstein's response quoted directly from GR, I agree with every word of it:


Now the onus is on you to prove Einstein was wrong about the spherical structure of the Universe, better known as the Second Law of Thermodynamics, ENTROPY. Now you're really lost aren't you?

Of course you always have WikiPedia to explain ENTROPY to you, but you'll never rise to the occasion of serious study in the subject matter because you also need to be able to do the math, Differential Equations.
Ojorf
3.7 / 5 (6) Aug 31, 2017
OK, so you don't understand the concept, therefore you can't explain it in your own words.

You keep dodging the question.
Try to just type Y or N.
I want to stick to baby steps, keep it simple for now.

I get your quote, don't worry. But you must understand where Einstein came from when he wrote that.
You also must realize that quote was from 1916, GR was brand new. All the implications of the theory had not been worked out, or even conceived yet.
A LOT more is known NOW about Enstein's theories than he knew at that time.
Ojorf
3 / 5 (4) Aug 31, 2017
Where is this known better?

the spherical structure of the Universe, better known as the Second Law of Thermodynamics, ENTROPY[/]
Benni
1 / 5 (5) Aug 31, 2017
OK, so you don't understand the concept, therefore you can't explain it in your own words.
......my "words" aren't necessary, only Einstein's "words" are necessary, I just don't disagree with anything in his GR, you're the one having the problem comprehending the contents of it as I quote excerpts directly from the document.

Where is this known better?
......once again it's you failing to read what I explained to you when I pointed out the topic of science about which Einstein was discussing, here read it again:

the spherical structure of the Universe, better known as the Second Law of Thermodynamics, ENTROPY


Again, it's called the 2nd Law of Thermodynamics, ENTROPY. Capiche? No, you don't & probably you never can. Thermodynamics is a series of courses we take in Engineering School, you would know that if you'd ever been educated in some structured physical science education where you had to pass a final exam & get a grade.

dnatwork
3.7 / 5 (3) Aug 31, 2017
@DaSchneib, thanks for taking me seriously and having such patience and respect for a person who is just wondering about these things.

I think one reason my posts don't make sense is because my intuition is that gravity doesn't exist and reference frames are real structures.

The centrifugal force isn't a force, it's an effect of inertia taking over when you let go of the string. You can calculate its effects with great precision, though, so it's called a pseudoforce. I think that also describes gravity. The "string" is the curvature of spacetime, and gravity is just inertia in action.

Physicists use reference frames all over, but it's not clear that they regard them as real. They discard them as soon as they make some point about the speed of light. I'm asking, what if you are not using an analogy, but that reference frame is a real thing?

What happens to the theory if you treat gravity as an analogy, and start calculating the effects of dynamic reference frames?
dnatwork
3.7 / 5 (3) Aug 31, 2017
Again, you're not getting it; cosmological constant is a property of spacetime. We already know that from the Casimir Effect. Vacuum exerts pressure; this is proven in the lab on Earth. If it pushes in, it can't help but push out....


But the Casimir effect as calculated and observed implies a cosmological constant that's much too large for the rest of the universe. That's where I tend to wonder if it might be an emergent effect: something that can be calculated precisely, but not the true explanation.

And I don't follow why it has to push out if it pushes in. I'm sure you're right about how the math works out to produce that necessity--photons and fermions dominating in different domains, infinite zero point energy summed over photon modes, blah blah blah. It's on me to learn more.
dnatwork
3.7 / 5 (3) Aug 31, 2017
You can't pay attention to half the evidence and expect to get a clear picture of what's going on.


I'm not being selective, just mostly uninformed and going on intuition. This is the internet, so I figure that's fair. Better than most people out here, probably, because I'm sincere, not trolling.

On the other hand, you state that much more is to be discovered, etc. Physicists probably don't have half the evidence yet, either, and they know their theories are incomplete. So I'm not going to feel bad about trying the intuitive route first.
Ojorf
3.7 / 5 (6) Aug 31, 2017
...my "words" aren't necessary, only Einstein's "words" are necessary...


Apparently neither is a straightforward answer "necessary".

Any parrot can copy someone else's words out of context without any comprehension.
Ojorf
3 / 5 (4) Aug 31, 2017
Let's make this even simpler, do you agree (with Einstein) that GR is a valid (as close as is currently testable) description of reality?

Yea or Nay?
Benni
1.7 / 5 (6) Aug 31, 2017
A LOT more is known NOW about Enstein's theories than he knew at that time.


Really? Like what?

do you agree (with Einstein) that GR is a valid (as close as is currently testable) description of reality?


Ojo, I answered your question before you even asked it, and what do you do? You ask it anyway:
....my "words" aren't necessary, only Einstein's "words" are necessary, I just don't disagree with anything in his GR, you're the one having the problem comprehending the contents of it as I quote excerpts directly from the document.
Capiche? Again, probably not.

Da Schneib
2.3 / 5 (3) Sep 01, 2017
@DaSchneib, thanks for taking me seriously and having such patience and respect for a person who is just wondering about these things.
Sure, as long as you're serious about it and don't mistreat me when I point out that science disagrees with your ideas, you'll find I'm pretty easy to get along with. I'll add a compliment: many people get so stuck on their ideas that they can't take being contradicted. It's a rarer quality than you might think not to object to that.

I think one reason my posts don't make sense is because my intuition is that gravity doesn't exist and reference frames are real structures.
The problem with this is that you can define many- usually an infinite number- of frames that all describe the same situation, and no matter which one you choose the physics comes out the same. That's the meaning of the relativity postulate, a foundational postulate of SRT and GRT. SRT only deals with inertial frames; GRT adds accelerated frames.

[contd]
Da Schneib
3 / 5 (4) Sep 01, 2017
[contd]
The centrifugal force isn't a force, it's an effect of inertia taking over when you let go of the string.
The real force is the centripetal force; it's the one that makes the weight fly away when you let go of the string. It's the constraint of the string, along with the real centripetal force, that makes the fictitious centrifugal force. Remember also that when the weight flies away, it doesn't fly straight out from the center of rotation; it keeps going in the direction it was moving when you released the string. This is the surest sign that the centripetal force is real and the centrifugal force is fictitious.

I'm asking, what if you are not using an analogy, but that reference frame is a real thing?
If it were there'd only be one frame in which physics was valid; the problem with this idea is that there are many frames in which physics is valid.

[contd]
Da Schneib
3 / 5 (4) Sep 01, 2017
[contd]
Pick a frame; as long as you stick to it consistently, or make the right transforms between frames, you always get the same physics. Physics is frame independent. This is the realization by Einstein that he is most famous for.

What happens to the theory if you treat gravity as an analogy, and start calculating the effects of dynamic reference frames?
I don't know what "treat[ing] gravity as an analogy" means. It's a real thing; if it weren't then light beams wouldn't curve in a gravity field.
Da Schneib
3 / 5 (4) Sep 01, 2017
But the Casimir effect as calculated and observed implies a cosmological constant that's much too large for the rest of the universe. That's where I tend to wonder if it might be an emergent effect: something that can be calculated precisely, but not the true explanation.
This is why we need quantum gravity; we can't calculate it precisely without it. We've left out an entire force, because we can't calculate it. We can't possibly get the right answer.

And I don't follow why it has to push out if it pushes in.
Newton's Second Law: for every action there is an equal and opposite reaction. It can't push in without pushing out. If it didn't push out, it couldn't push in; there'd be nothing for it to push against to push in.
Da Schneib
3 / 5 (4) Sep 01, 2017
On the other hand, you state that much more is to be discovered, etc. Physicists probably don't have half the evidence yet, either, and they know their theories are incomplete. So I'm not going to feel bad about trying the intuitive route first.
The problem with intuition is that it's not informed by detailed quantitative knowledge; we exist in a very limited set of circumstances, which don't correspond to the circumstances most objects in the universe find themselves in. We have air which creates friction for every moving object; we have gravity which makes every object show a tendency to move in a biased direction. Just as two examples of our intuitive biases.
Ojorf
3 / 5 (4) Sep 01, 2017
Boy you are slippery.
So you answered my question?
Was the answer YES?

Ojorf
3.7 / 5 (6) Sep 01, 2017
A LOT more is known NOW about Enstein's theories than he knew at that time.


Really? Like what?


Are you serious?

You think that we have learnt nothing new since 1916?
Maybe you should get up to date, a LOT has happened since.
Da Schneib
3.7 / 5 (6) Sep 01, 2017
Here's a nice demonstration of new predictions from GRT in the last few years: https://arxiv.org...01.04539

It took 99 years for someone to figure this one out.

GRT is incredibly mathematically complex. In addition, gravity is the weakest force. As a result testing some of its more esoteric predictions is very difficult in the weak gravity fields of our Solar System. Gravity Probe B is generally thought to have proven Lense-Thirring frame dragging; in fact, it only did so with a precision of about 19%. However, it did prove another effect that is very similar, the de Sitter precession, with a precision of 0.5%. Physicists have now turned to observation of stars orbiting the supermassive black hole at the center of the Milky Way for conclusive evidence of Lense-Thirring frame dragging.

Even figuring out some of these effects has taken nearly a hundred years. This is why referring to Einstein as if he was an oracle has many pitfalls for the unwary and naive.
[contd]
Da Schneib
3.7 / 5 (6) Sep 01, 2017
[contd]
Only now, a hundred years later, is it even possible to think of experimentally confirming some of the weaker effects of this complex and powerful theory, and we can barely get closer than 20% precision for some of them. Meanwhile, new mathematical research into the theory is still yielding new predictions of even weaker effects.

Pretending that "we know everything about GRT" is silliness in both theoretical and experimental physical terms. We will be analyzing the math of GRT for a long time to come yet; this is because people with the insight into and understanding of the theory, the mathematical talent to extract exact predictions from it, and the imagination to dream up tests of these subtle predictions, is extremely limited in any generation, even among the six billion minds we currently have on this planet.
Benni
1 / 5 (5) Sep 01, 2017
Boy you are slippery.
So you answered my question?
Was the answer YES?


Old man, I answer your question & you still can't figure out the answer? Here, try it again & see how you do:
....my "words" aren't necessary, only Einstein's "words" are necessary, I just don't disagree with anything in his GR, you're the one having the problem comprehending the contents of it as I quote excerpts directly from the document.
. Now old boy, give it another try.

You think that we have learnt nothing new since 1916?
Maybe you should get up to date, a LOT has happened since.
.........Again, like what? I answer your questions but you don't answer mine, I can only conclude that you have never taken a Nuclear Physics course, taken a final exam & gotten a passing grade, I have.

oxivape
Sep 13, 2017
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