Dan Piponi

It's very silly but often when I see a photo (or movie/TV scene) I'm tempted to use tools like Google maps to track down the exact location.

Anyway, my reading is a random walk through book-space and I find myself reading a kids' book about magic cats […]

[Original post on mathstodon.xyz]

@BoydStephenSmithJr @TechConnectify I haven't had good tasting results making tea from microwaved water. I don't know why not. It is slightly weird - adding a teabag to a boiled cup of water causes rapid local boiling, I guess the tea acts as nucleation points for superheated water. Maybe I […]

Living in a country where if you ask for a cup of tea in a restaurant they'll bring you a cup of lukewarm water and expect you to dunk a teabag in it I shouldn't be too surprised that I can't buy a decent electric kettle. This time I decided to get an expensive one rather than a cheap one that […]

A graph with two plots showing near identical outcomes for a fight against multiple foes and a fight against a single foe with suitably chosen stats.

Now I have a somewhat functioning library for dice game simulation I can do with it one of the things I originally intended.

The crunchier RPGs can lead you to situations where you have to resolve complex fights with many participants and it'd make sense to […]

[Original post on mathstodon.xyz]

@futurebird Reminds me of the Roman baths under King's College London where I was a grad student. I told lots of people how amazing it was. And then with the advent of the Internet I learnt they weren't Roman at all.
https://en.wikipedia.org/wiki/Roman_Baths […]

"So not binary but base four. Quaternary. This won’t be easy to crack."
So that bit was laughable. But the rest was excellent, and laugh out loud funny towards the end.
(Plur1bus.)

A histogram almost flat between its endpoints.

A "triangular" histogram going up from zero and then back down. Not symmetric.

A slightly skewed Gaussian histogram.

I can't believe I didn't know this fact before today - it seems so fundamental.

If you have a real symmetric matrix A, and pick some unit vector x, then x.Ax (the Rayleigh quotient) is bounded by the smallest and largest eigenvalues. So what happens if I pick […]

[Original post on mathstodon.xyz]

I wonder how many people the Apple Podcast app has killed. The amount of interaction and puzzle solving to get it to do the simplest thing must have fatally distracted several drivers by now.

@djspiewak @skewray It's not so much the memcpy that's the issue but if you want to copy data from old blocks to new blocks, deleting the old blocks, you need to be sure no data in the old block isn't still in use by some thread. The page table is really small. Profiling will tell...

@djspiewak @skewray Probably not a lot if your matrices are large.

The reason I was thinking about this subject is that I was playing with a scenario where it does matter: I wanted a concurrent (single producer/many consumer) expandable array with stable elements so instead of copying to the […]

@djspiewak @skewray And personality type :) I've a tendency to want to be a bit more careful with memory usage even when it's clear I have the resources to be a bit more profligate.

@skewray @djspiewak I feel like a 30% or so "tax" on memory allocations is a bit steep, especially in applications with heavy usage of this kind of array. So just by feel I'd use something around the golden ratio for A. There's an argument that precisely this value is optimal though I don't […]

A common strategy when implementing arrays that grow at the end is to allocate space for N bytes initially and then when more space is required resize to a block of size AN for some A, typically in the range (1, 2], and then keep reallocating as needed scaling […]

[Original post on mathstodon.xyz]

A large looking Lego model of the STTNG USS Enterprise with 9 crew minifigs.

https://www.lego.com/en-us/product/star-trek-u-s-s-enterprise-ncc-1701-d-10356

Woohoo! An official Lego Spot the cat. And a spaceship for her to live on.

Helix doesn't seem to let me resize windows. Of course I could run tmux or similar to carve up my terminal window. But not on Windows. However, vim supports resizable terminal windows fine on Windows so problem solved: launch vim and a helix in each of its windows.

If I had to describe in one word the political system in the US it'd be: nomic.

Such a nice paint job, inside and out. At the De Young museum.

Enjoying watching the marine layer float through the neighbourhood this evening.

@aniccia.bsky.social Most cars are not in use most of the time which is why I think I was seeing more Waymos than anything else in some areas. Entire "trains" of them at one point.

When I started at Google X years ago project Chauffeur, which eventually became Waymo, was pretty new. I feel like it took a significant piece of a lifetime to turn the idea into a reality and now it seems like Waymos are the most common car on the streets of San Francisco. But I only took my […]

@brouhaha That sounds, well, illegal.

Finding myself having to explain to Kobo that their no-return policy is irrelevant when they've just illegally sold me a DRMed book that was described as DRM-free.

@dougmerritt I'm not sure if the clocks all report their resolution and "calibrating" it yourself is an easy way to find out. I think resolution (and monotonicitiy) is an important requirement here.

@unnick Ha, no! I think they're local things like ntp (maybe, not sure).

Astronomical Engineering: A Strategy For Modifying Planetary Orbits - Astrophysics and Space Science The Sun's gradual brightening will seriously compromise the Earth'sbiosphere within ∼ 109 years. If Earth's orbit migrates outward,however, the biosphere could remain intact over the entiremain-sequence lifetime of the Sun. In this paper, we explore thefeasibility of engineering such a migration over a long timeperiod. The basic mechanism uses gravitational assists to (in effect)transfer orbital energy from Jupiter to the Earth, and therebyenlarges the orbital radius of Earth. This transfer is accomplishedby a suitable intermediate body, either a Kuiper Belt object or a mainbelt asteroid. The object first encounters Earth during an inward passon its initial highly elliptical orbit of large (∼ 300 AU)semimajor axis. The encounter transfers energy from the object to theEarth in standard gravity-assist fashion by passing close to theleading limb of the planet. The resulting outbound trajectory of theobject must cross the orbit of Jupiter; with proper timing, theoutbound object encounters Jupiter and picks up the energy it lost toEarth. With small corrections to the trajectory, or additionalplanetary encounters (e.g., with Saturn), the object can repeat thisprocess over many encounters. To maintain its present flux of solarenergy, the Earth must experience roughly one encounter every 6000years (for an object mass of 1022 g). We develop the details ofthis scheme and discuss its ramifications.

It did actually get published in a journal:

https://link.springer.com/article/10.1023/A:1002790227314

It must be serious :)

I feel like this is an excellent problem to investigate using automatic differentiation.

I couldn't get through Wandering Earth. Meanwhile here's how you actually move the Earth:

https://arxiv.org/abs/astro-ph/0102126

"In this paper, we have investigated the feasibility of gradually moving the Earth to a larger orbital radius in order to escape from the increasing radiative flux […]

Time is such a pain.

The Unreal engine has a clock function.

On Linux it's based on one of a number of clocks provided by the OS. At startup it chooses which clock to use by testing each of them to estimate their granularity, picking the one with the finest granularity.

The best two clocks […]

The Python Software Foundation shows more spine than every single tech giant in just one single decision.

> Diversity, equity, and inclusion are core to the PSF’s values

https://pyfound.blogspot.com/2025/10/NSF-funding-statement.html

@julesh I've not read it but I think maybe this is one of the themes in https://en.wikipedia.org/wiki/The_Last_Ringbearer

Basically anyone who has non-trivial creative ambitions is bad.

"...that amazing city of alchemists and poets, mechanics and astronomers, philosophers and physicians, the […]