semajian · HackerTrans

2 lata temudiscuss

I had the same issue with ingesting lots of csv files in a previous version (8.x), though it seemed to be hardware dependent; issue was only on windows not Ubuntu. I think setting the number of threads to low value helped. I had hoped these issues would be solved by v 0.10 but I am nevertheless a big fan of duckdb.

semajian

3 lata temudiscuss

I think Wolfram came up with some new theory of everything based on hypergraphs a couple of years ago, not sure what the current status is though. I would be surprised if it ever becomes a useful theory but hypergraphs are certainly interesting and worth studying.

semajian

3 lata temudiscuss

A quick look at the plots make me think this paper is legit and lk-99 is not a superconductor. Nice plots covering down to low temperature, unlike the original lk-99 papers which always seemed bizarre to me.

semajian

3 lata temudiscuss

Well, yes

semajian

3 lata temudiscuss

It's hard to imagine how this could be faked short of digital manipulation, and it seems implausible that it would be a known high TC superconductor because it would warm up too fast. Absent the former explantation, I'm starting to believe this is real. Also, it's not like all the author's are unknown hacks. Hyun Tak Kim has about 10k citations (Google scholar, which sometimes combines people who have the same name though) and authored a paper in scientific reports which got L&K interested in collaborating with him. The guy seems to know superconductivity so I'm feeling rather optimistic about this.

semajian

3 lata temudiscuss

Thanks for linking someone who knows what he's talking about, very painful to see these DFT papers overhyped as some kind of proof... It proves almost nothing

semajian

3 lata temudiscuss

It's basically an open secret, no one really believes DFT has much predictive power in strongly correlated systems (where relevant electrons cannot be treated as independent). It's not useless, but DFT calculations require many arbitrary choices and are hardly "first principles" in a meaningful way.

semajian

3 lata temudiscuss

There are so many bad DFT papers out there because it's cheap to do DFT compared to growing and measuring samples carefully. DFT is notoriously unreliable as a predictive tool in strongly correlated systems, though when electron correlations are small it works well. I mean, I want this to be true, but I put little stock in DFT that doesn't calculate observables. So yes, you're right.

semajian

3 lata temudiscuss

A bit too wordy for me, I wish Landau was around to rewrite books like these, they'd be much shorter. Can we get a LLM to make it happen?

semajian

7 lat temudiscuss

The standard model is basically a description of the fundamental forces, and is usually talked about by particle physicists studying things like the Higgs, quarks, etc. In condensed matter (materials) the only relevant interactions are electromagnetism and quantum effects, strong and weak interactions play no role because of the length scales at play (angstroms to nm) and the energy scales (meV to eV). Superconductivity involves phonons (vibrations) and electrons, at least in BCS, so you will never really find anyone discussing the 'Standard model' and superconductivity because the former is fundamental, while superconducting materials require consideration of emergent and many-particle effects which come about by having so many particles in a solid. Not sure I cleared anything up but hope that helps.

semajian

7 lat temudiscuss

Yes, well said.

semajian

7 lat temudiscuss

I've never come across a physicist who used the term "inertia" to refer to any of the common relativistic quantities.

semajian

7 lat temudiscuss

Mass is a Lorentz scalar and thus is invariant; the mass of relativistic particles does not increase as velocity increases. One can say the force necessary to keep a constant acceleration increases as velocity increase. This is a common misconception, and it appears even NASA engineers don't understand this. This is not science.

semajian

7 lat temudiscuss

I guess the most prominent counterexample is Germany, which has basically free tuition. They also have different kinds of high schools preparing people for universities or trades, not everyone needs to go to university.

semajian

8 lat temudiscuss

I've never seen a number that high in my field, maybe 500 or 600 for the big shots, and even that seems wildly unreasonable to me. Feynman had about 85 peer-reviewed papers over his lifetime, which is less than two per year during his career, which is a very reasonable number.

Authorship and citations are basically academic currency, and as such have undergone inflation just like real currency. Professors get their name on a paper as a form of payment for future or past services to other professors (often related to funding). There's just no incentive for anyone to stop this as far as I can't tell, and appealing to ethical conduct in authorship and citations is not enough.

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