i recently saw a paper that called into question the expansion of the universe. i think it was by a man called eric lerner. he provided evidence that seemed pretty convincing. is there anything to this?
Breakthrough Announced in Dark Matter Detection Technology
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Re: Breakthrough Announced in Dark Matter Detection Technology
#32I hope they detect nothing. I'm rooting for modified gravity theories.
I'm curious, why would you root for anything in particular?
Why do people root for anything? Emotions, aesthetics, etc. You can't always stop yourself from having that reaction, so you may as well let it out. Myself, I'm rooting for the spacetime-from-entanglement family of quantum gravity theories, because they're frickin cool.
Re: Breakthrough Announced in Dark Matter Detection Technology
#33Earlier quoted context omitted.
> Some would disagree Some do, but they're in the minority (which, to be clear, doesn't necessarily make them wrong). You can find scientists who refute climate change, too. That says nothing of the state of prevailing consensus, though.
> You can find scientists who refute climate change, too. That's an appeal to nature as well as a false equivalency. It is difficult to refute climate change because we have incredible amounts of tactile observations that match predictions - the stuff from which the scientific method stems. At one point science (well, philosophy as the progenitor of science) said that the Earth was flat. It was a small number of rebe…
> We didn't do that, which is why we can do so many useful things with heavier elements today.
This article is literally about the development of new sensor technologies designed to make that kind of progress for dark matter.
It seems you just have a chip on your shoulder and a complete misunderstanding of the concept of dark matter.
Re: Breakthrough Announced in Dark Matter Detection Technology
#34Earlier quoted context omitted.
> You can find scientists who refute climate change, too. That's an appeal to nature as well as a false equivalency. It is difficult to refute climate change because we have incredible amounts of tactile observations that match predictions - the stuff from which the scientific method stems. At one point science (well, philosophy as the progenitor of science) said that the Earth was flat. It was a small number of rebe…
> We didn't do that, which is why we can do so many useful things with heavier elements today. This article is literally about the development of new sensor technologies designed to make that kind of progress for dark matter. It seems you just have a chip on your shoulder and a complete misunderstanding of the concept of dark matter.
> This article is literally about the development of new sensor technologies designed to make that kind of progress for dark matter.
Which is exactly what the last paragraph in my comment addresses.
Re: Breakthrough Announced in Dark Matter Detection Technology
#35i recently saw a paper that called into question the expansion of the universe. i think it was by a man called eric lerner. he provided evidence that seemed pretty convincing. is there anything to this?
Looks like he's one of the electrical universe proponents.
Re: Breakthrough Announced in Dark Matter Detection Technology
#36Earlier quoted context omitted.
> Some would disagree Some do, but they're in the minority (which, to be clear, doesn't necessarily make them wrong). You can find scientists who refute climate change, too. That says nothing of the state of prevailing consensus, though.
> You can find scientists who refute climate change, too. That's an appeal to nature as well as a false equivalency. It is difficult to refute climate change because we have incredible amounts of tactile observations that match predictions - the stuff from which the scientific method stems. At one point science (well, philosophy as the progenitor of science) said that the Earth was flat. It was a small number of rebe…
> It is difficult to refute climate change because we have incredible amounts of tactile observations that match predictions
And yet people try. If this were a discussion on climate change, someone could link to a scientist trying to refute it and say "some disagree." We both agree that linking to a single blog post that refutes climate change would be unconvincing. Why hold this topic to a different standard?
> The so-called "evidence" that is continuously regurgitated is an image of the problem.
That's what evidence is, isn't it? Then scientists get to solve the mystery that's revealed by the evidence. Just like detectives solve a crime based on evidence at a crime scene. Evidence can precede answers.
Having evidence doesn't mean we've figured out what dark matter is. It means we can put constraints on possible explanations. So far, scientists have ruled out several theories, because they don't fit the evidence.
> As it stands, there is zero credible and scientific evidence for the stuff.
If there were no evidence, there wouldn't be a mystery to solve.
Re: Breakthrough Announced in Dark Matter Detection Technology
#37What frequency range are they scanning?
Re: Breakthrough Announced in Dark Matter Detection Technology
#38Earlier quoted context omitted.
Modified gravity theories don't fit all the evidence, such as the distribution of mass in the Bullet Cluster [1] or the large-scale structure of the CMB [2]. [1] https://en.wikipedia.org/wiki/Bullet_Cluster [2] https://en.wikipedia.org/wiki/Dark_matter#Cosmic_microwave_b...
Some would disagree: http://backreaction.blogspot.com/2018/04/no-that-galaxy-with... As a non-scientist, it seems like dark matter has been relentlessly adjusted and overfitted and still appears very inadequate to fit all the evidence.
> As a non-scientist
Unfortunately you're missing the thrust of Hossenfelder's developing argument: in upgrading MOND to a full relativistic theory, you necessarily seriously blur the difference between "modified gravity" and "particle dark matter".
There's some meat on this in the comments on that blog page, notably the point raised (and her subsequent reference to it) by "M_Malenfant".
Essentially her point is that when you relativize some theories of MOND (detailed examples in Famaey & McGauch https://arxiv.org/abs/1112.3960 section 7) you are inevitably adding a field to the existing fields. Whether you put it on the right or the left of the Einstein Field Equations is a matter of personal taste. The thoretical requirements however are that the field couples with matter somehow (even just gravitationally), just like the particle dark matter case (where particles may interact weakly or even just gravitationally). Moreover, when you have a dynamical, relativistic field like this, you tend to think of how to quantize it, which typically means particles as the field content and particles mediating the interaction between that and the field content of the Standard Model.
So, as she says, perhaps it's more a question of sociology than mathematics that splits particle dark matter theorists (solving cosmological problems like the details of the cosmic microwave background and its neutrino equivalent, or solving problems with the Standard Model like the QCD strong CP problem) or from modified gravity theorists (solving velocity curve problems). At some level, almost all of the still-viable proposals for these and related problems boil down to adding a field on curved spacetime.
On the other hand -- and this is where Hossenfelder (among others) deserves some credit -- this wouldn't have been quite so obvious ten or so years ago, let alone in the early 1980s when Milgrom began developing MOND.
Re: Breakthrough Announced in Dark Matter Detection Technology
#39Earlier quoted context omitted.
Modified gravity theories don't fit all the evidence, such as the distribution of mass in the Bullet Cluster [1] or the large-scale structure of the CMB [2]. [1] https://en.wikipedia.org/wiki/Bullet_Cluster [2] https://en.wikipedia.org/wiki/Dark_matter#Cosmic_microwave_b...
Some would disagree: http://backreaction.blogspot.com/2018/04/no-that-galaxy-with... As a non-scientist, it seems like dark matter has been relentlessly adjusted and overfitted and still appears very inadequate to fit all the evidence.
>relentlessly adjusted and overfitted and still appears very inadequate to fit all the evidence
Welcome to physics. The Copenhagen Interpretation is the most concise and robustly tested theory in all of physics. Yet it was dreamt up by a literal absurdist who thought that the universe itself has no objective state of existence. For all we know about the universe, we can still not answer many of the most basic questions about it. The lesson to be learnt from this is that our greatest theories are at best woefully incomplete, and that even our greatest scientists don't have the ability to talk about many things with any level of objective certainty.
Re: Breakthrough Announced in Dark Matter Detection Technology
#40Earlier quoted context omitted.
Some would disagree: http://backreaction.blogspot.com/2018/04/no-that-galaxy-with... As a non-scientist, it seems like dark matter has been relentlessly adjusted and overfitted and still appears very inadequate to fit all the evidence.
>relentlessly adjusted and overfitted and still appears very inadequate to fit all the evidence Welcome to physics. The Copenhagen Interpretation is the most concise and robustly tested theory in all of physics. Yet it was dreamt up by a literal absurdist who thought that the universe itself has no objective state of existence. For all we know about the universe, we can still not answer many of the most basic questio…
Incomplete in very extreme conditions such as the interiors of black holes or the first instants after the Big Bang. I’m not really sure that’s “woeful” in a sense that matters to almost anyone other than a particle physicist or a cosmologist. For example the confidence in QED has been tested and found that the theory makes accurate predictions to within 10^-8.
I’d also argue that you’re substituting “basic” for “fundamental” and that’s bordering on dishonesty. We don’t have answers to some of the. OST fundamental questions, assuming we’re even asking the right questions, but the basics are well covered.