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

Google and a nuclear fusion company have developed a new algorithm

theguardian.com

Post reply on HN
Print view View original

31–40 of 129 posts

Re: Google and a nuclear fusion company have developed a new algorithm

#31

Post by dwaltrip »

There was a talk about the state of nuclear fusion by some MIT folks linked here on HN a few days ago. One of the biggest takeaways was that many fusion efforts are very far away (3 to 6+ orders of magnitude) on the most important metric, Q, which is energy_out / energy_in. Additionally, much press and public discussion completely fail to discuss this and other core factors that actually matter for making fusion viable.

I remember Tri-alpha being listed on one of the slides near the bottom left of the plot, 4 or 5 orders of magnitude away from break even, where Q = 1 (someone please correct me if I'm remembering incorrectly).

Is the 50% improvement described in the article meaningful, as that would only be a fraction of an order of magnitude?

I understand the broader concept of combining experts and specialized software on complex problems is a powerful idea -- I'm just wondering if this specific result actually changes the game for Tri-alpha.

Re: Google and a nuclear fusion company have developed a new algorithm

#32

Post by Kenji »

lamp_book wrote: post #20

From the actual journal article: > Two additional complications arise because plasma fusion apparatuses are experimental and one-of-a-kind. First, the goodness metric for plasma is not fully established and objective: some amount of human judgement is required to assess an experiment. Second, the boundaries of safe operation are not fully understood: it would be easy for a fully-automated optimisation algorithm to pr…

In software jargon, this is called a "Wizard" (i.e. installer wizard, calibration wizard, etc. that guide you through a process that is more complicated by asking a series of simple questions) and is an idea that dates back decades.

Re: Google and a nuclear fusion company have developed a new algorithm

#33

Post by beambot »

EternalData wrote: post #4

Google might try to become the conglomerate of all forward-facing things but it is somewhat funny to see how through it all, it's their advertising revenues that form the core of the business.

Why is that surprising? Look at individuals... they work for money so that they can pursue their own ambitions. It is rare to find an individual with the luxury of pursuing their own, exact ambitions to also earn money.

Kudos for Google for using their vast funds to finance their ambitions rather than just hoarding it away.

Re: Google and a nuclear fusion company have developed a new algorithm

#34

Post by siscia »

I do have a naive question.

Suppose a big breakthrough comes out of a private company, and such innovation is necessary to use nuclear fusion.

The company will be free to do whatever it pleases with the technology or it will somehow "force" to let other use, maybe behind the payment of some royalties.

Re: Google and a nuclear fusion company have developed a new algorithm

#35

Post by tuco86 »

lamp_book wrote: post #20

From the actual journal article: > Two additional complications arise because plasma fusion apparatuses are experimental and one-of-a-kind. First, the goodness metric for plasma is not fully established and objective: some amount of human judgement is required to assess an experiment. Second, the boundaries of safe operation are not fully understood: it would be easy for a fully-automated optimisation algorithm to pr…

i also haven't read the full article. I wondered if it was worth reading before i clicked the link really. How did they determine it whould be faster than.. what? doing it without computers? And if it cuts down months worth of computation to just some hours, can i expect a working fusion reactor in the next 1-2 years instead of 10-30? How did this become HN #1?

Re: Google and a nuclear fusion company have developed a new algorithm

#37

Post by abefetterman »

jlarocco wrote: post #30
abefetterman wrote: post #16

This is actually a really exciting development to me. (Note, what is exciting is the "optometrist algorithm" from the paper [1] not necessarily googles involvement as pitched in the guardian). Typically a day of shots would need to be programmed out in advance, typically scanning over one dimension (out of hundreds) at a time. It would then take at least a week to analyze the results and create an updated research pl…

As a complete outsider, I don't understand what's special about the "optometrist algorithm." As described in the Nature article it's just hill climbing using humans as the evaluation function. Isn't it basically the same thing they were already doing but more granular?

Basically nobody was using automated gradient descent / etc because of the proclivity of these algorithms to get stuck on a boundary. The problem is the boundaries are not well defined. One example might be a catastrophic instability. If it gets triggered it has the potential to damage the machine. But the exact parameters in which the instability occurs are not well known. So with this algorithm you mix the best of both worlds: the human can guide away from the areas where we think instabilities are, the machine can do it's optimization thing. It's pretty simple overall but enables a big shift in how experiments are run.

Edit to add: these instabilities often look just like better performance on a shot-to-shot basis, which makes the algos especially tricky. Using a human we could say "this parameter change is just feeding the instability" vs "oh this is interesting go here"

Re: Google and a nuclear fusion company have developed a new algorithm

#38

Post by euyyn »

pm90 wrote: post #26
lamp_book wrote: post #20

From the actual journal article: > Two additional complications arise because plasma fusion apparatuses are experimental and one-of-a-kind. First, the goodness metric for plasma is not fully established and objective: some amount of human judgement is required to assess an experiment. Second, the boundaries of safe operation are not fully understood: it would be easy for a fully-automated optimisation algorithm to pr…

I mean, if it has not been done before, it doesn't look like they're overstating the novelty. Most algorithms look "obvious" in hindsight :).

It's a well-known technique in the out-of-fashion world of knowledge-based systems: To create an expert system, your experts often won't be able to articulate their utility function, so you extract it by presenting them A/B choices.

Re: Google and a nuclear fusion company have developed a new algorithm

#40

Post by Symmetry »

MrQuincle wrote: post #22

There are two directions within the energy world that I don't completely get. One of them is hydrogen storage, the other nuclear fusion. From what I always understood is that the high-energy neutrons produced by the fusion reaction irradiate the surrounding structure and that there is still considerable nuclear waste (although lifetimes are better than with nuclear fission). Do the scientists not care or is this outd…

The neutrons coming from the fusion reactor do have the potential to make the surrounding material radioactive. But that depends on exactly what the surrounding material is, some elements will become dangerous when exposed to neutrons and some won't. An important part of designing a fusion powerplant, and one of the reasons it is difficult, is that you have to make sure that the materials you use can safely handle the neutrons coming from the fusion reaction without transmuting into dangerously radioactive forms.

This is in contrast to a fission reactor where the fuel itself turns into dangerously radioactive elements when exposed to neutrons.

EDIT: The exception is that fusion powerplant designers will want to surround the reactor with lithium in the hopes that it will absorb a neutron and turn into tritium. The tritium is then carefully gathered because it forms the the fuel for the reactor and it's hard to get except in a nuclear reactor.

Post reply on HN