Just an observation:
Most toots by people whom I follow, I do not see from their posts, but due to BOOSTS or QUOTES by other people I follow.
Remember: On Mastodon, WE are the algorithm.
You like it?
Then Boost it!
Now playing on Green Valley Radio: 1941 'May News' by Green Valley Radio!
Tune-in for free at: GreenValleyRadio.net
#VintageRadio #OTR #1940s #History
A reminder, should you need it.
I'm not sure I've ever seen a product so effectively branded and marketed as Zuckerberg's "pervert glasses." They're getting a lot of buzz. Everyone is talking about them!
Summerland, a town of 20,000 people, evacuated, one person died.
#Wildfires #ClimateCrisis #BC
#Canada
source. The Canadian Press
Mijn huidige proza heeft 100% matches die gewoon regelrechte MT zijn
HIj zit vol onnodige tekst dat ik soms de woorden door de vertaling niet meer zie
Enfin, nog ff doorbijten
French paper #leMonde, reporting side-by-side on:
* Record orders and activity for the airplane manufacturing industry 🥳 🎉
* The 5th "heatwave" of the Summer hitting most of France (which has been living at near-nonstop 35C+ temps for the past 3 months)… 🥵 💀
It's as if something might be linking these two bits of completely unrelated news… 🤔
3h agoTetonius varleyorum is a newly identified, mouse-lemur-sized species of extinct omomyid primate that challenges the previously accepted step-by-step evolutionary model of early mammals.
#Paleontology #EvolutionaryBiology #BiologicalAnthropology #sflorg
https://www.sflorg.com/2026/08/pal08102601.html
Anteil junger Menschen in Deutschland bleibt historisch niedrig
Deutschland verliert seine Jugend: Der Anteil junger Menschen bleibt auf einem historisch niedrigen Niveau. Das zeigen Daten des Statistischen Bundesamtes. Besonders in Ostdeutschland fehlen junge Leute.
Ehlers Samlingen in Haderslev is a small museum cramped with traditional slipware ceramics from Denmark and Northern-Europe.
An absolute must visit when in Denmark.
https://www.visitsonderjylland.dk/turist/planlaeg-din-ferie/ehlers-samlingen-gdk611804
#slipware #slibversierdaardewerk #terrevernissée
#keramiek #keramik #ceramics #ceramique
If you're a serious mathematician and billiards sound too frivolous, good news:
Forni claims to derive his result from something more profound. Every compact 2-manifold with a flat Riemannian metric with finitely many conical singularities has a periodic geodesic!
(4/n, n = 4)
![From: https://arxiv.org/html/2606.10102v1
Introduction
In this paper we present a non-constructive solution to the problem of existence of a periodic orbit in a polygonal billiard or more generally for the geodesic flow on a flat compact surface with conical singularities:
Theorem 1.1.
Let 𝒫⊂ℝ2 be any finite bounded polygon. The billiard flow in 𝒫 has at least one (regular) periodic orbit.
This theorem is obtained as a corollary of the following:
Theorem 1.2.
Let (M,r) be any closed flat surface with a finite set of conical singularities. The geodesic flow on (M,r) has at least one (regular) periodic orbit.
The periodic orbit problem for billiards in polygons was included by A. Katok in a list of Five Most Resistant Problems in Dynamics (Problem 3 (ii) ) [7].](https://media.mathstodon.xyz/media_attachments/files/117/070/464/040/763/780/original/eebf37397fd2cbd3.jpg)
AI slaat weer toe? 🤔
“De populaireit van Donald Trump neemt steeds verder af. In de peilingen staat hij op het laagste punt van zijn tweede termijn, maar inmiddels beginnen steeds meer fans van de MAGA-beweging terug te komen op hun steun aan de Amerikaanse president.”
“, maar” -> “en”
https://www.nu.nl/329109/video/trump-zakt-in-peilingen-en-maga-beweging-vertoont-diepe-scheuren.html
Y a des travaux prévus sur la ligne Paris-Milan qui vont me permettre de profiter de trois changements au lieu d'un seul pour aller bosser gratos (mais dans la joie) en septembre à Rome.
Du coup je me demande si je rajoute pas un ou deux jours sur place pour le plaisir (mais ça, ce sera pas gratos pour moi, en revanche)
O het regent weer lekker!
detailed process on creating a zine of nature-themed CSS code poetry, and a couple of tiny websites, for html day. the resulting artifacts can now be viewed online. local habitats, kindness in technology, and a commitment to care, to grow together.
A new rail link reconnects Finland and Sweden.
A new rail service linking Oulu in northern Finland with Haparanda in Sweden began on Monday, with the first train departing in the morning.
Passenger rail service between Kemi, Tornio and Haparanda was discontinued in 1988, leaving the border region without a direct rail link for decades.
3h agoA painful first anniversary… A previous scene of slain journalist Anas Al-Sharif with his daughter, Sham.
One year ago, Israel assassinated Al-Sharif in a targeted strike on a journalists' tent near Al-Shifa Hospital in Gaza City, alongside five colleagues.
He had kept reporting through bombardment, starvation and immense loss, knowing the risks.
Now Giovanni Forni claims he sank it in the pocket and proved *every* polygon admits a periodic billiard orbit!
But I haven't checked his proof. And it's nonconstructive, so there's still room to develop algorithms to find period orbits - even for triangular billiard tables.
(3/n)
![Mathematics > Dynamical Systems
[Submitted on 8 Jun 2026]
Existence of a Periodic Orbit for Billiards in Polygons
Giovanni Forni
We prove that the billiard flow in any finite polygon has at least one periodic orbit. The proof by contradiction is based on a fundamental result on the dynamics of the billiard flow by Galperin, Krüger and Troubetzkoy, on the geometry of a one-parameter scaling of the natural Riemannian metric on the unit tangent bundle, and on the topology of the skeleton or cut-locus of the scaled metrics.
Subjects: Dynamical Systems (math.DS)
MSC classes: 37C83, 37C27, 58H15
Cite as: arXiv:2606.10102 [math.DS]
From: https://arxiv.org/abs/2606.10102](https://media.mathstodon.xyz/media_attachments/files/117/070/454/018/251/826/original/bbbcb3f371de1d41.jpg)
Engaging with Harry Potter books, movies, theme parks, etc and announcing it to social media is a bizarre thing to do in 2026.
We have been screaming from the rooftops for almost a decade about the harm this causes to trans people. You have no excuse.
If I see it, it’s an immediate unfollow.
