Thursday, July 16, 2015
Ordering pizza from Pluto
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?