Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The beginning of the Monte Carlo method (1987) [pdf]

lib-www.lanl.gov

Post reply on HN
Print view View original

11–20 of 50 posts

Re: The beginning of the Monte Carlo method (1987) [pdf]

#11

Post by BOOSTERHIDROGEN »

vasco wrote: post #7
bardcore wrote: post #6

I didn't realize how integral Monte Carlo sims were to our early advances in nuclear technology. It makes sense to me though- it seems like the Monte Carlo method lets you punch above your weight class in terms of measuring and predicting phenomena that are too complex, or too expensive to deterministically model. My intuition tells me that it's effectiveness would fall off as the complexity of the in/out relationshi…

You should be able to model "infinite" complexity, the way people design analog circuits is basically this.

Sorry for stupid question, what is infinite complexity in analog circuit ? Any examples/model ?

Re: The beginning of the Monte Carlo method (1987) [pdf]

#13

Post by acidburnNSA »

Nuclear engineer here (specialty in core design/simulation). It's fun to see the Monte Carlo method be used in so many other fields now. Even in nuclear, deterministic methods are still orders of magnitude faster for most 'normal' reactor analyses on reactor configurations that are common enough to have all the important deterministic effects known. But with computers so fast, it's quite common for people, especially in conceptual design space, to use Monte Carlo methods since it's a lot easier to believe the answer once you get it.

The code MCNP is still the most common nuclear analysis code, and it's directly descended from these original codes from LANL. [1]

There is also a very powerful research code called OpenMC from ANL that anyone can run on their (powerful) computer. [2]

[1] https://mcnp.lanl.gov/reference_collection.html

[2] https://docs.openmc.org/en/stable/

Re: The beginning of the Monte Carlo method (1987) [pdf]

#14

Post by dcminter »

melling wrote: post #9
atan2 wrote: post #2

I cannot believe a raw link to Wikipedia made it to the top stories.

Some people on HN farm for karma points. They frequently post Wikipedia articles. It seems somewhat effective. There are certain topics that attract a bit of quick attention.

I'm sure that's true, but also there's a lot of very interesting HN-relevant stuff on Wikipedia, and it's perfectly reasonable to share it when you find something pithy.

I've certainly done it and contrariwise have often enjoyed Wikipedia articles (including this one) from other users.

Apropos of which I wish I'd had Wikipedia when I was a kid - I recall being utterly baffled by Brittanica's "explanation" of the term "parsec" and only much later reading a definition that put it in the context of how stellar distances were actually resolved.

Edit: Looking at swibbler's submission history, they're clearly not a karma farmer btw.

Re: The beginning of the Monte Carlo method (1987) [pdf]

#16

Post by alhirzel »

It should be noted that modern graphics rendering techniques are a little more accessible and intuitive, while still having the same basic challenges and solutions as the nuclear simulations mentioned in this thread/in the Wikipedia article. Things get even more interesting because quantities are spectral in nature, can be polarized, etc. Wenzel Jakob is doing important work in this area out of EPFL[1].

[1]: https://rgl.epfl.ch/people/wjakob/

Re: The beginning of the Monte Carlo method (1987) [pdf]

#17

Post by mjb »

bardcore wrote: post #6

I didn't realize how integral Monte Carlo sims were to our early advances in nuclear technology. It makes sense to me though- it seems like the Monte Carlo method lets you punch above your weight class in terms of measuring and predicting phenomena that are too complex, or too expensive to deterministically model. My intuition tells me that it's effectiveness would fall off as the complexity of the in/out relationshi…

> the Monte Carlo method lets you punch above your weight class in terms of measuring and predicting phenomena that are too complex, or too expensive to deterministically model.

Yes, this is exactly why I like it. At AWS, we've used Monte Carlo simulations quite extensively to model the behavior of complex distributed systems and distributed databases. These are typically systems with complex interactions between many components, each linked by a network with complex behavior of its own. Latency and response time distributions are typically multi-modal, and hard to deal with analytically.

One direction I'm particularly excited by in this niche is converging simulation tools and model checking tools. For example, we could have a tool like P use the same specification for exhaustive model checking, fuzzing invariants, and doing MC (and MCMC) to produce statistical models of things like latency and availability.

Re: The beginning of the Monte Carlo method (1987) [pdf]

#18

Post by mjb »

mjb wrote: post #17
bardcore wrote: post #6

I didn't realize how integral Monte Carlo sims were to our early advances in nuclear technology. It makes sense to me though- it seems like the Monte Carlo method lets you punch above your weight class in terms of measuring and predicting phenomena that are too complex, or too expensive to deterministically model. My intuition tells me that it's effectiveness would fall off as the complexity of the in/out relationshi…

> the Monte Carlo method lets you punch above your weight class in terms of measuring and predicting phenomena that are too complex, or too expensive to deterministically model. Yes, this is exactly why I like it. At AWS, we've used Monte Carlo simulations quite extensively to model the behavior of complex distributed systems and distributed databases. These are typically systems with complex interactions between man…

A while ago I wrote this as a simple introduction to applying MC methods in distributed systems: https://brooker.co.za/blog/2022/04/11/simulation.html

Re: The beginning of the Monte Carlo method (1987) [pdf]

#19

Post by xhkkffbf »

I became a big fan of the Monte Carlo method when I watched an economist torture a problem until he found a way to turn it into the heat equation, a differential equation he knew how to solve. He made so many bogus assumptions that the answer was pretty much worthless. But, hey, he could claim he had a closed form solution!

Re: The beginning of the Monte Carlo method (1987) [pdf]

#20

Post by psd1 »

melling wrote: post #9
atan2 wrote: post #2

I cannot believe a raw link to Wikipedia made it to the top stories.

Some people on HN farm for karma points. They frequently post Wikipedia articles. It seems somewhat effective. There are certain topics that attract a bit of quick attention.

A high-karma Reddit account has monetary value, you can sell it to a bot operator.

Does an HN account have any value, or do you think karma farmers are just in it for the ego boost?

Post reply on HN