(urth) Sundial with "multitudinous faces"?

[Jerry Friedman]

> From: James Wynn crushtv at gmail.com
> 
> >> I would think you could. Any regular tick-tock could analogize a time using 
>a
> >> different synch. It would be incredibly complex though since a day 
somewhere
> >> else would be represented by more or less than a single cycle of the sun.
> > Jerry Friedman wrote:
> > It would have to be magic. Sundials don't have a regular tick-tock.
> 
> Sure they do. It's the yearly cycle of the sun. And that cycle (and fractions 
>of it) can be used to synchronize anything.

But there are no moving parts ticking that you can attach something too.

I guess you could have a photocell on the dial that notes when the shadow passes 
it (and distinguishes that from clouds and from shadows of random apprentices).  
Those times could be fed to a microprocessor that translates this timing to the 
period of some other planet and manipulates the gnomon, dial, or light source of 
another sundial to fake the time in some zone of another planet.  But it all 
seems rather rococo and unreliable, even for the Citadel.

Let me try to explain the same thing as Dan'l and Sergei.  When the sun is at a 
certain place in the sky (I mean when Urth is aiming the Citadel at a certain 
angle to the sun), the sundial will show a certain time.  A day later, the 
sundial will show  a similar time, and 365 days later [*], an even more similar 
time.  But if it was morning on Mongo during the first reading, there's no 
reason for it to be morning on Mongo at the later two readings, since Mongo's 
day presumably isn't the same length as Urth's.

[*] You'd do even better 1461 days later, since the year isn't a whole number of 
days.

> >> I'm not an expert on this but it seems I read something that implied that. 
>For
> >> example, traveling in a worm-hole (such the ones in the Stargate franchise) 
>is
> >> actually Time-travel as well.
> > Jerry Friedman:
> > If you can get from one place to another faster than light, as with a 
>wormhole,
> > then you *can* use that to travel faster than light.

Sorry, you can use that to travel *backwards in time*.

> But I got the idea somewhere that the actual mathematics of the wormhole theory 
>does not allow you to cheat Relativity, so that the farther you travel (that is, 
>the greater the actual distance of your destination) then your speed is all the 
>faster than FTL travel and you therefore (likely) move back further in Time as 
>well. It's just that when you return, you move the other way in Time so you 
>don't notice.
> 
> Of course, I might have been taken in by metaphor: They could have been 
>actually saying that if you travel instantaneously to a distant star, you are 
>moving FORWARD in Time since the star we can see from Earth is some number years 
>ago. Or something along those lines.

I don't understand the mathematics of wormholes.  What you're talking about 
seems to involve definitions and maybe indeed metaphor.

> Anyway, it's probably not physically possible even if you could muster the near 
>infinite energy to do it.

So true.

> There's all that Space being constantly  created between us and the stars. We 
>have enough trouble maintaining RF connectivity. Can you imagine the problems 
>establishing a physical connection between two distant locations? Too bad 
>because I really want one of those doors from "Howl's Moving Castle".
> 
> J
> 
> PS Incidentally, it's very annoying for me to watch movies that involve FTL 
>travel. They never plot the Time distortions caused by their daily job. Captain 
>Kirk spends months in Warp and never gets back to Earth just after he left 
>(except when he goes back to 1968).

Well, if there's FTL travel, then something is wrong with relativity (as I think 
Dan'l said), so we don't have a basis to say what would happen.

Jerry Friedman