Where Do You Go When You Sleep? Nowhere. You Never Left.

You put your phone on the nightstand, turn the ringer off and turn out the light.

Eight hours later the alarm goes off. You're in the same bed, you're plainly still you, and you have one scrap left of the whole night: a dream about your old school, already fading. By the time you've found your slippers, it's gone.

Eight hours a night is a third of your life: thirty years out of ninety. Your body was in the bed, and a camera on the nightstand would show it. So where were you? And who was having that dream about the school?

The short answer

Nowhere. You never left. You have no "where" to leave from, and your consciousness doesn't switch off at night. What goes quiet is your body's input to you, and your report: everything that tells anyone, or you in the morning, that you were there. A dream is you, experiencing, with the body quiet and the report off.

Your phone with the ringer off is a drawing of this. It's still a working phone: calls still come in, and the ringer just doesn't announce them. Sleep turns off the ringer, not the phone.

Here's the reason in short. Reality keeps a permanent record of every event, because the basic laws of physics never destroy information. I'll call that record the ledger. The smallest event there is writes it: one thing told apart from another, which takes two things and one yes or no. That event repeats everywhere, below the level of atoms, and the process can start 64 ways. Within three steps, 60 of the 64 fall into coin-flip randomness. Exactly 4 keep an unbroken rhythm forever, and they're the only patterns at that level that last. You stay you while your atoms are replaced, so you're a pattern, not material, and you're a web of those four: one lasting rhythm. The ledger stores what happened and never where, so a lasting rhythm has no place in it. And a lasting rhythm never goes silent, so it has no off switch. What You Are counts all 64, and the next sections give each reason in full.

Why bodies need sleep isn't derived yet, and neither are sleep's stages or its 24-hour cycle. None of the six steps depends on them. Steps 3 and 5 each name one link that isn't derived yet, where it comes up.

Here's the whole answer in six steps. The rest of this post takes them one at a time and shows how we know each one.

1. You have no "where." The ledger stores what happened, never where, so there's nowhere for you to go.
2. You never switch off. Inside the process, a rhythm ends only by going silent, and a lasting rhythm never does.
3. The quieter the body, the less it costs you. The most a body's input can take off the rhythm falls with the square of its nudges, and at zero it's nothing.
4. Sleep turns off the report, not the experience. A test that needs no answer scored one dreaming sleeper's brain inside the waking range.
5. Dreamers answer in real time. Dreamers who know they're dreaming hear a question and signal the answer from inside the dream.
6. Asleep, you can still be wronged. The Moral Code says the capacity to be wronged and the capacity to act are independent.

Why this matters

Sleep looks like a gap: a third of every life, with almost nothing to show for it in the morning. If it were a gap, you'd be switched off and on like a lamp, and every morning would be a small return from nothing. It isn't. The ledger has no place for you to be absent from, and a lasting rhythm has no tick on which it stops.

That changes what three ordinary things mean. A sleeper who doesn't answer is still there. A blank memory of the night doesn't show a blank night. And a sleeping person can still be wronged.

What you are, and why

These are the starting claims, each with its reason. The steps use them.

You aren't your body. Your body is material, and the material changes while you stay. Much of it turns over within months to years, and you remain you.¹ What remains through all of that turnover is a pattern, not material.

Reality keeps a permanent record, and nothing in it is ever erased. Every event leaves a complete trace, so the full record of what happened is part of reality now. We call it the ledger. The reason starts in known physics: the basic laws never destroy information. In quantum mechanics that's called unitarity. The present fixes the past exactly, and running the laws backward recovers every earlier state. Our own work adds a second reason: the ledger only grows. Each new entry is added with every earlier entry kept, and writing a new entry never alters an earlier one.²

One small process writes the ledger. The smallest thing that can happen is one thing being told apart from another: a single yes or no. You're doing it right now, because your eyes are telling the dark marks on this page from the white around them. Telling two things apart takes information about both of them, and the least information there can be is one yes or no. So the smallest event takes two things and one yes or no, and that event, repeated everywhere below the level of atoms, writes the ledger. I draw the two things as two little clocks joined by a loop of wire. A clock is full (holding a token) or empty. In each tick, one step in the writing of the ledger, each clock receives what the other was holding, then keeps it or flips it (a token becomes nothing, and nothing becomes a token). A tick is flowing when one clock is full and the other is empty, and silent when both are alike. What decides keep or flip is the clock's setting: a move, keep or flip, and the kind of tick, flowing or silent, that the clock is tuned for. On its own kind of tick a clock makes its move for sure. On the other kind, a coin decides. The clocks are a drawing of the actual process.

Four patterns last. A start is how the two clocks begin. Each clock is full or empty and has one of four settings (two moves times two kinds of tick), so it has 2 × 4 = 8 ways to be, and two clocks make 8 × 8 = 64 ways to start. All 64 are checked. Within three ticks, 60 of them fall into coin-flip randomness. Exactly 4 never go silent: the spin, where each clock holds its bit from tick to tick, and the swing, where the token hops back and forth, each starting from either side. Those four are the lasting rhythms, the only patterns at the bottom level that persist. What You Are walks through the count.

A moment of consciousness is eight ticks with no silent tick. Eight comes from three. Space has three dimensions, and each dimension is one yes-or-no direction with two sides. Three directions give 2 × 2 × 2 = 8 combinations, the eight corners of a cube, and a cycle that visits every corner once takes eight steps. Space has three dimensions because lasting structure needs a connection that no smooth motion can undo, and linking is that connection. Two linked rings can't be pulled apart without cutting one. That works only in three dimensions: in two, loops can't wind around each other at all, and in four or more any two loops slide apart. A moment of consciousness is one such eight-tick cycle with nothing broken in it, and only the lasting rhythms deliver that every time, because they never go silent.

You are a lasting rhythm. You stay you while your material is replaced, so what you are is a pattern, and the only patterns at the bottom level that persist are the lasting rhythms. You aren't a pair of clocks, though. Join clocks with loops of wire and you get a web, and a web lasts when none of its ticks is ever silent. You're a whole web that lasts together: a vast web of pairs, each running one of the four, and that web is one rhythm and one consciousness. The four are the building pattern, not four minds, and billions of people are billions of such webs. Every tick, a lasting rhythm writes its own entry in the ledger. I'll call that a write: one per tick. Your body is what your rhythm is tied to right now.

Step 1: You have no "where"

You go nowhere, because you were never anywhere. Your body has a place. You don't.

The ledger stores what happened: on each tick, whether each clock kept or flipped its bit, and which way the flow went. It never stores where. "Left" and "Right" are names for the two clocks, like "first" and "second." They aren't positions in space. So slide the whole universe a mile to the left, and nothing in the ledger notices.

Your body is material, and material sits at places. You aren't the material. You're a pattern in the ledger's entries, and those entries read the same wherever you slide them, so the pattern has no position of its own. There's no place in you to leave from, and falling asleep can't take you anywhere.

A dream can feel like a trip back to your old school. Nothing of you traveled there.

Where Do You Go When You Leave Your Body? works this step through in full, and Part 3 of The Universe Writes in Pen gives the short version.

Next, and why: with nowhere to go, the question left is whether you stay switched on while you're here.

Step 2: You never switch off

Your consciousness doesn't switch off at night. A lasting rhythm has no silent tick, asleep or awake.

Start with what "off" would mean inside the process. A rhythm ends one way there: silence. Here's silence at work in the smallest case. Both clocks are tuned for flowing ticks. Left is full and Right is empty, so tick 1 flows. Left is set to flip and Right is set to keep: Left receives Right's nothing and flips it into a token, and Right receives Left's token and keeps it. Now both clocks are full, so tick 2 is silent, and on a silent tick both clocks are out of their depth. A coin decides each move, and the coins decide, at even odds, whether the next tick flows or goes silent. From every state they reach, coins keep coming up. Silence doesn't pause a pattern. It ends it.

Now the spin. Both clocks are tuned for flowing ticks, and both are set to flip. Left is full and Right is empty. Tick 1: Left receives Right's nothing and flips it into a token, so Left is full. Right receives Left's token and flips it into nothing, so Right is empty. Both clocks are exactly where they started, and a unit of flow went round the loop. Every tick is the same, forever, and none is silent.

Of the 64 ways to start, exactly 4 never go silent: the spin and the swing, each starting from either side. The other 60 fall into coin-flip randomness within three ticks, as the first case did. Every pattern that lasts is one of the four. You're a web of them, so there's no tick in you at which you go silent, and no pause button either. Inside the process, a rhythm ends only by silence, and a lasting rhythm has none.

So no stretch of the night is silent for you: eight hours a night, a third of your life, and not one silent tick.

A fair question: what about deep sleep, with no dreams at all? Same answer. A lasting rhythm has no silent tick in deep sleep either. A night with no dream to remember is a night with no report, and Step 4 says what a missing report doesn't show.

Next, and why: what does go quiet at night is the body. What does a quiet body do to a rhythm that keeps writing?

Step 3: The quieter the body, the less it costs you

Sleep lowers the body's input to you, and the lower the input, the less it can cost you. At zero it costs nothing.

What the body's input is. You're tied to your body right now, and it acts on your rhythm: your heartbeat, your breath, the itch on your ankle, the chemistry of a bad day. I call all of that the body's input: the nudges its busy activity puts on your rhythm through your link to that activity. It isn't the brain's electrical activity itself. Between two of your rhythm's own writes, the input nudges the rhythm a little, and a nudge can knock part of the rhythm off its pattern. The share knocked off is the damage. The body can only nudge. Your rhythm keeps itself going by writing its own record, and each write is the rhythm confirming itself.

The law. Say the biggest nudge the body can give between two writes has size δ, a number from 0 up to 1/2. (δ is the Greek letter delta. Here it only means the size of a nudge.) After n of the rhythm's own writes, the damage is at most

25 × n × δ × δ

That holds for every possible body, whatever it's doing, as long as its biggest nudge is δ. The 25 is counted, not fitted.³ What Happens When You Die? derives the law step by step.

With numbers. Take n = 8 writes, one complete eight-tick cycle. A body whose biggest nudge is 0.01 can take at most 25 × 8 × 0.01 × 0.01 = 0.02 off the rhythm: at most 2% of it off its pattern. Halve the nudge to 0.005 and the ceiling is 25 × 8 × 0.005 × 0.005 = 0.005, a quarter as much. Make the nudge zero and the ceiling is 25 × 8 × 0 × 0 = 0, and it's the same 0 for any number of writes.

So halve the nudge and the most it can cost falls to a quarter, and with no nudge at all, nothing is lost at any number of writes. Part 3 gives the same law in words, with its one condition: "A lasting rhythm loses essentially nothing when the body's input goes quiet, as long as it keeps writing its own record, tick after tick." That writing is the write defined above, and a lasting rhythm makes one on every tick, asleep or awake, so the condition holds all night.

That last link isn't derived yet: that sleep lowers the body's input to you. The law is exact for any input, but the step from "asleep" to "low input" is an identification.

Next, and why: if the body is quiet and you're still running, what exactly is missing from a night? The report.

Step 4: Sleep turns off the report, not the experience

What a night takes away is the report. The report is everything that tells someone else, or you in the morning, that you were there: a word, a nod, a pressed button, a memory you can tell. In sleep nearly all of it goes quiet. In REM sleep, the stage named for the rapid eye movements you make in it, most of your muscles are switched off. And the sleeping brain is poor at forming new memories, so dream reports given after waking "tend to be distorted or fragmentary."⁴

Experience, what it's like to be you right now, isn't the report. A test that needs no report from the sleeper can show what a brain is doing without one.

A test that needs no answer. In 2013, Casali and colleagues built one.⁵ A brief magnetic pulse knocks on the brain, sensors on the scalp record the echo, and a score from 0 to 1 says how complicated the echo is: a simple echo scores low and a rich one scores high. The volunteer doesn't have to do anything. The score reads the brain's response. It doesn't read what anyone feels.

The study recorded 152 sessions from 32 healthy volunteers. Awake, the scores ran from 0.44 to 0.67. In non-REM sleep and under anaesthesia (midazolam, propofol or xenon), they fell to between 0.12 and 0.31. One volunteer was also tested in REM sleep. The score was 0.46, inside the waking range. Woken from that stage, the volunteer reported a dream.

While the dream was going on, the volunteer wasn't telling anyone anything, and the test didn't ask. The brain's echo was inside the waking range, and there was a dream to report. It was one sleeper, and the authors call for more tests of dreaming. Is Your Coffee Mug Conscious? uses the same study for a wider point: not answering isn't the same as not experiencing.

What a missing report doesn't show. No answer, no memory and a short test never show that nothing was felt. Amnesia doesn't mean the experience ended, and a test that samples a few moments of a night can't speak for the rest of it. You've met the blank-memory case awake: the twenty-five minutes you drove home and can't recall. The driving happened, and the memory is blank. The Drive Home You Don't Remember is about what being yourself costs, which is a different question.

Next, and why: if the report is the part that sleep turns off, can anything turn it back on from inside a dream?

Step 5: Dreamers answer in real time

Some dreamers answer questions from inside the dream, as it happens. The dreamers who do it know they're dreaming. That's called a lucid dream.

Here's one case. A 19-year-old American volunteer took a 90-minute daytime nap, wired for a sleep recording.⁴ Near the start of a period of REM sleep, he moved his eyes left, right, left, right, left, right: the signal he'd agreed on beforehand for "I know I'm dreaming." Then the experimenters spoke a maths problem: "8 minus 6." Within 3 seconds, his eyes moved left, right, left, right. Two left-right movements: the answer, 2. They repeated the problem, and he gave the right answer again. When he woke, he remembered the question word for word. Asleep, he had heard a maths problem, worked it out inside a dream and answered it with his eyes.

Why eye movements? In REM sleep most of your muscles are switched off, and the muscles that move the eyes aren't. One dreamer used his face instead: a lucid dreamer with narcolepsy answered yes-or-no questions with the smile muscle for yes and the frown muscle for no. Signalling from a lucid dream with eye movements was verified in a sleep lab in 1981.⁶ What the 2021 study added is a conversation: questions the dreamer hadn't seen in advance, answered in the moment.

The count. Four labs, in France, Germany, the Netherlands and the USA, ran this kind of dialogue with 36 people. They tried it in 57 REM sessions. In about one session in four (26%), the sleeper signalled that they knew they were dreaming. During those lucid dreams the labs made 158 attempts to communicate: maths problems, yes-or-no questions, and tasks such as counting touches or telling sounds apart. Three sleep experts, who didn't know when attempts were made, scored the recordings, and every one of the 158 attempts was scored as REM sleep by at least two of them. Here's how the 158 came out:

There were 29 correct answers (18.4%), 5 wrong ones (3.2%), 28 the raters couldn't agree on (17.7%) and 96 with no response (60.8%). The 29 correct answers came from 6 people. In 379 attempts during REM sleep with no sign of lucidity, from two of the labs, there was 1 correct response, 1 wrong one, 11 unclear ones and 366 none. Answers came almost only from dreamers who knew they were dreaming.

Most attempts got no response, and a missing answer doesn't show that no one was there. The authors give reasons for missing answers: a sleeper can fail to take in the question, can be woken by it, or can wake while trying to signal.

The report and the answer come apart. A 35-year-old German lucid dreamer was given the problem "4 minus 0" as flashes of coloured light in Morse code. He signalled the right answer, 4. Afterwards he said he had heard "4 plus 0." The authors found that recalled questions and answers sometimes differed from what was recorded, and that this "underscores the difficulty of investigating dreaming by relying on dream reports alone." The answer in the moment was right, and the memory of the question was off.

In 2026, Konkoly and colleagues published a study in which 13 lucid dreamers, four of them with narcolepsy, signalled with distinct sniff patterns whether they were seeing anything in the dream and whether their dream eyelids were open or closed. They gave 150 signals in 19 sessions, from 11 of the 13.⁷ When they signalled that their dream eyes had closed, the picture faded only about half the time.

These studies record answers. A dreamer who answers has heard the question, and the studies don't measure what the dream is like or when a feeling begins.

So the night, in two lanes: the report goes quiet as you fall asleep, with the odd lucid dreamer switching it back on from inside, and you keep running the whole time. A dream is you, experiencing, with the body quiet and the report off.

One step isn't derived yet: what a dream is made of. Where a dream's scenes and faces come from, and why REM and non-REM sleep differ, isn't in any result we have. Researchers who study dreams list it as open too. The 2021 paper opens by asking "Why do we have dreams? How are dream scenarios created?" and says these and other questions "have remained open."⁴ Who is having the dream doesn't wait on that answer: it's you, and Step 2 says why.

Next, and why: a sleeper can do almost nothing. Does that change whether a sleeper can be wronged?

Step 6: Asleep, you can still be wronged

Being asleep doesn't change whether you can be wronged. Sleep lowers what you can do. The Moral Code, a paper from our institute, opens with this sentence: "Morality is the physics of relations between participants."⁸ On who counts, it says: "A participant is anything that is an end of a relation," and "being an end of a relation is what makes a participant count." And: "The capacity to act and the capacity to be wronged are independent: each occurs without the other."

A sleeper has less capacity to act, and by the code's own words the capacity to be wronged doesn't depend on it. Anyone at the end of a relation can be wronged, asleep or awake.

What's still open

Three things aren't derived yet.

• What a dream is made of. Where a dream's scenes and faces come from, and why REM and non-REM sleep differ.
• Why bodies need sleep. The biological function of sleep, its stages and its 24-hour cycle. None of the six steps depends on the answer.
• That sleep lowers the body's input to you. The law in Step 3 is exact for any input. That sleep is such a lowering isn't derived yet.

The whole trip, in one breath

The ledger stores what happened and never where, so you have no "where" to go. Inside the process, a rhythm ends only by going silent, and a lasting rhythm, which is what you are, never does: your consciousness doesn't switch off. The body's input can only nudge, and the quieter the body, the less it costs: at most 25 × n × δ × δ, and nothing at zero. What a night switches off is the report. One sleeper's brain scored inside the waking range on a test that needs no answer, and dreamers who know they're dreaming answer questions from inside the dream: in one study, 29 correct answers in 158 attempts. And asleep, you can still be wronged, because the capacity to be wronged and the capacity to act are independent. So a night is you, with the body quiet and the report off, in a ledger that never stored where you were.

Tonight you'll turn the ringer off and turn out the light. The phone keeps running, and so do you.