Daniel Ruiz Palomo

PhD candidate at UAB. Enginyer Civil.

[Cesar Chavez @CesarChavezP29]

Why is causality harder to find than you think?
People see a correlation chart, or a time-series with an arrow marking a policy launch, and read it as causal evidence. But it almost never is.

New essay on the Transportation Problem in Causal Inference: https://t.co/F3AbqKlj4a

[Aakash Gupta @aakashgupta]

A woman who couldn’t hold a paid university position for most of her career produced the single deepest insight connecting mathematics to physical reality.

Emmy Noether proved her theorem in 1918. She was 36. The University of Göttingen wouldn’t let her teach under her own name. David Hilbert, one of the most powerful mathematicians alive, had to list her lectures under his course catalog so she could stand in front of a classroom. The faculty’s objection was explicit: soldiers returning from World War I shouldn’t be expected to learn from a woman.

What she proved while being denied a salary: every symmetry in nature corresponds to a conservation law. The laws of physics don’t change over time? Energy is conserved. They don’t change across space? Momentum is conserved. They don’t change when you rotate? Angular momentum is conserved.

This thread covers those three. There are dozens more.

Every force in the Standard Model of particle physics, electromagnetic, weak, and strong, arises from a gauge symmetry. Noether’s theorem is what ensures the corresponding charges are conserved. Photons, gluons, W and Z bosons all exist because of symmetry groups her theorem made calculable. The Higgs boson prediction that took until 2012 to confirm at CERN was built on symmetry arguments she made rigorous 94 years earlier.

Fermilab physicist Christopher Hill ranked her theorem alongside the Pythagorean theorem in its impact on human understanding. Stanford physicist Michael Peskin called it a basic tool in the construction of the Standard Model. Every time a physicist writes down a Lagrangian, identifies a conserved quantity, or predicts a particle interaction, they’re operating inside the framework one woman built before she was allowed to hold a faculty position.

She was fired when the Nazis came to power in 1933. She left for Bryn Mawr College and died two years later at 53 following cancer surgery.

107 years later, physics is still mining the implications. Quantum field theory, general relativity, string theory, condensed matter. All of it runs on Noether. Conservation laws looked like fundamental axioms for two centuries. Noether proved they’re consequences. Symmetry is what’s fundamental. And that single reframe changed how every generation of physicists since has understood the universe.

[Daniel Arjona @elarjonauta]

"Harari ha perfeccionado un arte curioso: envolver obviedades o errores técnicos en un papel de regalo filosófico tan brillante que nadie se atreve a rasgarlo".
https://t.co/0eVLPxjGS5

[Cesar Chavez @CesarChavezP29]

Every student learns that correlation does not imply causation. Few learn the converse: absence of correlation does not imply absence of causation.

This essay traces how economics came to think about causality. The story involves philosophers, statisticians, econometricians, and computer scientists. It spans three centuries and at least two methodological revolutions. And it remains, in important ways, unfinished. Link: https://t.co/U5YePoE4yD

[Daniel Ruiz Palomo @__DanielRuiz]

@TOPOenjoyer Recordo haver vist aquest mapa amb febre la setmana passada. Pensava que ho havia somiat.

[Gabriel Moreno @Gabri91MG]

Como cada Año Nuevo, hay que leer esta magnífica columna de Manuel Vicent en El País:

[Andrés Elías @andreseliascom]

Lo que aprendí leyendo…

“El fascismo de los antifascistas” – Pier Paolo Pasolini

Pasolini plantea algo incómodo: hay formas de poder que se disfrazan de virtud. Y cuando el discurso se convierte en moral absoluta, el resultado no es libertad, sino obediencia.

El antifascismo no es inmune al fascismo.
Cuando una causa se siente moralmente superior, puede caer en la misma lógica que pretendía combatir:
•imposición,
•cancelación,
•simplificación del adversario,
•dogmatismo.

Pasolini anticipó un fenómeno que vemos hoy: la política deja de ser debate y se convierte en identidad moral. Quien no piensa igual, no es adversario: es enemigo.

Y aquí viene la lección estratégica para mí:

La democracia no se destruye por una sola ideología. Se destruye cuando dejamos de escuchar al otro.

El verdadero peligro no es la derecha o la izquierda. Es cuando una parte se siente autorizada a decidir quién merece hablar
y quién debe ser silenciado.

Es el momento en que la libertad deja de ser un principio y se vuelve un privilegio.

Pasolini no invitaba a justificar al fascismo.
Advertía sobre algo más profundo: El poder cambia de traje, pero no de método.

Y leerlo hoy es un recordatorio incómodo:
defender la democracia exige más que buenas intenciones. Exige pluralidad, disenso, crítica y autocrítica. Exige reglas, límites y humildad.

Porque la línea entre combatir al fascismo
y reproducirlo sin darnos cuenta siempre es más delgada de lo que creemos.

Andrés Elías

[𝘓𝘶𝘥𝘮𝘪𝘭 🎙 @ludmil]

True story.

[Alice Evans @_alice_evans]

What happens when Swedish women are biologically incapable of naturally bearing children?

They earn roughly the same as men!

Bravo to @landais_camille et al - who examine a rare congenital condition to track the gender pay gap.

(Assuming these women are otherwise normal).

[Neil Renic @NC_Renic]

Returning to your draft after a long break

[Neil Renic @NC_Renic]

Flight attendant: “Is there a doctor on the plane?”

PhD: “yes, are you hiring?”

[Nick Tsivanidis @NTsivanidis]

My research team is looking for a full-time research assistant to be based in Lagos, Nigeria, to work on a project on the minibus transit industry

[The Nobel Prize @NobelPrize]

Over the last two centuries, for the first time in history, the world has seen sustained economic growth. This has lifted vast numbers of people out of poverty and laid the foundation of our prosperity. This year’s laureates in economic sciences, Joel Mokyr, Philippe Aghion and Peter Howitt, explain how innovation provides the impetus for further progress.

#NobelPrize

[The Nobel Prize @NobelPrize]

This year’s chemistry laureate Omar Yaghi was born in Amman, Jordan, in 1965 to parents who were refugees from Palestine. When we spoke to him he shared his story:

“I grew up in a very humble home, we were a dozen of us in one room, sharing it with the cattle that we used to raise. I was born in a family of refugees, and my parents could barely read or write. My father finished sixth grade and my mother couldn’t read or write. It’s quite a journey. Science allows you to do it. Science is the greatest equalising force in the world.

Smart people, talented people, skilled people exist everywhere. That’s why we really should focus on unleashing their potential through providing them with opportunity.”

Today Yaghi shared the 2025 Nobel Prize in Chemistry with Susumu Kitagawa and Richard Robson for their work developing metal–organic frameworks.

Learn more about the prize: https://t.co/4nmszg1ZIR

[Sephorah Mangin @SephorahMangin]

1/ Economic outcomes often depend on the distribution of some maximum value (e.g. the highest valuation, best idea, or lowest cost).

If the average number of options is large, do such outcomes change when some agents have more options than others?

A thread 🧵about this paper.👇

[Daniel Ruiz Palomo @__DanielRuiz]

@Gil_JavierGil ¿De dónde son los datos?

[Octavio Medina @octavio_medina]

Why has Europe lagged behind, and how can it become richer again?

Great overview of the main problems, and some ideas to fix them.

https://t.co/0eclRp3Sqp

[Rafael H. M. Pereira 🚡 Urban Demographics @UrbanDemog]

📢We released {r5r} v.2.3.0 today with a few major updates! https://t.co/A1HvlJWUvZ

1. New function `arrival_travel_time_matrix()` to calculate travel time matrix considering the time of arrival, instead of a depature time. +

[Daniel Ruiz Palomo @__DanielRuiz]

@Depejota @The_Real_Oriol @antihacienda @transportcat @grok ¿Puedes hacer un cálculo aproximado del coste de mantenimiento de todas las carreteras y calles de España? A continuación, ¿puedes aproximar la recaudación por las multas de los radares? ¿Qué porcentaje del coste total cubren las multas?