> The implications of this are nothing short of a revision of Einstein’s theory of gravitation. Why the scientific community is in denial about the falsification of the dark matter model (...)
This is easy to explain. For Einstein's theory of gravitation you have the experimental evidence of every experiment every done, and against you have one guy with a half-baked argument.
Plus accusing the mainstream scientific community of "blindly and religiously believing in [...]" is a page taken directly from the Crackpot Index [1].
That's a pretty fun index. If you removed the bias of accepting the current cosmological model as consensus and read it like it was submitted by a grad student how many points would the dark matter & dark energy model accrue? Is it logically consistent to propose a model that requires such a large adjustment by the inclusion of variables that have never been experimentally proven to exist? Does this model rest on the laurels and works of Albert Einstein? "10 points for each new term you invent and use without properly defining it." Do dark matter and dark energy not qualify here?
IANAP (physicist) but using this index it's hard not to imagine another place in the multiverse where this dark energy/matter cosmological model receives a high score on this rubric.
Well, the Crackpot Index is obviously tongue in cheek, but also born out of frustration, I think. It must get tiresome for scientists to listen to cranks trying to "disprove" established science with bizarre theories and a complete disregard for the literature. You can address one, two, three of these people, but it soon becomes a bother and you're tempted to write the Index instead.
I agree it's probably very difficult to tell really novel and paradigm-shifting theories from the ramblings of cranks.
I suppose the Dark Matter model scores highly in some items of the Crackpot Index but very low in "the government is trying to suppress this", "everything they told you is a lie", and also the scientists who proposed it understood the established science and didn't randomly disregard it. I think the "conspiracy" aspect is what sets a crackpot apart.
Again, it's possible that a person is a crackpot AND he/she is also right about a particular theory!
Dark matter doesn't contradict general relativity, so it's entirely plausible that a) every experiment confirms Einstein, and yet b) we still need dark matter to explain some observations.
"Dark matter" is a synonym for "some unknown stuff that causes experiment to disagree with theory based on what we currently observe." It's not dark matter per se that contradicts GR, it is the experimental observations that require dark matter to be postulated in the first place that contradict GR.
No, there's nothing in the dark matter hypothesis or observations that necessarily contradicts GR.
However, it's true that some other theories that claim to explain the dark matter observations are in conflict with GR, which is why those theories are received very skeptically.
> there's nothing in the dark matter hypothesis or observations that necessarily contradicts GR
That is true for the "hypothesis" part, it is not true for the "observations" part. The observations do contradict GR. To be precise, they are at odds with the predictions of GR on the assumption that the universe is made entirely of ordinary matter. So there are two possibilities: 1) GR is wrong, 2) the universe is not made entirely of ordinary matter, i.e. there is "something else", which we call "dark matter". The problem is, there is no evidence for the existence of dark matter other than the observations that are at odds with the predictions of GR, and so the possibility that GR could be wrong still needs to be taken seriously at this point.
“The observations do contradict GR” and “the observations are at odds with GR under the assumption that the universe is made of ordinary matter” are two very different statements, and the latter does not imply the former.
You could also say that deviations in Uranus’s orbit contradict GR under the assumption that Neptune doesn’t exist. But Neptune does exist, so this isn’t really a statement about GR at all.
The difference is that Neptune is there, indeed, was discovered because it was exactly where Newtonian mechanics predicted it would be. The situation here is completely different because all of the plausible hypotheses about the nature of dark matter have been tested and falsified. The only thing left is "some weird stuff that is fundamentally unlike anything we have ever observed before". It is more analogous to the luminiferous aether than to Neptune. If that doesn't count as contradicting GR, at least potentially, then nothing contradicts anything because you can always resort to this kind of special pleading to explain any observation under any hypothesis.
I'm not suggesting it, those were literally the exact words that I wrote.
Of course, that claim turns entirely on the meaning of "plausible", so I'll amend my claim to simply say that all attempts to detect dark matter to date have failed.
I’m no expert in this area, but my understanding is that weakly-interacting particles aren’t “something we’ve never seen before”, and in fact the neutrino is an excellent example of such a particle. However the neutrino isn’t a candidate for the specific particle causing the observed effect because the distribution of observed effects on normal matter would look different, hence the search for more massive particles: a search that is very much at its early stages.
> weakly-interacting particles aren’t “something we’ve never seen before”, and in fact the neutrino is an excellent example of such a particle.
That's right. But the only reason we know about the neutrino is that it was predicted by theory.
> However the neutrino isn’t a candidate for the specific particle causing the observed effect because the distribution of observed effects on normal matter would look different, hence the search for more massive particles:
Correct again.
> a search that is very much at its early stages.
That depends on what you consider "early". There are only so many places in the standard model that wimps can be hiding, and the vast majority of them (if not all of them -- I haven't been keeping up with the latest developments) have been ruled out.
Which is odd, because by far our best experimentally verified theory is also in conflict with GR. Our measurements for QED are orders of magnitude more accurate, so I'm inclined to believe GR is the incorrect theory.
Some of our measures of QED are very accurate (10 decimal places give or take), but the measurements QCD are much more complicated and the theory doesn't produce nearly as clean values. Also, there are purely QED experiments (muon G2 for example) where there are some serious contradictions.
I don't believe we have yet managed to conduct an experiment to detect dark matter. We have observations that seem to contradict Einstein, but no experiment that concludes. I believe a couple of experiments are currently underway, exciting times.
The theory of gravitation is not at question here, it is in fact the basis for proposing the existing of some yet-unseen matter to account for why the observed galaxies behave. Someone proposing that there is no such thing as the thing we have never observed is... a pretty "baked" argument.
I would like to toss my own idea into this discussion. This idea incorporates a mechanism that would explain why gravity might slightly deviate from Newtonian and/or GR in some circumstances.
This paper also adapts GR in such a way that it is consistent with galactic rotation rates, the anisotropies of the CMB, and cosmological expansion -- while showing that the simple operation of gravity is the cause of each of these phenomena.
Cyclic Gravity and Cosmology (CGC) predicts that there are discrete specific sizes allowable for macro-objects. The instability of Bennu and the fact that it behaves more like loosely held scree rather than a compact mass -- is an example of a mass that is not exactly at one of the discrete allowable sizes. Please also refer to the link I included wherein I uploaded a video simulation of the formation of a solar system using this type of force law. (This is in section 18 of the paper)
I would greatly appreciate any comments on this idea. Copies may be downloaded here:
Actually, the hard thing about dark matter is that the arguments for it and the arguments against it are both relatively compelling. No matter how this shakes out, we're going to have a very different view of the universe when we finally understand what is really happening.
“Fudge factor” massively undersells it. For instance, measurements from the bullet cluster are quite compelling that there is significant mass in a galaxy that we don’t directly measure. That’s the definition of dark matter.
We don't understand why our numbers don't add up so we made up a number to explain it is "compelling" to you?
Dark matter has always reeked of "ether" to me. I looked into some of the alt science on this a long time ago. There is a compelling case that our model of gravity is wrong. Fortunately gravity is such a weak force that at small ie solar system scales it doesn't matter. Which is why we can launch satellites around the system. However the failure shows at large scale like galaxies.
Dark matter isn't just a made-up number. It's an observed phenomenon that MOND and other modified-gravity theories cannot explain.
It is an observable fact that dark matter is a distinct substance from baryonic matter. Modified gravity is thoroughly disproven by the many galaxies that have been discovered that have been separated from their dark matter[1], or seem to have never had any in the first place [2]. A galaxy can't be separated from, or be lacking in, something that doesn't exist.
Any attempt to dismiss dark matter entirely without addressing this highly conclusive evidence is not valid.
Its been a very long time since I looked at any of these stuff and I'm certainly not a subject matter expert. I just remember reading about it and the entire idea of dark matter and dark energy came from the fact that the math models they had at the time didn't add up. They needed a way to rectify the math and they did it by saying well if we put this LITERALLY made up number in the equations everything balances out. Then they made up the explanation as to why this number needed to exist as "dark matter/energy" There have been mountains of research made trying to prove this since then that muddy the water of how flimsy the origin was.
Dark matter has always smelled of phlogistons to me. It's this mystery substance that solves all of our problems, and doesn't make any predictions. I have no idea what a more accurate explanation for the observations would look like, but dark matter can't be it.
The thing is, it's an extremely simple mechanism which solves all our problems at once. Everything that's currently explained by that of one extra particle, would need separate explanations without dark matter; general relativity + dark matter fits all the data we have. It's not just about galaxy rotation speeds, it's about observations of gravitational mass (as measured by lensing) moving independently from the visible mass, it explains structure formation in the early universe, and other stuff.
It's such a simple explanation which explains so many otherwise unexplained things that I feel we should have pretty strong priors that it's true.
It does make the prediction that there's a lot of detectable massive particles out there. That's not a prediction which is easy to test, but to say there are no predictions isn't right.
My point is that the same could be said about phlogistons back in the day. There were a lot of completely different advances in the understanding of physics and chemistry needed to explain combustion and oxidation, and it's a lot more complex than just saying "because phlogistons". It was an extremely simple mechanism which solved all the problems at once, and fit all the data available at the time.
And it doesn't explain anything! We have this entirely new substance and we don't know what it is, what it's made of, where it came from, or why we only have circumstantial evidence for its presence.
It does seem like that, and so there have been many attempts to revise the math to make it fit all known observations. But nobody has been successful, and so dark matter remains, at the very least, by far the best explanation we have. It fits the data.
To use an analogy from the world of finance, that sounds like building a Balance Sheet model that "plugs" Retained Earnings so that Assets and Liabilities always balance. Of course it fits the data, its very existence is to explain away the part of the model that doesn't fit the data
Dark matter is not just an imaginary number that fills some holes in math. It is a thing that has been observed. Galaxies can have it or not have it. Galaxies can be separated from it in collisions. You can't be separated from something that doesn't exist.
This article has introduced me to "Modified Newtonian dynamics", which is a field of study I didn't know existed. The premise is pretty obvious now: Newton was pretty cool and all, but he wasn't right about high acceleration environments. Why then should we presume that he was be right about low acceleration environments, when the observations don't fit the predictions? The fact that nobody has come up with an answer doesn't mean there isn't any, and at least these people are actively trying to come up with one. I understand why the author appears to be very frustrated -- I'd be frothing-at-my-mouth angry in his position.
But that's my point. If the strength of the force is constant, independent of distance, then the farther away quarks contribute the same as the nearer quarks. In other words, distance doesn't matter, whether something's farther away or closer has no bearing on the strength of the force.
The UI, the user interface, is the part of a system that you directly interact with. The UX, the user experience, is what it's actually like to use it, which is affected not only by the UI but also by other parts of the software.
"When I press this button, nothing happens for five seconds and then it displays the results." Bad UX. Probably partly the UI (if something might take a while, the UI should at least show some sign that something is happening, preferably in a way that gives some clue how long you're likely to be waiting). Probably partly not the UI (maybe the reason it's five seconds rather than 0.1 seconds is that the internals of the program are doing something time-consuming; maybe that's unavoidable, maybe a better algorithm would fix it. Or maybe it's waiting for a server somewhere else, and maybe smarter cacheing would help. All of that is UX, none of it is UI.)
"When I open the app, the first thing I see every time is an annoying popup inviting me to buy the premium version. I have to close it every time." Bad UX, at least from the user's point of view (it might be exactly the experience the business folks want users to have). I suppose the popup is part of the user interface, but the actual problem here is a business decision (advertise at users in the hope that they will be convinced and/or pay just to make the advertisement go away) that's contrary to users' interests. The best UI designers and implementers in the world won't change this.
"This thing is incredibly confusing to use". Bad UX. Might be the result of bad UI (e.g., no one has thought through how the menus should be organized). Might be because the underlying software is designed in a way that doesn't fit this user's brain, and changing this would need deep changes to the insides and not just UI changes.
UI is specifically about the points of interaction between the user and the system. UX is about the entire, holistic experience of using the system, whether interactive or not.
UX (User Experience) is more about the process a user goes through. UI is more about the visual or physical elements a user interacts with.
For example, imagine you're designing about an online account creation flow.
The UX design would be deciding to identify people using email address, and then giving them the option of setting a password or logging in with a magic link to an email address[1].
UI would be about how you present that on screen. What is the layout? How do you make the two different choices clear, how do you indicate an invalid email address etc.
[1] Obviously there are other considerations here than UX such as security, but we're just talking about UX
They are related and probably sometimes overlapping. But you can think of UX as "what happens when a user clicks this button" and UI as "what color should the button have".
A user interface needn't be all visual (e.g., in a device with physical buttons, the buttons are part of the UI).
Some visual things might not be best thought of as part of the UI (e.g., if you have a piece of software for making publication-quality graphs, and when you ask it to plot a smooth curve through some points it does a lousy job of picking the smooth curve you actually wanted, arguably that's a visual matter but it isn't really part of the user interface, it's about the algorithms underneath).
It's not really how the work is split in bigger commercial teams. The folk fixing the layout bugs aren't the folk who designed the page aren't the folk who designed the flow. I like to avoid big teams but even for me UI/UX mean very different things, you can find this split even on relatively small teams
A 2-3 person team might have frontend/UI/UX being the single 'frontend developer'
A 5-7 person team might have one or more frontend people and one UI/UX person living in Adobe suite all day
Maybe the 7 person team is receiving storyboards from a parent team where all the UX work was done centrall across several 5-7 person teams.
TFA is about evidence of efforts to change the definition of a word which is both prescriptive and descriptive.
Please fulfill your own need for evidence without interjecting this where a valid conversation already exists.
Pedants don't think they're pedants. Like Carlin said, anyone driving faster than you is a maniac, anyone driving slower is a moron. (Anyone less rigorous than you is sloppy, anyone more is a pedant.)
It's a mindset shift to a more declarative model. The idea has also popped up in other niche orchestrators.
This is an oversimplification but IMO the easiest way of picturing it is instead thinking of defining your graph as a forward moving thing w/ the orchestrator telling things they can be run you shift to defining your graph nodes to know their dependencies and they let the orchestrator know when they're runnable.
