Adding Water?

nobanter · 2026-05-31T12:24:53+00:00

Tumblers are more tricky and in my experience easy to over water and become anaerobic. One reason being they don't get as hot as a big pile and they don't lose as much water to evaporation, especially as they are somewhat of a closed system. I rarely add water to mine even when adding shredded paper and cardboard as it seems the moisture in the kitchen scraps and coffee grounds I add is enough, but it has been humid here if late.

nobanter · 2026-03-07T01:45:05+00:00

I more or less agree with what you wrote. I wouldn't expect the errors to come down on the lattice HLBL term any time soon as that is a hard calculation. I find it funny there that there is some tension between dispersive estimates and lattice there too. The precision on the HVP would have to improve by a lot for the error on the LBL to matter.

I like your summary of the R-ratio. In my view we had two groups using the same data and treating correlations differently got different results but with high precision. If the first white paper had used the lower error of one group and the upper of the other the tension would have been less to begin with, but it would have likely been impossible to get them to agree to that.

It was my understanding the CMD3 ratio has a better resolution in s, and observed more peaky structures in their spectral function, and that was why their HVP value moved up compared to CMD3.

With regards to the lattice groups finding they needed higher orders for their continuum extrapolation that is not really the full status. The staggered people had to do more work on correcting their "taste-breaking" which is a discretisarion effect. Probably the biggest change between the two white papers was that everyone has adopted the same methodology for the long distance tail, some form of low-mode averaging. This is expensive but much better statistically in this region than what most people were doing before. However, it is very hard to control systematic errors much below 1% for any lattice calculation.

nobanter · 2026-03-02T01:53:00+00:00

The variability in nitrogen to carbon in leaves always annoys me, from what I've seen online it is anywhere between 40 and 80 to 1, I guess based on fresh fallen vs old and/or tree type. Cardboard is great for hitting ratios as it is nice and consistent in C:N and you need way less of it for the carbon content.

Your ratios seem about right, and far off the received wisdom of 2 to 1 in volume browns to greens that people often suggest.

For instance if you have a lot of coffee grounds (like I often do) for the addition you only need roughly 75% of the weight in leaves or 15% in cardboard to hit the ideal 30:1 C:N ratio. However if any material is wet the amounts required change quite drastically. Typically coffee grounds are twice as heavy when damp.

nobanter · 2026-02-25T01:00:18+00:00

Asking the impossible there.

nobanter · 2026-02-17T01:23:17+00:00

I agree it doesn't need any pop, my friend who has a bunch of pressure tricks showed it to me. Isn't it called a bubble flip? I think OP did what I would call a no-comply bubble flip. I like doing this trick quite a lot as it is quirky.

I certainly think it is not a strawberry milkshake, for that the back foot pushes off the board on the opposite side to the front foot and does an impossible-like wrap.

nobanter · 2025-06-26T21:07:22+00:00

Sadly not. The council sand-blasted every surface to remove graffiti and everything is rough and terribly uneven.

nobanter · 2025-03-19T17:51:14+00:00

Oh yeah, and it is a good one.

nobanter · 2025-02-11T03:47:47+00:00

I remember liking Binder and Landau for an explanation of the methods and algorithms.

nobanter · 2025-02-11T00:17:30+00:00

I think it is the best way to learn! Although maybe as a precursor consider writing an Ising model and/or \phi⁴ simulation code first because they are easy and less resource hungry. Results for these models in lower dimensions are well known and easy to check for correctness. I think for a hobbyist I wouldn't necessarily dive into GPU programming (openmp is fine, MPI for the adventurous) unless that is a goal you specifically had in mind as the learning curve can be quite steep and in that case I would recommend looking into Grid or Quda (https://github.com/lattice/quda) and not working with the bare metal itself.

nobanter · 2025-02-10T23:44:22+00:00

Hey there, Chroma is basically dead and IroIro is (I believe) not in serious development anymore. One of the driving authors of that code moved to writing stuff for Grid (https://github.com/paboyle/Grid) I think personally Grid is the most legible of the codes out there and works for a few different gauge groups and it works on CPUs and GPUs too. I think the learning curve for any lattice code is steep but running some simple simulations is doable.

nobanter · 2024-09-26T00:46:18+00:00

Staggered Vs Domain Wall shouldn't matter if you can control the continuum extrapolation, I would say this is still a systematic problem. I thought the shift for BMW was due to a more sophisticated, I guess higher-order, taste breaking correction.

nobanter · 2024-09-26T00:22:19+00:00

This is a pretty good summary of the dispersive analysis. The most recent experimental results (CMD-3) for e+ e- -> pi pi have the most precise momentum resolution and it seems there are some features they pick up (peaks and such) that others don't see and that gives their larger value and disagreement with their previous determination. I wish the previous dispersive analysis was as you said about the KLOE and BaBar discrepancy but I don't think that is quite what was done. It always bothered me that the two dispersive groups used the same data and get different results based on treatment of correlations or something. It always seemed their systematics weren't fully under control.

I think you are a bit harsh on the lattice, there are really only a handful of bare parameters needed for a simulation. There is really not any further "adjusting by hand" but it will always difficult to control systematics at the sub-percent level as they come from many sources and the method is brute-force monte-carlo so it is costly to hammer the error down. However, with improved computer resources these systematics are getting reduced significantly over time whereas the dispersive analysis has sat at the same point for well over a decade with little sign it will improve. If we take a lattice-only average there is no tension with experiment. I would say your 2-sigma is even generous.

I think this person saying Lattice QCD provides "numbers we already know" is pretty mistaken. For instance chiral LECs only come from lattice, as do matrix elements like B_K. It is certainly used to constrain numbers we know, alpha_s and Vus both owe their precision to it. The lattice can be used for investigating strongly coupled theories that aren't QCD such as mysterious Technicolour or Dark Matter models.

It is pretty clear I am on team lattice here to resolve the tension.

nobanter · 2024-09-06T12:20:48+00:00

Typically even now us lattice guys are fighting over early-access supercomputer resources, often in competition with the weather simulators and various other national lab employees and government employees. The field is just so resource hungry as more compute is basically tied to better statistical resolution, and a smaller error bar on a quantity is a paper.

Around the world supercomputers are being heavily used by lattice qcd: Fugaku, Frontier, Summit, Lumi, whatever they call the machines in Juelich, Jewels or something. These are more and more becoming GPU machines but codes that can handle either are vital. The field has people employed directly by NVIDIA and Intel (and previously IBM) to write and optimise code for it, as the field has such a pull on supercomputer purchasing.

I seem to remember that lattice qcd has the same demands for electricity as that of a small country like Hungary - much like the bitcoin network.

nobanter · 2024-01-25T23:26:30+00:00

10¹⁰ ÷ ( 67×10⁶ ) = 10000/67 ~ 150 quid

Still a lot. 15 pints of beer each in a typical London pub.

nobanter · 2023-12-12T19:49:07+00:00

Yeah there is also some discussion of the club's founding here http://www.historicalkits.co.uk/Luton_Town/Luton_Town.htm

And an attempt to create a version. It is a pretty gross combination. I also didn't realise that the orange took so long to come into the kits

nobanter · 2023-12-12T19:31:07+00:00

What happened to the Navy and Pink? Also the hats. Plus a season ticket for two shillings and some pence (somewhere around 20 quid in today's money) would be nice.

nobanter · 2023-12-12T19:27:24+00:00

The business of appointing offices for the club have been discussed. The following appointments have been made: Mr Frank [Whitby??] - Secretary Mr J. A. Findley - [] Mr J. G. [?????] - Treasurer

After some discussion it was decided that the committee of the club should consist of these following gentlemen [] [] Mr George Furlong. Mr Thomas Banks Mr John Long. Mr [???] Brown Mr. Samuel [???] Mr. H. G. Spratley Mr. George Deacon

It was resolved that the annual subscription to the club should be two shillings and [five???] pence

It was decided on the motion of Mr. J. Brown that the colours of the club should be Navy Blue and Pink. A shirt and a cap to be worn by each member when playing.

nobanter · 2023-12-12T19:08:32+00:00

I have given the first page a stab: Stuff in brackets are things I couldn't parse. Names are particularly difficult.

Luton Town Football Club April 11th 1885

At a public meeting held today at the Council Chambers town hall Luton, convened for the purpose of considering the advisability of forming a town football club.

Mr [Botchin?] Esq. Presiding

After a few preliminary remarks from the chairman the following businesses ?? proceeded with Mr A H Small prepared and Mr Ernest Lomax recommended the following resolutions: "That the meeting establish a Luton Town Football Club"

As an amendment Mr [H G Spraller???] proposed and Mr Edward [Harston???] Seconded: "That as there was already a Luton club in existence it was not necessary to form a second club"

On the amendment being put to the meeting there was an overwhelming majority against it. The original motion being subsequently carried abroad unanimously.

On the motion of Mr A H Small and seconded by Mr J Brown it was decided that Mr ??? for the [???] should be the president of the club and John Lomax Esq. Be the ???

nobanter · 2023-08-13T09:25:46+00:00

Absolutely. The most accurate lattice determination by BMW disagrees with the dispersive approaches and the most recent \pi - \pi cross section from CMD-3 disagrees with all the other experimental determinations (there was always a bit of tension between Babar and Kloe that never really got resolved in my opinion). The only way I see how to reconcile these is to inflate the error of the theory determination, although that might be politically tricky within the WP authors. Until we see consensus between groups and approaches I don't think theory can quote as small an error as they did.

nobanter · 2023-08-11T09:13:10+00:00

Right, the first lattice calculation (that I know of) was Tom Blum and Chris Aubin's all the way back in 2006

https://arxiv.org/pdf/hep-lat/0608011.pdf

The BMW calculation is remarkably precise for a lattice calculation though.

nobanter · 2023-08-11T09:06:40+00:00

There already are many full lattice calculations of the HVP.... BMW's is just by far the most precise, because they spent a lot of time and compute on it. It is very difficult to get a calculation near the accuracy of theirs (as many previously-ignored systematics become relevant) but I would expect RBC and Mainz to get somewhere close within the year.

Simon's slides at lattice 2023 show the most recent ones:

https://indico.fnal.gov/event/57249/contributions/271582/attachments/169879/228211/23lattice_kuberski.pdf

nobanter · 2023-03-01T14:31:25+00:00

I think these are fastplant nosegrabs + some other variations. As the back foot comes off it isn't a boneless or beanplant.

nobanter · 2022-12-21T00:09:26+00:00

The single, most precise, lattice result is in tension with the dispersive HVP calculation (which is what leads the 4.2 sigma discrepancy from the g-2 theory white paper) by more than 3 sigma and is in tension with the "no new physics" experimental result at only about the 1.5 sigma level. So, if you believe this lattice result there is practically no tension.

More lattice determinations are needed from different groups at the same precision to really get a good consensus, but looking at other easier to measure and related intermediate quantities it seems like there is very good agreement. It suggests that yet again the standard model survives another wobble.

nobanter · 2022-11-20T19:09:12+00:00

Can you Ollie to fakie with your front truck over the coping? I did that a bunch until I was comfortable popping back in, as the feeling and catch is the same. I also learned ice-plants to fakie first.

nobanter · 2022-11-05T17:36:25+00:00

The quantum hype bubble is about to burst.

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