"James E. Gunn - The Listeners" - читать интересную книгу автора (Gunn James E)

_ Wer immer strebens sich bemueht,_
_Den koennen wir erloesen._
Lily sighed. "Okay, boss."
"And enjoy yourself!"
"Okay, boss, okay."
"Find a man, Lily," MacDonald muttered. And then he, too, turned toward
the living room, for Lily had been the last who might come.
He listened for a moment at the doorway, sipping slowly from the
warming can.
" -- work more on gamma rays -- "
"Who's got the money to build a generator? Since nobody's built one
yet, we don't even know what it might cost."
" -- gamma-ray sources should be a million times more rare than radio
sources at twenty-one centimeters -- "
"That's what Cocconi said nearly fifty years ago. The same arguments.
Always the same arguments."
"If they're right, they're right."
"But the hydrogen-emission line is so uniquely logical. As Morrison
said to Cocconi -- and Cocconi, if you remember, agreed -- it represents a
logical, prearranged rendezvous point. 'A unique, objective standard of
frequency, which must be known to every observer of the universe,' was the way
they put it."
" -- but the noise level -- "
MacDonald smiled and moved on to the kitchen for a cold can of beer.
" -- Bracewell's 'automated messengers'?" a voice asked querulously.
"What about them?"
"Why aren't we looking for them?"
"The point of Bracewell's messengers is that they make themselves known
to us!"
"Maybe there's something wrong with ours. After a few million years in
orbit -- "
" -- laser beams make more sense."
"And get lost in all that star shine?"
"As Schwartz and Townes pointed out, all you have to do is select a
wavelength of light that is absorbed by stellar atmospheres. Put a narrow
laser beam in the center of one of the calcium absorption lines -- "
In the study they were talking about quantum noise.
"Quantum noise favors low frequencies."
"But the noise itself sets a lower limit on those frequencies."
"Drake calculated the most favorable frequencies, considering the noise
level, lie between 3.2 and 8.1 centimeters."
"Drake! Drake! What did he know? We've had nearly fifty years
experience on him. Fifty years of technological advance. Fifty years ago we
could send radio messages one thousand light-years and laser signals ten
light-years. Today those figures are ten thousand and five hundred at least."
"What if nobody's there?" Adams said gloomily.
_Ich bin der Geist der stets vernient._
"Short-pulse it, like Oliver suggested. One hundred million billion
watts in a ten billionth of a second would smear across the entire radio
spectrum. Here, Mac, fill this, will you?"