"Damon Knight - Anachron" - читать интересную книгу автора (Knight Damon)

"No, no. Look here." The viola d'amore lay on the bench, precisely
where it had been before. Harold reached into the sphere and drew it out.
Peter started. "Give me that." He took it in his hands, rubbed the
smoothly finished wood. He stared at his brother. "By God and all the saints,"
he said. "Time travel."
Harold snorted impatiently. "My dear Peter, 'time' is a meaningless
word taken by itself, just as 'space' is."
"But, barring that, time travel."
"If you like, yes."
"You'll be quite famous."
"I expect so."
Peter looked down at the instrument in his hands. "I'd like to keep
this, if I may."
"I'd be very happy to let you, but you can't."
As he spoke, the bubble went cloudy; the viola d'amore was gone like
smoke.
"There, you see?"
"What sort of devil's trick is that?"
"It goes back... Later you'll see. I had that thing out once before,
and this happened. When the sphere became transparent again, the viol was
where I had found it."
"And your explanation for this?"
Harold hesitated. "None. Until I can work out the appropriate
mathematics -- "
"Which may take you some time. Meanwhile, in layman's language -- "
Harold's face creased with the effort and interest of translation.
"Very roughly, then -- I should say it means that events are conserved. Two or
three centuries ago -- "
"Three. Notice the sound holes."
"Three centuries ago, then, at this particular time of day, someone was
in that room. If the viola were gone, he or she would have noticed the fact.
That would constitute an alteration of events already fixed; therefore it
doesn't happen. For the same reason, I conjecture, we can't see into the
sphere, or -- " he probed at it with a fountain pen -- "I thought not -- or
reach into it to touch anything; that would also constitute an alteration. And
anything we put into the sphere while it is transparent comes out again when
it becomes opaque. To put it very crudely, we cannot alter the past."
"But it seems to me that we did alter it, just now, when you took the
viol out, even if no one of that time saw it happen."
"This," said Harold, "is the difficulty of using language as a means of
exact communication. If you had not forgotten all your calculus ... However.
It may be postulated (remembering of course that everything I say is a lie,
because I say it in English) that an event which doesn't influence other
events is not an event. In other words -- "
"That, since no one saw you take it, it doesn't matter whether you took
it or not. A rather dangerous precept, Harold; you would have been burned at
the stake for that at one time."
"Very likely. But it can be stated in another way or, indeed, in an
infinity of ways which only seem to be different. If someone, let us say God,
were to remove the moon as I am talking to you, using zero duration, and