Dossiers
Some are more alike than they look.
Each Dossier marks what’s known, what’s our read, and what’s still open.
Thinking without a center
Thinking, a sense of self or an ability is spread across several bodies, parts or paths rather than held in one center.
Where it breaks Spread out is not the same as connected: an octopus arm and a fermentation tank do not think together.
A mind doesn’t have to live in one place
Octopus arms, ant colonies and AI swarms all complicate our favorite picture of intelligence: one command center doing the deciding.
A crow can plan four calls without a word for four
Carrion crows learned to produce one to four calls on command, and their first call hinted at how many were coming.
One brain, different early paths
In mouse embryos, much of the front and middle of the brain grows from one group of early cells, and much of the back grows from another. The two groups are already separate before the brain has its familiar shape. Together they build one brain.
Biology is learning to leave the body
We once needed the whole organism to obtain what it made. Now insulin can come from bacteria, milk proteins from microbes, and tissue from cells growing on their own.
The instrument is part of the result
In these Dossiers, the measuring tool, numerical estimate or bodily feeling limits what can be claimed.
Where it breaks A shaky measurement can shrink a finding below its headline without making it false.
The scariest number in microplastics research may also be the least certain
A 2025 study reported high levels of tiny plastic fragments in human brains. Critics questioned the amounts, partly because brain fat can look like plastic in the test used. Evidence that plastic is present is stronger than evidence for the reported amounts.
Loneliness leaves biological traces but may cause less than it seems
In more than 42,000 UK adults, lonely and isolated people had different levels of blood proteins tied to inflammation and immunity. A separate genetic analysis found potential causal evidence for six of 26 diseases tested.
Trees may not be talking through fungi after all
Fungal threads in the soil can connect the roots of neighboring trees. The popular “wood wide web” story, in which older trees feed and warn their own seedlings through those links, goes beyond what field studies show.
Your body is not a truth detector
A chill can feel like recognition. The science suggests several paths to that feeling, and none of them can tell you whether the thing that moved you was true.
A brain scanner once found a dead salmon thinking
In 2005 researchers put a dead salmon in a brain scanner, showed it photos of people, and ran a standard analysis. A few spots in its head appeared to respond. The analysis had tested thousands of tiny spots, so some passed by chance; correcting for the number of tests erased them.
Hot water can start freezing first
A hotter cup of water can begin forming ice before a cooler one. Water can stay liquid below zero, and a hot cup can change how it loses heat. Even deciding whether two laboratories have repeated the same experiment takes care.
Sensed, but never noticed
Something is detected or sent outside conscious perception, and a body or organism responds anyway.
Where it breaks A signal being real is not the same as anything using it.
A bird may see a direction you cannot
Migratory birds use Earth's magnetic field to find their way. No one yet knows what that sense is like for the bird.
Thirsty plants click more often
Tomato and tobacco plants make clicking sounds too high-pitched for human ears. Plants short of water click far more often than watered ones, and researchers could tell a plant’s condition from its clicks alone.
Some light changes you without becoming sight
Your eyes do two jobs with the same light. They build the picture you see, and they tell your body clock what time of day it is, which shifts your alertness, hormone levels and when you get sleepy.
Your gut can tell sugar from sweetener
Cells in the gut lining can distinguish sugar from a zero-calorie sweetener. In mice, they signal the brain through a nerve within milliseconds, and switching them off left no clear preference for sugar. The signal works without tasting sweetness.
A copy shows its maker
A model, a machine or a reconstruction distorts what it represents in ways that reflect its makers and their data.
Where it breaks A skewed copy can still recover real text or real patterns.
AI can improve your idea and flatten the room at the same time
People who brainstormed with ChatGPT came up with ideas rated more creative. Their ideas were also more alike: in one test, nine people separately named their invented toy “Build-a-Breeze Castle.”
The library inside a lump of charcoal
Ancient books survived Vesuvius as fragile rolls of carbon. Reading them takes X-rays, software trained on examples to spot ink, and a careful distinction between recovering words and supplying them.
Your AI twin may be a stereotype with your name on it
Researchers built “digital twins,” AI copies of real people made from each person’s answers to 500-plus questions. Asked new questions, the copies matched their people only weakly and missed them in systematic ways, stereotyping among them.
One skull can wear very different faces
To rebuild the face of someone long dead, an artist lays clay or digital muscle and skin over the skull. The skull fixes the bones, but much of the nose, lips, skin and hair has to be estimated. Two faces built on the same skull can look like different people, because each maker fills those gaps differently.
The standard human genome is mostly one person
When a lab reads someone's DNA, it lines up millions of short fragments against a standard human genome, a reference copy of a full set of human DNA. That standard is stitched together from more than 20 people, and one of them makes up most of it. DNA that differs from that one person is easier to misread or miss.
The flaw does the work
A defect, a delay or a constraint is what makes the effect happen.
Where it breaks Most flaws are just flaws; the ones in these Dossiers have evidence that they do useful work.
Surprise is a memory technology
In a study drawing on 17 NBA seasons, surprise was linked to better recall of the plays, games and seasons fans felt worst about, and of the plays and seasons they felt best about. Researchers estimated surprise using betting odds and play-by-play win probabilities.
The flaw in Roman concrete may have been the feature
Roman concrete is dotted with white lumps of lime, long blamed on sloppy mixing. When a crack reaches one and water seeps in, the lime can dissolve and harden again as new mineral that seals the crack.
The Morning Tax
Each morning, a thin mat of microbes starts making oxygen, but the oxygen has to build up inside the mat before any escapes into the water. In a 2021 study's models, a longer day lets more of it out from the same photosynthesis. The study asks whether Earth's lengthening days helped fill the air. Geophysicists still disagree about how the day lengthened.
The right amount of noise can sharpen a sense
A touch too faint to feel becomes easier to detect when a random buzz is added to the skin. The buzz now and then lifts the faint signal over the point where a nerve fires. Too little buzz does nothing, and too much drowns the signal. The effect is called stochastic resonance.
More Dossiers
Some land sinks and never comes back up
Pumping groundwater below its old lowest level squeezes water out of clay layers underground, and the clay stays squeezed. The land sinks, and the ground permanently loses a small share of the space that held well water.
Some words need the listener’s hands
In protactile, a tactile language developed in DeafBlind communities, the recipient’s hands can help form the expressions they receive.