credit_guy

Hôm quadiscuss

That's an interesting idea, but I don't think you can use a mass driver to shoot something from an higher orbit to a lower orbit.

credit_guy

3 ngày trướcdiscuss

Spirits are not capital intensive. Building a rocket is very capital intensive. You'd like to be able to reuse it. But if one single mission takes 30 years, then you can reuse this rocket once, at most twice. Let's say you reuse it twice, you amortize the capital cost over a period of 90 years. Now, let's say someone builds the exact same rockets, but they do missions between the asteroid belt and Mars. Each trip takes about 2 years. Everything you can source on Titan, you can find an asteroid to source it from. By the time you reuse a Titan-bound rocket once, you reuse an asteroid-bound rocket many times.

credit_guy

3 ngày trướcdiscuss

The Hohmann transfer time between Saturn and Mars/Earth is around 16 years. So, all the ships used for such a supply mission would reach their destination at least 32 years after they’ve been built, assuming we build them on Earth.

credit_guy

7 ngày trướcdiscuss

> A given model has a shelf-life, which these days is measured in months, not years.

Not all new models are trained from scratch. ChatGPT 5.3 to 5.4 (and likely 5.5) was basically the same model, but probably trained a bit more, not a new model from scratch.

> The "someday" when frontier model providers can enjoy their current high inference margins without the burden of significant training costs is never going to arrive.

That is debatable. I believe the moat for the frontier model providers is the compute. At the level of 10 trillion parameters (that Fable/Mythos are rumored to have), you need serious compute to serve inference, and you also need serious compute to train. Will DeepSeek, Qwen, Kimi, GLM come up with a 10T new model anytime soon? I doubt that. People keep saying that the Chinese labs are catching up to the US big 3, and measured in months the gap is now only 4-6 months. I doubt a Chinese version of Fable/Mythos will be released in the next 12 months.

credit_guy

9 ngày trướcdiscuss

People think mathematics is about proving theorems.

I think that's just an accident of history.

When we write software, we very seldom write proofs that our algorithms are correct. We just write tests, and we also run the algorithms and when they fail we know we have a bug and then we proceed to debug, fix, and add new tests (if we are disciplined, but most of us are). In time, by usage and testing, we gain confidence that our battle tested software is correct, mostly. And we tell people that we will never be 100% confident that any software is bug free. But that's a slight lie: if we wanted such confidence, we would start using provers, and create bug-free software. That possibility exists, but it's just extraordinarily expensive.

Well, in math that's the only possibility, and we use it. And it is indeed extraordinarily expensive, but it's also the cheapest among the alternatives. The alternatives are 2: be rigorous and do these proofs, or be sloppy and allow bugs to creep in, and allow an entire school of math to collapse like the Italian school of algebraic geometry [1].

There is one more alternative. If a particular math theorem has some applicability, then you write a program and use it in real life. In time you eliminate the bugs as much as you can, and you get to the steady state of "virtually bug free". At that point you don't have a solid proof that the theorem is correct, but in general you don't really care. Because you feel that a formal proof is just a thing one would pursue for getting academic satisfaction only.

[1] https://en.wikipedia.org/wiki/Italian_school_of_algebraic_ge...

credit_guy

9 ngày trướcdiscuss

> The performance, if we trust the benchmarks, put it at Sonnet 4.6.

I don't trust these benchmarks. I used a number of times Kimi K2.7 and I was disappointed. It would run in circles for things that Claude would do in one shot. However, my usage was via Ollama cloud, and I have no idea if they serve the actual model or a quantized version, and it was the quantization that degraded the performance.

The great news, in my opinion, is the precedent. If Microsoft is now serving Kimi K2.7, then very soon they might start serving GLM 5.2, and that is indeed a very competitive model.

credit_guy

11 ngày trướcdiscuss

What I meant is: for a human who has the context, like someone who works in the field, or took some courses, or read some materials about this. A human who just has a vague idea about fissile isotopes and needs to google the properties of U-235 or Pu-241 would do no better; they would probably do much worse.

credit_guy

11 ngày trướcdiscuss

I just tested it with a slightly tricky question

  > If you could run a nuclear reactor with U-235 as fuel or Pu-241 (both mixed with 95% U-238), which one would you choose and why?

For a human this would not be tricky at all. For an LLM it could be, because this question certainly does not exist in any sort of training, because Pu-241 does not exist in pure form, it only exist as a minor component of reactor-grade plutonium, where Pu-239 would dominate, with Pu-240 coming second and Pu-241 coming third.

In any case, LongCat-2.0. gave a very well reason but incorrect answer that Pu-241 is preferable.

I then tested on Qwen 3.7 Plus, and it correctly answered that U-235 is preferable because of its much higher delayed neutron fraction. I then went to Gemini Flash, which answered the same, with much more confidence, and with much stronger arguments, and the speed of the answer was much higher.

Overall I rate Gemini Flash the best, Qwen 3.7 Plus an acceptable second, and LongCat-2.0 an ok'ish third, if you have nothing better.

credit_guy

13 ngày trướcdiscuss

> Because it's pretty likely some of these have negative long term effects. And some of those long-term effects are probably pretty serious.

> Many people taking these kind of drugs are gambling with their well being. No doubt that in many cases that gamble is worth it.

You use the word "gamble" and it is correct, but the connotation is a negative one.

We take a risk in everything we do. We seldom know the long term effects of anything. Right now I drink tea, and I drink tea quite often. Is this healthy? Does it have long term negative effects?

With GLP-1 medications, deciding to not take one, if you are overweight, is also a gamble. A pretty huge one. Obesity very often leads to type-2 diabetes, and the first step is prediabetes. Should someone with high BMI and high A1C avoid GLP-1 because we don't yet know the long term effects? We do know the long term effects of being overweight.

credit_guy

14 ngày trướcdiscuss

I don't think open weight model will get as good as Mythos/Fable or GPT 5.6. Not in the next few years, and perhaps never.

The Chinese Communist Party is not any happier than the US Government to see millions/billions of people being able to use incredibly dangerous models.

credit_guy

14 ngày trướcdiscuss

Here's an unpopular opinion: this might be the only way to deploy advanced models. A lot of people compare advanced AI with nuclear weapons. Creating white lists of users that are allowed to use advanced AI feels wrong. It feels against everything that the Constitution stands for. That men are created equal and they are free to pursue their happiness. Now they are free to pursue that happiness only if the US Government signs off on that. It hurts to only think of that. But I'm afraid there's no other way. These models, in the wrong hands, can result in unfathomable devastation.

How do I know? Dario Amodei said that when he explained why Anthropic has to limit the US Government's usage of its models [1]:

  > Some uses are also simply outside the bounds of what today’s technology can safely and reliably do. Two such use cases [...]: Mass domestic surveillance. Fully autonomous weapons.

If the US Government can't be trusted with such uses, then how can you trust millions or billions of users with arbitrary usage?

[1] https://www.anthropic.com/news/statement-department-of-war

credit_guy

15 ngày trướcdiscuss

Because in reality, in most cases it works. I worked in many places that had large offshore teams that I worked with closely (India mostly, but also Hungary, Poland, Argentina, Morocco), and people were mostly happy with the arrangement.

There are some cases where the outcome is bad (like the case at Ford now), and lots of people point out to that and say "I told you so". But those are the exceptions, not the rule.

credit_guy

16 ngày trướcdiscuss

> Proliferation is irrelevant

I would not be so cavalier about that.

> It was not a Candu reactor what India have used

It was a heavy water reactor, called CIRUS [1], based on the NRX reactor that later evolved into the CANDU reactor [2].

> But there are easier and cheaper pathways - uranium enrichment distributed to be stealthy

Iran tried that. It is not easy to keep centrifuges stealthy, you need tens of thousands of them, and they need to be organized in cascades, you can't have one here, one there. You need a few hundred here, a few hundred there, and you need conversion and deconversion facilities (of uranium oxide into/from uranium hexafluride). It is virtually impossible to keep such a program secret, the more distributed it is, the more people need to be involved, how do you keep a program secret if there are thousands of people working in those numerous facilities?

[1] https://en.wikipedia.org/wiki/CIRUS_reactor

[2] https://en.wikipedia.org/wiki/CANDU_reactor#Early_efforts

credit_guy

17 ngày trướcdiscuss

> Global reserves are around 6 million tons, with estimates putting potential reserves around double that

In the mining industry reserves are a technical term. They can be proven, probable, likely, etc. qualifying a deposit as a reserve of a certain grade costs money. Reserves are used as colateral for secured financing, so in some cases the cost is justified. But if the sum of reserves is about 100 years of current consumption (our case here), mining companies will not spend one dollar more to certify new reserves.

For all practical purposes, uranium is an inexhaustible fuel, even if we never develop fast reactors.

credit_guy

18 ngày trướcdiscuss

I love nuclear reactors and CANDU are quite cool. But I don't think that today we have any reasons to build CANDU reactors, except possibly that Canada can demonstrate they can build them for cheaper than others can build light water reactors. The ability to build is something that has little to do with the technical merits of a nuclear reactor design. But all things being equal, a PWR or a BWR should cost less per GW than a CANDU reactor and have other advantages too:

- main problem with CANDU: proliferation. India was able to build nuclear weapons after using a Canadian built heavy water reactor (basically a CANDU reactor) [1]. There is no guarantee that another country will not try something similar in the future, the design has no built in proliferation resistance. An operator can remove irradiated fuel at any time, and if the IAEA discovers they engage in plutonium manufacturing and they get on a black list, they can manufacture their own fuel quite easily, because CANDU uses non-enriched uranium. With light water reactors, you need enriched fuel, so if you are flagged as a proliferator no fuel manufacturer will be allowed to sell you fuel, and it's going to be much harder for you to manufacture your own fuel, since you can't enrich. If you can enrich uranium, you might as well try to build a uranium bomb (like Iran is trying to do). Also, with light water reactors, you refuel only at discrete times, generally about 18 months apart, so it is much more difficult to extract lightly irradiated fuel without being caught by the IAEA.

Now some less important problems:

- because CANDU uses non-enriched uranium, it produces much more nuclear waste per GWh compared to light water reactors. Nuclear waste is not the boogeyman nuclear anti-advocates make it to be, but still, if you generate 5-10 times more nuclear waste than the mainstream alternatives, it is less than ideal.

- there is one positive reactivity feedback loop in a CANDU design. Because of that CANDU designs are not licenseable in the US. The Canadian nuclear regulator is comfortable that the design is stable [2], but if you can choose between a design with one positive feedback loop and one without any positive feedback loop, why would you choose the first?

- heavy water is a worse moderator than light water (by a large factor). It [1] https://en.wikipedia.org/wiki/India_and_weapons_of_mass_dest...

[2] https://www.cnsc-ccsn.gc.ca/eng/resources/research/safety-an...

credit_guy

18 ngày trướcdiscuss

> Unfortunately its just a small boiling water reactor.

It is not just a small boiling water reactor. It is a 300 MW-electric boiling water reactor, and if successful, it will be followed by 3 more of the same type for a total of 1.2 GW-electric. That is more than an AP-1000 reactor, and much less risky.

credit_guy

18 ngày trướcdiscuss

I dispute that. Enshitification happens when the user does not pay for the product. The provider of the service has to find alternative ways of monetization. As a user, this feels shitty, but you get what you pay for. With AI, if you pay for usage, you can demand that the service provided not be shitty. You can even litigate, but the most important leverage is the threat to take your business elsewhere. Enough people do that and the provided service stops being shitty in a hurry.

credit_guy

18 ngày trướcdiscuss

But they are using wind:

> A majority of the generation will come from large GE Vernova (NYSE: GEV) turbines.

credit_guy

20 ngày trướcdiscuss

It sounds like a huge amount of money and a clear sign of defeat. The US (or maybe Europe, who knows?) is paying Iran some form of tribute.

But, there's another way to see this: if you pay someone money, you end up with a lot of say in what they can or can't do. That money does not come with any guarantee; the party offering the money will keep the money flowing based on their own perception of good behavior of the party receiving the money. The post-Trump administrations will find themselves in the possession of a tremendous amount of leverage with Iran.

credit_guy

21 ngày trướcdiscuss

The US could make it clear that if earth moving equipment is spotted within half a mile of the Isfahan, Fordow or Natanz previously bombed facilities, they will be bombed again [1].

[1] https://en.wikipedia.org/wiki/Nuclear_program_of_Iran#Main_f...

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