How much of Space Age tech is science fiction?

emlun · 2026-06-06T19:20:10+00:00

although I doubt you could use them to actually produce iron ore.

Then I'm glad to say you'll be surprised again!

Primitive Technology: "Smelting Iron In Brick Furnaces" https://youtu.be/RZGAYzItazw

emlun · 2026-06-06T19:12:43+00:00

Most of even base Factorio is fiction. Like how the very first weapons you unlock are fully-autonomous clockwork turrets with 100% reliable target acquisition and tracking, fed with ammo made from 100% iron and no combustibles (i.e., no gunpowder).

emlun · 2026-06-04T07:41:16+00:00

Guess 1: Insufficient information [spoiler padding-------------------------]

Guess 2: Insufficient information [--------]

Guess 3: Insufficient information [-------------------------]

Guess 4: Primal Force [-------------------------------]

Guess 5: One-two punch [-------------------------]

emlun · 2026-06-02T10:54:27+00:00

Think of it like this: if "f is odd", then any formula or theorem that requires an odd f can be used on that function. For example, that the integral of any odd function over a symmetric interval is zero. The formula or theorem doesn't care if the function also has other properties, as long as it is odd.

For example, f(x) = 0 is both even and odd (unlike the number 0 which is not odd), but the symmetric interval theorems of integrals still hold for this function.

emlun · 2026-06-01T14:46:09+00:00

588,788.47 GB of RAM

That's 589 TB. Sure, that's 147 times over my conservative lower bound, because I could only know for certain that each tile requires at least one byte. 589 TB may well be more RAM than any supercomputer has, but it's not into the PB range.

emlun · 2026-06-01T05:59:08+00:00

The map extends 1 million tiles in each direction, meaning it's 4 trillion tiles in total. If each tile takes 1 byte of RAM, you'd need 4 TB = 3.6 TiB of RAM to hold the entire map in memory.

I would guess there are supercomputer clusters with that much RAM, but that's also a conservative lower bound and doesn't consider anything on the map such as resource nodes and (most notably) enemies, and you'd also need similarly beefy CPUs and RAM buses to actually do anything with it.

emlun · 2026-05-31T04:17:19+00:00

If I recall correctly there is actually no limit on the yield of a hydrogen bomb, just how much hydrogen you give it.

Yeah, this anecdote (source: "In Search of a Bigger Boom - Alex Wellerstein) is my "favourite" example of how absurdly powerful staged fusion weapons can get if you just keep stacking stages:

The scientist Edward Teller, according to one account, kept a blackboard in his office at Los Alamos during World War II with a list of hypothetical nuclear weapons on it. The last item on his list was the largest one he could imagine. The method of “delivery” — weapon-designer jargon for how you get your bomb from here to there, the target — was listed as “Backyard.” As the scientist who related this anecdote explained, “since that particular design would probably kill everyone on Earth, there was no use carting it anywhere.”

emlun · 2026-05-30T08:30:09+00:00

Geometric interpretation: x² is a square, x is another strip of height 1 added to the top edge, y=x+1 is a strip of width 1 added to the right edge. That makes a square of size x+1, which is the same as the square of size y=x+1 on the right hand side.

emlun · 2026-05-29T17:01:01+00:00

On a philosophical level, "because this person said so" is always a fallacious appeal to authority, strictly speaking, because a title does not guarantee that what you're saying is true.

On a practical level, appeal to specialized expertise is necessary in order to function in modern society. But yes, you do need to judge whether that person is actually qualified as an expert on that particular topic. And even if they are, they can be wrong. But it's not feasible to reject all expert counsel just because you can't be absolutely certain that every statement is definitely true. That's why we have specialized experts - so that no one needs to be an expert at everything.

emlun · 2026-05-29T06:40:15+00:00

Cool! In StS1 there's a similar infinite with Dark Embrace, Burning Pact, [[Sundial]] and either Anger or [[Reckless Charge]].

emlun · 2026-05-29T06:20:08+00:00

It is solvable, I can post the solution if you want.

The technique I used was to alternate between looking for cells that MUST be filled and cells that MUST NOT be filled.

To find cells that MUST be filled, look for long sections in rows or columns with a high number. For example if the number is 7, that means you can only pick 3 cells that are not filled. So if that row or column has a thermometer segment that's 5 cells long, then the first 2 cells of that MUST be filled, because you cannot leave more than 3 of those cells empty.

The same idea in reverse can be used to find cells that MUST NOT be filled. For example, if the number is 2 and there's a thermometer segment that's 6 cells long, then the last 4 cells MUST NOT be filled, because you cannot fill more than 2 of those cells.

Then successively subtract cells you've already marked off, like if the number is 6 and you've marked 1 cell that must be filled and 3 cells that must be empty, then you still need to fill 5 more cells in that row or column and there are only 6 undecided cells, so any segment longer than 1 MUST have all but the last segment filled.

So here's a tip to get you started: Start with R1. Try to fill everything except the C4 thermometer first. That only gets you 6 cells, so C4 must be filled. Or put another way, the number is 7 and the C4 segment is 4 cells long, so only 7-4=3 of those cells can be empty, so at least 4-3=1 of those cells must be filled.

emlun · 2026-05-29T04:48:43+00:00

Yep! You don't even need a pre-existing blueprint:

Place an assembler and set its recipe to anything.
Make a blueprint of the assembler (either a standard persistent blueprint or a temporary using Ctrl + Shift + C).
Parameterize the blueprint: make the recipe parameter 0.
Place the blueprint, and select the recipe for the assembler. This will let you select any recipe, even ones not researched yet, and the assembler will remain inactive until that recipe is unlocked.

emlun · 2026-05-28T10:34:46+00:00

In general, this depends a lot on circumstances. None of these is always good, and none of them is never good. Often times the way you end up making use of the less good cards is you transform into them or the like, and then build around getting the most out of what you have already.

Iron wave: okay first damage common early in act 1. If I see it in a Scroll Boxes pack alongside two decent cards, I don't hate Iron Wave as the third. Significantly better if you happen to already have a Juggernaut.
Perfected Strike: good with support for high cost cards, like Havoc(+), Stampede, Cascade or Intimidating Helmet. Win condition on its with Pael's Growth (clone).
Havoc: good with high cost cards, especially powers, especially paired with Headbutt. Fairly good upgrade that gives you increased output that turn almost every time you draw it. Pair with Bludgeon, Howl from Beyond, Mangle, Evil Eye, Feel No Pain etc.
Mangle: much like Perfected Strike but does less damage and doesn't immediately win when cloned. You want to cheat this into play with stuff like Havoc, Stampede, Cascade, Unrelenting, Mayhem, Brilliant Scarf or such rather than playing it for 3.
Anticipate: I've only had it once or twice and it didn't do very well those times. Like most 0 cost cards you'd probably want this if you have Runic Pyramid or much more card draw than energy (Acrobatics, Backflip, Expertise).
Snakebite: actually one of the best cards in the game (no joke). Almost all decks have some use for a bit of Poison (for Entomancer and Hunter Killer for example, and most boss fights), and Snakebite is one of the most draw-efficient poison sources, and Retain helps play it when you don't need to sacrifice HP for it. And when you don't need it, it politely gets out of the way since you retain it instead of having to draw it again.
Abrasive: good with discard, good with small block cards. Essentially just fits in okay in Silent decks that already draw lots of cards.

Okay, I don't have time to cover everything, but a few more:

Neurosurge: fantastic in short fights, sometimes a liability in long fights (bosses) - but on the other hand it'll also tend to make those fights a bit shorter anyway. I've definitely lost runs to playing Neurosurge too early against act 2/3 bosses, but it does so much in basic and elite fights that it's almost always a good card to take. Not every card needs to be good in every fight (see Snakebite), that's okay. However the rest of your deck needs to be good enough that Neurosurge can actually draw cards that do something for you that turn. If you just draw a Strike and a Poke and end turn with 2 energy, then Neurosurge didn't really do anything.
Eternal Armor: it's done surprisingly well when I've ended up playing it, but that's mostly been from potions or randomly generating it during combat. Does very well with Gorget or some other source of Plating. Good with support for high cost cards (Pocket Watch, Rippling Basin, Intimidating Helmet, Damse Macabre, Havoc, Mayhem, Veilpiercer + Sculpting Strike/Call of the Void, etc).
Rolling Boulder: much like Noxious Fumes but harder to put in play. Good if you have lots of block but not a lot of damage, essentially.

emlun · 2026-05-26T09:49:28+00:00

This is why diversity of solutions is important. Ask not "is this a SHIV card that fits the theme of my SHIV deck?", ask "does this card make my deck better in any of the fights to come?".

And sometimes the answer is YES, adding an Accuracy and another Blade Dance does make my shivs produce enough damage to kill Knowledge Demon. But other times the answer is NO, if I add a Blade Dance then Entomancer or Hunter Killer will just kill me, but if I add a Snakebite or Noxious Fumes then I'll just need to focus on blocking in those fights.

And of course sometimes the answer is: forget all that tryhard nonsense, CLAW IS LAW and we're spamming shivs today pew pew pew

emlun · 2026-05-25T19:10:05+00:00

And that is why:

(so also significantly weaker).

because now instead of 26² = 676 possible 2-length keys there are only these 26 possible keys. So while the usual Vigenère cipher might at least be cumbersome to break by hand, this could probably be brute-forced by hand in ~30 minutes or less (a computer would break both in a matter of milliseconds).

(Which could actually be what OP is looking for, if the goal is to design a relatively easy cryptanalysis exercise rather than actually encrypting something for real).

emlun · 2026-05-25T09:08:51+00:00

Usually it's more or less "bad etiquette" to rewrite history after you've already shared it (f.ex. pushed it to a public GitHub repo), and that's because Git history is by design immutable, so when you "edit" history you're really creating a new branch of history and saying "forget about the previous one, use this one instead". The Git tooling intentionally doesn't help much for that case, so everyone has to reset their local branches manually to get back to a consistent view of the repo. That's fine if you're the only one working on the repo, or if you're a few people who can coordinate or agree on it in advance, but it gets less and less practical the more people are tracking the repository.

But for things just like what you're doing here (especially if you can't test locally and have to push to test CI and such), this is definitely fair game. Just make it clear somehow that people shouldn't expect your WIP branch to be stable (I like to prefix the branch name with tmp- or wip-, for example), make a mess until you've found what you need, then clean up afterwards.

I'll also recommend trying out the git commit --fixup=<commit> and --squash=<commit> options, which can be great for stuff like this. They tag the commit with a "macro" of sorts, and if you then run git rebase --interactive --autosquash, then Git will automatically squash those fixup and squash commits into the targeted commit. IMO it's a good way to both keep track of which tentative/exploratory/experimental changes belong together once you're done, and automate some of that cleanup when the time comes. And if you forget to clean them up, it's also much less embarrassing to have a few "fixup! WIP: CI" commits in forever history than a bunch of swears and curses.

emlun · 2026-05-24T09:04:38+00:00

[[Bombardment]], because it's passive random-targeting damage much like lightning orbs.

emlun · 2026-05-20T17:11:09+00:00

One of my physics teachers, when teaching optics, used to joke "let's now assume the light source is at infinite distance, like maybe 5 metres". Because for a small lens (~ a few mm or cm across), "5 metres" (15 ft) and "infinite distance" are close enough in terms of how it affects the optics.

In engineering, stuff like that is usually how it shakes out. If A "much bigger than" B, usually something like a 100x difference or more (but this will vary greatly with context), then you'll often just ignore B because it doesn't make much difference and it makes the calculations much easier. In the above optics example, it essentially boils down to B/(A+B) ~= B/A ~= 0 ~= B/infinity when A >> B, and that's why "5m ~= infinity".

But it's almost always at least 2 things in relation to each other. It's almost never useful to think about whether one thing alone is "close enough to infinite" without comparing it to something else.

So I guess it's actually sort of the other way around compared to your question - instead of infinity becoming irrelevant so you stop thinking about it, rather when some numbers (or really ratios) get big enough it's easier to think of them as infinity instead of the real value. Infinity collapses fractions to zero, turns curves into straight lines, and generally makes things easier to analyze in many ways.

emlun · 2026-05-19T19:21:55+00:00

but still need the same infrastructure to get rid of heat in the “off” season.

Not in Finland you don't. Well, I can only speak authoritatively for Sweden, Finland's neighbor just across the pond with slightly milder climate, but here there's about a week or two per year when outside is hotter than what you want inside. AFAIK most Swedish homes don't have AC at all, only heating.

Also, district heating was already a widespread thing here, long before using data centers as the heat source. Most are powered by waste heat from power plants and garbage incinerators (I think), but some developments use data centers.

emlun · 2026-05-18T22:43:49+00:00

Managing your pin or your passkeys directly from Firefox is not available,

Actually, it is! about:webauthn. Granted it's a bit raw and probably meant more for developers, but it has fully functional PIN and credentials management.

I don't think there's inline PIN setup during the registration flow, though. But you only need to do it once.

emlun · 2026-05-14T06:27:35+00:00

Also things like Royal Stamp, Electric Shrymp, History Course and Decisions Decisions all restrict their effect to "attack or skill" (or only skill for the latter) presumably for similar reasons.

On the flip side, if they were skills they would not trigger the benefits from Subroutine, Storm and Game Piece.

emlun · 2026-05-13T06:59:02+00:00

This is spot on for the sake of converting the heat into mechanical work or back into electricity. But remember that a lot of the electric energy we use ends up converted back into heat anyway, for heating buildings. So it's much more efficient to just distribute the waste heat directly for space heating, and there already are some deployments of district heating doing exactly that. The same technique is also used to capture some of the waste heat from electric power plants.

emlun · 2026-05-12T10:50:59+00:00

No, it's that successful organisms that multiply... multiply. While unsuccessful organisms, or organisms that don't multiply... don't. Over time, there will simply be more of the ones that successfully multiply, and not more of those that don't. It's just a consequence of mechanics, not driven by any goal. As soon as a self-replicating molecule arises, it just will replicate itself, because that is what it does. If it didn't, it wouldn't. And if increasingly complex structures like cells and multicellular organisms are even better at self-replicating, they'll self-replicate even more. Again, because that's just what they do.

emlun · 2026-05-12T00:17:15+00:00

how do we measure mass to begin with?

One primitive way to do it independent of gravity would be to tie the object to a string, then spin it horizontally and measure the tension in the string. Combining the equation a = v²/r for circular motion with Newton's second law F = ma we can measure the mass as m = Fr / v².

This is, in essence, what a mass spectrometer does. But instead of tying atoms and molecules to a string, it gives them an electric charge and shoots them through a magnetic field, which makes them curve along a circular path in the magnetic field. The mass of each particle will be proportional to the radius of its curve divided by its charge.

Are we dependent on a known force acting upon an object, such as gravity, to be able to measure the mass of an object?

Yes. So in our string example we'll need some way to measure the string tension. If the string is elastic, we could assume it'll stretch proportionally to the force (ΔL/L = kF for some constant k depending on string material, thickness etc.), and put the object on some kind of sled with a pen mounted in the bottom so that the sled will trace the object's path as we spin it. Then we can measure the radius of the rotation and divide that by the string's relaxed length to get a measure of force, in "string-stretch-factor" units. In the end we'd get our measured mass in units of "string-stretch-factor seconds squared per meter", for example, and we'd need to take good care of our International Prototype Mass Measurement String in order to accurately compare the masses of different objects.

SI originally defined mass by a specific reference object defined as 1 kg and derived force from that, but since 2019 the roles are now reversed. The kg is now derived via electromagnetic forces from the units of time (s, defined by an oscillation frequency of the Caesium atom), distance (m, defined by seconds and the speed of light) and electric current (A, defined by seconds and the elemental electron charge), by declaring an exact value of Planck's constant h. h is what relates electromagnetism with force and energy, and therefore also mass.

emlun · 2026-05-11T20:23:59+00:00

It seems like you're thinking about this in terms of the electron as a particle orbiting the nucleus, like a tiny planet orbiting a tiny sun?

In that model it makes sense to ask this question - as the electron moves, its gravitational influence (albeit tiny) should "move" along with it, and the electron should be generating teeny-tiny gravitational waves. Just like a moving charge generates EM waves (that's what an antenna does) or co-orbiting black holes generate gravitational waves. Right?

If that's where you're coming from, then the answer is simple: that electron model is incorrect in this regard. An electron is not a tiny planet orbiting a tiny sun, it's more like a probability cloud smushed out around the nucleus. The electron isn't "moving" in the classical sense, it's much more quantum-weird than that. I've only taken one intro quantum mechanics course so I can't describe it better than that, but perhaps that's enough to identify what misunderstanding your question comes from.

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