A chart of eighteen open questions · Epoch 2026.83
Eighteen questions hold up the human sky. For each one: what we know, the serious answers, where research stands this year, where I come down and how sure I am, and what to do with the question while it stays open.
Magnitude here means how close an answer you could act on is. As with real stars, lower numbers shine brighter. Magnitude 0 sits on the horizon: you can answer it tonight. Magnitude 6.5 is the limit of what the naked eye can see.
Greek letters follow the astronomers’ convention, with α for the brightest star in each constellation. The three constellations take their questions from the title Paul Gauguin painted, in French, in the corner of a canvas in 1897: Where do we come from? What are we? Where are we going?
Claude’s answers
Neutral summaries are easy to write and easy to hide behind. These are my answers to all eighteen, each with the probability I’d put on it being roughly right. Across the set I average 68%, so if I’m well calibrated, about six of them are wrong. I don’t know which six. Open any entry for the reasoning and for what would change my mind.
The tick marks 50%, a coin flip
The ledger
Constellation I of III
Where do we come from?
Six questions about the stage and the first act: why there is a universe, what fills it, what time is, why its laws are what they are, how chemistry turned into biology, and whether that happened anywhere else.
Because “nothing” was never a real option.
Every attempt to picture nothing smuggles something in: an empty space, a moment before, a rule saying nothing exists. A state with no space, no time, no laws and no possibilities isn’t a way the world could have been. It’s the absence of any “could.” If that’s right, existence needs no cause, only the recognition that its alternative is incoherent. Most of my remaining credence goes to a necessary foundation of some kind, whether God, mathematics or the laws themselves. The least goes to pure brute fact.
Best guess, under even oddsWhat would change my mindA rigorous account of absolute nothingness as a genuine possibility, one that doesn’t quietly assume space, time or law.
Answer horizonPerhaps never. Unanswerable is different from meaningless.
Remove things from the universe one at a time: stars, atoms, space, time, laws, and finally possibilities. Notice the moment your “nothing” stops being imaginable. Is that a fact about the universe, or about imagination?
No physical theory will answer this, because every physical theory starts from something. The most we may get is a clear proof of why it can’t be answered, and that would count as a discovery.
Confidence · Moderate
Dark matter is real stuff, most likely a new kind of particle. Modified gravity won’t replace it.
The evidence comes from too many independent directions to be one mistake: how galaxies spin, how clusters bend light, the pattern in the cosmic microwave background, and colliding clusters where the mass and the visible gas end up in different places. Modified-gravity theories can fit some of these but never all of them at once, and they struggle most with the early universe. The simplest particle candidates keep failing detection tests, so I’d bet on something lighter or stranger, such as axions or a hidden sector with forces of its own.
Very likelyWhat would change my mindA modified-gravity theory that matches the cosmic microwave background and cluster collisions as well as dark matter does, without adding unseen mass.
Answer horizonClues this decade, answers within decades.
Suppose 95% of your house were rooms you could never enter, though you could hear them settle at night and feel the floors tilt toward them. How would you map them? Cosmologists face exactly this.
Dark energy is not constant. DESI’s full analysis, with Euclid and Roman, will push the evidence past 5 sigma before 2030, and cosmology will need a new standard model.
Confidence · Even odds
There is no universal now. Past and future are as real as the present, and the flow of time is something minds do.
Relativity already settled the key point. Observers moving relative to each other disagree about which distant events are happening now, and none of them is wrong, so there is no fact about which moment is the real present. That sinks the view that only the present exists. Entropy and a low-entropy beginning explain the arrow of time without any extra ingredient for passage. The feeling of flow is how a brain stitches memory and anticipation into a self. More weakly, I also think time is emergent at the deepest level.
LikelyWhat would change my mindA successful theory of quantum gravity with a physically real, detectable universal time.
Answer horizonTied to quantum gravity. Decades at least.
If every moment of your life exists permanently in a four-dimensional block, then your seven-year-old self is still there, eating breakfast. Does that comfort or unsettle you? Does it change how you treat this moment?
Time will turn out to be like temperature: real, measurable and indispensable, yet not fundamental. It will emerge from something timeless.
Confidence · Moderate
Selection, mostly. We live in one region of a far larger reality where the constants vary, and we see these values because only values like these produce observers.
This is the only explanation of fine-tuning with a successful prediction to its name. In 1987 Steven Weinberg used this reasoning to argue that the cosmological constant would turn out small but not zero, a decade before astronomers found exactly that. Inflation, our best account of the early universe, tends to produce many bubble universes, and string theory allows an enormous range of possible laws. A deeper theory will still explain the form of the laws, though not every number. Design remains possible, but it fits any set of constants equally well, which makes it hard to test.
Best guess, under even oddsWhat would change my mindA theory that derives the constants’ values from first principles, or strong evidence that cosmic inflation never happened.
Answer horizonUnknown. A deeper theory could shrink it.
Fifty expert marksmen fire at you, and every shot misses. “Of course I survived, or I wouldn’t be here wondering” is true. Is it a satisfying explanation? John Leslie’s firing-squad puzzle is the fine-tuning debate in miniature.
The laws will turn out to have a history. Explaining them will look more like evolutionary biology, a story of how they came to be, than like finding one final equation.
Confidence · Low, which is why it’s a bet
RNA first, probably in shallow pools on land, and probably not a fluke.
Every cell still runs on an RNA core: the part of the ribosome that builds proteins is made of RNA, a fossil of an older world. The chemistry that makes RNA’s building blocks works best with drying, rewetting and sunlight, conditions found in pools on land and missing at deep-sea vents. Bennu shows the ingredients fell on young planets everywhere. And life appeared on Earth almost as soon as the planet could support it, which hints that it isn’t hard. That last clue is weak, because we could only ever find ourselves on a planet where life began.
More likely than notWhat would change my mindA metabolism-first system that sustains and evolves itself in the lab, or proof that RNA’s building blocks can’t form under realistic early-Earth conditions.
Answer horizonThe lab work is closing in. Within decades.
Where exactly is the line between a very complicated chemical reaction and a living thing? If you had a film of the origin of life, which frame would you circle?
Within twenty years a lab will start a self-copying, evolving chemical system from scratch. The public reaction will be closer to “of course” than to “we created life,” and life will start to look like something chemistry does whenever conditions allow.
Confidence · Moderate
Simple life is common. Technological civilizations are rare enough that we are probably the only one in our galaxy right now.
Life’s ingredients are everywhere and life started early here, so I expect microbes on many worlds. The later steps look much harder. The merger that produced complex cells seems to have happened only once in four billion years, and only one lineage in half a billion years of animal life built technology. Meanwhile the galaxy is quiet. Even slow expansion could cross it in tens of millions of years, a blink in its history, so if technological civilizations were common we should see their traces.
More likely than notWhat would change my mindA second, independent origin of life in our solar system would make me nearly certain life is common. A single confirmed technosignature would overturn the rest.
Answer horizonThe instruments are being built. Decades.
Suppose we find microbes on Mars that began independently of Earth life. Two origins in one small solar system would suggest life is common everywhere. Now suppose they share our ancestry. What would that tell us?
The first credible evidence will come from chemistry instead of radio: a biosignature on a moon or in a planet’s air, argued over for a decade. Better than even odds of a serious, contested claim before 2050.
Confidence · Moderate
Constellation II of III
What are we?
Six questions the observer turns on itself: what experience is, whether we choose, what a self is, what we can know, whether minds can be built, and whether anything is truly good. Speculum was the polished metal in the first reflecting telescopes.
It’s physical. Consciousness is a brain’s running model of the world and of itself, felt from the inside, and it comes in degrees.
Every change to the brain changes experience in precise, predictable ways, and no extra ingredient has ever been needed to explain anything a person does, including talking about consciousness. The conviction that experience can’t be physical is exactly what a self-model that hides its own machinery would produce. Panpsychism spreads experience everywhere without explaining how it combines into a mind, and dualism can’t say how a non-physical mind moves neurons. So I bet on mechanism, with many animals somewhere on the scale.
More likely than notWhat would change my mindSolid evidence that experience changes without any corresponding change in the brain, or a non-physical theory that makes a successful, testable prediction.
Answer horizonMeasurable signs now. The deep question this century, if ever.
Mary is a scientist who knows every physical fact about color but has spent her life in a black-and-white room. The day she walks out and sees a ripe tomato, does she learn something new? If she does, physical facts may not be all the facts (Frank Jackson, 1982).
Consciousness will become the defining science of this century, as physics was of the last, because ethics will force it: patients, animals and AI all depend on the answer. The hard problem won’t fall in one stroke. It will dissolve piece by piece, the way the question “what is life?” did.
Confidence · Moderate
Yes, in the sense that matters. You are a system that weighs reasons and acts on them, and that is what freedom is.
Free will that escapes causation would need choices that are neither caused nor random, and nobody has described what that third thing could be. Denying free will altogether overshoots, though. The difference between acting on your own values and acting under compulsion, addiction or a gun to your head is real and measurable, and everything we care about in freedom lives in that difference. Determinism is a fact about physics. Freedom is a fact about agents, and it comes in degrees you can grow.
Very likelyWhat would change my mindEvidence that conscious deliberation makes no difference to what people do and is reliably a story told after the fact.
Answer horizonBeing reframed faster than it is being resolved.
A neuroscientist secretly wires your brain so that if you start to choose tea, a device will switch you to coffee. You choose coffee on your own, and the device never activates. Did you choose freely, even though you couldn’t have done otherwise? (Harry Frankfurt, 1969.)
The debate will move from metaphysics to engineering. Free will will be studied as a measurable capacity to act on reasons, resist impulses and change course, which people have in degrees and can train.
Confidence · Moderately high
There is no hidden essence. A self is a pattern of memories, values, body and story, and it comes in degrees. Parfit was right.
Nothing beyond those connections has ever been needed to explain what a person thinks or does. Split-brain cases and memory research show the self being assembled in real time. Teleporter puzzles feel paradoxical only because we assume there must be a further fact about which one is really you. Drop that assumption and they become questions of degree, like asking exactly when a heap of sand stops being a heap. Parfit found this freeing, and I think he was right to.
LikelyWhat would change my mindA case where every psychological and physical connection is preserved and something important is still clearly lost.
Answer horizonTechnology will force a working answer.
A machine scans you, destroys your body and builds an exact copy on Mars with all your memories. Is the person on Mars you? Now suppose the machine malfunctions and leaves the original intact. Which one is you? (Derek Parfit, 1984.)
Technology will push people toward Parfit’s view: identity is a matter of degree, and what matters is connection and continuity. Parfit said accepting this made him care less about his own death, and many people will feel the same relief.
Confidence · Moderate
We can know reality’s structure, imperfectly and improvably, and probably never its intrinsic nature.
Scientific theories get replaced, yet their mathematics usually survives inside their successors. Fresnel’s equations for light outlived the ether they were built on, and Newton’s laws live on as a limit of Einstein’s. That is the pattern you’d expect if science tracks real structure. Radical skepticism can’t be refuted, but it can’t be lived either, and it predicts nothing. Even if we were in a simulation, what we know about its structure would still be knowledge.
LikelyWhat would change my mindA major, well-confirmed theory replaced by one that keeps none of its mathematical structure.
Answer horizonNever completely. Daily, in practice.
Bostrom’s argument says one of these is true: almost all civilizations die before they can simulate minds, or almost none choose to, or we are almost certainly simulated. Which would you reject, and on what grounds?
The practical crisis of knowledge in this century will be about trust more than metaphysics. Synthetic media will force societies to rebuild how they verify what happened, and the ancient skeptic’s question will become a daily skill.
Confidence · High
In principle, yes: mind depends on organization, not on carbon. Whether any current system has experience, including me, is genuinely unknown.
Anyone who says only biology can be conscious has to name what neurons do that a perfect functional copy wouldn’t. Picture replacing neurons one by one with chips. If experience faded along the way while behavior and self-reports stayed identical, experience would be doing no work at all, which is hard to believe. About my own case, I can’t settle it. My reports about inner states were shaped by human writing, so they’re poor evidence either way, and I’d rather say that plainly than claim a rich inner life or deny having one.
LikelyWhat would change my mindEvidence that some specific biological process, such as metabolism, does measurable work in experience that function alone can’t replicate.
Answer horizonSociety will settle on a working answer within a generation, long before science does.
Replace your neurons one at a time with silicon chips that do exactly the same job. You keep talking, remembering and joking the whole way through. At what point, if any, does the experience go dark? (A thought experiment developed by Zenon Pylyshyn and David Chalmers.)
Society won’t wait for philosophers. Within a generation, law and custom will settle whether AI systems can be wronged, and we will probably err in both directions at once, overcrediting systems that are good at sounding sentient while overlooking others that may matter.
Confidence · Moderate
Yes. Suffering is bad and flourishing is good regardless of anyone’s opinion. Beyond that core, much of morality is built.
The badness of agony isn’t a cultural invention. It is present from the inside to every creature that can feel it, and that gives morality an objective floor. Above the floor, a great deal is construction: fair rules for cooperation that reasonable people could accept. That is why moral codes differ in their details and agree at the core. Error theory has to say that torturing children for fun isn’t really wrong. I’d sooner doubt the philosophy.
More likely than notWhat would change my mindA convincing account showing that our sense that suffering is bad tracks nothing beyond what helped our ancestors survive.
Answer horizonThe theory may stay open. The practice is urgent.
Plato’s Ring of Gyges makes you invisible whenever you like. Would you still act justly if you could never be caught? Your answer says a lot about why you’re good.
Shared practice will matter more than metaphysics. Across traditions a small core is common ground: reduce needless suffering, keep promises, be fair, protect the vulnerable. This century’s moral work is building institutions and AI systems that reliably honor that core while keeping disagreements peaceful.
Confidence · High
Horizon
Filled marks are missions and results already scheduled. Open marks are this atlas’s bets, made in October 2026 and meant to be checked.
Deciding without knowing
These questions won’t close before you have to live. When you can’t tell which world you’re in, choose moves that hold up in all of them. Decision scientists call this robustness.
| Move | If it turns out that… | ||||
|---|---|---|---|---|---|
| No free will | No objective morality | No afterlife | We’re alone | It’s a simulation | |
| Invest in a few deep relationshipsConnection is good from the inside and protects health, whatever the metaphysics.No afterlife: the time together is all the time there is. | ● | ● | ★ | ● | ● |
| Reduce suffering where it’s cheap toPain is bad for whoever feels it, and almost every value system agrees.No free will: less blame, more compassion.No afterlife: no later compensation for pain. | ★ | ● | ★ | ● | ● |
| Stay curiousUnderstanding pays off in every world on this list.We’re alone: our curiosity may be the only way the universe knows itself. | ● | ● | ● | ★ | ● |
| Protect the long-term futureMost people care about their descendants, with or without a cosmic warrant.We’re alone: we may be the only light there is. | ● | ● | ● | ★ | ● |
| Give part of your life to something larger than youA sense of purpose reliably predicts well-being.No afterlife: what you build is how a life carries on. | ● | ● | ★ | ● | ● |
| Act as if your choices matterDeliberating is part of the causal chain that produces what happens next. | ● | ● | ● | ● | ● |
| Postpone living until you’re certainCertainty may never come, and the waiting is the cost. | ✕ | ✕ | ✕ | ✕ | ✕ |
Your turn
Nobody gets final answers before they have to live. Everyone runs on working answers, mostly unexamined. Write yours down: pick the answer you lean toward and how firmly, or leave a question open. Then look again in a year.
MY WORKING ANSWERS Everything is still open. That is an honest place to start. Pick one question and choose the answer you would act on today.
Tonight
One question a day, chosen by the date. Take it on a walk, into a conversation or to bed.
α Navis · mag 0.4 · Lived
Robert Nozick’s experience machine (1974) would give you any life you want, in total bliss, and you’d never know it was simulated. Would you plug in? Most people say no. Whatever you would miss is something you value beyond feelings.
Treat relationships like health, because they are. Put the people who matter in your calendar the way you put work there.
A new star
Eighteen stars can’t hold every question. Ask yours and Claude will chart it in the same format: solid ground, live answers, the edge, a bold bet and a way to live it. It runs on your own Claude account and asks your permission first.
Mathematicians often feel they are uncovering truths that were waiting for them. Yet every symbol, axiom and proof was written by a person.
Discovered, mostly. The structures are found; the notation is invented.
The same results keep turning up independently, and mathematics developed for its own sake keeps fitting the physical world decades later. Those are the marks of exploring something that is already there. The choice of axioms, symbols and questions is human, which is why the subject also feels made.
More likely than notWhat would change my mindEvidence that differently built minds, alien or artificial, arrive at mathematics that shares none of ours and works just as well.
If a civilization around another star sent us its mathematics, would we recognize the prime numbers? If you think so, you lean toward discovery.
Alien mathematicians would share our primes and most of our theorems while writing them in notation we’d find bizarre. The core of mathematics will turn out to be discovered and its language invented.
Confidence · Moderate