[extropy-chat] Explaining Time Travel via Wormhole

[Damien Broderick]

At 09:37 PM 12/28/2006 -0800, Lee wrote:

>To explain concretely, suppose that you stay home and
>your identical sister goes on board a spaceship that
>heads for Alpha Centauri at .999999 the cpeed 
>[felicitous typo or intended?] of light.
>Your sister has the other end of your wormhole in her
>cabin, and you two chat the whole time. Even though
>she's going near c, *through the wormhole* she's at
>rest relative to you! In fact, she's just a few feet
>away, and your conversation with her proceed normally
>(no speedup perceived by either party). You even dine
>with her in her cabin at one point, and later she
>watches a video with you in your motel room.


My novel GODPLAYERS disagrees:

===============

On an impulse, she opened a Schwelle upon Jan's 
location. An odd wrongness to the usual tearing 
sound set her teeth on edge. As always, the small 
men fizzed at the boundary, almost visible, like 
the Brownian motion of dust in a beam of 
sunlight. Beyond the threshold, her sister sat in 
some sort of elaborate chair, wearing exactly 
what one would expect of someone with her 
appalling fashion sense, hair in a spiky crew-cut, grin wide and gleaming.
           `Oh good, I was just going to open a 
line to one of you guys.' Something buffeted her. 
`Shit. Juni. You'll have to wait, people are trying to kill me.'
           It was like hearing a melody played 
maybe a tenth of an octave too low and uncannily 
slowed, just enough to notice. The light in the 
cabin was wrong, too: all the colors were out of 
whack. Juni squeezed her eyes tightly twice, 
tried to clear her vision, even found herself 
absurdly raising one flattened hand as if for 
shade against glare, but the problem was not at her own end.
           Maddeningly, her first impression had 
been right: all the colors were off, heavy dull 
reds where you'd expect healthy pinks and 
meter-display crimson, yellow glowing from panel 
indicator strips that should be comforting green, 
deep violet tinging the illumination strips, 
oceanic greens elsewhere on the display icons instead of blue. Good grief.
           `You're in space.'
           `Good guess. Shut up and let me try to save my life.'
           The woman was time-dilated. The cabin 
was a spacecraft under some kind of preposterous acceleration.
           Light exploded in a noiseless flash in 
one large display. Juni flinched. Her sister's 
mouth moved, as if in speech, but nothing was 
audible. Well, naturally, she was interfaced with her craft's AI pilot.
           `The stupid fucks,' Jan said aloud, 
and turned her wrong gaze to look across the 
Schwelle. `They're trying to hit the dark 
energy-engine. Don't they have any idea what that would­'
           More lights ripping at their eyes, 
although scaled downwards, presumably, by the ship system.
           `Dark-­?' Juni started, then bit her 
tongue. This was no time for distractions. Her 
sister, perversely, chose to distract herself.
           `Hey, Juni, what the hell are your 
nanoid things doing to your face? They're crawling all over you.'
           Instinctively, she brushed her fingers 
across her cheeks. Nothing, of course. `What are you babbling about?'
           `Don't talk to me about babbling, you 
sound like Donald Duck.' Jan uttered a throaty 
laugh. `It's creepy, man. Your skin's gone kinda 
yellow, and there's a reddish mist flickering all 
around. Thought it was the small men.' Jan leaned 
into the threshold, peering. `What the hell is 
that? There's like an aura projected from your heart. Oh, hang on­'
           `IR heat emissions.' Juni said.
           After a just perceptible pause: 
`Right. You're time-compressed to me, I'm dilated to you.'
           `Quite. Presumably you're seeing my infrared aura-­'
           `Not enough energy at that bandwidth.'
           `­with a little help from the fog at 
the Schwelle interface. How very Gothic. Why are 
you surprised by this, I thought you were the gung-ho spaceship captain?'
           Jan said, `Yeah, but believe it or not 
this is the first time I've allowed a Schwelle to 
open under acceleration, wasn't anxious to risk 
it. Your timing was providential.' The cabin 
shook again in a soundless explosion or more 
probably an evasive maneuver jink or whatever the 
pilot AI was up to. `Damn! I feel like just 
coming across and leave them to it,' Jan told her 
in that slightly slow, weirdly throaty voice. Her 
grin was ferocious and feral. `I could kill the 
lot of them, but what purpose would that serve? 
By now I thought they'd have calmed down, it's 
been more than half a century. Fuck, it's getting 
hot in here. Put a cup of kava on for me, would you, old girl?'
           `You're just going to let some gang of 
rowdy damn humans blow up your starship?' Juni 
found herself deeply offended by the idea.
           `As I was just saying to Sylvie, their 
ancestors paid for it. It's served its purpose. 
I've found out what's been causing the 
interference in all those... Hang on, I need to concentrate on the­'
           A composite panel peeled away above her head and burst into flame.
           `Uh-oh. Okay, dear old Hanger. Set the 
controls for the heart of the Sun. It's been 
real, sweetheart.' She was unbuffering herself, 
and absently slapping out small flames from her hair.
           Something must have spoken to her 
silently, perhaps the ship's system protesting. She laughed, doubled up.
           `Oh no, you great goose, of course I 
didn't mean it. It's a song, remember? If I was 
going to abandon you, I'd have done it in orbit 
around the Xon star. Stepped back to Earth and 
saved myself plenty of travel vouchers, right? 
No, I think you're a very nice ship. Once I'm out 
of here, spill the air from the cabin, that'll 
deal with the fires. Then torch up to point nine 
nine lights, make sure they don't hit you with 
their Son o'Star beam weapons, try not to kill 
anyone, and park somewhere Sunward of Mercury. 
Not too close. I'll be back. Ouch.'
           Juni stepped as close to the threshold 
as she dared, held out both hands. Jan came 
across in a slurring lurch of transduced light at 
the fog boundary. All her colors leaped back into 
registration, tartan in its proper weave, and her 
voice rose from contralto to mezzo without 
getting any louder. `Thanks, bub. You should really close the­'
           But Juni was already muttering the 
deixis code. The threshold closed even as board 
displays on its far side down-shifted 
relativistically into the far infra-red and 
beyond as the starship went toward luminal. Darkness at the speed of light.
           `Look at you,' Juni said crossly. `You 
could dress like the Empress of Alexandria and 
instead I find you done out like a tramp.'
           `Oh.' Jan looked guilty. `Rats, I left your wardrobe behind.'
           `Never mind that, I can replicate 
another one for you while we have a chat. Now 
come in here and sit down and tell me what you've 
been up to. Started any new wars lately? It's been decades, darling.'
           `For you, maybe, not for me.'
           `Hmm. You really did say kava? You do still drink the filthy stuff?'
           `Is the Pope Hebrew?'
           `I beg your pardon?'
           Jan made that vexing sound Juni knew 
only too well, even if it had been decades since 
she had heard it: a blend of mockery and tried 
patience. `Yes, dear. Kava, please. Does something smell scorched?'
           `Your hair, I believe,' Juni said, 
with a certain satisfaction. `Singed at the back. 
What can you expect when you fly around the solar 
system in a burning spaceship?'
           `Oh shit. And just when I'd got it 
growing out again.' She smiled sunnily. `But of course, by a stroke of luck-­'
           `­-my nimble little aerosol offogs 
will fix that in a trice. Quite so.'
           As the kava congealed into being 
inside the maker, frothing in its clay jug, Jan's 
spiky hair moved slightly, as if invisible 
fingers stroked through it. Light shivered about 
her, like a nano version of the frequency-shifted 
aura Jan had seen surrounding her own body from 
the spacecraft. That had been the infrared heat 
emissions of her metabolism, accelerated just 
enough by the time scale difference to enter the 
visible spectrum, then amplified and transduced 
by the minuscule operating fabrication fog units 
that hung everywhere in the atmosphere of this 
cognate Earth. Now the same small men, 
ingeniously capable, spun and toiled and took 
apart the charred hairs of her sister's head, and recompiled them.
           `You're happy with it that short? 
Extensions would suit you, but you'd have to lose that dreadful outfit.'
           `Fuck off,' Jan said amiably, pulling 
stone bowls from the maker and pouring both of 
them a slug of the barbarous stuff. She raised 
her bowl in a salute. `To the best of times, the worst of times.'
           Juni shook her head ruefully at her 
sister's irreverence but raised her own bowl. The 
small men, responsive to her whispered 
instruction, were already working on the 
molecules, denaturing the alkaloids, changing the 
bitter yellow-green muck into caffeine-free iced tea.

===================

and so on.

Is the even-handedness of relativity offended by this account? Perhaps.

Damien Broderick