Eva Miranda
@evamirandag.bsky.social
Mathematician, Full Professor at UPC Icrea Academia @icreacommunity
@CRMatematica @AvHStiftung @UniCologne
living on a "mote of dust suspended in a sunbeam".
@CRMatematica @AvHStiftung @UniCologne
living on a "mote of dust suspended in a sunbeam".
Pinned
Eva Miranda
@evamirandag.bsky.social
· Jan 5
What’s next? Billiards are toy models for near-collision dynamics in the 3-body problem. If billiards can compute, undecidability should be hiding in celestial mechanics. In 2026 we plan to address this for the 3-body problem with A. Gonzalez, D. Peralta #wisemen @crmatematica.bsky.social @upc.edu
Reposted by Eva Miranda
My 25th (!) newsletter post shares my main takeaway from the #RockyWorlds4 conference: Hot rocks are what's cool in rocky exoplanet research right now.
Lava planets, especially look like they're about to teach us a *ton* about how rocky planets work.
So come on in, the lava's fine! 🧪🔭
Lava planets, especially look like they're about to teach us a *ton* about how rocky planets work.
So come on in, the lava's fine! 🧪🔭
Hot rocks are what's cool in rocky exoplanet research
Habitable zone? Pfft. For exciting planetary science discoveries, keep your eye on lava worlds and hot rocks.
www.reviewertoo.com
January 22, 2026 at 7:33 PM
My 25th (!) newsletter post shares my main takeaway from the #RockyWorlds4 conference: Hot rocks are what's cool in rocky exoplanet research right now.
Lava planets, especially look like they're about to teach us a *ton* about how rocky planets work.
So come on in, the lava's fine! 🧪🔭
Lava planets, especially look like they're about to teach us a *ton* about how rocky planets work.
So come on in, the lava's fine! 🧪🔭
🎱 A ball.
🎱 A table.
🎱 A computation.
With Isaac Ramos, we show that a sufficiently weird billiard table is Turing complete.
🕳️ The 8-ball hits the halting wall. Game over.
Selected as one of the Papers of the Month by @elisecutts.bsky.social in Reviewer Too
www.reviewertoo.com/paper-roundu...
🎱 A table.
🎱 A computation.
With Isaac Ramos, we show that a sufficiently weird billiard table is Turing complete.
🕳️ The 8-ball hits the halting wall. Game over.
Selected as one of the Papers of the Month by @elisecutts.bsky.social in Reviewer Too
www.reviewertoo.com/paper-roundu...
Paper Roundup December 2025: computing billiards, an impossible atmosphere, and Roman constructions
Papers on big questions at the frontiers of science, curated by hand each month
www.reviewertoo.com
January 9, 2026 at 10:07 PM
🎱 A ball.
🎱 A table.
🎱 A computation.
With Isaac Ramos, we show that a sufficiently weird billiard table is Turing complete.
🕳️ The 8-ball hits the halting wall. Game over.
Selected as one of the Papers of the Month by @elisecutts.bsky.social in Reviewer Too
www.reviewertoo.com/paper-roundu...
🎱 A table.
🎱 A computation.
With Isaac Ramos, we show that a sufficiently weird billiard table is Turing complete.
🕳️ The 8-ball hits the halting wall. Game over.
Selected as one of the Papers of the Month by @elisecutts.bsky.social in Reviewer Too
www.reviewertoo.com/paper-roundu...
Reposted by Eva Miranda
This month's paper roundup is live!
This time around we've got 2D billiards that can compute, an atmosphere that shouldn't exist, a Roman construction site, and more.
Check it out here: www.reviewertoo.com/paper-roundu... 🧪
This time around we've got 2D billiards that can compute, an atmosphere that shouldn't exist, a Roman construction site, and more.
Check it out here: www.reviewertoo.com/paper-roundu... 🧪
Paper Roundup December 2025: computing billiards, an impossible atmosphere, and Roman constructions
Papers on big questions at the frontiers of science, curated by hand each month
www.reviewertoo.com
January 8, 2026 at 6:16 PM
This month's paper roundup is live!
This time around we've got 2D billiards that can compute, an atmosphere that shouldn't exist, a Roman construction site, and more.
Check it out here: www.reviewertoo.com/paper-roundu... 🧪
This time around we've got 2D billiards that can compute, an atmosphere that shouldn't exist, a Roman construction site, and more.
Check it out here: www.reviewertoo.com/paper-roundu... 🧪
Fascinated once again to see @walkingthedot.bsky.social
work his magic, explaining this story with the perfect touch. Happy to have contributed a small grain to it. Congratulations on this piece! It beautifully captures the emotion of the moment and the roller-coaster nature of research 🎢
work his magic, explaining this story with the perfect touch. Happy to have contributed a small grain to it. Congratulations on this piece! It beautifully captures the emotion of the moment and the roller-coaster nature of research 🎢
Understanding the equations that describe a river current or a breeze is one of the greatest mathematical challenges. Researchers are tackling it with a new computational approach. @walkingthedot.bsky.social reports: www.quantamagazine.org/using-ai-mat...
Using AI, Mathematicians Find Hidden Glitches in Fluid Equations | Quanta Magazine
A $1 million prize awaits anyone who can show where the math of fluid flow breaks down. With specially trained AI systems, researchers have found a slew of new candidates in simpler versions of the pr...
www.quantamagazine.org
January 9, 2026 at 6:14 PM
Fascinated once again to see @walkingthedot.bsky.social
work his magic, explaining this story with the perfect touch. Happy to have contributed a small grain to it. Congratulations on this piece! It beautifully captures the emotion of the moment and the roller-coaster nature of research 🎢
work his magic, explaining this story with the perfect touch. Happy to have contributed a small grain to it. Congratulations on this piece! It beautifully captures the emotion of the moment and the roller-coaster nature of research 🎢
What’s next? Billiards are toy models for near-collision dynamics in the 3-body problem. If billiards can compute, undecidability should be hiding in celestial mechanics. In 2026 we plan to address this for the 3-body problem with A. Gonzalez, D. Peralta #wisemen @crmatematica.bsky.social @upc.edu
January 5, 2026 at 10:14 PM
What’s next? Billiards are toy models for near-collision dynamics in the 3-body problem. If billiards can compute, undecidability should be hiding in celestial mechanics. In 2026 we plan to address this for the 3-body problem with A. Gonzalez, D. Peralta #wisemen @crmatematica.bsky.social @upc.edu
2025, you were:
The Sant Cugat Prize, a feeling of recognition and belonging
Gauss in May
A Chinese Dragon in July re-energising, unstoppable.
Zurich in winter
A private concert at the Petite Malmaison
Bach Oratorium at the Fraumünster and vermicelli closing the circle
Thank you!
The Sant Cugat Prize, a feeling of recognition and belonging
Gauss in May
A Chinese Dragon in July re-energising, unstoppable.
Zurich in winter
A private concert at the Petite Malmaison
Bach Oratorium at the Fraumünster and vermicelli closing the circle
Thank you!
January 1, 2026 at 8:07 AM
2025, you were:
The Sant Cugat Prize, a feeling of recognition and belonging
Gauss in May
A Chinese Dragon in July re-energising, unstoppable.
Zurich in winter
A private concert at the Petite Malmaison
Bach Oratorium at the Fraumünster and vermicelli closing the circle
Thank you!
The Sant Cugat Prize, a feeling of recognition and belonging
Gauss in May
A Chinese Dragon in July re-energising, unstoppable.
Zurich in winter
A private concert at the Petite Malmaison
Bach Oratorium at the Fraumünster and vermicelli closing the circle
Thank you!
Reposted by Eva Miranda
This is exciting for a lot of reasons. But I am smug every time I see this stuff because it further reinforces my theory that computation or something directly related to it is in some sense universal, and perhaps even fundamental, to our universe.
Classical billiards can compute.
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
December 27, 2025 at 11:13 PM
This is exciting for a lot of reasons. But I am smug every time I see this stuff because it further reinforces my theory that computation or something directly related to it is in some sense universal, and perhaps even fundamental, to our universe.
Reposted by Eva Miranda
If there's an aesthetics of the intersection of CS and physics --and I think field-specific aesthetics is an insufficiently explored area in mathematics, programming, and data modeling-- this paper is surely in the purest Classical tradition.
Classical billiards can compute.
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
December 27, 2025 at 10:35 PM
If there's an aesthetics of the intersection of CS and physics --and I think field-specific aesthetics is an insufficiently explored area in mathematics, programming, and data modeling-- this paper is surely in the purest Classical tradition.
Reposted by Eva Miranda
It reaffirms my belief that anything sufficiently complex can serve as a universal computer and thus obeys the theorems regarding those. All is well.
December 23, 2025 at 6:59 PM
It reaffirms my belief that anything sufficiently complex can serve as a universal computer and thus obeys the theorems regarding those. All is well.
Reposted by Eva Miranda
After the Magic game, classical billiards as a Universal Turing Machine :)
New result: you can build a universal computer using a single billiard ball on a carefully crafted table!
More precisely: you can create a computer that can run any program, using just a single point moving frictionlessly in a region of the plane and bouncing off the walls elastically.
(1/n)
More precisely: you can create a computer that can run any program, using just a single point moving frictionlessly in a region of the plane and bouncing off the walls elastically.
(1/n)
December 23, 2025 at 9:45 PM
After the Magic game, classical billiards as a Universal Turing Machine :)
Reposted by Eva Miranda
Since the halting problem is undecidable, this means there are some yes-or-no questions about the eventual future behavior of a point bouncing around in this region of the plane that cannot be settled in a finite time by any computer program.
(2/n)
arxiv.org/abs/2512.19156
(2/n)
arxiv.org/abs/2512.19156
Classical billiards can compute
We show that two-dimensional billiard systems are Turing complete by encoding their dynamics within the framework of Topological Kleene Field Theory. Billiards serve as idealized models of particle mo...
arxiv.org
December 23, 2025 at 10:26 AM
Since the halting problem is undecidable, this means there are some yes-or-no questions about the eventual future behavior of a point bouncing around in this region of the plane that cannot be settled in a finite time by any computer program.
(2/n)
arxiv.org/abs/2512.19156
(2/n)
arxiv.org/abs/2512.19156
Reposted by Eva Miranda
New result: you can build a universal computer using a single billiard ball on a carefully crafted table!
More precisely: you can create a computer that can run any program, using just a single point moving frictionlessly in a region of the plane and bouncing off the walls elastically.
(1/n)
More precisely: you can create a computer that can run any program, using just a single point moving frictionlessly in a region of the plane and bouncing off the walls elastically.
(1/n)
December 23, 2025 at 10:21 AM
New result: you can build a universal computer using a single billiard ball on a carefully crafted table!
More precisely: you can create a computer that can run any program, using just a single point moving frictionlessly in a region of the plane and bouncing off the walls elastically.
(1/n)
More precisely: you can create a computer that can run any program, using just a single point moving frictionlessly in a region of the plane and bouncing off the walls elastically.
(1/n)
Happy Holidays! arxiv.org/abs/2512.19156
December 23, 2025 at 2:22 PM
Happy Holidays! arxiv.org/abs/2512.19156
This Christmas 🎄 the balls left the tree, bounced across a billiard table 🎱, and—inevitably—started computing.
With Isaac Ramos, we show that billiard dynamics is undecidable: arxiv.org/abs/2512.19156
In the computational universe of Cris Moore and @stephenwolfram.bsky.social
With Isaac Ramos, we show that billiard dynamics is undecidable: arxiv.org/abs/2512.19156
In the computational universe of Cris Moore and @stephenwolfram.bsky.social
Classical billiards can compute
We show that two-dimensional billiard systems are Turing complete by encoding their dynamics within the framework of Topological Kleene Field Theory. Billiards serve as idealized models of particle mo...
arxiv.org
December 23, 2025 at 9:54 AM
This Christmas 🎄 the balls left the tree, bounced across a billiard table 🎱, and—inevitably—started computing.
With Isaac Ramos, we show that billiard dynamics is undecidable: arxiv.org/abs/2512.19156
In the computational universe of Cris Moore and @stephenwolfram.bsky.social
With Isaac Ramos, we show that billiard dynamics is undecidable: arxiv.org/abs/2512.19156
In the computational universe of Cris Moore and @stephenwolfram.bsky.social
Ever wondered why you were never very good at billiards?
This might be why. 🎱
This might be why. 🎱
Classical billiards can compute.
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
December 19, 2025 at 9:57 PM
Ever wondered why you were never very good at billiards?
This might be why. 🎱
This might be why. 🎱
With this article we are closing an open problem by Cris Moore on whether 2D billiards can simulate a universal Turing machine. So, stay tuned next time you play billiards....you could be computing....
Classical billiards can compute.
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
December 19, 2025 at 9:52 PM
With this article we are closing an open problem by Cris Moore on whether 2D billiards can simulate a universal Turing machine. So, stay tuned next time you play billiards....you could be computing....
Classical billiards can compute.
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
December 19, 2025 at 8:16 PM
Classical billiards can compute.
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
With Isaac Ramos, we show that 2D billiard systems are Turing complete, implying the existence of undecidable trajectories in physically natural models from hard-sphere gases to celestial mechanics.
Determinism ≠ predictability. 🎱🧠 @upc.edu @ricardsole.bsky.social
My stay at @ethz.ch as Nachdiplom lecturer is coming to an end. Inspiring audience, deep exchanges in lectures, people knocking on my door to discuss maths. I’ll miss this more than I expected. Was bleibt, ist Dankbarkeit für das Gelebte und Sehnsucht nach dem, was kommt #Sehnsucht
December 12, 2025 at 10:56 PM
My stay at @ethz.ch as Nachdiplom lecturer is coming to an end. Inspiring audience, deep exchanges in lectures, people knocking on my door to discuss maths. I’ll miss this more than I expected. Was bleibt, ist Dankbarkeit für das Gelebte und Sehnsucht nach dem, was kommt #Sehnsucht
Reposted by Eva Miranda
Our call for nominations for the Hardy Lectureship 2025 is open!
Nominate a distinguished mathematician based outside of the UK to give a series of lectures within the UK.
Previous Hardy Lecturers incl. Emily Riehl, Eva Miranda, Nalini Joshi.
➡️ www.lms.ac.uk/events/lectu...
Nominate a distinguished mathematician based outside of the UK to give a series of lectures within the UK.
Previous Hardy Lecturers incl. Emily Riehl, Eva Miranda, Nalini Joshi.
➡️ www.lms.ac.uk/events/lectu...
November 6, 2025 at 8:30 AM
Our call for nominations for the Hardy Lectureship 2025 is open!
Nominate a distinguished mathematician based outside of the UK to give a series of lectures within the UK.
Previous Hardy Lecturers incl. Emily Riehl, Eva Miranda, Nalini Joshi.
➡️ www.lms.ac.uk/events/lectu...
Nominate a distinguished mathematician based outside of the UK to give a series of lectures within the UK.
Previous Hardy Lecturers incl. Emily Riehl, Eva Miranda, Nalini Joshi.
➡️ www.lms.ac.uk/events/lectu...
À lire : cet entretien dans La Gazette qui révèle pleinement la personnalité et la force de Michèle Audin. Page 52.https://smf.emath.fr/system/files/filepdf/issue-BD.pdf
Je viens d’apprendre le décès de Michèle Audin. La nouvelle me bouleverse profondément.
Mathématicienne brillante, écrivaine engagée, elle va terriblement manquer.
Voici une photo de Michèle en action au CIRM, ainsi qu’une photo de groupe où nous sommes côte à côte lors d’un colloque en 2006.
Mathématicienne brillante, écrivaine engagée, elle va terriblement manquer.
Voici une photo de Michèle en action au CIRM, ainsi qu’une photo de groupe où nous sommes côte à côte lors d’un colloque en 2006.
November 15, 2025 at 7:49 PM
À lire : cet entretien dans La Gazette qui révèle pleinement la personnalité et la force de Michèle Audin. Page 52.https://smf.emath.fr/system/files/filepdf/issue-BD.pdf
Je viens d’apprendre le décès de Michèle Audin. La nouvelle me bouleverse profondément.
Mathématicienne brillante, écrivaine engagée, elle va terriblement manquer.
Voici une photo de Michèle en action au CIRM, ainsi qu’une photo de groupe où nous sommes côte à côte lors d’un colloque en 2006.
Mathématicienne brillante, écrivaine engagée, elle va terriblement manquer.
Voici une photo de Michèle en action au CIRM, ainsi qu’une photo de groupe où nous sommes côte à côte lors d’un colloque en 2006.
November 15, 2025 at 3:23 PM
Je viens d’apprendre le décès de Michèle Audin. La nouvelle me bouleverse profondément.
Mathématicienne brillante, écrivaine engagée, elle va terriblement manquer.
Voici une photo de Michèle en action au CIRM, ainsi qu’une photo de groupe où nous sommes côte à côte lors d’un colloque en 2006.
Mathématicienne brillante, écrivaine engagée, elle va terriblement manquer.
Voici une photo de Michèle en action au CIRM, ainsi qu’une photo de groupe où nous sommes côte à côte lors d’un colloque en 2006.
Just as Smale's horseshoe is the shape of classical chaos — what is the shape of logical chaos?
What is the shape of the undecidable? Soon at @ethz.ch
@walkingthedot.bsky.social
What is the shape of the undecidable? Soon at @ethz.ch
@walkingthedot.bsky.social
Excited to bring the problem of existence of undecidable trajectories in the n-body problem (n=?) and Fluid Dynamics to a “Chalk and Cheese” session at the ITS ETHZ🌀🧀
Join us on November 20 @ethz.ch @upc.edu @icreacommunity.bsky.social @crmatematica.bsky.social @climatebook.bsky.social
Join us on November 20 @ethz.ch @upc.edu @icreacommunity.bsky.social @crmatematica.bsky.social @climatebook.bsky.social
November 8, 2025 at 11:24 PM
Just as Smale's horseshoe is the shape of classical chaos — what is the shape of logical chaos?
What is the shape of the undecidable? Soon at @ethz.ch
@walkingthedot.bsky.social
What is the shape of the undecidable? Soon at @ethz.ch
@walkingthedot.bsky.social
Reposted by Eva Miranda
Avui donem el tret de sortida a l’ #AnyGaudí2026 des de la seva terra natal, Reus i Riudoms. Un homenatge que difondrà, al llarg del 2026, la figura i obra de l'arquitecte.
✅ Comissariat per Galdric Santana, director Càtedra Gaudí #UPC.
Totes les activitats➡️ consellantonigaudi.cat
✅ Comissariat per Galdric Santana, director Càtedra Gaudí #UPC.
Totes les activitats➡️ consellantonigaudi.cat
November 8, 2025 at 12:07 PM
Avui donem el tret de sortida a l’ #AnyGaudí2026 des de la seva terra natal, Reus i Riudoms. Un homenatge que difondrà, al llarg del 2026, la figura i obra de l'arquitecte.
✅ Comissariat per Galdric Santana, director Càtedra Gaudí #UPC.
Totes les activitats➡️ consellantonigaudi.cat
✅ Comissariat per Galdric Santana, director Càtedra Gaudí #UPC.
Totes les activitats➡️ consellantonigaudi.cat
Reposted by Eva Miranda
Una conversa profunda, inspiradora i plena de connexions entre matemàtiques, emoció i vida.
November 6, 2025 at 2:40 PM
Una conversa profunda, inspiradora i plena de connexions entre matemàtiques, emoció i vida.