mattheww

Did my thesis research at Brookhaven National Lab, home of the Relativistic Heavy Ion Collider (RHIC), which is the predecessor of the heavy ion program at the LHC.

While there, one of the more senior scientists relayed an exchange from an ongoing review of the program. At the time, RHIC was colliding gold in the heavy ion program.

One of the reviewers asked if RHIC could save money by switching to a cheaper element, like lead. None of the RHIC representatives knew what to say. I don't remember the exact numbers, but RHIC used something like < 1 milligram of gold over the lifetime of the program.

You're right, the thing limiting the value is not demand - there are more than enough faculty and high-level staff that want to live there.

The thing limiting the value is the other restrictions that Stanford imposes on these houses - namely they essentially control the price the houses sell for because they all have to be financed through a Stanford-controlled lending program.

FYI, if you make a realistic calculation (including tax and multiple winners), the EV of a lottery ticket is still negative.

Depending on your tax bracket, the non-jackpot prizes have about $0.19 of EV.

In a state where you don't pay tax on lottery winnings, like CA, you cash option post-tax is currently estimated at $408,403,045.

My estimate of the multiple winner correction to the EV is 0.8, based on numbers of winners for prizes >$500M.

Your jackpot EV is therefore $1.08 and the total winnings EV is therefore $1.27, meaning the overall EV is -$0.73.

For there to be positive EV, that delta needs to all come from the jackpot, so the headline jackpot number would need to go from $1.1B to $1.8B to get it there.

There are four questions at the end of the post.

For sure, the second one is answered - it is possible to parallelize GNNs to the billion-scale, while still using message passing. It requires rethinking how message passing is implemented, modifying objective functions that work in parallel, and changing ML infrastructure. You're not going to get to large graphs with generic distributed Tensorflow.

I don't know if the third question is fully answered, but there are many approaches to preserving locality, either by changing architectures or changing objective functions.

Also, errata: PinSage was developed for Pinterest, not Etsy (hence, not EtsySage).

It's unbelievable that nobody has done this well - I and most people I know are tracking their own job searches on a spreadsheet.

Pretty obvious value-add for job searchers. Not to mention that having access to this data would enable tons of other product features. Shows that most services/sites don't care that much about the applicant experience.

If you know a way to find clusters of intersections of hyperplanes, I'm pretty sure you can get a highly acclaimed paper out of it, but that is not what a Hough transform is. The Hough transform is an approximate solution to that problem which works by sampling the hyperplanes and then polling them. There's no way to perform a Hough transform without having many more transformed points than input points, and the more precision you need, the more points you need.

To be fair, 50 PU is above design peak luminosity, much less mean. And I'm sure I've seen plots from both ATLAS and CMS at the end of LS1 that show improvements in the processing time at 100 PU by factors of roughly 10.

Hough transform is basically useless for precision tracking in a high multiplicity environment. Tracks have 5 degrees of freedom, so the memory costs make it infeasible. I think ATLAS uses it in the trigger, where you don't need to actually reconstruct all tracks, just find out if there are a couple passing certain criteria.

Depends exactly how you limit the problem, but going from detector hits to abstract arcs takes a few seconds.

The main thing of interest here is whether a system that knows about physics (traditional approaches) can be beaten by a system that has no a-priori knowledge of physics (OOB DL) or if someone will find a way to integrate physics knowledge into a DL approach.

RE 2: What I mean is that "N-sigma" and local p-value are being used interchangeably, which you can see from this plot. There's no "number ... calculated without including info about any theory/evidence regarding the Higgs boson".

RE 3: The model used to calculate the background are unphysical in the sense that they set the Higgs production cross section to zero without changing anything else. There's no physical Higgsless theory.

RE 4: I was agreeing with you and adding some facts.

>That number is calculated without including info about any theory/evidence regarding the Higg's [sic] boson.

That's not true. You can see plots in the 2011 and 2012 papers that give these calculations as a function of mass. It's basically impossible to make a mass-independent calculation. (Not withstanding the fact that there's no Higgsless theory to do calculations for the background).

>As an example, I'd imagine detecting the Higg's [sic] boson at 1 eV energy levels is theoretically predicted to be even less likely than billions/trillions to one odds, therefore detector noise would be a more likely explanation for such results, despite the low p-value.

You're right, the p-value is much lower. Previous experiments have long since excluded such a low Higgs mass. Also, if the Higgs mass were so low, we probably wouldn't exist.

So there's no obvious practical application (right now).

Also, the proton is not 4% smaller. Protons are obviously whatever size they are.

The discrepancy comes from the fact there are two techniques to measure the proton size. Both experiments do their thing and then there's a way to interpret the results that would tell you the size of the proton (look up proton form factors).

However, when you do the interpretations, which depend on some theoretical calculations, you get different results. The general thinking around this result, because nobody has found any issue with the experimental results, is that there are some additional interactions that are stronger than expected that need to be accounted for (there are some unknown quantities that allow this).

One of the interactions would only affect the muonic hydrogen measurement - basically there are some different interactions between muons and protons than between electrons and protons because of the muon's mass and those might be different than originally thought.

The other is a type of interaction that could affect both normal and muonic hydrogen. This new measurement shows that the interactions that affect both has to play an important role in understanding this discrepancy. There are other measurements trying to measure this effect independently (not using hydrogen at all).

As you can imagine, the long-lived particles can have "any" lifetime. Since the lifetime is unknown, it makes sense to probe many lifetimes. The experiment being suggested by Lubatti and his collaborators probes lifetimes on the order of 10^5 - 10^7 m. There aren't strong constraints on this range, which can appear as missing energy in CMS or ATLAS (or not). CMS, ATLAS, and LHCb are giving constraints at 10^-6 to 10^2 m. Interestingly, the different experiments are probing mostly different ranges.

To correct something in the grandparent (?) post, the LHC experiments do not know the incoming energy. Even though the beam energy is 6.5 TeV on 6.5 TeV, the collisions are only a fraction of that. We only know that the energy has to balance in the perpendicular direction. However, if a collision produces two invisible particles that balance each other, it would appear that there is no missing energy. In many of models, pair production of new particles is preferred, so if the particles are long-lived, they can be hard to find.

The argument in favor of an electron-positron collider is that there is much less "junk" in the detector from the hadron collision. So the trade-off is that you produce a lot fewer Higgs bosons, but, in principle, you are able to measure each Higgs much more precisely. Having a machine at 250 GeV puts us at the sweet spot for producing the Higgs with mass 125 GeV.

There is some discussion in the community about whether it truly is going to advance the field to build such a machine. It's not super clear whether the various proposed 250 GeV machines will improve on what will be done by HL-LHC. From the Chinese point of view, though, it absolutely is the right decision to build this machine on the way to a 100 TeV hadron collider, since they desperately need to build up some local expertise in constructing/operating a large collider.