abainbridge

Yes. I don't really understand why Zig gets more attention than dlang. It seems that it is more to do with the personality of the authors, rather than the technicalities. I get the impression that Walter is more laissez-faire, while Andrew is more single-minded. I'm grateful to the contributions both have made.

Another point I liked was that there was, apparently, an influential book called Structured Programming, whose content was so universally agreed upon, that all programming became Structured Programming. Nobody needs the book anymore.

There are many well documented cases of rapid evolution: a population of African elephants became 50% tuskless at birth in a single generation, urban fox anatomy diverged from rural, frogs in the Chernobyl Exclusion Zone turned black, the Peppered Moth turned black in the industrial revolution.

I'd have no idea how to find him. But I think it'd be a fruitless task anyway. I'm sure they'd have no memory of what, to them, was a moment as mundane as any other that day. I've definitely had people recount a shared experience to me, reminiscing about how profound it was, and me having no idea what they're talking about.

I think I have an observation that defies the info on that page. That page was written around the time that STEVE (an aurora related phenomenon) was first named. https://en.wikipedia.org/wiki/STEVE

I mention this because in the 1990s, while at uni in St Andrews, Scotland, I remember a trip to the astronomy observatory one evening. There was a peculiar cloud overhead - whitish purple, tube shaped and shimmering. I asked the astro professor what it was. He said, "Its a cloud" and showed no further interest. I took a photo. When I got the film developed and photos printed, you could see bright colours either side of the tube. I've always wondered a) what it was and b) why that astronomy professor was an astronomy professor when he had no interest in what the universe had to reveal to him.

I now believe it to have been a STEVE. I've still got no insight into the mind of the astro professor.

For a few years I worked in the team that wrote software for an embedded audio DSP. The power draw to do something was normally more important than the speed. Eg when decoding MP3 or SBC you probably had enough MIPS to keep up with the stream rate, so the main thing the customers cared about was battery life. Mostly the techniques to optimize for speed were the same as those for power. But I remember being told that add/sub used less power than multiply even though both were single cycle. And that for loops with fewer than 16 instructions used less power because there was a simple 16 instruction program memory cache that saved the energy required to fetch instructions from RAM or ROM. (The RAM and ROM access was generally single cycle too).

Nowadays, I expect optimizations that minimize energy consumption are an important target for LLM hosts.

> seems like x86 and the major 8bit cpu's had the same speed, pondering in this might be a remnant from the 4-bit ALU times.

I think that era of CPUs used a single circuit capable of doing add, sub, xor etc. They'd have 8 of them and the signals propagate through them in a row. I think this page explains the situation on the 6502: https://c74project.com/card-b-alu-cu/

And this one for the ARM 1: https://daveshacks.blogspot.com/2015/12/inside-alu-of-armv1-...

But I'm a software engineer speculating about how hardware works. You might want to ask a hardware engineer instead.

Those aren't the only resources. I could imagine XOR takes less energy because using it might activate less circuitry than SUB.

> Code is formal, and going from C to assembly is deterministic.

OK, this is the main thing. Going from C to assembly is not deterministic in a sense because different compilers can produce different output. But the behaviour of the generated assembly is always the same. This isn't true of a spec.

> A spec is an envelope that contains all programs that comply. Creating this spec is often going to be harder than writing a single compliant program.

This perfectly explains the feeling I had when, 20 years into my career, I had to start writing specs. I could never quite put my finger on why it was harder than coding. My greater familiarity with coding didn't seem a sufficient explanation.

When writing a line of spec, I had to consider how it might be interpreted in the context of different implementations of other lines of spec - combinatorial nightmare.

But code is just a spec as far as, say, a C compiler is concerned. The compiler is free to implement the assembly however it likes. Writing that spec is definitely easier than writing the assembly (Fred Brookes said this, so it must be true).

So why the difference?

I wasn't comparing the two studies. I was just asking what the first sentence of the abstract of study 1 meant when it appears to be a false statement given study 2's result. Usually this is because I don't understand something and someone around here explains what I'm missing.

The abstract begins, "Growing evidence supports early eating to control appetite and energy balance". What does that mean? My unskilled reading of it is that there is recent evidence that eating breakfast helps with weight loss. But I'm confused because there was a 2019 meta-analysis that found that eating breakfast does NOT help with weight loss. https://www.bmj.com/content/364/bmj.l42

> try using obscure CPUs

I tried asking Gemini and ChatGPT, "What opcode has the value 0x3c on the Intel 8048?"

They were both wrong. The datasheet with the correct encodings is easily found online. And there are several correct open source emulators, eg MAME.

In the UK the wholesale price was about £80/MWh in 2025. The retail price was about £270/MWh + a standing charge. If you factor in the standing charge, an average user paid about £344/MWh. So the cost of generation was only about 23% of the retail price. I believe the green levies + CfDs accounted for about another 15% of the retail price.

Does this mean that if generation was free, and there were no green policy costs, our electric would still be expensive?

edit: "Network and Distribution" appears to contribute about 23% of the retail price. I guess green energy increased that cost because wind/solar are more spread out and sometimes off-shore.

Doh. Thanks.

We're seeing this galaxy as it was 280 million years after the Big Bang. But the universe didn't become transparent to photons until 100 million years after that (https://en.wikipedia.org/wiki/Recombination_(cosmology)). So that's impossible. Who's wrong, Recombination theory or this paper?

Or have I missed something?

Yep, I think it is. The point is there's almost no history of oral peptides, other than stomachs destroying them.

FTA: "So to summarize the state of the art in oral peptide delivery: there are exactly two FDA-approved products that use permeation enhancers to get peptides into your bloodstream through your GI tract. Both achieve sub-1% bioavailability. Both required over a decade of development, thousands of clinical trial participants, and hundreds of millions of dollars."

The British government continued to negotiate with Hitler after Kristallnacht (November 1938). They only stopped once he invaded Prague in March 1939.

Seems like it is no longer considered to be anything to do with a meteorite impact. It's hard to find a good source. This is the best I found: https://en.wikipedia.org/wiki/List_of_possible_impact_struct...

I think this paper's abstract claims that wooden debris from the landslide has been dated to 5000 years older than the Sumerian tablet: https://www.researchgate.net/publication/329153343_The_produ...

That wouldn't make me happy. If the sharpie on the tape said it was bad, I'd still look at it, sniff it and probably eat it. Certain foods scare me though. eg there's a common claim that boiled rice shouldn't be kept for more than a day and then re-heated. I follow this received wisdom even though it never seems bad and I don't know anyone who got ill from eating re-heated boiled rice. On the other hand, raw chicken does not scare me because I have an uncontrollable revulsion to it when it has actually gone bad. And of course, Camembert isn't worth eating until at least a fortnight after the expiry date.

Edit: I think that was too strong. I don't have any real knowledge of this subject. The explanation in the article seemed reasonable to me. That is all.

> The video does not counter the parents argument about measuring fit.

I know. I mainly just wanted to link that video because it is awesome.

The article does explain how the Inca did it - only the front edges are tight fitting. The gaps between the inside surfaces are filled with mortar. They sat the stone where it was to be placed, but with the front edge raised up by resting on some spacers, then just incrementally improved the fit of the edge and re-tried the fit. I'd have still thought that was impossible without seeing something like the video I linked - my intuition of what can be achieved with hammer and chisel was wrong.

Pounding stone seems reasonable to me. Obviously I don't have any proof or even strong evidence but I saw a video that changed my perception of what is possible. It showed two old men making a millstone with hand tools: https://www.youtube.com/watch?v=lscs5ZgNQrE. The amount of labour involved and quality of the finished item was astonishing to me. Maybe you'll think that the hideous amount of labour needed to make a simple geometric shape makes you even more convinced the Inca has some other way to achieve their even harder task. But it is a fun video anyway.

Similarly astonishing to me is that Michelanglo's David was carved from a single piece of marble with a hammer and chisel. I mean, just look at it: https://en.wikipedia.org/wiki/David_(Michelangelo)

Good point. I guess there are more cases than just this one where I'd like to be able to tell the compiler I don't care about rounding behaviour and would prefer the fastest code. Like -ffast-math but for integer operations. I don't think that exists. I wonder why.

Fair point. It doesn't do the optimization if you ask to optimize for size '/Os' either.

Ooo, I'd never thought of using & like that. Interesting.

> (also note you got the endianness wrong in your hand-optimized version) Doh :-)

Ah, yes, good point. I think this is a nice example of "I didn't notice I needed to tell the compiler a thing I know so it can optimize".

eg 4:

   int foo(char const *s) {
     if (s[0] == 'h' && s[1] == 'e' && s[2] == 'l' && s[3] == 'l')
        return 1;
     return 0;
   }

The outputs 4 cmp instructions here, even though I'd have thought 1 was sufficient. https://godbolt.org/z/hqMnbrnKe

Nice.

Is the best way to think of optimizing compilers, "I wonder if someone hand wrote a rule for the optimizer that fits this case"?

Hmmm, really? Switching compiler seems sufficient: https://godbolt.org/z/xnevov5d7

BTW, the case of it not optimizing was MSVC targetting Windows (which doesn't support LD_PRELOAD, but maybe has something similar?).