Caught red handed @eseprimo@mathstodon.xyz

If there is anyone reading this who knows a little about the Riemann Hypothesis, could you let me know?

I have a thing and I need someone with a little pre-existing knowledge to have a glance and tell me why it's rubbish.

It passes "The Crank Test".

If you're an academic, you're probably unhappy with Chegg. I know I am. Not so much for promoting intellectual property theft, but because they profit from miseducating students by luring them into copying rather than getting the benefit of their own work, and because they greatly boost my workload by forcing me to make up new problems instead of reusing them. But did you know that your university's retirement fund investors may well be financial supporters of Chegg? See https://www.chronicle.com/article/work-in-public-education-and-hate-chegg-you-might-be-an-investor

Does anyone have any idea what this character is for: ⋳
"element of with vertical bar at end of horizontal stroke (U+22F3)"

I just released #Tusky 18.0, but do you know what is even more exciting?
The feature drop coming to Tusky nightly today!
Unified push 👀

From an old Donald Knuth paper, discovered a scheme for implementing operator precedence that was used in the first Fortran compiler:

Just do a search-and-replace of + with )))+(((, of * with ))*((, etc., then put ((())) around the whole thing. More parens = lower precedence operator. Since this is purely textual preprocessing, the compiler doesn't need to know about operator precedence after that. Surprisingly, it actually works!

https://www.kmjn.org/notes/operator_precedence_fortran.html

Anyone know a Masto instance for gardeners? It might be the gateway for my wife to get off FB. #ask #garden

Just saw a post that compared website cookie pop-ups to cigarette warnings and..
Yes! Let's make "having your data stolen" be the new "smoking".

Minimizing harm from corporate data theft is WAY easier than quitting nicotine, too.

While taking shots of this Ichneumonid Wasp (family Ichneumonidae), I noticed something on its back leg. Zooming in, I saw it had a hitch-hiker: a Chernetid Pseudoscorpion (family Chernetidae). Taken at Sungei Buloh Wetland Reserve, Singapore, on 1 May 2022.

On iNaturalist:
- https://www.inaturalist.org/observations/114162572
- https://www.inaturalist.org/observations/114162573

#iNaturalist #Nature #Singapore #Photography #Insects #Wasps #Hymenoptera #Arachnids #Arachnida #Pseudoscorpions #Pseudoscorpiones

Terry Tao tries to make mathematical sense of notations like ± or O(...) that specify something partially rather than exactly: https://terrytao.wordpress.com/2022/05/10/partially-specified-mathematical-objects-ambient-parameters-and-asymptotic-notation/

It's a long post, but I think much less technical than most of Tao's posts.

Dear #Scipy, #Python, and #GraphTheory experts, I want to find a sparse distance matrix of a subgraph, using #CSR matrices. I appreciate any ideas, here are the details: https://stackoverflow.com/questions/72184296/run-a-multiple-source-dijkstra-to-the-k-closest-sinks-via-a-scipy-csr-matrix?stw=2.

Hey coding peeps! 👋 What project practice makes you smile when you join a community:

* concise commit messages?
* tons of inline code documentation?
* well maintained changelogs?
* code of conduct?
…

And what makes you go nuts?

#TryingToDoThingsRightFromTheStart

Here's something I made a couple of weeks ago, before The Stressful Week: Farmyard Befunge.

https://checkmyworking.com/posts/2022/05/tractor-befunge/

Digital marbling: https://amandaghassaei.com/projects/digital_marbling/

A recent physics-based simulation project for paper marbling, by Amanda Ghassaei, who was also responsible for an origami simulator (https://origamisimulator.org/) that I linked with a different url a few years ago.

A Martian Eclipse: Phobos Crosses the Sun: apod.nasa.gov/apod/ap220509.… youtube.com/watch?v=aKK7vS… https://twitter.com/apod/status/1523520663369121793

I think these two grids are all you need to memorise. Suppose you're multiplying by \(10a+b\), [^0]. Rotate the grid so that \( b\) is in the top left. If \( b \lt 5\), write down the \(a\) times table in front, but bump it up by one every time you cross a vertical line. If \(b\gt5\), write down the \(a+1\) times table, but drop it by one each time you cross a vertical line.

[^0] Sigh, because mathematicians: \(a\) and \(b\) integers, \(0\le a\lt10\) and \(1\le b\le 9\), \(b\ne 5\). Honestly.

For example, for the 47 times table, write down the grid with 7 in the top right:

| 7 4 1
| 8 5 2
| 9 6 3

Then prepend the five times table, knocked down by one for each line you've crossed:

\( \begin{pmatrix} 47 & 94 & 141 \\ 188 & 235 & 282 \\ 329 & 376 & 423 \end{pmatrix} \)

Boom!

Optimist: The glass is ½ full.
Pessimist: The glass is ½ empty.
Excel: The glass is January 2nd.