evanb

9 ms·

91.
by evanb 2y ago
Good luck making your tenure case!
92.
by evanb 2y ago
pfd is not standard and is doing all the work---what is it?
93.
by evanb 2y ago
Molecules of nitrogen and oxygen both have a distinguished axis (along the bond), but because they're gaseous there's no reason to expect them to align throughout the atmosphere. So too with galaxies---which, from a cosmological p
94.
by evanb 2y ago
Now you’re talking efficiency—-certainly a wavelet transform may also work. But wavelets tend to be more localized than FTs.
95.
by evanb 2y ago
A cartoon: To form a coherent idea you need to coordinate a lot of tokens. In other words, ideas are long-distance correlations between tokens. Ideas are the long-wavelength features of streams of tokens. Is it exactly right? No. But as
96.
by evanb 2y ago
For an exception, Kebapland in Ehrenfeld, Cologne is in the shadow of the mainline rails to Aachen and on top of the Ehrenfeld U-Bahn. It has the hands-down best kebap (and euro-for-euro meal) found in Köln. This is not a paid endorsement,
97.
by evanb 2y ago
See, every rule has an exception.
98.
by evanb 2y ago
https://info.arxiv.org/help/submit_pdf.html explains all the constraints on direct PDF publication. If you disagree with their good reasons https://info.arxiv.org/help/faq/whytex.html to subm
99.
by evanb 2y ago
There are exceptions to every rule.
100.
by evanb 2y ago
You get a DOI on the arXiv. You can just publish the PDF on the arXiv, but this is a sure sign you are a crackpot.
101.
by evanb 2y ago
You will have a hard time constructing Markov Chain that correctly models the real-time evolution of physical quantum-mechanical observables. The problem is that the transition matrix that governs quantum-mechanical evolution is exp[i t H]
102.
by evanb 2y ago
> People did not like it at all that it was not about quantum physics. As a physicist: You would not believe how annoying it can be to find good information about actual quantum physics. It's not just WFC, people love to name stu
103.
by evanb 2y ago
If you want to study a quantum mechanical system in equilibrium at inverse temperature β, the interesting quantity is the partition function Z = tr exp[-β H]. This can be converted into a path integral Z = ∫ dφ exp[-S[φ]] which can be impo
104.
by evanb 2y ago
> Wouldn't the fact that entropy must increase mean that you can never get to the exact same state as you were before? What you're running into is the observation that near closed timelike curves quantum mechanics inevitably be
105.
by evanb 2y ago
A closed timelike curve is the name in General Relativity for a time machine: you go forward in time and wind up in your past, and you go around and around the loop forever. The point is that when you get to the same point in the loop your
106.
by evanb 2y ago
In 2016 India demonetized some bank notes (true, not the whole currency) https://en.wikipedia.org/wiki/2016_Indian_banknote_demonetis...
107.
by evanb 2y ago
... for the angular dependence; there is also radial dependence.
108.
by evanb 2y ago
> [I also declare] to have awarded and given 75 Carolus guilders of twenty stivers apiece per year as heritable annuity, to be paid one half of the annuity aforesaid on the 9 th of June 1625 and the other half the 9th of December followi
109.
by evanb 2y ago
Give LQCD practitioners resources on the scale of the experiment, the computations will get faster! I'm not sure what they mean by "Predictions rely on approximate analytical methods such as effective field theories." The pr
110.
by evanb 2y ago
Decoherence may be enough. The idea is that the starting wavefunction of us and some experiment (say, an electron) is a tensor product | us > ⊗ | electron in superposition > and unitary time evolution governed by the Schröd
111.
by evanb 2y ago
> There are infinitely many primes that can be formulated by squaring two whole numbers and adding them together. [...] By insisting that one of the numbers you’re squaring be odd, perhaps [...] makes the problem much harder. Does it?
112.
by evanb 2y ago
Not all consequences are punishments.
113.
by evanb 2y ago
The question is not whether a problem is easier to verify than to solve but whether there is a problem that is provably faster (in the complexity sense) on a quantum computer than a classical computer that is easy to verify on a classical c
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by evanb 2y ago
You can use Consentomatic to have it automatically handled. It's from Aarhus University, open source. https://consentomatic.au.dk/
115.
by evanb 2y ago
I've been telling my computational physics students that the best computation is the one they don't need to bother with.
116.
by evanb 2y ago
GIMPS is not typically targeting HPC, it is typically targeting hobbyists who have spare cycles to burn.
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by evanb 2y ago
The reason those lattice field theory computations are done that way is that they provide stochastic but polynomial-time algorithms for exactly the same kind of exponentially-large state space that appears in quantum chemistry.
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by evanb 2y ago
Computational physicists have been thinking about algorithms for simulating quantum systems essentially since computers were invented. We have decent algorithms for approximating ground states, or for systems in equilibrium (contingent on
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by evanb 2y ago
> The MUTR was constructed in 1960 by Allis-Chalmers, and upgraded to a TRIGA core in 1974. > the MITR-I was constructed back in 1956! The core was upgraded in 1974...
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by evanb 2y ago
There are functioning reactors at a variety of institutions. In College Park https://radiation.umd.edu/reactor/ In Cambridge https://nrl.mit.edu/reactor

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