The Last Hero

surrounded by rubbish.
    "Technically, my lord, an omniscope can see anywhere," said Archchancellor Ridcully, who was technically the head of All Known Wizardry. [2]
    "Really? Remarkable."
    "Anywhere and any time," Ridcully went on, apparently not impressed himself.
    "How extremely useful."
    "Yes, everyone says that," said Ridcully, kicking the floor morosely. "The trouble is, because the blasted thing can see everywhere , it's practically impossible to get it to see anywhere . At least, anywhere worth seeing. And you'd be amazed at how many places there are in the universe. And times, too."
    "Twenty past one, for example," said the Patrician.
    "Among others, indeed. Would you care to have a look, my lord?"
    Lord Vetinari advanced cautiously and peered into the big round glass. He frowned.
    "All I can see is what's on the other side of it," he said.
    "All, that's because it's set to here and now , sir," said a young wizard who was still adjusting the device.
    "Oh, I see ," said the Patrician. "We have these at the palace, in fact. We call them win-dows ."
    "Well, if I do this ," said the wizard, and did something to the rim of the glass, "it looks the other way." Lord Vetinari looked into his own face.
    "And these we call mir-rors ," he said, as if explaining to a child.
    "I think not, sir," said the wizard. "It takes a moment to realise what you're seeing. It helps if you hold up your hand..."
    Lord Vetinari gave him a severe look, but essayed a little wave.
    "Oh. How curious. What is your name, young man?"
    "Ponder Stibbons, sir. The new Head of Inadvisably Applied Magic, sir. You see, sir, the trick isn't to build an omniscope because, after all, that's just a development of the old-fashioned crystal ball. It's to get it to see what you want. It's like tuning a string, and if —"
    "Sorry, what applied magic?" said the Patrician.
    "Inadvisably, sir." said Ponder smoothly, as if hoping that he could avoid the problem by driving straight through it. "Anyway... I think we can get it to the right area, sir. The power drain is considerable; we may have to sacrifice another gerbil."
    The wizards began to gather around the device.
    "Can you see into the future?" said Lord Vetinari.
    "In theory yes, sir," said Ponder, "But that would be highly... well, inadvisable, you see, because initial studies indicate that the fact of observation would collapse the waveform in phase space."
    Not a muscle moved on the Patrician's face.
    "Pardon me, I'm a little out of date on faculty staff," he said. "Are you the one who has to take the dried frog pills?"
    "No, sir. That's the Bursar, sir," said Ponder. "He has to have them because he's insane, sir."
    "Ah," said Lord Vetinari, and now he did have an expression. It was that of a man resolutely refraining from saying what was on his mind.
    "What Mr Stibbons means , my lord," said the Archchancellor, "is that there are billions and billions of futures that, er, sort of exist, d'yer see? They're all... the possible shapes of the future. But apparently the first one you actually look at is the one that becomes the future. It might not be one you'd like. Apparently it's all to do with the Uncertainty Principle."
    "And that is... ?"
    "I'm not sure. Mr Stibbons is the one who knows about that sort of thing."
    An orangutan ambled past, carrying an extremely large number of books under each arm. Lord Vetinari looked at the hoses that snaked from the omniscope and out through the open door and across the lawn to... what was it? ... the High Energy Magic building?
    He remembered the old days, when wizards had been gaunt and edgy and full of guile. They wouldn't have allowed an Uncertainty Principle to exist for any length of time; if you weren't certain, they'd say, what were you doing wrong? What you were uncertain of could kill you.
    The omniscope flickered and showed a snowfield, with black mountains in the distance. The wizard called Ponder Stibbons appeared to be very pleased with this.
    "I thought you said you could find him with this thing?" said Vetinari to the Archchancellor.
    Ponder Stibbons looked up. "Do we have something that he has owned? Some personal item he has left lying around?" he said. "We could put it in the morphic resonator, connect that up to the omniscope and it'll home in on him like a shot."
    "Whatever happened to the magic circles and dribbly candles?" said Lord Vetinari.
    "Oh, they're for when we're not in a hurry, sir," said Ponder.
    "Cohen the Barbarian is not known