gmkiv

Joined 6 years ago

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Sep 7

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Oh, he's so close! He's already constructed an electroscope. Now he just needs to use that to perform Cavendish's experiment, and he'll have verified Coulomb's law.

Comment · 3 years ago

How does ALiBi compare to rotary positional embeddings? That method makes similar claims. I find ALiBi much easier to understand, but that’s probably not the best reason to chose it over other methods.

Comment · 3 years ago

> I'm not sure if Burton was a Luddite who didn't believe in statistics or the scientific method, or if he didn't care about learning from his tests.

It's possible. It's also possible that he had a good sense of how test results are presented by program managers to Congress, and was trying to accurately convey the situation. Congress typically doesn't have time to delve into the details of the test, they get top-line results like "the Bradley did not catch fire when shot by an RPG" even though the footnotes would talk about the water in the tanks.

More generally, there is a tendency even today to make test results look good through judicious selection of test conditions. Program managers will refuse to do tests where "we already know the answer" - but only when we think the system won't work. We do plenty of tests when we have high confidence the system will work. So you get headlines like "86 of 105 hit-to-kill intercept attempts have been successful" [1], without the context that we never attempted the shots that we think we would miss, even if those scenarios are tactically important.

I'll grant that there are several motivations for testing like this, but let's not pretend that they are all purely technical.

[1] https://www.defense.gov/Portals/1/Interactive/2018/11-2019-M...

Comment · 4 years ago

The link you provide seems to say that the cost of wholesale PV + storage is $85-$158 (bottom figure, line 3). Am I misreading that?

I’ve noticed that many solar+storage installations these days are 4-hour storage, so not sufficient for baseload. I think the number would be higher if we were shooting for baseload from our storage.

Comment · 4 years ago

It's not obvious how to translate this figure into a standalone plant cost. The COB study is quoting the acquisition cost premium of a nuclear ship over a non-nuclear ship. I believe that estimate is the premium for taking a non-nuclear design and adding a nuclear reactor to it, so it does not include a lot of plant infrastructure that is part of the cost of civilian power stations. Also I would think the requirements for the containment structure and safety systems would be significantly different.

Comment · 4 years ago

They don't want to exacerbate racial disparities, which is noble. They could have used that as their sole justification, but for some reason they also try to say that the crime datasets are inaccurate. Their reasoning for this is surprisingly weak. Regarding the National Crime Victimization Survey: "And there are troubling signs of this [racial bias]: in the 2019 survey, people reporting crimes were more likely to describe their offender as young, male, and Black than would be expected given the representation of those groups in the population."

Comment · 5 years ago

The value is to inform the larger discussion of the risks and benefits of gain of function research.

Comment · 5 years ago

The state (phase) of the received photon will depend on the position of the receiver. Even if you have a perfect quantum hard drive, you still need to maintain the position of your receivers to within a wavelength. That will be hard to do if they are separated by a long distance.

Comment · 5 years ago

I shudder to think of the difficulty in maintaining phase coherence at optical wavelengths for the baselines they mention in this article.

Comment · 5 years ago

The directive to strike a positive tone could be nefarious or benign; we can’t tell from the info in the article. Every research paper has a tone that depends on the personality of the author - I’ve seen it even in my dry field of quantum optics. Every result has many implications and how you discuss them, which implications you emphasize, and the language you use will affect the tone, even if you are not explicitly furthering an agenda. A given article could have a range of legitimate tones, depending on who wrote it. Asking a researcher to be on the positive end of the legitimate spectrum is benign. It can of course go to far.

Comment · 6 years ago

I happen to agree with you, the observer is a quantum system must get entangled with the quantum system, but that still doesn't explain probabilities. If you prepare a system - say sqrt(1/3) spin-down + sqrt(2/3) spin-up, and then observe it, repeatedly, your subjective experience is that you saw spin-down 1/3 of the time, and spin-up 2/3 of the time. I don't understand how purely unitary evolution can explain this. Does it?