acadien

10 ms·

31.
by acadien 11y ago
Pu-238 has the highest energy density which is why its so useful (both as a weapon and an energy source). Its the cheapest to use because it adds the least amount of weight to the launch vehicle.
32.
by acadien 11y ago
This concept of "drop everything and study only the most 'important' areas" is misguided. Research doesn't work that way. There are already an enormous number of talent scientists studying climate change, how would
33.
by acadien 11y ago
I feel like these are special cased, searching for: graph looks like <object> with any random object turns up junk. Edit: then again it does work with Obama but not with Richard Nixon.
34.
by acadien 11y ago
Yeah I suspected it was a typo or something, but I kind of like it...
35.
by acadien 11y ago
I agree, as others have said the dynamics of a barge is a necessary challenge to prove the technology. But they need some more positive press, maybe a gif that doesn't end in an explosion hehe. On a side note the colloquialism 'su
36.
by acadien 11y ago
Musk commented himself on twitter something to the effect that the explosion is from the pressure difference of the fuel canister when it is breached. Also the fuel mostly burned at high heat and didn't explode per say.
37.
by acadien 12y ago
The author says multiple times: "an acceleration of [X] km/s is required", maybe they meant to imply that the magnitude of the change of the velocity?
38.
by acadien 12y ago
It draws some doubt that the author lists accelerations in units of km/sec, not km/sec^2.
39.
by acadien 12y ago
There are big data people running on supercomputers too. I know there are people writing custom asynch job managers to handle big data type problems because the top supercomputers have low memory latency. Also I think the dichotomy you&#x27
40.
by acadien 12y ago
Think of it as loops in 5 dimensions (x,y,z,a,b). I believe each node connects to 10 different neighboring nodes (2 in each of 5 dimensions), although I could be mistaken on that. You can actually tune which direction you prefer the nodes t
41.
by acadien 12y ago
Yeah the 5 dimensional torus network used at MIRA is just too cool not to bring up here. Modern supercomputers are increasingly become less and less discrete. https://computing.llnl.gov/tutorials/bgq/
42.
by acadien 12y ago
Again I'm not sure if I agree or disagree with this. My hatred of MPI is only outweighed by the fact that I can use it... and my code works. I think a large part of the inertia behind MPI is legacy code. Often the most complex part of
43.
by acadien 12y ago
Yeah good point. I just felt it might be a misleading of the author to suggest Chapel as an alternative when you cannot possibly write a useful program with it.
44.
by acadien 12y ago
I've heard there is a new effort being led by Torsten Hoefler to modernize MPI and address a number of the issues mentioned in this article. http://htor.inf.ethz.ch/ I was at a talk of his last year and there are a num
45.
by acadien 12y ago
In particle simulations interactions can happen at a distance, so at every time step all particles need to be checked with all other nearby particles to get their distances and compute the force of their interaction. It looks like your simu
46.
by acadien 12y ago
Yeah that's what I'm saying, if this demo has been 80,000 interacting particles it would be extremely impressive.
47.
by acadien 12y ago
Particles can be misleading too because if they're simply propagated by some PDE on a regular mesh (or even no mesh) it is an embarrassingly parallel problem. But if they're interacting particles then you need neighbor lists and p
48.
by acadien 12y ago
If only our government taxed people appropriately and had a system for foreign aid that was well studied and effective. Is whats proposed in this article as effective or better than the alternative? I have no idea but it certainly seems les
49.
by acadien 12y ago
It is a phase transition, it takes energy to evaporate because of the change in entropy/volume (from Clausius Clapeyron).
50.
by acadien 12y ago
Some of the comments made there are pretty interesting, specifically that it's not about the use of water its about the waste. -Ground water can be at least partially recouped through wells. This would be a really interesting number to
51.
by acadien 12y ago
1 hamburger or 1 cow? Genuinely curious, also could you source that? Thanks!
52.
by acadien 12y ago
All the runners came in 2nd to last, I guess.
53.
by acadien 12y ago
How much design and algorithm design did you do in simulation as opposed to using the physical robot itself?
54.
by acadien 12y ago
>The success the U.S. has had in being innovating in STEM fields is due to our cultural tradition of comprehensive education rooted in the liberal arts. There is no evidence for this. >A focus only on STEM is what gets you modern-day
55.
by acadien 12y ago
Its about an educated and critical thinking public. A public that approaches everything with a critical eye is less susceptible to political pandering and more accepting of good science and evidence/data based laws. The average person
56.
by acadien 12y ago
Yes, I remember friends having that problem in undergrad in Canada. There was a way around it but it was an application process with an interview. I believe they were concerned with people trying to game the system to get lower tuition fees
57.
by acadien 12y ago
Why not just make it a graduated tuition based on parental income?
58.
by acadien 12y ago
I'm guessing they just took the figures from the Chinese press release and turned it into an article. Lazy journalism at its best.
59.
by acadien 12y ago
You get a range of skills while working on a science PhD that will benefit you in industry no matter where you end up. If you choose to study an area that actually has industry applications then its even better. If, on the other hand, you g
60.
by acadien 12y ago
Just because someone doesn't understand how a jet engine works doesn't mean its incomprehensible to them. It just means they haven't spent the time and effort to understand it. There are very very few topics out there in this

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