A few years back, I had an incredibly vivid dream that seemed to be real. One of the characters in the dream informed me that my whole life had been a dream, and I didn't believe her. We got in an argument, where I pointed out how vivid and detailed my surroundings were, how vivid and detailed my memories of growing up in California were, and how unlikely it was that a character in my own dream would disagree with me. The character challenged me to try to open my eyes, and I did, confident that they were already open. I opened my eyes, and it was 3:00 in the morning in my little apartment in Texas. I have never even been to California. My entire life had been a dream, and a small fragment of my subconscious had known it was a dream when I had not. I was a solipsist for the rest of the week.

(Repost of an old message I sent to SL4 in 2003.)

Usually, like everyone, I forget my dreams. When I'm suddenly woken up, for example, by an alarm clock or by my cellphone ringing, it seems - I'm not quite sure if this is what is happening, but it's the explanation that seems most likely - it seems as if the last fifteen seconds of mental imagery are still "in my loop" when I wake up, so I remember them too, just as if they were lucid.

So the memory I actually have is of waking up, and then five seconds or fifteen seconds later, the phone rings. With an experience like that, it's easy to see why anyone less than a dedicated rationalist would assume psychic powers; "Oh, look, I become lucid fifteen seconds before the phone rings, I must be psychic".

Sometimes I'll even apparently remember that I have a dream in which an alarm goes off in my dream, which wakes me up, and then five seconds later the alarm goes off.

One needs to have done quite a lot of reading in cognitive science before one looks at that and says, "Timing fault in memory formation - yes, the brain really is that fragile", and not "I had a precognitive dream."

This ... (read more)

When I was about seven years old I was playing an imagination game which gradually became unusually vivid and complex. In the fantasy I was delivering some kind of technical presentation depicting what looked like electron microscope images of small tube structures and I kept using the word 'microhydraulics' in my speech.

After a long time I snapped out of the fantasy and just sort of stood transfixed, introspecting on what I had just experienced. I realized it was far more immersive than my typical fantasies, even at the time, and I had the distinct sense that a lot of time had passed since I was actually aware of my surroundings. Further, I did not typically fantasize about giving technical presentations, I didn't know what the word 'microhydraulics' meant and I probably had never seen an image from an electron microscope..

Decades later I have earned my PhD in a topic concerning modeling of fluid flow through micro- and nanoscopic media. I have given many technical presentations on the topic. Many of these technical presentations have included SEM images of such microscale flow features. Occasionally I will use the word "microhydraulics" in these talks, even though... (read more)

It's well known that we're all a lot stupider and a lot more ready to believe things when we first wake up. So here's my story.

I woke up a bit before my 7:00am alarm in the spring when the sun was rising not long before I got I up. It was just barely starting to lighten outside a little and I didn't feel like sleeping anymore, so I sat up and looked out the window as I had the nicest view from that apartment that I will likely ever have. I could see across the valley and just over the next set of hills there was the rising sun, a brilliant flat orange but not so strong that I couldn't simply look, at enjoying its color. The sky around still had most of the darkness of night, none of the reddening of sunrise which made the sun look all that brighter in contrast to such a subdued background. A single dark cloud cut a narrow horizontal line across the sun just over the midpoint.

I thought it was the most beautiful sunrise I had ever seen and decided to take a picture of it even though I knew that my poor phone camera would do an abysmal rendition of it. It took me a bit to get the phone into camera mode as I really hardly used it. But then I looked back out at the sunrise to snap a pi... (read more)

I had a large file to copy from my laptop to a friend. We were on a break between lectures - no external drive, wifi way too slow - so we used cable. The copy was taking a while so eventually we started making jokes about data flowing down the cable faster because of, you know, gravity. It didn't take long before we placed the receiving machine on the floor and... the speed increased. Not radically, but definitely more than what you'd expect from random fluctuations. We replicated the experiment three or four times, in both directions. Every time when the receiving machine was physically below the source the transfer was better. To this day I can't explain it and to me this is a proof of how a relatively simple and well understood system can be unpredictable.

Since high school I've been involved in conworlding - collaborative development of fictional worlds and societies, then setting stories or games in them.

Around 2005, I and some friends set a story in a culture with a goddess named Per married to a god named Elith. The religion gets called "Perelithve".

Skip to 2008. Neil Stephenson publishes Anathem, One throwaway reference mentions two of the avout, a woman named Per who marries a man named Elith. The marriage rite they invent gets called "Perelithian"

If names can have between 3 and 8 letters, and always alternate vowels and consonants, and ''th' counts as one sound, I calculate that the chances of someone who needs two names coming up with "Per" and "Elith" is on the order of one in a billion. The similarity in stories maybe adds another two or three bits of unlikelihood. If I've read 1000 novels, each of which has 100 minor characters, and my conworlds contain 1000 characters, then the odds aren't really that bad, maybe as high as 1%

Still freaks me out, though.

I have a recurring memory glitch that tells me I used to be able to levitate or fly. According to this memory, I used to be able to float a few feet off the ground simply by jumping up and holding there, choosing not to come down. There's a specific sensation memory associated with this, a tugging or lifting feeling in my abdomen.

The inference that follows, since I can't do it now, is that I forgot how to do it, or lost the ability somehow. This is moderately disappointing until I tell myself that it's just a memory glitch and humans can't levitate.

I have a few hypotheses about this:

• It's a memory of a dream, possibly a recurring dream. Dreams of flying are pretty common.
• It's a distorted memory of being picked up and carried as a small child.
• It's a distorted memory of a childhood habit of jumping off of things. (Which I did frequently, sometimes getting in trouble in grade school for jumping off of things that were too high for an adult to safely jump off of, but never injured me any.)

I was playing a card game with about 6 people in an AP calc class. One component of the game involved guessing: some of the cards were "good' and some were "evil". You had the option to either pick up a card or pass it on to the next player, and the objective was to pick up the "good" cards and pass on the "evil" ones.

Prior to guessing, I would look in my opponents eyes, and ask them: "Is it good or is it evil?". If it was good, I'd get this mischievous, friendly vibe from them. If it was evil, I'd get a sort of adversarial or guilty vibe.

I must have guessed between 60-120 times throughout the game. I got every single guess correct. It was creeping me out.

After the game was over, we tried having the professor draw some cards and pass it to me, and I was supposed to guess whether it was good or evil. My professors face was like a stone, and I was guessing at chance. (Note, however, that this wasn't a real game so there was no winning-losing at stake - that might have made it easier to avoid micro-expressions.)

This sort of thing had never happened to me before and has never happened to me since. I attributed it to luck and temporarily ... (read more)

One evening, when I was in my mid-teens, my parents had gone out and were due back very late. For story-unrelated reasons there was a lot of tension, nervousness and worry in the household at that time. My younger brothers went to bed, and I stayed up a bit watching the film Cat's Eye, a mild horror film written by Stephen King.

In the final part of the film, a girl is threatened by a vicious troll, a short, ugly, nasty creature with a dagger. It repeatedly creeps in to her bedroom in the night, first slaughtering her pet parrot, and then trying to kill her by sucking her breath out. She's defended by a stray cat, but unfortunately when her parents come in, there's no sign of the troll, only the cat, so the parents don't believe her and blame the luckless animal for the mayhem.

While I was watching this, one of my brothers came in from his bedroom, clearly upset. He'd heard something creeping in to his bedroom, first opening the door, then walking across the floor. He was scared. I instantly thought of the vicious troll from the film, but with my rational brain knew it couldn't possibly be that. I also knew he hadn't seen the film. So I tried to reassure him, and talked about how the... (read more)

One of the few times I have doubted my sanity and/or memory: http://www.gwern.net/Notes#true-dreams

I suddenly remembered what was my surreal story, perfect for rationalist creepiness :)

It was I think 1999 or so, and one afternoon it began to rain strange, white filaments from the clear sky. It seemed like cobweb, only that they were a lot thicker and the threads were about two feet long. I was in a large parking lot of a supermarket, and the rain covered it completely. It went on for some minutes, and I was utterly amazed: the strangest thing though was that nobody paid attention to the strands rain. I was running around trying to collect sample of that substance, but as soon as you touched it, it shrinked to almost nothing. A fistful of that sticky thing, if kept in one hand, would reduce to almost a black grain of sand.
I finally managed to collect a sample by wrapping the substance around a thick pen. I kept it in the fridge for about a week, unchanged. But I didn't know anyone who could perform an analysis, so in the end I threw it away.
I still don't have any explanation for the phoenomenon, it has never happened before and I've never witnessed it after.

When I was maybe 12 or 13, I woke up after having a nightmare and just sat in bed for a while, trying to remember what the dream was about. I was sitting up in bed, and for some reason I drew back the curtains to look outside. My back yard was filled with floating balls of light, which seemed to be larger than a softball. Occasionally the lights would flare up and glow even brighter. I just stared transfixed for a while, I couldn't believe I was awake.

The next day I was walking home in the early evening hours and saw fireflies floating near my house, and I realized that was what I had been seeing. I think my pupils were so sensitive from being in my pitch-black room that I could actually see the fireflies' bioluminescence in between light flashes.

I'd bought some apples from a store on campus and was carrying them in a plastic bag while waiting in line to pay at a different store. I heard a thud, and looked down, and there was an apple on the ground. I picked it up, and then felt the bag for holes. I didn't find any. I also counted the number of apples in the bag, and the number of apples I remembered buying were still in there. I knew that it was very, very unlikely that the apple had just appeared there, but I did assign a very small probability that I'd just seen something that didn't fit with known physics. A couple minutes later, the same thing happened again - another thud, another apple appearing on the floor. It only happened twice, though. Orpnhfr nsgre gung, n olfgnaqre cbvagrq bhg gb zr gung gurer jnf n grne va gur fvqr bs gur ont gung jnf arkg gb zl obql, juvpu unq znqr vg uneq gb qrgrpg ol whfg srryvat gur bhgfvqr naq obggbz bs gur ont.

BadBIOS: sounds awfully spooky. Worse than Cylons. I estimate the odds of an indestructible multi-platform virus that can jump air gaps being a real thing at less than 1%, but I wasn't overly Bayesian in my estimate. See also the relevant discussion on Reddit. What would be your estimate of such a spooky thing being real?

When I was about 14 there was supposed to be a meteor shower and my family went out to into the country to watch it. It was beautiful and wonderful, until one of the meteors made a noise. Exactly the sort of noise you would expect a shooting star to make, starting when it appeared and stopping when it fizzled. No one else thought this was strange, but I was intensely confused: how could we hear a meteor? It's so far away! And perfectly synchronized? Even airplanes are far enough away that their visual and auditory positions don't match.

Jura V tbg byq... (read more)

I have two modes of dreaming. One is first-person, and may not be obvious as being a dream at all, even in retrospect; the other is third-person. Sort of. There dream will have a character, who is usually not quite myself, and I'm simultaneously aware of the character's thought processes and my own; the character, however, is not. Usually. Sometimes the fourth wall breaks.

This is background information. Now, then...

I first read about the simulation argument when I was, oh, twelve years old or so. Shortly afterwards I had a new type of dream, where the thir... (read more)

Reading that ZFC has countable models spooked me. How can uncountable sets exist and an axiomatization of set-theory have a countable model? For a fraction of a second it made me doubt mathematics was real. For a few seconds after that I was thinking of giving up on understanding maths, or at least logic. Then I realized that there had to be a trick about it that made everything make sense again.

At first I thought this would be suggesting horror stories that are particularly horrifying to rationalists, such as the one Eliezer mentioned on the HP:MoR author's notes about the Friendship is Optimal fanfiction.

The most anomalous experience I can recall was when I was 14 or maybe 15. My workplace was a makeshift walk-down below ground level, in which the restroom was constructed from plywood with a bare electric light bulb hanging over it IIRC. At the time of this incident, I was being frequently harassed by a co-worker about the same age as myself. While using the restroom on one occasion, it seemed for an instant that I was spraying blood into the toilet, yet in the next instant there was no sign of blood anywhere and the water in the bowl seemed perfectly clea... (read more)

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