Tootfinder

URL parts explainer tool
https://url-parts.glitch.me/?url=https://cats.example.org.au:1234/stripes/fur.html?pattern=tabby#claws

url-parts.glitch.me
Interactive tool for showing the names of URL components

In this episode of "C things I knew by feeling but not for sure":
A #cpp lambda is a class w overloaded function-call operator (), confirmed 3 different ways with the example in Pic 1:
1. Assembly has operator() function members for A, C, D
2. Can explicitly call function call operators on A, C, D
3. A passes the trait std::is_class but fails std::is_function
Pic…

Compiler Explorer - C++ (x86-64 gcc 13.2)
auto A = []() { std

Another great example of (charitably) Kruger-Dunning (or more realistically, towering naivity) among the vljmstoligy community.
https://www.theguardian.com/environment/ng-interactive/2024/may/08/hopeless-and-broken-why-the-worlds-top-climate-scientists-are-in-despair
The reason GHG emissions still aren't falling far or fast enough to avoid global catastrophe is "lack of political will" and "corporate vested interests". The fact is that governments of even nations with undemocratic and tyrannical regimes are in the hands of the populace in the medium to long term. How long would, say, Putin remain in power if he announced a ten year programme to tax meat to the point it's a rare luxury reserved for the wealthy, to transition from petrol and diesel fuels, a crash programme to dump coal and gas for power generation and heating and roll out renewables, abolishing hidden subsidies for concrete manufactures to ensure the the emission externalities are priced in, virtual bans on civilian aviation and so on? Certainly there'd be an interesting Keynesian multiplier effect from all the expenditure and investment*, but he'd still be dangling from a metaphorical lamppost within a few years.
*actually the debt incurred would cause huge inflation.
The other big problem, still, is lack of public understanding. There's "awareness", but here are still huge misapprehension. Eg., many people still seem to think thst net zero would mean a return to mid-20thC climates; people still don't grasp the consequences of passing major tipping thresholds, or that many climate elements (ice sheet melting, ocean circulations,..) have multi-decadal or multi-century lags before reaching a final equilibrium. And they still have no clue how fragile civilisation is, or what life in 2100 -- or 2050! - will be like.
I remain more optimistic than I was 25y ago when I first started taking an interest, though. 2.5°C still looks plausible to me, if current reductions continue to accelerate, given a few weather megadisasters to chivvy us along.

“Delays in U.S. assistance, particularly since Israel’s war with Hamas began to preoccupy top administration officials, triggered deep concerns in Kyiv and Europe. Blinken, for example, has visited the Middle East seven times since the Gaza conflict began in October. His last trip to Kyiv was in September.”
https://

Russia-Ukraine war: Blinken visits Ukraine to affirm US support for Kyiv
U.S. Secretary of State Antony Blinken has arrived in Kyiv on an unannounced diplomatic mission to reassure Ukraine that it has American support as it struggles to defend against increasingly intense Russian attacks. The two-day visit starting Tuesday comes less than a month after Congress approved a long-delayed foreign assistance package that sets aside $60 billion in aid for Ukraine, much of which will go toward replenishing badly depleted artillery and air defense systems. It's Blinken's fo…

Towards a Stallings-type theorem for finite groups
Johannes Carmesin, George Kontogeorgiou, Jan Kurkofka, Will J. Turner
https://arxiv.org/abs/2403.07776 h…

Towards a Stallings-type theorem for finite groups
A recent development in graph theory is to study local separators, vertex sets that need not separate graphs globally but just locally. We use this idea to conjecture an extension of Stallings' theorem to finite nilpotent groups. We provide an example demonstrating that the assumption of nilpotency is necessary, and prove a stronger form of this conjecture for low connectivities, as follows. A finite nilpotent group that has a Cayley graph with a local separator of size at most two is cyclic,…

‘Hopeless and broken’: why the world’s top climate scientists are in despair
“The big difference…was that all of the scientists I worked with were incredibly frustrated. Everyone was at the end of their rope, asking: what the fuck do we have to do to get through to people how bad this really is?”

P\'olya-type estimates for the first Robin eigenvalue of elliptic operators
F. Della Pietra
https://arxiv.org/abs/2402.08474 https://

Pólya-type estimates for the first Robin eigenvalue of elliptic operators
The aim of this paper is to obtain optimal estimates for the first Robin eigenvalue of the anisotropic $p$-Laplace operator, namely: \[ λ_F(β,Ω)=λ_{F}(p,β,Ω)= \min_{ψ\in W^{1,p}(Ω)\setminus\{0\} } \frac{\int_ΩF(\nabla ψ)^p dx +β\int_{\partialΩ}|ψ|^p F(ν_Ω) d\mathcal H^{N-1} }{\int_Ω|ψ|^p dx} \] where $p\in]1,+\infty[$, $Ω$ is a bounded, convex domain in $\mathbb R^{N}$, $ν_Ω$ is its Euclidean outward normal, $β$ is a real number, and $F$ is a sufficien…

Do you recognize the "Phil Swift Slaps On Flex Tape" #meme?
Details on that meme with examples: https://knowyourmeme.com/memes/phil-swift-slaps-on-flex-tape…

Deriving Dependently-Typed OOP from First Principles - Extended Version with Additional Appendices
David Binder, Ingo Skupin, Tim S\"uberkr\"ub, Klaus Ostermann
https://arxiv.org/abs/2403.06707

Deriving Dependently-Typed OOP from First Principles - Extended Version with Additional Appendices
The expression problem describes how most types can easily be extended with new ways to produce the type or new ways to consume the type, but not both. When abstract syntax trees are defined as an algebraic data type, for example, they can easily be extended with new consumers, such as print or eval, but adding a new constructor requires the modification of all existing pattern matches. The expression problem is one way to elucidate the difference between functional or data-oriented programs (e…

Brock-type isoperimetric inequality for Steklov eigenvalues of the Witten-Laplacian
Jing Mao, Shijie Zhang
https://arxiv.org/abs/2404.07412 https://…

Brock-type isoperimetric inequality for Steklov eigenvalues of the Witten-Laplacian
In this paper, by imposing suitable assumptions on the weighted function, (under the constraint of fixed weighted volume) a Brock-type isoperimetric inequality for Steklov-type eigenvalues of the Witten-Laplacian on bounded domains in a Euclidean space or a hyperbolic space has been proven. This conclusion is actually an interesting extension of F. Brock's classical result about the isoperimetric inequality for Steklov eigenvalues of the Laplacian given in the influential paper [Z. Angew. Math.…