Thursday, July 16, 2015

Ordering pizza from Pluto

Like everyone else even remotely interested in space, the Universe and everything, the close encounter with Pluto has my mind completely boggled. Water ice? On Pluto? That is going to have huge ramifications. I'm all agog waiting for  the scientists to produce their theories which may well have implications on the development of life on Earth.

Since I'm not a scientist, I'll wait and see. But the encounter with Pluto does raise another point, often ignored in science fiction. It takes over four hours for data to transmit from the New Horizons ship back to Earth. Let's extrapolate on that. Imagine you're a crew member on the New Horizons ship and you have an attack of the munchies. You ring Earth, a copy of the Domino's flyer from ten years ago in your hand.

“Hi, I’d like to order the peperoni, please. With anchovies, no pineapple.” (Wait nine hours)
“Sure. Would you like garlic bread with that?”
I think your pizza might be cold before it was delivered.

Real time conversations are even more of a problem in space opera if you’re planet hopping. If light can take years to go from one star to us, how long would it take any other type of signal? (We’ll leave out sound waves, which don’t move through a vacuum.) Answer – same as light. About 300,000km per second. Sure, that’s fast. But having a conversation with someone, say, four light years away is going to be a tad tedious.

And yet, so often space opera ignores this fact of physics and has folks chatting from spaceship to planet, or planet to planet, as though they were using Skype back in the 21st Century on jolly old Earth. A case in point is the famous scene in The Empire Strikes Back, where Darth Vader’s Executor is chasing the Millenium Falcon through an asteroid field. Admiral Piett was delighted to be able to tell Vader the Emperor was on the line, so the star destroyer could be moved out of the asteroid field in order to send a clear signal. And then they had the little chat, the Emperor’s ominous figure dwarfing Vader, down on one knee, while he plotted betrayal.

Now, let’s think about this. The Emperor is on Coruscant, Executor is down in the Imperial boondocks, messing around near Hoth. I’m not suggesting the exchange was impossible. No, let’s put that another way. It’s impossible without some sort of futuristic device. Even within our own solar system, it takes anywhere from 3.4 – 21 minutes (depending on how close the planets are to each other) for a a signal to go from Mars to Earth.

It’s a known problem, though. Ursula Le Guin was the first to dream up a device which could enable people on different planets to converse in real time. She called it the ansible. The name has wheedled its way into the genre, rather like ‘hyperspace’. Elizabeth Moon wrote a whole series of books (the Vatta saga) around a company which specialised in setting up ansibles in orbit around inhabited planets, and maintaining them. And the subsequent danger when the ansibles were sabotaged, a bit like taking down the telegraph line across America in the Old West.

I don’t call them ansibles, but since my books involve much planet-hopping, I had to come up with something, which I suppose is an ansible by any other name. A multi-dim transmitter is a device which uses one of the many dimensions of space, a dimension which is not available to physical entities like ships, to transmit a signal from one place to another. They can be fitted to ships, but they are expensive.  Needless to say, if you don’t have access to an ansible or its equivalent, you can’t have a real-time conversation over a long distance.

What ways have you seen for getting around this limitation? Or is it simply ignored?

5 comments:

  1. I don't think this is an aspect I've tackled in my stories as yet. My telepathic characters have trouble communicating over distance, but it's instantaneous. The only time I have written long distance comms by more mundane means, I had in mind some superspeedy relays that don't use normal space and its limitations, but that story never saw the light of day. Jaine Fenn uses tech called (I think - haven't read it for a while) bees (not actual bees but a piece of technology that allows instant communication in sound and image. Or was it a vee? Must re-read!). And of course Anne McCaffrey's crystal comms. Never really understood how those worked as they supposedly used sound waves, which don't even travel in vacuum?! Again, years since I've read them. Darn, I think I just added to my already massive TBR list...

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    1. I think it's something that's often ignored.

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    2. The Crystal Comms between systems were done using "Black Quartz" which essentially was a set of crystals cut from the same face of rock in different musical notes / frequencies that resonated together when under electrical stimulation.

      As I understood it, a message transmitted through one crystal would be received by all the other crystals and I should imagine that the operators just ignored it if they weren't the recipient.

      Kind of a space age equivalent of the quartz crystal in an old radio?

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  2. I use "skip buoys" that amplify and accelerate communication signals within the solar system in The Outer Planets. I don't go into an explanation of how they work (it's not important to the story), but they essentially "skip" the radio waves through extra-dimensional space like a flat stone skips over water. It allows communication between Earth and Jupiter (or Saturn) orbit in close to real time.

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  3. Interesting, Greta. Not sure I knew it was Ursula K. LeGuin who invented the (very useful) ansible! My Interstellar Rescue series uses the same jump node system (essentially stable wormholes)used for travel to pass messages along in much the same way Laurie uses the skip buoys. Still takes time if you're on a ship and moving through space. Easier if you're on a planet and more or less staying put.

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