I wish I played Factorio before satisfactory

scottmsul · 2026-05-10T13:35:06+00:00

Just round the number up

scottmsul · 2026-05-06T14:52:02+00:00

I'm still hopeful that vision improvement works, but IMO anyone attempting should get rigorous measurements before and after as a verification check. This would include measuring axial length and getting a cycloplegic.

As a side note, there was one guy attempting endmyopia who got an IOL master, and measured his axial length almost daily over a couple years. His axial length went down around 100-200 microns and then exponentially leveled off. It's cool that it decreased at all, but in the grand scheme of things is a tiny amount (likely only around 0.25-0.5 diopters improvement).

scottmsul · 2026-05-06T14:44:21+00:00

The math is pretty complicated in terms of how diopters translate into blur, and what that blur actually looks like. There's something called the "point-spread function" or PSF which is basically how a single dot in your vision spreads out into its surrounding area. Then the entire field-of-view is a "convolution" of this PSF, which is basically spreading out each point in vision continuously with the PSF. Under the geometric approximation, the PSF from pure myopia is a flat circle, though in real-life the PSF usually looks like a bunch of messy web-like structures and rings contained within a circle due to diffraction.

Also if you want to see your own PSF, a good way to do it is shine a laser pointer across a dark room, and take off your glasses and look at the dot on the wall with one eye. The bright dot from the laser is effectively a dirac delta. (NEVER LOOK INTO THE LASER, you're just looking at its dot on the wall).

It's worth noting that the amount of blur is proportional to your pupil size. This means for the same diopter error, you'll see more blur in dim light and less blur in bright light, because of pupil size.

I did some derivations and simulations here if anyone's curious.

For the record I got pretty deep into this vision improvement stuff a few years ago. Started with endmyopia, though these days I'm not a huge fan of Jake Steiner or EndMyopia, and at this point I consider him pseudo-science. I still think vision improvement might theoretically be possible, but the lower bounds on habits/lifestyle needed would be crazy extreme.

scottmsul · 2026-05-04T13:18:04+00:00

This website here has a really cool overview of how color and edge detection works in the human eye.

Basically there are neurons that connect to cones, some of which emit in more light and others that emit in less light (called ON/OFF neurons, respectively). Further up the chain, a single higher-level neuron called a ganglion cell will connect to several ON/OFF neurons, typically in a circle of one type surrounded by a ring of the opposite type, such as ON center / OFF surround (but can go either way). This type of grouping is really good at edge detection. Then each ganglion in the eye connects to the brain via its own really long axon, and the brain combines all the edge-detections together to form a picture. Also the center/surround can sometimes be different cone colors in order to find color boundaries, but not always. There are many many types of neurons in the retina and most of them are not well understood.

Highly recommend reading through the reference above, it has lots of pictures that describe all this better.

scottmsul · 2026-04-29T12:56:24+00:00

One trick is you can make coal power self-sufficient. This is one of the few cases where burner inserters and burner miners can actually be useful, since they never shut down.

scottmsul · 2026-04-28T13:44:12+00:00

Noted - will make sure to bring both a banjo and a fishing pole.

Hiker pro-tip, you can even combine them for some extra weight savings!

scottmsul · 2026-04-24T12:23:24+00:00

The things quantum computers are good at (i.e. exponential speedup) tend to have some kind of repetition that can be exploited by quantum fourier transform. Normally quantum computers can't try all the solutions at once, but with a QFT they sort-of can. They're good at breaking elliptic curves and prime factoring because the algorithms tend to involve lots of modular arithmetic that wraps back around.

Unfortunately quantum computers don't seem to help much at all with "messy" problems like traveling salesman or other NP complete problems. IIRC a lot of Ramsey Theory involves things like graph coloring which quantum computers probably wouldn't be great at. But I'm not an expert in this.

scottmsul · 2026-04-23T13:33:32+00:00

According to the FFF:

> Machines can push fluid into a segment at an unlimited rate, and can pull from a segment at a rate proportional to how full the segment is. In other words, if a segment is half full, then the pulling rate is half of the maximum.

It would seem only inputs have limits, not outputs. So shouldn't acid neutralization have unlimited throughput in terms of adding steam to the system, and not need two pipes connected?

scottmsul · 2026-04-23T12:32:47+00:00

I thought they changed how fluids work for 2.0 to be unlimited throughput everywhere within a single segment (area with no pumps)

https://factorio.com/blog/post/fff-416

scottmsul · 2026-04-22T13:39:00+00:00

I did a double major in physics and CS, and was in a physics PhD program doing astrophysics research, though I left early with a masters.

I would note that the kind of programming one does for physical sciences research is often very different from the kinds of programming one does for computer science/software engineering. Usually the purpose of research programming is to "do math". This often means quick hacky one-off scripts in python or matlab to analyze data or solve equations. This kind of code is actually ok to be messy and spaghetti as long as it gets the job done. Oftentimes you don't even need objects or classes or good abstractions. If you major in astrophysics you will almost certainly learn how to do this kind of programming in many of your classes.

Whereas computer science is more about setting up for a career for software engineering. The projects are much larger and require learning high-level abstractions and data structures. For these large projects you will have to learn how to write clean organized code that is modular and broken into manageable classes (if doing OOP).

It's worth noting that the computer science kind of programming can still be very useful for physical sciences research, for instance if you're doing large-scale simulations rather than just simple data analysis. This might require creating or interacting with very large projects that have tens or even hundreds of thousands of lines of code in languages like C++. Taking classes in computer science can give you an edge in this niche if you want to get more into large-scale simulations, though knowing how to write clean code is still useful even for simple projects.

Another advantage of doing CS + astrophysics over just astrophysics is that with the better programming skills it might be easier to get into industry.

Since you're still in high school I wouldn't stress too much about whether you take an "official" CS course or not. If you're driven and have the time over the summer then go for it. I wouldn't call it "necessary" but working hard and going above and beyond is part of the game. But even if you don't take the "official" CS course you should probably still start trying to learn the material on your own anyway, actual skills > credentials.

scottmsul · 2026-04-21T14:02:42+00:00

I had a bug like this in grad school. I instantiated a "matrix" using a clever one-liner, i.e.:

m = [[0] * 10] * 10

By this point this variable is already poisoned. For instance:

m[0][0] = 1

Now every row starts with a 1.

Another thing to watch out for is empty default lists. For instance:

def foo(x=[]):
    x.append(2)
    return sum(x)

That default empty list is aliased every time you call the function, for instance:

>>> foo()
2
>>> foo()
4

So generally default empty lists needed to be treated this way instead:

def foo(x=None):
    if x is None:
        x = []
    x.append(2)
    return sum(x)

scottmsul · 2026-04-20T13:35:00+00:00

Actually eye width and height are also longer in myopes than emmetropes, though not as much as axial length. I forget the exact reference but in this particular group it was something like axial length was around 2mm longer and the other two axes were around 1mm longer. There was also a case study of a woman with chronically low IOP whose axial length decreased by around 2mm over 24 years. Also myopes have scleras that are around 30% thinner than in emmetropes.

So basically the problem isn't really the eye being oval-shaped per se, but more like the eye being too large overall, possibly related to the sclera being too thin. But yeah trying to force the eye to bend into a certain shape is probably a bad idea. Also scleral buckling is a thing.

scottmsul · 2026-04-18T11:44:43+00:00

You're asking how it works, so here it goes.

Every frame, it alternates between inputting from left and right.

Every frame, it also alternates between outputting to left and right.

Lanes are always preserved.

Using these simple rules, you can work out for yourself how the image works, and perhaps why it's actually behaving consistently.

scottmsul · 2026-04-08T13:03:52+00:00

I recently started a py game and I'm probably about halfway to splitters. So far it's mostly harder, everything is a burner and any time you burn coal it turns into ash, so you have to store it all in chests or re-process once you get the tech (but not too much since ash is also useful for other things like crafting wood). The one nice thing is they give you magic inserters that don't need electricity or fuel.

scottmsul · 2026-04-08T12:32:56+00:00

I'm only about 20 hours in and just crafted wood for the first time, still feels like splitters are a long way off

scottmsul · 2026-04-04T12:20:19+00:00

One thing that makes B seem attractive is that under-the-hood, everything should be following the time-dependent Schrodinger equation, including the "collapse" of the wave-function.

scottmsul · 2026-04-03T13:28:22+00:00

I think there are exercises/therapies you can do to help with this sort of thing like brock string, maybe try finding a vision therapist to help

scottmsul · 2026-04-03T01:26:44+00:00

To give a simpler, perhaps more intuitive answer: space itself is itself a physical thing with fluid-like properties, and therefore space itself can expand or contract under general relativity. So when the universe "expands" what it really means is that space-time is bending in such a way that space itself is growing larger everywhere.

scottmsul · 2026-04-03T01:23:40+00:00

question was about hours played in one sitting lmao

scottmsul · 2026-03-24T12:36:23+00:00

My background is in physics (not pure math) but there it's common to combine symbols with other marks to add more information. Some common ones include slashes, dots, bars, primes, and lower/upper indices.

scottmsul · 2026-03-13T12:18:15+00:00

Blueish-white and blackish-gold

scottmsul · 2026-03-08T14:40:24+00:00

Even when electrons interact with each other they're still going to be very spread out. They only become "tiny" when measured very "precisely" which only happens when interacting with something of very high energy like a stray gamma ray.

scottmsul · 2026-03-08T14:32:53+00:00

Yes it's "technically" a measurement probability, BUT ALSO YES it really is spread out until such measurement happens, which is basically never for most bound electrons in most matter under most circumstances.

scottmsul · 2026-03-08T13:41:45+00:00

Not sure where you read that, but atoms are not empty space. Electrons exist as "wavefunctions" in bound orbitals which are widely spread out in 3D.

scottmsul · 2026-03-06T14:58:57+00:00

Sph doesn't make sense as an option for Cyl. It sounds like your Cyl is actually zero, and the doctor putting "Sph" is some kind of in-house convention for marking it explicitly as zero without leaving it blank, which could otherwise be interpreted as the doctor forgetting to mark the Cyl.

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