Magical adventures in fantasy otherworlds 
may sound fun on paper, but more often than

not they’re a surprisingly risky gamble. In 
the best-case scenario you’ll come back home

and find only seconds have passed since you left 
and you won’t even get in trouble for being gone.

Sometimes time passes at a one-to-one rate and 
the whole time you’re gallivanting around in

the magical otherworld, time’s still passing 
back in the real one and you’re gonna have

some serious explaining to do if and when you 
get back. But the worst case scenario flips

that first one on its head - you might think 
you only spent a few days in the otherworld,

but hundreds of years could be passing in 
reality. The concept of localized time dilation

is a staple in fiction and folklore because it’s 
frankly deeply unnerving. As a bonus fun fact,

it’s a real thing in relativity - it’s almost 
totally unobservable under normal circumstances,

since we tend to stay in mostly one place 
relative to the earth and don’t usually

move at an appreciable fraction of the speed of 
light, but a clock moving relative to an observer

can be observed to tick slower than a relatively 
stationary one, and a clock close to a gravitating

mass will measure less time passing than a 
clock farther away from the same mass. Thanks to

gravitic time dilation, the core of the earth is 
about two and a half years younger than the crust.

This is bananas, you may 
remember it from Interstellar,

that's basically the only time 
pop culture ever used this.

Maybe those magical otherworlds simply reside… 
close to the event horizon… slowed and distorted

by the very nature of space-time……… or maybe 
it’s fiction and we don’t need to read too

far into it. Anyway, today let’s talk about a 
japanese folktale about the dangers of magical

otherworlds and the importance of following 
instructions from people who know more than you.

Our story begins with a young fisherman 
called Urashima who’s a very sweet guy

without a mean bone in his body. His profession 
of “fisherman” does make it a little difficult

for him to be completely harmless, but he’s very 
conscientious about the whole thing and doesn’t

do any more harm than he has to. So that’s why 
one day, when he fishes up a massive turtle,

he remembers hearing that turtles are 
supposed to live for a thousand years,

and he feels bad about cutting that short just for 
a tasty dinner, so he throws the turtle back and

settles in for a nice little fishing-boat nap.
This is when a beautiful woman rises out of

the water, steps into the boat and tells Urashima 
that she was that turtle and is also the daughter

of the sea god and she’s here because he 
just proved himself in a secret test of

character and is qualified to be her husband. 
Urashima likes the sound of that, and he and

the princess sail out to the Dragon Palace to be 
married, where they settle in to live together in

riches and luxury for a thousand blissful years.
And if only the story ended there. But while

Urashima is a big fan of this magical palace and 
dragon princess wife situation, after about three

years of divine marital bliss he starts feeling a 
little bit homesick and he wants to sail back to

his humble village to check in on his family and 
friends, you know? The Dragon Princess doesn’t

think this is a very good idea, but she won’t stop 
him, so she just warns him to be very careful,

because she has a feeling something very bad might 
happen if he does anything reckless. She gives him

a small box and warns him not to open it under any 
circumstances or he won’t be able to come back.

So Urashima tucks the box away, grabs his boat 
and sails back home - but it’s not quite what he

was expecting to see. The mountains and rivers 
are all the same, but the buildings are gone,

including his house. He flags down a couple 
beachgoers and asks them what happened to the

Urashima house, and they tell him that’s a weird 
thing to ask, since it’s an old folktale around

these parts - four hundred years ago some kid 
named Urashima drowned on a fishing trip and never

came home. His family are, of course, long dead, 
and even the village he lived in has fallen into

ruin. Urashima realizes the dragon palace might 
just be one of those magical fairy realms he’s

heard about, where time passes a lot slower on the 
inside than the outside. He thought it was only

three years, but it’s been centuries out here.
Well, that’s a bummer, but what are you gonna do,

right? With no surviving friends or 
family and no reason to stick around,

Urashima prepares to head back - only to realize… 
he doesn’t remember the way. Surprise surprise,

the ocean doesn’t have too many identifiable 
landmarks. Urashima freaks out and panics for

a bit before remembering the box and thinking 
maybe there’ll be something inside he can use.

Surprise surprise - there isn’t. When he cracks 
the box the only thing inside is a vaguely ominous

cloud of vapor and the recollection that that 
was the one thing he was supposed to not do.

Whoops! Whatever magic was in the box dissipates 
and Urashima gets hit with four hundred years of

backlogged time all at once, rapidly aging 
all the way up into a corpse. Total bummer.

Moral of the story? Well, aside from the 
standard “don’t disobey magical orders

from fairy tale ladies”, maybe, you know, make 
sure you and your fiancee are fully on the same

page before moving in together. You know, 
you might handle your chores differently,

or have different standards of organization… 
that’s just the kind of stuff you should really

talk out first. And also your fiancee’s house 
might be a relativistic anomaly that completely

cuts you off from your friends and loved ones 
forever, which is just generally a red flag.

[Maybe This Time]