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Paper Roundup

Paper Roundup August 2025: Alpha Centauri Ab, Worm Circuits, AI Chess

Every month, I publish a curated list of scholarship on "big questions" in science — the stuff you'd find sitting on the desk of an old timey natural philosopher whisked to the present.

Elise Cutts

Elise Cutts

— 20 min read
Paper Roundup August 2025: Alpha Centauri Ab, Worm Circuits, AI Chess
Magpies are notorious thieves, but I like to think they see themselves as curators. Art: American Magpie by Robert Havell after John James Audubon (1837) in the National Gallery of Art

How did life begin? What is emergence? Are we alone? Every month, I publish a curated list of the most fascinating, groundbreaking, inflammatory, or otherwise bold new scholarship on "big questions" in science. I like to imagine these are the papers you'd find sitting on the desk of an old timey natural philosopher who'd been whisked to the present.

Send recommendations for next month's roundup to elise@reviewertoo.com. And if this is your kind of weird, why not share it with a friend or post it on Bluesky or wherever else you hang out online?

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Highlights

A first picture of a habitable-zone (gas) planet in the closest star system to Earth

Worlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Centauri A. I. Observations, Orbital and Physical Properties, and Exozodi Upper Limits (The Astrophysical Journal Letters, August 11) by Charles Beichman, Aniket Sanghi, Dimitri Mawet, Pierre Kervella, Kevin Wagner, Billy Quarles, Jack J. Lissauer, Max Sommer, Mark Wyatt, Nicolas Godoy, William O. Balmer, Laurent Pueyo, Jorge Llop-Sayson, Jonathan Aguilar, Rachel Akeson, Ruslan Belikov, Anthony Boccaletti, Elodie Choquet, Edward Fomalont, Thomas Henning, Dean Hines, Renyu Hu, Pierre-Olivier Lagage, Jarron Leisenring, James Mang, Michael Ressler, Eugene Serabyn, Pascal Tremblin, Marie Ygouf, and Mantas Zilinskas

Worlds Next Door: A Candidate Giant Planet Imaged in the Habitable Zone of α Cen A. II. Binary Star Modeling, Planet and Exozodi Search, and Sensitivity Analysis (The Astrophysical Journal Letters, August 11) by Aniket Sanghi, Charles Beichman, Dimitri Mawet, William O. Balmer, Nicolas Godoy, Laurent Pueyo, Anthony Boccaletti, Max Sommer, Alexis Bidot, Elodie Choquet, Pierre Kervella, Pierre-Olivier Lagage, Jarron Leisenring, Jorge Llop-Sayson, Michael Ressler, Kevin Wagner, Mark Wyatt

That smudge of light labeled S1 is, maybe, a gas giant planet orbiting in the habitable zone of Alpha Centauri Ab, one of the closest stars to Earth. Credit: NASA, ESA, CSA, Aniket Sanghi (Caltech), Chas Beichman (NExScI, NASA/JPL-Caltech), Dimitri Mawet (Caltech), and Joseph DePasquale (STScI)

There could be a gas giant in the habitable zone of Alpha Centauri A, the nearest Sun-like star. And scientists may have just taken a picture of it.

This is exciting for a few reasons: 1) directly imaging exoplanets with current technology is very hard so any direct images are exciting and 2) this gas giant, if confirmed, could host moons. There could be an entire system of habitable little worlds spinning away in the solar system next door. I get into more detail about what this detection means — and what it doesn't — in my post all about this planet.

A habitable world next door?
More than you needed to know about the smudge of light that might be a planet in the habitable zone of the nearest Sun-like star
Reviewer, tooElise Cutts

The full circuit diagram of an animal

Whole-body connectome of a segmented annelid larva (eLife, August 27,) by Csaba Verasztó, Sanja Jasek, Martin Gühmann, Luis Alberto Bezares-Calderón, Elizabeth A. Williams, Réza Shahidi, and Gáspár Jékely

Platynereis dumerilii. Anterior end. Credit: Arne Nygren | Institutionen för marina vetenskaper, Göteborgs Universitet (CC BY 4.0)

If you want to know how something works, having an accurate diagram is a good place to start. We'd really like to know how the brain works, and ideally how it connects to the body. So having a full diagram of the nervous system would be great. Making one, however, is hard. It has only been done for two species: lab legend C. elegans and a sea squirt larva. C. elegans has less about 1000 cells in total. The sea squirt larva has 301 cells, 117 of which are neurons.

Now, scientists have diagrammed the entire nervous system of the most complex animal yet: the 3 day old larva of a weirdly cute marine worm called Platynereis dumerilii. It contains about 900 cells and nearly 1000 neurons. Mapping and characterizing them all took scientists about 10 years.

For a scientist's perspective on why the circuit of this specific worm matters, see this commentary by Alex Winsor and Paul Katz. I'm excited about this for a less sophisticated reason: I'm just a fan of P. dumerilii. The worms' gruesome reproductive cycle is synced to the moon and it is the best established lab critter for studying life's lunar clock. Fertile adults metamorphose into muscular sacs of sperm and eggs, throwing out unnecessary extras like the digestive tract to make more room, and then explode — hopefully in company, or else the whole transformation, called epitoky, is for nothing.

I had trouble confirming whether P. dumerilii explodes this fantastically, but Kristin Tessmar-Raible, who studies these worms, told me in an interview that they essentially swim around so fast that they "basically burst open."

Obviously, you can only explode in a cloud of gametes once in a lifetime. So the worms use a lunar calendar to coordinate their final "nuptial dance." We know far less about the biological details of circalunar rhythm than those of the circadian clock, which scientists worked out in great detail by studying fruit flies. But the sun isn't the whole story. Plenty of sea creatures clearly keep time to the moon — and humans have our own monthly cycles, even if males of our species are mostly circadian creatures. Evolution is nothing if not resourceful. So could the menstrual cycle have been cobbled together from bits of old cellular clockwork that our sea-dwelling ancestors used to keep time to the moon? Kristin Tessmar-Raible at the University of Vienna, one of the scientists pioneering P. dumerilii as a model organism, told me in an interview for Quanta that this might be exactly what happened.

Now, as only the 3rd species to have its neural circuits fully mapped, P. dumerilii could be on its way to becoming a "model" organism.

How This Marine Worm Can Tell Moonglow From Sunbeams | Quanta Magazine
For the first time, scientists have decoded the molecular structure of a protein that helps to sync a biological clock to the phases of the moon.
Quanta MagazineElise Cutts

A brain on a brainy chip

Neuromorphic Simulation of Drosophila Melanogaster Brain Connectome on Loihi 2 (arXiv preprint, August 22) by Felix Wang, Bradley H. Theilman, Fred Rothganger, William Severa, Craig M. Vineyard, and James B. Aimone

The 50 largest neurons in the fly brain connectome. Credit: Credit: Tyler Sloan and Amy Sterling for FlyWire, Princeton University, (Dorkenwald et al., 2024)

Speaking of wiring diagrams, it'd sure be great to be able to simulate them on computers. That'd obviously make it easier to test neuroscience hypotheses without needing to meddle with organisms, but it could also open up new ways to build AI that's more like real-I. Simulating activity on invertebrate connectomes is becoming feasible, but doing this for even pared-down models of a human brain is beyond the capabilities of all but the most powerful computers. Some scientists think a solution could be to develop chips built like brains — neuromorphic hardware. In this preprint, scientists at the Sandia National Lab simulated a "biologically realistic" connectome on neuromorphic chips for the first time, achieving speeds order of magnitude faster than on conventional computers.

AI chess players keep opponents in suspense

AI sustains higher strategic tension than humans in chess (arXiv preprint, August 16) by Adamo Cerioli, Edward D. Lee, and Vito D. P. Servedio

A tension network in chess. The network on the right represents the possible interactions between pieces on the board shown to the left. Colors represent different kinds of interactions, like attack or defense, and which color they originate from. Black and white pieces are black and white nodes, and open squares are brown circles. Credit: Adapted from Cerioli et al. 2025 (CC BY 4.0)

At a certain point, strategy requires commitment. Some strategies are mutually exclusive and picking one means abandoning others. But up until that point, it can pay off to keep your options open and keep your opponent in suspense.

An analysis of highly competitive AI chess players found that the bots maintain "strategic tension" for longer than their human counterparts. AIs had more tolerance for complicated positions on the board and balance between offensive and defensive tactics, and maintained that tolerance for longer. Humans winnowed down their strategic options faster. Chess is just a game. But this finding raises the perhaps disturbing possibility that we've already created machines capable of outfoxing us in complicated, shifting strategic environments that favor adaptability — and arguably, that's our niche. Are we intentionally engineering players that beat us at our own game?

Hunting for exoplanets on the dark side of the moon

Identifying Habitable Exoplanets with Radio Telescopes on the Lunar Farside (arXiv preprint, August 19) by N. Mahesh, J. D. Bowman, J. O. Burns, S. D. Bale, T.-C. Chang, S. Furlanetto, G. Hallinan, A. Hegedus, J. Mirocha, J. Pober, R. Polidan, D. Rapetti, N. Thyagarajan, and J. Turner

The "dark side of the moon" isn't really dark — it experiences day and night just like the moon's familiar face. But because is the one place int the solar system that's consistently shaded from our radio chatter and astronomers have thrown around the idea of building a radio telescope below the lunar farside's radio "dark sky for decades. This preprint suggests that proposed telescope concepts could detect planetary magnetic fields around rocky, Earth-like worlds. It's widely believed that terrestrial planets can't hold onto substantial atmospheres — and therefore can't be habitable — without a magnetic field, even though the science on how and why planets keep their atmospheres isn't that clear. But whether or not you think magnetospheres are necessary for habitability, detecting them in other systems would be very helpful for understanding how and why they form and what influence they do (or don't) have on atmospheres.

The Road Map to Alien Life Passes Through the ‘Cosmic Shoreline’ | Quanta Magazine
Astronomers are ready to search for the fingerprints of life in faraway planetary atmospheres. But first, they need to know where to look — and that means figuring out which planets are likely to have atmospheres in the first place.
Quanta MagazineElise Cutts

Special issue: life and planets

Chance and purpose in the evolution of biospheres, introduction to a special issue of Philosophical Transactions of the Royal Society B (August 7) by Philip C. J. Donoghue, Timothy M. Lenton, Samir Okasha, Graham A. Shields, and Anja Spang

Earth history, planetary science, and geobiology enthusiasts, this is for you: a whole special issue of Philosophical Transactions of the Royal Society B dedicated to the co-evolution of metabolism and the planet. If you check out nothing else, take a peek at W. Ford Doolittle's essay "Darwinizing Gaia." Whether you agree or disagree with him, it's a great introduction to James Lovelock and Lynn Margulis' controversial Gaia Hypothesis, which proposes that the Earth is a single organism. There are several articles of interest to exoplanet astrobiologists as well.

A massive effort to map how mouse brains decide

A brain-wide map of neural activity during complex behaviour (Nature, September 3) by International Brain Laboratory, Dora Angelaki, Brandon Benson, Julius Benson, Daniel Birman, Niccolò Bonacchi, Kcénia Bougrova, Sebastian A. Bruijns, Matteo Carandini, Joana A. Catarino, Gaelle A. Chapuis, Anne K. Churchland, Yang Dan, Felicia Davatolhagh, Peter Dayan, Eric EJ DeWitt, Tatiana A. Engel, Michele Fabbri, Mayo Faulkner, Ila Rani Fiete, Charles Findling, Laura Freitas-Silva, Berk Gerçek, Kenneth D. Harris, Michael Häusser, Sonja B. Hofer, Fei Hu, Félix Hubert, Julia M. Huntenburg, Anup Khanal, Christopher S. Krasniak, Christopher Langdon, Christopher Langfield, Petrina Y. P. Lau, Zachary F. Mainen, Guido T. Meijer, Nathaniel J. Miska, Thomas D. Mrsic-Flogel, Jean-Paul Noel, Kai Nylund, Alejandro Pan-Vazquez, Liam Paninski, Alexandre Pouget, Cyrille Rossant, Noam Roth, Rylan Schaeffer, Michael Schartner, Yanliang Shi, Karolina Z. Socha, Nicholas A. Steinmetz, Karel Svoboda, Anne E. Urai, Miles J. Wells, Steven J. West, Matthew R. Whiteway, Olivier Winter, and Ilana B. Witten

What's going on the brain during decision-making? To help find out, a massive scientific collaboration has produced a map of neuron activity in the mouse brain during decision-making. Researchers working in about a dozen labs compiled measurements of 620,000 individual neurons across 139 different mice taken during a standard set of complicated tasks. This is a significant step, because historically it has been very hard to compare results across groups using different recording methods and experimental setups. For a first result, see this paper in the same issue: Brain-wide representations of prior information in mouse decision-making.

I happened to write a story about work on food poisoning and aversive learning by the new study's last author Ilana Witten earlier this year. Rodents typically aren't great at associating a cause with a delayed effect. Food poisoning is an exception: make a mouse sick after giving it an unfamiliar meal, even hours later, and it'll still learn to avoid that food in the future. Understanding how aversive learning works and breaks might help demystify disorders like ARFID (too much aversion) and addictions (too little aversion).

Mouse brains hint at why it’s so hard to forget food poisoning
Scientists mapped a neural circuit that associates an unfamiliar flavor with food poisoning symptoms in mice.
Science Newsashley

Cicad-ian rhythm

Photometric decision making during the dawn choruses of cicadas (August 1, Physical Review E) by Rakesh Khanna A., Raymond E. Goldstein, Adriana I. Pesci, and Nir S. Gov

A 17-year cicada drawn by Robert Evans Snodgrass in 1930. Source: Wikimedia Commons

The sunrise doesn't happen all at once. It gets lighter and lighter, bit by bit. But still, somehow, cicadas all start screaming all at once, all together, sometime before dawn. They're not the only species that sings on a schedule: many birds, which I like quite a lot more than bugs, do as well. But how do you schedule a "dawn chorus" without a clock? In this study, researchers try to explain how a gradual ramp-up in sunlight produces the sudden, coordinated onset of cicada screeching. I love studies like this: nerdy, detailed examinations of everyday things like bug screeching, which only seem simple until you take a closer look.

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The Rest

Astrobiology

Earth

Origins and nature of life

Can a strange state of matter explain what life is – and how it began?
Laboratory experiments have coaxed simple molecules into states that naturally become more complex, hinting at the origins of evolution itself
New Scientist#author.fullName}

If you're interested in synthetic replicators and evolution without life, check out my feature in New Scientist on the work being led by Wu's thesis advisor Sijbren Otto: Can a strange state of matter explain what life is – and how it began?

Evolution and function in biology

Physical biology and biophysics

Physics

Emergence

Networks

Society

The Brain

Language

Consciousness

Artificial Intelligence

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