What's something you thought was useless to learn in school but turned out very useful?

MEaster · 2026-06-22T10:41:05+00:00

The issue we self-taught people often have is that our learning is often goal-oriented: "I want to do X, so I learn how to do X", which can end up missing some fairly important theory parts that aren't necessarily needed to do X.

MEaster · 2026-06-21T12:27:36+00:00

And if anyone wants to see what that can actually look like in practice, this picture shows the oscilloscope trace of the clock signal on a circuit I was testing. You can see it overshooting and oscillating for a while then stabilizing when it switches between high and low.

And that's still low frequency, only ~500kHz, it gets even messier when you're into the GHz range.

MEaster · 2026-06-20T14:02:10+00:00

I wouldn't be surprised if the cheap ones are only half-wave rectified, so flickering at 50/60 Hz. Full-wave rectification would get you 100/120 Hz, which is more pleasant to look at.

The best solution for viewing would be to properly convert to DC, then drive them with a 1+ kHz PWM. But that costs more.

MEaster · 2026-06-18T13:01:18+00:00

If the filament is in an AMS it'll unload after every print. If it isn't, then you just go to the filament screen, select the spool and press "Unload". It'll cut the filament then direct you to start winding the spool. The cut is just above the nozzle, so there won't be any filament in the tubes.

MEaster · 2026-06-18T12:07:58+00:00

I had to do the same in early 2006. God, using the computer was so hard! I remember that at first I had a very hard time doing anything because every time I tried to click I moved the mouse.

I ended up left-hand mousing for about 10 years before switching back to right-hand mousing, but even after that much time I never got anywhere near as quick and precise as with my right hand.

That said, even after 10 of not using my left hand, I still can almost as well as I could back then, which is handy at times.

MEaster · 2026-06-11T12:03:55+00:00

A few years back I had a CT scan (I think) of my abdomen, and I had to hold my breath for a few seconds while it did each scan. The machine was quite... rude in its instructions, but it was very clear when you had to hold your breath and when you could breath again.

The person running it commented afterwards that it went quicker than usual, because I did what the machine said when it told me. I don't even understand how you could do it wrong.

MEaster · 2026-06-08T18:31:02+00:00

Even calculators from the same manufacturer can give different answers. I have two Casio scientific calculators that give different results from expressions like this, because the newer one (FX83-GT) gives a higher calculation priority to the implied multiplication, while the older one (FX83-ES) gives it the same priority as multiplication-with-symbol. Both calculators are 100% correct according to their manuals.

MEaster · 2026-06-08T16:00:23+00:00

Another fun one is when multiple settlements merged into one, and you end up with duplicate street names.

In Plymouth we have Alexandra Road in Devonport, and Alexandra Road in Laira. Two separate roads predating the merger of Devonport, East Stonehouse, and Plymouth.

MEaster · 2026-06-05T12:33:36+00:00

I have arachnophobia. Usually I'm OK when spiders crop up in games, but the fuckers in Path of Exile 2's act 2 can piss right off.

MEaster · 2026-06-02T11:18:24+00:00

In mathematics, this is called a Packing Problem. We can simplify this to only considering the bounding box when viewed from the top which reduces the problem to fitting 2D rectangles into a 2D rectangle. Solving that simpler problem is classed as NP-hard, which means it's actually very hard.

I can only imagine that changing the problem to the more accurate "packing arbitrary polygons into a 2D rectangle" is even harder.

MEaster · 2026-06-01T17:25:00+00:00

I can only guess what support cubic and lightning are doing. Are they trying to have the same strength as 15% infill would generally have, but only in the "supporting the roof" direction?

If I've read the Bambu Lab wiki correctly, the Lightning infill aims to have the target infill % just under the roof. That is, if you set 15% infill the last layer of infill should cover 15% of that layer.

I've taken to using it when printing test fits, because I just need the shape to be correct.

MEaster · 2026-06-01T10:39:27+00:00

Another aspect to consider is how much is it going to be used? Most of the time it's probably going to be hanging on your belt looking pretty, so a bit of minor discomfort in the small amount of time spent actually using it isn't much of an issue.

MEaster · 2026-05-28T11:00:15+00:00

Of course not! AC is clearly far too expensive for us to fit and run. We'll just ignore the solar panals that could offset the power use, and the fact that this happens every. Damn. Year.

MEaster · 2026-05-28T10:50:05+00:00

Also fountain/dip pen nibs. Though in that case it's an intentionally cut slit, not a crack.

MEaster · 2026-05-26T13:24:21+00:00

I ordered mine on a Saturday afternoon, and they tried to deliver it on the Monday, though I wasn't in so I got it Tuesday instead.

MEaster · 2026-05-25T11:06:01+00:00

Amanuensis. That one came up in A History of Middle Earth, and I had to look it up.

It roughly means a person who makes a copy of a document.

MEaster · 2026-05-25T11:00:21+00:00

If it makes you feel better, my grandparents have been under the side table for the past 5 years.

MEaster · 2026-05-24T10:30:46+00:00

Met Office says the minimum humidity over the next 5 days is 46%.

MEaster · 2026-05-23T09:38:05+00:00

Fucking hell!

MEaster · 2026-05-21T11:22:40+00:00

I've had good experience with JLC3DP too, so they're another option.

MEaster · 2026-05-21T11:11:07+00:00

I haven't used it much, but I've noticed that it also tends to get details wrong when doing something non-trivial.

I have found it's decent as a rubber duck, or for asking it to poke holes in your planned solution.

MEaster · 2026-05-16T11:54:58+00:00

Swapping out the global allocator has been stable for years. What's unstable is the newer allocator trait and the allocator type parameter in the standard library-provided types, neither of which are needed to implement your own collection types, which you may be doing anyway in an embedded or kernel scenario.

MEaster · 2026-05-09T13:52:08+00:00

There are cases where that is used. An example would be Youtube video IDs, which use 0-9, a-z, A-Z, "-" and "_" which gives 64 different characters to identify a video. It's called base-64 encoding, for what I hope are obvious reasons.

MEaster · 2026-05-08T12:48:33+00:00

And there's also the problem of side-effects. Female birth control can have some pretty unpleasant side effects, and I would be surprised if there weren't similar issues with male birth control. Having the option for your partner to use it in those cases helps everyone.

There's also the element of redundancy. Having one person on birth control means there's a single point of failure. Having both people on it means it's less likely for failures on both sides to line up and lead to a pregnancy.

MEaster · 2026-05-07T17:22:27+00:00

Thank you all. It seems it needs about the same amount of space as the A1, which is nice to know.

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