mattheww

6 ms·

1.
by mattheww 1y ago
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
2.
by mattheww 3y ago
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 -
3.
by mattheww 4y ago
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 t
4.
by mattheww 4y ago
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, m
5.
by mattheww 5y ago
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 t
6.
by mattheww 8y ago
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 probl
7.
by mattheww 8y ago
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.
8.
by mattheww 8y ago
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 a
9.
by mattheww 8y ago
Depends exactly how you limit the problem, but going from detector hits to abstract arcs takes a few seconds.
10.
by mattheww 8y ago
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
11.
by mattheww 9y ago
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 th
12.
by mattheww 9y ago
>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 mas
13.
by mattheww 9y ago
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 ex
14.
by mattheww 10y ago
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 o
15.
by mattheww 10y ago
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
16.
by mattheww 10y ago
Experiments like IceCube answer different questions than accelerator based experiments. You couldn't, for example, measure the Higgs branching ratio to bottom quarks at IceCube. On the other hand, you can't measure high-energy neu
17.
by mattheww 11y ago
This is not a very straight-forward question to answer. The short answer is that both CMS and ATLAS detected a couple thousand Higgs events. The long answer depends on your definition of detected. As you probably know, the Higgs decays into
18.
by mattheww 12y ago
I am a scientist, and I have seen a lot of terrible code. Most scientists have no formal training in computer science or coding. Many advisors don't place much value in having their grad students take such classes, though even a short
19.
by mattheww 12y ago
It's based on the fact that particle energies follow a continuous distribution. See, for example: http://www2.astro.psu.edu/users/nnp/cr.html .
20.
by mattheww 12y ago
Close to nothing would happen. The relevant quantity to understand is the stopping power (usually referred to by us physicists as dE/dx). Stopping power drops significantly as energy of the charged particle increases. So for very large
21.
by mattheww 12y ago
Actually, it does follow. If there are particles of the energy described in the original link, there are many more particles of lower energies also hitting the Earth's atmosphere, including energies accessible at the LHC. And none of t
22.
Statistcs on HN Usage(mattheww.svbtle.com)
1 points by mattheww 13y ago|0 comments
23.
by mattheww 13y ago
These off-base criticisms reflect the fact that commenter did not read the whole paper and likely did not even read the introduction, which ends on page 3, where he found "serious" problems. For example, the paper nowhere conflate
24.
by mattheww 13y ago
Why do you want to limit by location when the the data is already separated by cause? All of the Tesla fires were caused by collision. If you compare (Fires caused by collision)/Vehicles on the road, then I agree Tesla does not compare
25.
Nobel Prize in Physics awarded to Englert and Higgs(nobelprize.org)
329 points by mattheww 13y ago|83 comments
26.
by mattheww 13y ago
I will explain why lisper's explanation of light speed is wrong. The fundamental problem is that it violates the premise of relativity and is a classic example of appealing to an absolute frame. Velocities are only measured relative to
27.
by mattheww 14y ago
There are two separate questions here. The first question, "is the Higgs mechanism how elementary particles get their mass?" is now essentially answered. Whether or not the Higgs boson is a single particle or part of a hierarchy of related
28.
by mattheww 14y ago
Unfortunately, the idea that supersymmetry is "dead" has been propagated by journalists covering science who don't know any better and people with an agenda. Generally, it's people who just don't know any better. Unfortunately, you see comm
29.
by mattheww 14y ago
There are a lot of people thinking about what kind of structure the model of dark matter particles could have. And there are a lot of different ways for there to be more than one dark matter particle, and even if the only way those other pa
30.
by mattheww 14y ago
In flights I've been on with obvious unaccompanied children, someone from the flight crew tells the child to stay in his/her seat until everyone else has gotten off the aircraft.

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