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A new experiment casts doubt on the leading theory of the nucleus

quantamagazine.org

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Re: A new experiment casts doubt on the leading theory of the nucleus

#111

Post by godelski »

jfengel wrote: post #94
godelski wrote: post #27

Earlier quoted context omitted.

Experimental physics works a bit differently than most people think. While string theory was/is popular, very few hold it as certainty. From the very beginning the discussions around it were that it was a non-testable theory. While out-group conversations around physics are "physicists believe" in-group conversations are more "the leading theory is". Uncertainty is deeply ingrained in the study and the focus is more…

I don't get why the arguments are confined to string theory. The standard model plus general relativity are so good that any theory that resolves the conflict is necessarily only testable when you've got a stellar mass black hole in your lab. That could be a call to stop bothering with exploring the domain entirely as infeasible. But I don't understand why string theory gets singled out for finger waggling when any o…

No serious physicist only considers String Theory. That's part of the point I was making. Really String Theory is only a guide used while we wait for something better and more testable to come along. Nothing is set in stone, they are just guides to being less wrong.

Re: A new experiment casts doubt on the leading theory of the nucleus

#112

Post by cyberax »

jcranmer wrote: post #39
cyberax wrote: post #35

Earlier quoted context omitted.

The problem with the nucleus is that the internal dynamics there are impossible to describe with any reasonable precision. If for the electron shell we can calculate pretty much anything we want from the first principles (energy spectra, the half-lives of unstable and metastable states, etc.), we can't do anything similar for the nucleus. For example, we can't compute half-lives of unstable nuclear isotopes. The best…

> If for the electron shell we can calculate pretty much anything we want from the first principles (energy spectra, the half-lives of unstable and metastable states, etc.), we can't do anything similar for the nucleus. As I understand it, we can only really do that for a single-electron atoms. Multi-electron interactions get the same problem as inside the nucleus.

> As I understand it, we can only really do that for a single-electron atoms.

We can do it analytically for single-electron atoms. We can solve it numerically for much larger systems.

Re: A new experiment casts doubt on the leading theory of the nucleus

#114

Post by consilient »

oneshtein wrote: post #67
lilgreenland wrote: post #14

Earlier quoted context omitted.

They also go wrong with large scale phenomena like inflation, dark matter, and dark energy.

IMHO, "Inflation" is false theory, because it doesn't obey law of conservation of energy. If no inflation, then no Big Bang, so our Visible Universe is much older. If our Universe is much older, then life evolved multiple times already. Red stars are shallow gravity wells, so they are primary target of an expansive civilization, because it easy to enter/exit them, so they are colonized first and their light is captur…

> because it doesn't obey law of conservation of energy.

Energy is in general only conserved locally. More precisely, the covariant derivative of the stress-energy tensor `\nabla_{\mu}T^{\mu \nu}` is zero, but this can only be put into integral form in a few special cases.

Re: A new experiment casts doubt on the leading theory of the nucleus

#115

Post by 6nf »

denton-scratch wrote: post #72
6nf wrote: post #56

Earlier quoted context omitted.

'everything that underpins daily life' does not include everything in the universe, for example it excludes dark matter and dark energy, neither of which matter at planetary scales like here on earth.

> neither of which matter at planetary scales like here on earth ...except, isn't it true that the galaxy that contains the earth wouldn't exist were it not for dark matter?

There's nothing preventing the formation of galaxies, stars and planets if you take away dark energy. Dark matter is not as clear cut but it's still likely to be unimportant.

Re: A new experiment casts doubt on the leading theory of the nucleus

#116

Post by oneshtein »

Thiez wrote: post #76
oneshtein wrote: post #67

Earlier quoted context omitted.

IMHO, "Inflation" is false theory, because it doesn't obey law of conservation of energy. If no inflation, then no Big Bang, so our Visible Universe is much older. If our Universe is much older, then life evolved multiple times already. Red stars are shallow gravity wells, so they are primary target of an expansive civilization, because it easy to enter/exit them, so they are colonized first and their light is captur…

Cool story. Now explain why almost everything we see is moving away from us, where fresh hydrogen for stars comes from in an ancient universe, where the cosmic background radiation comes from, why the distant universe appears 'younger'... Note that the 'laws' of physics are no better than normal scientific theories, scientists just had more hubris back then.

> Now explain why almost everything we see is moving away from us

(Not a native speaker).

Most galaxies in our galaxy cluster are moving away from us because of coincidence: Shappley attractor makes accretion disk by attracting mater from Dipole Repeller void[0], so our local group of galaxies is stretched along the way. At scale of our local galaxy cluster, Doppler Shift is responsible for majority of Red Shift.

At cosmic scale, Red Shift cannot be explained by Doppler Shift alone. If we take into account gravitational waves, then at least part of Red Shift can be explained by gravitational noise: gravitational waves are slowing down light a bit, so photon loses tiny bit of energy with every such interaction, which causes major part of Red Shift at cosmic scale.

> where fresh hydrogen for stars comes from in an ancient universe,

This is though question which is hard to answer. If elementary particles are bubbles, then they are popping up because something is stretching our Universe, i.e. our Universe is inflating ... oh, fck.

> where the cosmic background radiation comes from

[If inflation theory is false, no Big Bang, and visible Universe is much older, then] Cosmic microwave background is just light from distant galaxies with large Red Shift z=1000 (light was stretched about 1000 times from galaxies in range of about 4 trillion light years).

> why the distant universe appears 'younger'...

James Webb infra-red telescope is proving that this assumption is false right now. Read the news.

[0]: https://www.youtube.com/watch?v=1mQr6mzmzbU

Re: A new experiment casts doubt on the leading theory of the nucleus

#117

Post by rcxdude »

orra wrote: post #106
rcxdude wrote: post #58

Earlier quoted context omitted.

The operation of a D-type flip-flop and NAND gates explains everything in computers upwards of digital logic. What else is there to explain or explore in software?

Mmm, I don't agree with your analogy. Yes, you can model things at a higher level, but surely that is for efficiency, not because the model breaks down, in terms of accuracy. In contrast, there are phenomenon which we know standard particle physics and quantum mechanics gives the wrong answere (despite getting so much else right).

higher-level models are not just for efficiency (though they are mandatory for that: quantum mechanics is intractable to solve directly for even a carbon atom). They also are important for understanding. These two problems are much bigger in terms of applying the standard model for the purposes of 'explaining everything' than the problem of the edge cases it does not explain accurately even in principle.

Re: A new experiment casts doubt on the leading theory of the nucleus

#118

Post by hjkl0 »

enkid wrote: post #79
jxy wrote: post #28

The fundamental theories we have is Quantum Electrodynamics and Quantum Chromodynamics. This new experiment tells you that "modern nuclear forces, including those derived within chiral effective field theory" break down and cannot be used to describe what they observed. Here is the arxiv: https://arxiv.org/abs/2112.10582 It just tells you that their effective theory is no longer effective in these circumstances. Unle…

A title of "theory mostly sound, except some extreme edge cases," would cover about 95% of science research.

You think that 95% of science research is news worthy?

Re: A new experiment casts doubt on the leading theory of the nucleus

#119

Post by enugu »

rambojohnson wrote: post #104
jxy wrote: post #28

The fundamental theories we have is Quantum Electrodynamics and Quantum Chromodynamics. This new experiment tells you that "modern nuclear forces, including those derived within chiral effective field theory" break down and cannot be used to describe what they observed. Here is the arxiv: https://arxiv.org/abs/2112.10582 It just tells you that their effective theory is no longer effective in these circumstances. Unle…

why do we clutch pearls whenever a publication uses a "click-baity" title? at least it manages to a: get people to actually read the publication, and b. publisher/site makes money. nobody's running a charity of information in a capitalist society.

Having an standard of truth is important as a reputation for an organization(whether for commercial or non-commercial reasons). Besides, click-baitiness is not sustainable as in the equilibrium, readers will change expectations to assume artices are click-baity and information on the real breakthroughs will have fight all the fake breakthroughs.

BTW, This is not about Quanta which I find is a really good resource. Although, there might indeed be some click-baitiness not with the motive of profit(you could describe it as a charity run by Jim Simons), but in the sense of someone trying to get students interested with a provocative title for a science talk.

Re: A new experiment casts doubt on the leading theory of the nucleus

#120

Post by rambojohnson »

enugu wrote: post #119
rambojohnson wrote: post #104

Earlier quoted context omitted.

why do we clutch pearls whenever a publication uses a "click-baity" title? at least it manages to a: get people to actually read the publication, and b. publisher/site makes money. nobody's running a charity of information in a capitalist society.

Having an standard of truth is important as a reputation for an organization(whether for commercial or non-commercial reasons). Besides, click-baitiness is not sustainable as in the equilibrium, readers will change expectations to assume artices are click-baity and information on the real breakthroughs will have fight all the fake breakthroughs. BTW, This is not about Quanta which I find is a really good resource. Al…

agreed. It's a fine line that publishers have to walk between capturing attention and maintaining credibility. As you've said, the long-term sustainability of clickbait is questionable. It's a short-term strategy that may inflate traffic numbers, but can lead to a loss of trust over time.

The challenge is to strike the right balance between making content appealing and keeping it accurate and valuable, especially crucial with scientific publications, where the accuracy and trustworthiness of information is paramount.

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