2025-03-19 17:22:50
Radioactive atoms have a half life; that’s the time it takes for 50% of the elements to decompose.
I often talk about the half-life of personal identity: how long does it take before you only feel 50% connected to the person you used to be?
I'm not sure if the thing I'm "really" talking about is the half life of memory, the half life of personal identity, or something slightly different. Maybe there's a parallel to Derek Parfit's arguments in Reasons and Persons, and there's various braided strands of continuities that together add up to something that matters to us.
Regardless, when I bring this up at parties I get (or at least think I get) a pretty immediate sense of recognition, and people generally having a sense of how long their personal half-life is. Which makes me think it's tapping into something.
How long is the half-life of your personal identity? Let us know in the comments....
2025-03-17 16:10:01
Stop me if you’ve heard this one: imagine a world where people’s consciousness is split in two.
Twice each day, they cross the invisible chasm between their parts, living first as one part (let’s call it their "Outie") and then as the other part (shall we say, an "Innie").
The Outie exists in the regular outside world, while the Innie lives in a constrained reality that they can’t really escape from.
In the moment of switching the perspective suddenly jolts, and neither half can remember what the other one experienced.
Obviously I’m describing the insanely popular TV show Severance, but I want to argue that for many of us this also applies to our waking and sleeping selves. And I semi-seriously think we should wonder: is it possible that we’re torturing our Innies?
Think about a person who can never remember their dreams. They know that for the last eight hours they have been in some state, and had some experiences. But they don’t know what those experiences are. They tell themselves that their dream-self was probably happy, was probably having good dreams and interesting experiences. Still, every so often they wake up with a feeling of strange post-boding, as if something bad just happened but they can’t remember what it was.
The relationship between our waking selves and our dreaming selves is something like the relationship between Severance’s Outies and Innies.
There is some parallelism between the Innies and the Outies – neither half can fully remember the experiences of the other, and there is some bleeding of mood across the boundaries in both directions.
That said, there is also some power imbalance between the two halves: it was the Outie who decided to undergo the consciousness-splitting procedure in the first place, while the Innie just has to live with the consequences.
I’m not actually sure what we can do to give our sleeping selves better experiences. But I feel certain that there are tradeoffs between my Outie and my Innie’s wellbeing. For example, if I take on a stressful but high-paying job, my Outie gets to enjoy more money and resources, but my Innie merely gets the stress with no benefits of his own.
It would be hard to quit a stressful job merely because of the possibility that it is causing my dream-self unfair unhappiness. But what if I knew for sure that my dream self (innie) was suffering for something that only benefited my outie? Would I be able to cause myself harm for the benefit of a dream-self I never actually see?
One cornerstone of moral philosophy is that there are tradeoffs a person may make within herself – accepting some harm for some compensating good – while it wouldn’t be moral to impose the same harms on an unconsenting stranger in order to claim benefits for oneself.
For example, it’s perfectly moral for me to do a workout that feels like getting punched in the face, because the health benefits are worth it to me; it’s not moral for me to punch random strangers in the face, although that’s also probably going to help me stay in shape.
There are tough moral questions whenever it’s ambiguous whether two entities are or aren’t separate moral agents in the relevant sense:
To this list, I’d like to add “the moral rights of our dreaming selves;” my attempt at a literature review found 0 examples of anyone talking about this, but the expanding circle of moral consideration has ever further to go.
While I can’t find anyone discussing dreamers’ rights, the psychologist Paul Bloom has apparently posed a similar question about undergoing anaesthesia.
As I understand it, the medical understanding of anaesthesia is that the patient feels no pain and lays down no memories. But Bloom asks, philosophically: what if some patients (in their Innie, anaesthesetized states) are feeling an extraordinary amount of pain, and then having those memories wiped as they zoom back out into awake consciousness?
In some sense, if this were true, it would be better to do a surgery without anaesthetic: at least then the person suffering would be the person benefitting. Currently there is a separate person who briefly comes into existence, gets tortured, then snaps out of existence again. And perhaps this is also true of our dreaming selves, though it’s not clear what we can do about it.
2025-03-12 17:39:58
When I was a kid we were told that 1 dog year was equivalent to 7 human years. This was based on 1) an average dog lifespan of 10 years, 2) an average human lifespan of 70 years, 3) a desires to convince children that their dog had lived a long and happy life.
I figured that both of these figures are now well out of date, so I wondered what the correct modern figure would be.
First, on the human side, average lifespan has gone up from ~70 in the 1960s to almost 80 in the 2020s.
If dog lifespans had remained unchanged, this would make a dog year equivalent to 7.7 human years.
For dog life expectancy, I was delighted to stumble on the 2023 paper "Life expectancy tables for dogs and cats derived from clinical data" from Frontiers of Veterinary Science. Incredibly, they had a dataset of 13 million dogs:
(If you're wondering about your own pet, I converted this into a life expectancy calculator for dogs, and another one for cats)
The average life expectancy for dogs in general was 12.69; dog lifespans have increased more than human lifespans have in the relevant period. As a result, even with the increase in human life expectancy, a dog year in 2025 should more accurately be referenced as "6.1 human years", or 6 years if you're rounding.
That said, I suspect there's a huge bias in the fact that this data was collected by a pet hospital. This means stray dogs would be excluded, though maybe that's less of a problem to the extent that the dog-year calculation is intended for children who have a specific pet in mind, but it also excludes people who never take their pet to the vet (or who only take their pet to the vet once, etc).
There's lots of variation in life expectancy by dog size: going from 9.5 years for giant, 11.5 years for large ones, 12.7 years for medium dogs, 13.5 years for small, but reversing slightly to 13.4 years for toy dogs. I don't really understand this: across species, big animals live longer (in general), but within a species (apparently) big animals live shorter. I found a paper on this but I didn't really understand it, if any of you do please throw your thoughts in the comments.
In other news, dog and cat life expectancy have both increased meaningfully even just between 2013 and 2019:
Why the increase in life expectancy? I'm speculating wildly here, but my bets are on two things. I think pet food has increased in quality a ton since I was younger: you can frame this in a positive way, but the negative frame is that I fear our old-school pet food was (in some sense) poisoning our pets.
Second, castrated animals tend to live longer [citation needed], and I wonder if there's more neutering and spaying these days.
2025-03-05 16:26:01
There's a pretty short list of Fundamental Things We Do Every Day – eat, sleep, breathe – where it's plausible that spending vast amounts of our time and money on improving them is actually worthwhile, because they'll have such an impact on the course of our lives. Yet, like most people, I struggle to implement that in practice.
The long version of how to breathe better is in books like Breath. I'm now in the weird position of believing that Butyeko Breathing might improve my life really significantly, if I managed to do a 10 minute exercise most days for a year, but (spoiler) I have been completely unable to follow through on that belief by doing the exercise. However, I do think I've got some of the benefits by doing the following easy things:
Your nose is made for breathing; your mouth is not. Your nose warms, moisturizes and filters air for you, your mouth does not. In short, mouth breathing should be used only as an absolute last resort. The best training for this is
1) consciously breathe through your nose while exercising – this is hard at first, and might require targetting your cardio level to be just as much as you can manage without opening your mouth, but it seems to pretty quickly increase your capacity/instinct for nose-breathing more generally.
2) just generally shut your mouth whenever you notice you're breathing through it – over time your mouth will just shut more by default.
The last time I recommended mouth-tape on here, beloved friends of the blog S. & S. reported they "kept thinking this was some sort of a satire." I assure you I'm serious: buy a box of 3M Surgical Micropore tape and tape your mouth shut every night before you sleep. This will make you breathe through your nose rather than your mouth at night.
2025-03-03 16:16:20
In a good whodunnit, the identity of the murderer is a surprise. But if you're watching a rom-com and somebody gets murdered, that's more like a meta-surprise.
Talking about "spoilers" is more complicated for meta-surprises. Obviously if you're reading/watching a mystery you should "keep the secret of whodunit locked in your heart," so that other people can enjoy the discovery for themselves.
But for a meta-surprise, even just revealing that there is a surprise is a spoiler. Some of the best meta-surprising books are almost unrecommendable: sometimes just saying that there is a twist can spoil part of the experience of the twist.
Maybe counterintuitively, working in a brand new medium seems to give more space for meta-surprises. You would think that the lack of pre-set expectations would make it harder to subvert expectations. Perhaps it's more a fact about the selection effects in publishing, where once expectations get set in stone perhaps it's harder to get your expectation-defying work published. Or perhaps it's a fact about human psychology, somehow: with an untouched field ahead of us, any path we take feels surprising.
2025-02-19 16:40:09
One thing I think is underrated is lifting your legs much higher when you're walking, and then varying the motion of your ankles/knees/hips with each step.
When you look at people walking, most of them are lifting their feet just barely off the ground. If you try lifting your feet up significantly higher, you'll notice two things:
1) it's much harder work than you think it would be – you can feel your breath go faster, so you're getting more exercise and burning more calories. This makes sense because you're significantly increasing the component of your motion that's going against gravity (vertically upwards) and therefore requires more force. (By comparison, moving forward is the easy bit)
2) you have way more options for how you move each of your joints, and can vary those choices with every step. (Despite the title of this piece, they don't have to be observably silly, you can just position and rotate your joints in slightly different ways).
The benefits of (1) are presumably self evident; the benefits of (2) I took from nutritious movement. The basic claim is that your joints etc would historically get a wide range of movement from walking barefoot on hilly ground (or whatever), such that walking gave you a varied diet of movements throughout the course of the day. As a modern person walking in shoes on flat asphalt, you get none of that natural variation, so to prevent your joints etc falling into "grooves" you need to generate more variation in your movement in tons of small ways.
My one note of caution is not to strike the ground too hard, you can definitely feel the difference that the additional height generates, although (frankly) this is presumably still less strain on your joints than jogging.